Blood
definitioBlood
definition-by oxford dictionaries-
Red liquid that circulates in the arteries and veins of humans and other vertebrate animals, carrying oxygen to and carbon dioxide from the tissue of the body.
by CCM,- Blood is a biological red liquid circulating in the arteries and veins under the impulse of the heart. An individual contains 5-7 L of blood in his body, which represents about 8% of its total weight. Blood is made up of plasma, red blood cells, white blood cells and platelets. Its distributes oxygen, hormones and nutrients to all cells, all tissues and all organs of the body, then get rid of their waste. Blood also plays a role in immune defense.
COMPOSITION OF BLOOD-
Blood consists of 55% plasma (liquid portion) and 45% formed elements ( blood cells)
Formed elements are RBC(Erythrocytes), WBC( Leukocytes), Platelets (Thrombocytes)
Complete Blood Count (CBC)
Also known as: Complete blood picture(CBP), Haemogram
Red Blood Cells, Platelets , T Lymphocyte, Monocyte
as seen through a scanning electron microscope.
The CBC is the measurement of the number of circulating RBC’s, WBC’s, platelets, the concentration of haemoglobin and characteristics of RBC’s.
Anticoagulated blood is processed through automatic blood analysers which using variety of technologies ( particle sizing, radiofrequency, laser instrumentation) to measure different parameters.
These includes number of circulating cells, the proportion of red cells (haematocrit) and red cell indices which gives information about size of red cells (MCV), and amount of Hb present in RBC’s(MCH), and WBC’s and differential counts.
CBC includes
WBC (TLC) – Total leucocyte count
RBC – Red blood cell count
Hb - Haemoglobin
Hct - Haematocrit value
MCV – Mean corpuscular volume
MCH – Mean corpuscular Haemoglobin
MCHC – Mean corpuscular Haemoglobin concentration
Peripheral smear.
RDW – Red cell distribution width
Plt – Platelet count
Mean platelet volume (MPV)
DLC – Differential count
CBC is a screening test, used to diagnose numerous diseases.
HEMOGLOBIN-
The hemoglobin test measures the amount of hemoglobin in blood and is a good measure of the blood's ability to carry oxygen throughout the body.
Hb is measured in gram per deciliter (g/dL) of blood
Methods for estimation of Hb-
1 Colorimetric method
Cynamethaemoglobin method
Oxyhaemoglobin method
Electronic counter method
Direct reading electronic haemoglobinometer
Sahlis method
2 Measurement of oxygen carrying capacity of Hb
3 Measurement of iron content of Hb
4 Specific gravity method
Hemoglobin (Hb)
Men: 14-17.4 grams per deciliter (g/dL) or 140-
174 grams per liter (g/L)
Women: 12-16 g/dL or 120-160 g/L
Children: 9.5-20.5 g/dL or 95-205 g/L
Newborn: 14.5-24.5 g/dL or 145-245 g/L
Hemoglobin interfering factors-
It increases at higher altitude in children
Low in excess fluid intake and in pregnancy
Gentamycin, methyldopa increases the values.
Causes of Increased Haemoglobin-
Primary :
Polycythemia vera (neoplastic)
Secondary :
Associated with hypoxia-Cardiovascular diseases, pulmonary diseases, High altitude, hypoventilation, Smoking, Methaemoglobinemia.
Increased erythropoietin production- Kidney diseases and tumours
liver tumours, Associated with adrenocortical steroids, testosterone supplements., Associated with chronic chemical exposure, nitrites, cobalt, alcohol
Relative:
*Stress
*Dehydration: vomiting, diarrhoea
*Plasma loss: burns.
Causes of Decreased haemoglobin level-
Blood loss
- Internal, External
Impaired red cell production
- Deficiency of iron, Vit B12
- Infection, renal failure, liver disease, chronic diseases.
- Aplastic, sideroblastic & dyserythroblastic anemia
- Bone marrow infiltrations with tumor cells
Increased destruction of RBC (Haemolysis)
Haemodilution
- Pregnancy, oedema
Increased destruction of RBC (Haemolysis)
Haemodilution
- Pregnancy, oedema
HEMATOCRIT (PCV)-
Hematocrit (HCT, packed cell volume, PCV). This test measures the amount of space (volume) red blood cells take up in the blood. The value is given as a percentage of red blood cells in a volume of blood. It is one of the most precise methods of determining the degree of anemia or polycythemia.
Normal Range: Male :- 40-55%
Female :-36-48%
Ratio of Hemoglobin to Hematocrit = 3: 1
Method for estimation-
Macro method ( Wintrobes method)
Micro haematocrit method
Electronic method.
Blood is collected in a hematocrit tube with anti coagulant and centrifuged for 30 min at 3000 rpm, the RBC’s settle down at bottom having a clear plasma at top. In between the plasma and RBC’s there is a thin layer of white buffy coat which is formed by white blood cells and platelets.
Increased PCV value-
Polycythemia
Dehydration due to severe diarrhoea & Vomitting
Burns
Spleen hyperfunction,
Decreased PCV value
Anaemia
Pregnancy
low thymus function.
RBC COUNT-
The scientific name for red blood cells is Erythrocytes.
The most numerous of all cells in the blood.(4-5million/cmm)
Produced at a rate of 4-5 billion every hour in an adult human!(Life span 120 days).
RBC- M: 4.7 to 6.1 x10^12 /L
F: 4.2 to 5.4 x10^12 /L
Biconcave disc shape with diameter of about 8 µm
Function: - transport hemoglobin which carries oxygen from the lung to the tissues.
Red blood cell (RBC) count
Men: 4.5-5.5 million RBCs per microliter (mcL) or 4.5-5.5 x 1012/liter (L)
Women: 4.0-5.0 million RBCs per mcL or 4.0-5.0 x 1012/L
Children: 3.8-6.0 million RBCs per mcL or 3.8-6.0 x 1012/L
Newborn: 4.1-6.1 million RBCs per mcL or 4.1-6.1 x 1012/L
METHOD- Visual haemacytometer method
Electronic method
RBC Interfering factors-
In lying position count is low.
Excitement and exercise raises the count.
Count is highest in morning then falls.
Count is high at high altitude.
Increased red blood cell count-
Increase in Red Cell production
Primary: Polycythemia vera (Neoplastic)
Secondary: To compensate for low oxygen levels (Poor heart / lung function, high altitude )
Erythropoietin (EPO)- Internal / External
Anabolic Steroids
Smoking, Alcohol, Carbon Monoxide
Liver disease, Kidney diseases,
Long term lung diseases, Heart diseases, Cancers Haemoglobinopathies
Decreased Red blood cell Count-
Decreased Production (Aplastic Anemia, deficiency of Iron / VitB12 / Folic acid etc) Blood loss. Internal / External, Haemolytic Anaemias, sickle cell anemia, Tumors, Addison's disease, Thalassemia, other haemoglobinopathies, Lead poisoning, stomach ulcers, Bowel diseases, Splenectomy.
Red blood cell indices-
There are three red blood cell indices:
Mean corpuscular volume (MCV), Mean corpuscular hemoglobin (MCH), and Mean corpuscular hemoglobin concentration (MCH
Red blood cell indices
Mean corpuscular volume (MCV): 80-100 cubic millimeters (mm3) or 80-
100 femtoliters (fL)
Mean corpuscular hemoglobin
(MCH): 26-34 picograms (pg) or 0.40-0.53
femtomoles (fmol)
Mean corpuscular hemoglobin
concentration (MCHC): 32-36 grams per deciliter (g/dL) or
320-360 grams per liter (g/L)
Absolute Values
Based on normal values of RBC,Hb, PCV red cell indices are derived which are of diagostic importance.
1 Mean corpuscular volume
= PCV in L/L
RBC count/L
2 Mean corpuscular haemoglobin MCH
= Hb/L
RBC count/ L
3 Mean corpuscular haemoglobin concentration MCHC
= Hb/dl
PCV IN L/L
Since MCHC is independent of red cell count and size, it is greater clinical importance as compared with other values.
SIGNIFICANCE OF RED CELL INDICIES
Decreased MCH, MCV, MCHC = Iron deficiency anemia & thalassaemia.
Increased MCV = Megaloblastic anemia
Normal MCV, MCH, MCHC = Anemia due to acute blood loss and haemolytic anaemia.
Mean Corpuscular Volume (MCV)-
The MCV relates to the average size of the red blood cell.
Abnormal MCV associated with changes in MCH is a significant finding for folic acid and/or B12 need (increase) or iron, copper or vitamin B6 need (decrease).
MCV and MCH are always be viewed together.
Optimum range is 80.0 to 100.0 femtolitres.
It indicates whether RBC’s are Microcytic, Normocytic or Microcytic
If MCV is less than 80fl then it is Microcytic
If MCV is More than 96fl then it is Macrocytic
If it is with in 80-96fl then it is Normocytic.
Macrocytosis-
- Hereditary anemia(s).
- Megaloblastic Anemias
- Reticulocytosis
- Liver disease .
- Hypothyroidism .
- Drugs (anti-convulsants).
- Zidovidune treatment (AIDS).
Alcoholism, sprue, def b12, folate
Microcytosis
Copper and iron deficiency
Low stomach acid (Hypochlorhydria).
Vitamin C and Vit B6 insufficiency.
Rheumatoid arthritis.
Lead poisoning.
Hereditary (thalassemias, sideroblastic anaemia)
After a splenectomy
Hemolytic anemia
Mean Corpuscular Hemoglobin (MCH)
The amount of hemoglobin in a single RBC
It is the ratio of Hb and the RBC count.
Optimum values: 28.0 to 32.0 picograms.
Increased & decreased in the same conditions as the MCV.
It is significantly less in when Microcytosis is associated with Hypochromia
Ex :- Iron Deficiency anaemia & Thalessemia minor
Mean Corpuscular Hemoglobin Concentration (MCHC)
The average hemoglobin concentration per unit volume(100 ml) of packed red cells. Optimum values: 32 to 36 %.
MCHC (32-36%)
Increased – spherocytosis
Decreased – IDA, microcytic anaemia, thalassemia, pyridoxine responsive, anaemia
Red cell Distribution Width (RDW)
The red blood cell distribution width (RDW or RCDW) is a measure of the variation of red blood cell (RBC) volume.
Usually red blood cells are of about 6-8 μm. Certain disorders, however, cause a significant variation in cell size.
Higher RDW values indicate greater variation in size. Normal reference range is 11–15%.
An elevated RDW (red blood cells of unequal sizes) is known as anisocytosis
RDW test results are often used together with mean corpuscular volume (MCV) results to determine the cause of the anemia. It is mainly used to differentiate an anemia of mixed causes from an anemia of a single cause.
Vitamin B12 deficiency produces a macrocytic anemia (large cell anemia) with a high RDW.
However, iron deficiency anemia initially presents with a varied size distribution of red blood cells, and as such shows an decreased RDW.
In the case of a mixed iron and B12 deficiency, there will normally be a mix of both large cells and small cells, causing the RDW to be elevated.
Mathematically the RDW is calculated with the following formula:
RDW = (Standard deviation of MCV ÷ mean MCV) × 100.
The RDW is often increased in:
^ Pernicious anemia
^ Folic acid anemia
^ Hemolytic anemia
^ Transfusions
^ Sideroblastic anemia
^ Alcohol abuse
^ Maturation defect anaemias
The RDW is often decreased in:
< Iron deficiency anemia (blood loss, parasites infection, poor iron absorption, etc.)
< Vitamin B6 anemia.
< Rheumatoid arthritis.
Peripheral smear- A blood film or peripheral blood smear is a thin layer of blood smeared on a microscope slide and then stained to examine various blood cells microscopically.
Blood films are usually examined to investigate hematological problems (disorders of the blood) and, occasionally, to look for parasites within the blood such as malaria and filaria.
The smear offers the functional status of the bone marrow. It is particularly important when assessing cytopenic states (eg, anemia, leukopenia, thrombocytopenia).
Analysers cannot indentify abnormalities of red cell shape and contents( howell- jolly bodies, basophilic stippling, malarial parasite) or fully defined abnormal white cells such as blasts.
Peripheral smear is especially important in,
Hemolytic anemia — Review of red cell morphology may identify the cause of erythrocyte destruction (eg, the presence of bite cells points to a Heinz body hemolytic anemia).
Thrombocytopenia — Distinguishing between increased platelet consumption and reduced platelet production can often be made through review of platelet size in blood smear.
White cell disorders — The disease classification rely upon evaluation of abnormal circulating cells (eg, the presence of Auer rods in a blast form in patients with acute myeloid leukemia)
Microcytosis ( reduced average cell size, MCV< 76 fl):
Iron deficiency Anemia, Thalassemia, Sideroblastic anaemia.
Macrocytosis ( increased average cell size, MCV> 100 fl):
Megaloblastic Anemia because of vit B12 & folic acid deficiency, liver disease, alcohol, hypothyroidism, drugs like zidovudine.
The presence of target cells may be due to:
Hemoglobin abnormalities (hemoglobinopathies)
Iron deficiency
Liver disease
Spleen removal
Thalassemia
The presence of sphere-shaped cells (spherocytes) may be due to:
Autoimmune hemolytic anemia
Hereditary spherocytosis
Post splenectomy
The presence of red cell fragmented (schistocytes) may be due to:
Artificial heart valve
Disseminated intravascular coagulation
Hemolytic uremic syndrome (HUS)
Microangiopathic hemolytic anemia
Thrombotic thrombocytopenic purpura (TTP)
The presence of a type of immature red blood cell called a normoblast ( nucleated RBC’s) may be due to:
Cancer that has spread to bone marrow infiltration
Erythroblastosis fetalis
Leukoerythroblastic anemia (myelophthisis process)
Miliary tuberculosis
Myelofibrosis
Removal of spleen
Severe hemolysis
Thalassemia
The presence of teardrop-shaped cells may indicate:
Leukoerythroblastic anemia
Myelofibrosis
Severe iron deficiency
Thalassemia major
The presence of Howell-Jolly bodies( small round nuclear remnants) may indicate:
Dyshaemopoiesis
Post-splenectomy
Sickle cell anemia
The presence of Heinz bodies may indicate:
Alpha thalassemia
Congenital hemolytic anemia
G6PD deficiency
Unstable form of hemoglobin
The presence of slightly immature red blood cells (reticulocytes) polychromasia may indicate:
Anemia with bone marrow recovery
Hemolytic anemia
Acute Hemorrhage
The presence of basophilic stippling( abnormal ribosomes appear as blue dots) may indicate:
Lead poisoning
Myelofibrosis
Dyshaemopoiesis
The presence of sickle cells may indicate sickle cell anemia.
PLATELETS (Thrombocytes)
Fragments of cells that participate in clotting.
Initiate repair of blood vessel walls.
Optimum values: 150,000 to 400,000/ mm3 of blood.
Small granular non-nucleated discs.
Diameter about 2-4 µm
Function; involved in coagulation and blood haemostasis.
Life span 7-10 days
METHOD
Visual haemacytometer method
Electronic method
Platelet (thrombocyte) count
Adults: 140,000-400,000 platelets per mm3 or
140-400 x 109/L
Children: 150,000-450,000 platelets per mm 3 or
150-450 x 109/L
Thrombocytosis(Platelets increased )
Infections
Acute blood loss
Disseminated carcinoma
Splenectomy
Thrombocythemia
Polycythemia Vera
Myeloproliferative Disorders
Chronic Granulocytic Leukemia
Hemolytic anemia(s)
Myelosclerosis
Essential (without known cause)
After sever injuries,
major surgery, parturation, haemorrhage.
Thrombocytopenia (Platelets decreased)
Decreased Production
Marrow depression/ infiltration
Megaloblastic anemia. Aplastic anaemia
Congenital
Increased Destruction
Immunologic (ITP, SLE), Infectious mononucleosis ,Rubella, EBV
Lymphoma, Multiple myeloma, Leukemia
Drugs-chemotherapy, Quinine, Sulphonamides, Rifampicin, heparin.
Hypersplenism ,Liver dysfunction (cirrhosis).
Dilution due to overhydration
Platelet aggregation or large platelets
Low platelet values can occur in pregnancy or idiopathic thrombocytopenic purpura (ITP)
A large spleen can lower the platelet count
Mean platelet volume (MPV)
Mean platelet volume (MPV) is a measurement that describes the average size of platelets in the blood. It is part of a complete blood count (CBC). The importance of mean platelet volume is that, it is an indicator as to whether the bone marrow is manufacturing them normally.
Elevated mean platelet volume is common in patients with certain forms of diabetes. If combined with a low Plt result, indicates a condition resulting in destruction of platelets such as immune thrombocytopenia, pre-eclampsia, sepsis, various hereditary conditions. High MPV with a normal Plt test result is a sign of chronic myeloid leukemia, hyperthyroidism. Accompanied by a high Plt result, it may indicate a bone marrow disorder that causes excessive cell production.
Conditions Associated with Low MPV
In association with a low Plt value, this indicates anemia, chemotherapy. If combined with a normal Plt, indicates chronic kidney failure. Accompanied by a high Plt, indicates an infection, inflammation or some form of cancer.
DLC (Differential Leucocyte Count):
Neutrophils (polys and bands)
Lymphocytes
Monocytes
Eosinophils
Basophils
White blood cell (WBC, leukocyte) count
Men and non pregnant women: 5,000-10,000 WBCs per cubic millimeter (mm3) or 5.0-10.0 x 109 WBCs per liter (L)
White blood cell types (WBC differential)
Neutrophils: 50%
Lymphocytes: 25%-40%
Monocytes: 3%-7%
Eosinophils: 0%-3%
Basophils: 0%-1%
When the total leucocyte count is increase above the normal level called Leucocytosis.
When the total leucocyte count is decrease below the normal level called Leucocytopenia.
Normal Range: Adult :- 4000- 11000 /mm3 of blood
New borns :- 10000-25000/mm3 of blood
Infants :- 6000-18000/mm3 of blood
Children :- 5000-15000/mm3 of blood
There is NO sex difference in value, as seen in RBC count.
METHOD
Visual haemacytometer method
Electronic method
Differential Leucocyte COUNT
Visual counting
Automated DLC counters have differential counting capacity of counting 3 or 5 part ( P,L,M,E,B)
Interfering Factors
In new born and infants count is high values reaches normal at puberty.
Physical activity, food, pain, emotional disturbance will slightly increase the count.
Chronic leukemia may decrease the count.
Early morning values are low during evening hours are high.
Leucocytosis
Physiological conditions
New borns & infants
Physical exercise
After food intake
Exposure to sun & increased environment temp.
Pregnancy
Parturition
Pain, nausea, vomiting
Menstruation
Emotion & Anxiety
Pathological conditions
Acute Bacterial infections Ex- pyogenic bacteria ,boils, abscess, pneumonia Chronic bacterial infection ,Tuberculosis, Tissue injury
Infarction, Burns, Surgery, Splenectomy
Haemorrhage, Neoplasia, Stress states & hyperactivity, Convulsions
Severe colic, Inflammatory disorders, Rheumatic fever, Metabolic disorders, Diabetic ketoacidosis, RA, Corticosteroid therapy, Leukemia, cancer,
Leucocytopenia-
Conditions that can lower WBC values include chemotherapy and reactions to other medicines, aplastic anemia, viral infections, malaria, alcoholism, AIDS, lupus, or Cushing's syndrome.
A large spleen can lower the WBC count.
Physiological
Exposure to severe cold
Pathological
Infections:-Typhoid fever, Paratyphoid fever
Viral infections(early phase :- infectious hepatitis )
Overwhelming sepsis
Replacement of haemopoietic tissue in the bone marrow by neoplastic infiltrative cells
Acute leukemia
Lymphoma
Multiple myeloma
Myelofibrosis
Aplastic anaemia
Cytotoxic therapy
Drugs
Chloramphenicol
Sulpha drugs
Aspirin
Hyperspleenism
Starvation & Malnutrition
Neutrophils (Granulocytes)
polymorphonuclear leukocytes
Nucleus 3-5 lobes.
Diameter 10-14 µm
50-70% WBC
Function: Phagocytosis of bacteria and cell debris
Numbers rise with all manner of stress, especially bacterial infections
Interfering factors-
In children neutrophilia develops more prominently in case of infection.
Weak debilitated people fail to respond with neutrophilia in infection.
ACTH, Myelosuppressive chemotherapy don’t allow proportionate neutrophilia in infection.
NEUTROPHILIA-
Physiological
Exercise
Pregnancy last week
Parturition
Food intake
Emotional stress
Exposure to cold & heat.
Emotional disturbance Infants during first days.
Pathological
Acute pyogenic infections
Pneumonia, tonsillitis,
Acute infective inflammatory conditions
Rheumatic fever
Non inflammatory conditions
Pulmonary embolism, MI
Acute haemorrhage
Trauma
Leukemia, Neoplasm
Metabolic diseases-uremia, gout, acidosis
Chronic myeloid leukemia
Toxic conditions
Uremia, hepatic coma
Corticosteroid therapy
Eosinophils-
A type of leukocyte with coarse orange red round granules of uniform size and bilobed nucleus.
Eosinophils are so named because their cytoplasmic granules stain red with the dye eosin.
Eosinophils constitute 1 to 3 % (350 to 650 /cmm).
Pathological conditions
Allergic conditions Parasitic infestations Bronchial asthama Hookworm
Urticaria Filariasis
Hay fever Hydatid disease
Psoriasis Collagen disease
Bronchial asthama Periarteritis nodosa
Skin diseases Hodgkins disease
Food allergy Addisons disease
Pemphigus Certain leukemias , Neoplasm
Pulmonary Drugs – Streptomycin, penicillin etc.
eosionophilia
EOSINOPENIA-
ACTH therapy, Adrenalin, Insulin
Cushings syndrome, Acromegaly
Acute pyogenic infection, Aplastic anaemia, SLE
Stress, sever shocks, sever burns
Interfering factors-
Eosinophil count is lowest in morning
Burns electric shock, post operative states will decrease the count
ACTH reduces the count.
Basophil-
Coarse bluish-black granules of uniform size and typically a bilobate nucleus.
Basophils are so named because their cytoplasmic granules stain with basic dyes.
Constitute 0.5 to 1% of the peripheral blood leukocytes.
Release histamine and serotonin
BASOPHILIA
Chronic myeloid leukemia
Polycythemia vera
Hypersensitivity, mylosclerosis, Hodgkins lymphoma, cirrhosis of liver, early stage of Hodgkins disease, Lead poisoning
BASOPENIA
Severe septicaemia
Aplastic anaemia
Hyperthyroidism
Corticosteroid
Lymphocytes
Lymphocytes are of large and small types.
Normal range is 20-45%.
No specific granules
20-40% of WBC
Diameter 8-10 µm
T cells: cellular (for viral infections)
B cells: humoral (antibody) Natural Killer Cells
LYMPHOCYTOSIS
Chronic infection
Tuberculosis, Brucellosis, syphills,
Infection mononucleosis, hepatitis, rubella, pertusis
Lymphatic leukemia
Lymphomas
Endocrine – Thyrotoxicosis, hypopituritism, neoplasm
LYMPHOCYTOPENIA
Immune suppressive therapy
ACTH
Hodgkins disease
Bone marrow failure, pancytopenia, CHF, AIDS
Monocytes-
Monocytes share the 'vacuum cleaner' function of neutrophils.(2-9%).
Present pieces of pathogens to T cells, so the pathogens may be recognized again and killed, thus an antibody response may be mounted.
Also known as macrophage after they leave the bloodstream
and enter tissues.
MONOCYTOSIS
Protozoan disease
Malaria
Kala-azar
Hodgkins disease, RA, SLE, Sarcoidosis, ulcerative colitis
Monocytic leukemia, lymphoma, multiple myeloma
ACTH therapy, Infection brucellosis, typhus, typhoid.
MONOCYTOPENIA
Bone marrow failure
Aplastic anaemia
Septicaemia
Steroid, low immunity
CONCLUSION-
The results of CBC shows how well the vital organs are functioning which is indicator of general state of health.
Reflects problems of blood loss & fluid volume (dehydration)
Shows any abnormalities in the production, destruction & life span of blood cells.
Reflects acute or chronic infection, allergies, and problems with clotting
Screening for high and low values before surgery.
Finds the cause of symptoms such as fatigue, weakness, fever, bruising, or weight loss.
Diagnosing diseases of the blood, such as Leukemia, Polycythemia, Thrombocytosis.
Checks how the body is dealing with some types of drug or radiation treatment.
n - by oxford dictionaries-
Red liquid that circulates in the arteries and veins of humans and other vertebrate animals, carrying oxygen to and carbon dioxide from the tissue of the body.
by CCM,- Blood is a biological red liquid circulating in the arteries and veins under the impulse of the heart. An individual contains 5-7 L of blood in his body, which represents about 8% of its total weight. Blood is made up of plasma, red blood cells, white blood cells and platelets. Its distributes oxygen, hormones and nutrients to all cells, all tissues and all organs of the body, then get rid of their waste. Blood also plays a role in immune defense.
COMPOSITION OF BLOOD-
Blood consists of 55% plasma (liquid portion) and 45% formed elements ( blood cells)
Formed elements are RBC(Erythrocytes), WBC( Leukocytes), Platelets (Thrombocytes)
Complete Blood Count (CBC)
Also known as: Complete blood picture(CBP), Haemogram
Red Blood Cells, Platelets , T Lymphocyte, Monocyte
as seen through a scanning electron microscope.
The CBC is the measurement of the number of circulating RBC’s, WBC’s, platelets, the concentration of haemoglobin and characteristics of RBC’s.
Anticoagulated blood is processed through automatic blood analysers which using variety of technologies ( particle sizing, radiofrequency, laser instrumentation) to measure different parameters.
These includes number of circulating cells, the proportion of red cells (haematocrit) and red cell indices which gives information about size of red cells (MCV), and amount of Hb present in RBC’s(MCH), and WBC’s and differential counts.
CBC includes
WBC (TLC) – Total leucocyte count
RBC – Red blood cell count
Hb - Haemoglobin
Hct - Haematocrit value
MCV – Mean corpuscular volume
MCH – Mean corpuscular Haemoglobin
MCHC – Mean corpuscular Haemoglobin concentration
Peripheral smear.
RDW – Red cell distribution width
Plt – Platelet count
Mean platelet volume (MPV)
DLC – Differential count
CBC is a screening test, used to diagnose numerous diseases.
HEMOGLOBIN-
The hemoglobin test measures the amount of hemoglobin in blood and is a good measure of the blood's ability to carry oxygen throughout the body.
Hb is measured in gram per deciliter (g/dL) of blood
Methods for estimation of Hb-
1 Colorimetric method
Cynamethaemoglobin method
Oxyhaemoglobin method
Electronic counter method
Direct reading electronic haemoglobinometer
Sahlis method
2 Measurement of oxygen carrying capacity of Hb
3 Measurement of iron content of Hb
4 Specific gravity method
Hemoglobin (Hb)
Men: 14-17.4 grams per deciliter (g/dL) or 140-
174 grams per liter (g/L)
Women: 12-16 g/dL or 120-160 g/L
Children: 9.5-20.5 g/dL or 95-205 g/L
Newborn: 14.5-24.5 g/dL or 145-245 g/L
Hemoglobin interfering factors-
It increases at higher altitude in children
Low in excess fluid intake and in pregnancy
Gentamycin, methyldopa increases the values.
Causes of Increased Haemoglobin-
Primary :
Polycythemia vera (neoplastic)
Secondary :
Associated with hypoxia-Cardiovascular diseases, pulmonary diseases, High altitude, hypoventilation, Smoking, Methaemoglobinemia.
Increased erythropoietin production- Kidney diseases and tumours
liver tumours, Associated with adrenocortical steroids, testosterone supplements., Associated with chronic chemical exposure, nitrites, cobalt, alcohol
Relative:
*Stress
*Dehydration: vomiting, diarrhoea
*Plasma loss: burns.
Causes of Decreased haemoglobin level-
Blood loss
- Internal, External
Impaired red cell production
- Deficiency of iron, Vit B12
- Infection, renal failure, liver disease, chronic diseases.
- Aplastic, sideroblastic & dyserythroblastic anemia
- Bone marrow infiltrations with tumor cells
Increased destruction of RBC (Haemolysis)
Haemodilution
- Pregnancy, oedema
Increased destruction of RBC (Haemolysis)
Haemodilution
- Pregnancy, oedema
HEMATOCRIT (PCV)-
Hematocrit (HCT, packed cell volume, PCV). This test measures the amount of space (volume) red blood cells take up in the blood. The value is given as a percentage of red blood cells in a volume of blood. It is one of the most precise methods of determining the degree of anemia or polycythemia.
Normal Range: Male :- 40-55%
Female :-36-48%
Ratio of Hemoglobin to Hematocrit = 3: 1
Method for estimation-
Macro method ( Wintrobes method)
Micro haematocrit method
Electronic method.
Blood is collected in a hematocrit tube with anti coagulant and centrifuged for 30 min at 3000 rpm, the RBC’s settle down at bottom having a clear plasma at top. In between the plasma and RBC’s there is a thin layer of white buffy coat which is formed by white blood cells and platelets.
Increased PCV value-
Polycythemia
Dehydration due to severe diarrhoea & Vomitting
Burns
Spleen hyperfunction,
Decreased PCV value
Anaemia
Pregnancy
low thymus function.
RBC COUNT-
The scientific name for red blood cells is Erythrocytes.
The most numerous of all cells in the blood.(4-5million/cmm)
Produced at a rate of 4-5 billion every hour in an adult human!(Life span 120 days).
RBC- M: 4.7 to 6.1 x10^12 /L
F: 4.2 to 5.4 x10^12 /L
Biconcave disc shape with diameter of about 8 µm
Function: - transport hemoglobin which carries oxygen from the lung to the tissues.
Red blood cell (RBC) count
Men: 4.5-5.5 million RBCs per microliter (mcL) or 4.5-5.5 x 1012/liter (L)
Women: 4.0-5.0 million RBCs per mcL or 4.0-5.0 x 1012/L
Children: 3.8-6.0 million RBCs per mcL or 3.8-6.0 x 1012/L
Newborn: 4.1-6.1 million RBCs per mcL or 4.1-6.1 x 1012/L
METHOD- Visual haemacytometer method
Electronic method
RBC Interfering factors-
In lying position count is low.
Excitement and exercise raises the count.
Count is highest in morning then falls.
Count is high at high altitude.
Increased red blood cell count-
Increase in Red Cell production
Primary: Polycythemia vera (Neoplastic)
Secondary: To compensate for low oxygen levels (Poor heart / lung function, high altitude )
Erythropoietin (EPO)- Internal / External
Anabolic Steroids
Smoking, Alcohol, Carbon Monoxide
Liver disease, Kidney diseases,
Long term lung diseases, Heart diseases, Cancers Haemoglobinopathies
Decreased Red blood cell Count-
Decreased Production (Aplastic Anemia, deficiency of Iron / VitB12 / Folic acid etc) Blood loss. Internal / External, Haemolytic Anaemias, sickle cell anemia, Tumors, Addison's disease, Thalassemia, other haemoglobinopathies, Lead poisoning, stomach ulcers, Bowel diseases, Splenectomy.
Red blood cell indices-
There are three red blood cell indices:
Mean corpuscular volume (MCV), Mean corpuscular hemoglobin (MCH), and Mean corpuscular hemoglobin concentration (MCH
Red blood cell indices
Mean corpuscular volume (MCV): 80-100 cubic millimeters (mm3) or 80-
100 femtoliters (fL)
Mean corpuscular hemoglobin
(MCH): 26-34 picograms (pg) or 0.40-0.53
femtomoles (fmol)
Mean corpuscular hemoglobin
concentration (MCHC): 32-36 grams per deciliter (g/dL) or
320-360 grams per liter (g/L)
Absolute Values
Based on normal values of RBC,Hb, PCV red cell indices are derived which are of diagostic importance.
1 Mean corpuscular volume
= PCV in L/L
RBC count/L
2 Mean corpuscular haemoglobin MCH
= Hb/L
RBC count/ L
3 Mean corpuscular haemoglobin concentration MCHC
= Hb/dl
PCV IN L/L
Since MCHC is independent of red cell count and size, it is greater clinical importance as compared with other values.
SIGNIFICANCE OF RED CELL INDICIES
Decreased MCH, MCV, MCHC = Iron deficiency anemia & thalassaemia.
Increased MCV = Megaloblastic anemia
Normal MCV, MCH, MCHC = Anemia due to acute blood loss and haemolytic anaemia.
Mean Corpuscular Volume (MCV)-
The MCV relates to the average size of the red blood cell.
Abnormal MCV associated with changes in MCH is a significant finding for folic acid and/or B12 need (increase) or iron, copper or vitamin B6 need (decrease).
MCV and MCH are always be viewed together.
Optimum range is 80.0 to 100.0 femtolitres.
It indicates whether RBC’s are Microcytic, Normocytic or Microcytic
If MCV is less than 80fl then it is Microcytic
If MCV is More than 96fl then it is Macrocytic
If it is with in 80-96fl then it is Normocytic.
Macrocytosis-
- Hereditary anemia(s).
- Megaloblastic Anemias
- Reticulocytosis
- Liver disease .
- Hypothyroidism .
- Drugs (anti-convulsants).
- Zidovidune treatment (AIDS).
Alcoholism, sprue, def b12, folate
Microcytosis
Copper and iron deficiency
Low stomach acid (Hypochlorhydria).
Vitamin C and Vit B6 insufficiency.
Rheumatoid arthritis.
Lead poisoning.
Hereditary (thalassemias, sideroblastic anaemia)
After a splenectomy
Hemolytic anemia
Mean Corpuscular Hemoglobin (MCH)
The amount of hemoglobin in a single RBC
It is the ratio of Hb and the RBC count.
Optimum values: 28.0 to 32.0 picograms.
Increased & decreased in the same conditions as the MCV.
It is significantly less in when Microcytosis is associated with Hypochromia
Ex :- Iron Deficiency anaemia & Thalessemia minor
Mean Corpuscular Hemoglobin Concentration (MCHC)
The average hemoglobin concentration per unit volume(100 ml) of packed red cells. Optimum values: 32 to 36 %.
MCHC (32-36%)
Increased – spherocytosis
Decreased – IDA, microcytic anaemia, thalassemia, pyridoxine responsive, anaemia
Red cell Distribution Width (RDW)
The red blood cell distribution width (RDW or RCDW) is a measure of the variation of red blood cell (RBC) volume.
Usually red blood cells are of about 6-8 μm. Certain disorders, however, cause a significant variation in cell size.
Higher RDW values indicate greater variation in size. Normal reference range is 11–15%.
An elevated RDW (red blood cells of unequal sizes) is known as anisocytosis
RDW test results are often used together with mean corpuscular volume (MCV) results to determine the cause of the anemia. It is mainly used to differentiate an anemia of mixed causes from an anemia of a single cause.
Vitamin B12 deficiency produces a macrocytic anemia (large cell anemia) with a high RDW.
However, iron deficiency anemia initially presents with a varied size distribution of red blood cells, and as such shows an decreased RDW.
In the case of a mixed iron and B12 deficiency, there will normally be a mix of both large cells and small cells, causing the RDW to be elevated.
Mathematically the RDW is calculated with the following formula:
RDW = (Standard deviation of MCV ÷ mean MCV) × 100.
The RDW is often increased in:
^ Pernicious anemia
^ Folic acid anemia
^ Hemolytic anemia
^ Transfusions
^ Sideroblastic anemia
^ Alcohol abuse
^ Maturation defect anaemias
The RDW is often decreased in:
< Iron deficiency anemia (blood loss, parasites infection, poor iron absorption, etc.)
< Vitamin B6 anemia.
< Rheumatoid arthritis.
Peripheral smear- A blood film or peripheral blood smear is a thin layer of blood smeared on a microscope slide and then stained to examine various blood cells microscopically.
Blood films are usually examined to investigate hematological problems (disorders of the blood) and, occasionally, to look for parasites within the blood such as malaria and filaria.
The smear offers the functional status of the bone marrow. It is particularly important when assessing cytopenic states (eg, anemia, leukopenia, thrombocytopenia).
Analysers cannot indentify abnormalities of red cell shape and contents( howell- jolly bodies, basophilic stippling, malarial parasite) or fully defined abnormal white cells such as blasts.
Peripheral smear is especially important in,
Hemolytic anemia — Review of red cell morphology may identify the cause of erythrocyte destruction (eg, the presence of bite cells points to a Heinz body hemolytic anemia).
Thrombocytopenia — Distinguishing between increased platelet consumption and reduced platelet production can often be made through review of platelet size in blood smear.
White cell disorders — The disease classification rely upon evaluation of abnormal circulating cells (eg, the presence of Auer rods in a blast form in patients with acute myeloid leukemia)
Microcytosis ( reduced average cell size, MCV< 76 fl):
Iron deficiency Anemia, Thalassemia, Sideroblastic anaemia.
Macrocytosis ( increased average cell size, MCV> 100 fl):
Megaloblastic Anemia because of vit B12 & folic acid deficiency, liver disease, alcohol, hypothyroidism, drugs like zidovudine.
The presence of target cells may be due to:
Hemoglobin abnormalities (hemoglobinopathies)
Iron deficiency
Liver disease
Spleen removal
Thalassemia
The presence of sphere-shaped cells (spherocytes) may be due to:
Autoimmune hemolytic anemia
Hereditary spherocytosis
Post splenectomy
The presence of red cell fragmented (schistocytes) may be due to:
Artificial heart valve
Disseminated intravascular coagulation
Hemolytic uremic syndrome (HUS)
Microangiopathic hemolytic anemia
Thrombotic thrombocytopenic purpura (TTP)
The presence of a type of immature red blood cell called a normoblast ( nucleated RBC’s) may be due to:
Cancer that has spread to bone marrow infiltration
Erythroblastosis fetalis
Leukoerythroblastic anemia (myelophthisis process)
Miliary tuberculosis
Myelofibrosis
Removal of spleen
Severe hemolysis
Thalassemia
The presence of teardrop-shaped cells may indicate:
Leukoerythroblastic anemia
Myelofibrosis
Severe iron deficiency
Thalassemia major
The presence of Howell-Jolly bodies( small round nuclear remnants) may indicate:
Dyshaemopoiesis
Post-splenectomy
Sickle cell anemia
The presence of Heinz bodies may indicate:
Alpha thalassemia
Congenital hemolytic anemia
G6PD deficiency
Unstable form of hemoglobin
The presence of slightly immature red blood cells (reticulocytes) polychromasia may indicate:
Anemia with bone marrow recovery
Hemolytic anemia
Acute Hemorrhage
The presence of basophilic stippling( abnormal ribosomes appear as blue dots) may indicate:
Lead poisoning
Myelofibrosis
Dyshaemopoiesis
The presence of sickle cells may indicate sickle cell anemia.
PLATELETS (Thrombocytes)
Fragments of cells that participate in clotting.
Initiate repair of blood vessel walls.
Optimum values: 150,000 to 400,000/ mm3 of blood.
Small granular non-nucleated discs.
Diameter about 2-4 µm
Function; involved in coagulation and blood haemostasis.
Life span 7-10 days
METHOD
Visual haemacytometer method
Electronic method
Platelet (thrombocyte) count
Adults: 140,000-400,000 platelets per mm3 or
140-400 x 109/L
Children: 150,000-450,000 platelets per mm 3 or
150-450 x 109/L
Thrombocytosis(Platelets increased )
Infections
Acute blood loss
Disseminated carcinoma
Splenectomy
Thrombocythemia
Polycythemia Vera
Myeloproliferative Disorders
Chronic Granulocytic Leukemia
Hemolytic anemia(s)
Myelosclerosis
Essential (without known cause)
After sever injuries,
major surgery, parturation, haemorrhage.
Thrombocytopenia (Platelets decreased)
Decreased Production
Marrow depression/ infiltration
Megaloblastic anemia. Aplastic anaemia
Congenital
Increased Destruction
Immunologic (ITP, SLE), Infectious mononucleosis ,Rubella, EBV
Lymphoma, Multiple myeloma, Leukemia
Drugs-chemotherapy, Quinine, Sulphonamides, Rifampicin, heparin.
Hypersplenism ,Liver dysfunction (cirrhosis).
Dilution due to overhydration
Platelet aggregation or large platelets
Low platelet values can occur in pregnancy or idiopathic thrombocytopenic purpura (ITP)
A large spleen can lower the platelet count
Mean platelet volume (MPV)
Mean platelet volume (MPV) is a measurement that describes the average size of platelets in the blood. It is part of a complete blood count (CBC). The importance of mean platelet volume is that, it is an indicator as to whether the bone marrow is manufacturing them normally.
Elevated mean platelet volume is common in patients with certain forms of diabetes. If combined with a low Plt result, indicates a condition resulting in destruction of platelets such as immune thrombocytopenia, pre-eclampsia, sepsis, various hereditary conditions. High MPV with a normal Plt test result is a sign of chronic myeloid leukemia, hyperthyroidism. Accompanied by a high Plt result, it may indicate a bone marrow disorder that causes excessive cell production.
Conditions Associated with Low MPV
In association with a low Plt value, this indicates anemia, chemotherapy. If combined with a normal Plt, indicates chronic kidney failure. Accompanied by a high Plt, indicates an infection, inflammation or some form of cancer.
DLC (Differential Leucocyte Count):
Neutrophils (polys and bands)
Lymphocytes
Monocytes
Eosinophils
Basophils
White blood cell (WBC, leukocyte) count
Men and non pregnant women: 5,000-10,000 WBCs per cubic millimeter (mm3) or 5.0-10.0 x 109 WBCs per liter (L)
White blood cell types (WBC differential)
Neutrophils: 50%
Lymphocytes: 25%-40%
Monocytes: 3%-7%
Eosinophils: 0%-3%
Basophils: 0%-1%
When the total leucocyte count is increase above the normal level called Leucocytosis.
When the total leucocyte count is decrease below the normal level called Leucocytopenia.
Normal Range: Adult :- 4000- 11000 /mm3 of blood
New borns :- 10000-25000/mm3 of blood
Infants :- 6000-18000/mm3 of blood
Children :- 5000-15000/mm3 of blood
There is NO sex difference in value, as seen in RBC count.
METHOD
Visual haemacytometer method
Electronic method
Differential Leucocyte COUNT
Visual counting
Automated DLC counters have differential counting capacity of counting 3 or 5 part ( P,L,M,E,B)
Interfering Factors
In new born and infants count is high values reaches normal at puberty.
Physical activity, food, pain, emotional disturbance will slightly increase the count.
Chronic leukemia may decrease the count.
Early morning values are low during evening hours are high.
Leucocytosis
Physiological conditions
New borns & infants
Physical exercise
After food intake
Exposure to sun & increased environment temp.
Pregnancy
Parturition
Pain, nausea, vomiting
Menstruation
Emotion & Anxiety
Pathological conditions
Acute Bacterial infections Ex- pyogenic bacteria ,boils, abscess, pneumonia Chronic bacterial infection ,Tuberculosis, Tissue injury
Infarction, Burns, Surgery, Splenectomy
Haemorrhage, Neoplasia, Stress states & hyperactivity, Convulsions
Severe colic, Inflammatory disorders, Rheumatic fever, Metabolic disorders, Diabetic ketoacidosis, RA, Corticosteroid therapy, Leukemia, cancer,
Leucocytopenia-
Conditions that can lower WBC values include chemotherapy and reactions to other medicines, aplastic anemia, viral infections, malaria, alcoholism, AIDS, lupus, or Cushing's syndrome.
A large spleen can lower the WBC count.
Physiological
Exposure to severe cold
Pathological
Infections:-Typhoid fever, Paratyphoid fever
Viral infections(early phase :- infectious hepatitis )
Overwhelming sepsis
Replacement of haemopoietic tissue in the bone marrow by neoplastic infiltrative cells
Acute leukemia
Lymphoma
Multiple myeloma
Myelofibrosis
Aplastic anaemia
Cytotoxic therapy
Drugs
Chloramphenicol
Sulpha drugs
Aspirin
Hyperspleenism
Starvation & Malnutrition
Neutrophils (Granulocytes)
polymorphonuclear leukocytes
Nucleus 3-5 lobes.
Diameter 10-14 µm
50-70% WBC
Function: Phagocytosis of bacteria and cell debris
Numbers rise with all manner of stress, especially bacterial infections
Interfering factors-
In children neutrophilia develops more prominently in case of infection.
Weak debilitated people fail to respond with neutrophilia in infection.
ACTH, Myelosuppressive chemotherapy don’t allow proportionate neutrophilia in infection.
NEUTROPHILIA-
Physiological
Exercise
Pregnancy last week
Parturition
Food intake
Emotional stress
Exposure to cold & heat.
Emotional disturbance Infants during first days.
Pathological
Acute pyogenic infections
Pneumonia, tonsillitis,
Acute infective inflammatory conditions
Rheumatic fever
Non inflammatory conditions
Pulmonary embolism, MI
Acute haemorrhage
Trauma
Leukemia, Neoplasm
Metabolic diseases-uremia, gout, acidosis
Chronic myeloid leukemia
Toxic conditions
Uremia, hepatic coma
Corticosteroid therapy
Eosinophils-
A type of leukocyte with coarse orange red round granules of uniform size and bilobed nucleus.
Eosinophils are so named because their cytoplasmic granules stain red with the dye eosin.
Eosinophils constitute 1 to 3 % (350 to 650 /cmm).
Pathological conditions
Allergic conditions Parasitic infestations Bronchial asthama Hookworm
Urticaria Filariasis
Hay fever Hydatid disease
Psoriasis Collagen disease
Bronchial asthama Periarteritis nodosa
Skin diseases Hodgkins disease
Food allergy Addisons disease
Pemphigus Certain leukemias , Neoplasm
Pulmonary Drugs – Streptomycin, penicillin etc.
eosionophilia
EOSINOPENIA-
ACTH therapy, Adrenalin, Insulin
Cushings syndrome, Acromegaly
Acute pyogenic infection, Aplastic anaemia, SLE
Stress, sever shocks, sever burns
Interfering factors-
Eosinophil count is lowest in morning
Burns electric shock, post operative states will decrease the count
ACTH reduces the count.
Basophil-
Coarse bluish-black granules of uniform size and typically a bilobate nucleus.
Basophils are so named because their cytoplasmic granules stain with basic dyes.
Constitute 0.5 to 1% of the peripheral blood leukocytes.
Release histamine and serotonin
BASOPHILIA
Chronic myeloid leukemia
Polycythemia vera
Hypersensitivity, mylosclerosis, Hodgkins lymphoma, cirrhosis of liver, early stage of Hodgkins disease, Lead poisoning
BASOPENIA
Severe septicaemia
Aplastic anaemia
Hyperthyroidism
Corticosteroid
Lymphocytes
Lymphocytes are of large and small types.
Normal range is 20-45%.
No specific granules
20-40% of WBC
Diameter 8-10 µm
T cells: cellular (for viral infections)
B cells: humoral (antibody) Natural Killer Cells
LYMPHOCYTOSIS
Chronic infection
Tuberculosis, Brucellosis, syphills,
Infection mononucleosis, hepatitis, rubella, pertusis
Lymphatic leukemia
Lymphomas
Endocrine – Thyrotoxicosis, hypopituritism, neoplasm
LYMPHOCYTOPENIA
Immune suppressive therapy
ACTH
Hodgkins disease
Bone marrow failure, pancytopenia, CHF, AIDS
Monocytes-
Monocytes share the 'vacuum cleaner' function of neutrophils.(2-9%).
Present pieces of pathogens to T cells, so the pathogens may be recognized again and killed, thus an antibody response may be mounted.
Also known as macrophage after they leave the bloodstream
and enter tissues.
MONOCYTOSIS
Protozoan disease
Malaria
Kala-azar
Hodgkins disease, RA, SLE, Sarcoidosis, ulcerative colitis
Monocytic leukemia, lymphoma, multiple myeloma
ACTH therapy, Infection brucellosis, typhus, typhoid.
MONOCYTOPENIA
Bone marrow failure
Aplastic anaemia
Septicaemia
Steroid, low immunity
CONCLUSION-
The results of CBC shows how well the vital organs are functioning which is indicator of general state of health.
Reflects problems of blood loss & fluid volume (dehydration)
Shows any abnormalities in the production, destruction & life span of blood cells.
Reflects acute or chronic infection, allergies, and problems with clotting
Screening for high and low values before surgery.
Finds the cause of symptoms such as fatigue, weakness, fever, bruising, or weight loss.
Diagnosing diseases of the blood, such as Leukemia, Polycythemia, Thrombocytosis.
Checks how the body is dealing with some types of drug or radiation treatment.
definitioBlood
definition-by oxford dictionaries-
Red liquid that circulates in the arteries and veins of humans and other vertebrate animals, carrying oxygen to and carbon dioxide from the tissue of the body.
by CCM,- Blood is a biological red liquid circulating in the arteries and veins under the impulse of the heart. An individual contains 5-7 L of blood in his body, which represents about 8% of its total weight. Blood is made up of plasma, red blood cells, white blood cells and platelets. Its distributes oxygen, hormones and nutrients to all cells, all tissues and all organs of the body, then get rid of their waste. Blood also plays a role in immune defense.
COMPOSITION OF BLOOD-
Blood consists of 55% plasma (liquid portion) and 45% formed elements ( blood cells)
Formed elements are RBC(Erythrocytes), WBC( Leukocytes), Platelets (Thrombocytes)
Complete Blood Count (CBC)
Also known as: Complete blood picture(CBP), Haemogram
Red Blood Cells, Platelets , T Lymphocyte, Monocyte
as seen through a scanning electron microscope.
The CBC is the measurement of the number of circulating RBC’s, WBC’s, platelets, the concentration of haemoglobin and characteristics of RBC’s.
Anticoagulated blood is processed through automatic blood analysers which using variety of technologies ( particle sizing, radiofrequency, laser instrumentation) to measure different parameters.
These includes number of circulating cells, the proportion of red cells (haematocrit) and red cell indices which gives information about size of red cells (MCV), and amount of Hb present in RBC’s(MCH), and WBC’s and differential counts.
CBC includes
WBC (TLC) – Total leucocyte count
RBC – Red blood cell count
Hb - Haemoglobin
Hct - Haematocrit value
MCV – Mean corpuscular volume
MCH – Mean corpuscular Haemoglobin
MCHC – Mean corpuscular Haemoglobin concentration
Peripheral smear.
RDW – Red cell distribution width
Plt – Platelet count
Mean platelet volume (MPV)
DLC – Differential count
CBC is a screening test, used to diagnose numerous diseases.
HEMOGLOBIN-
The hemoglobin test measures the amount of hemoglobin in blood and is a good measure of the blood's ability to carry oxygen throughout the body.
Hb is measured in gram per deciliter (g/dL) of blood
Methods for estimation of Hb-
1 Colorimetric method
Cynamethaemoglobin method
Oxyhaemoglobin method
Electronic counter method
Direct reading electronic haemoglobinometer
Sahlis method
2 Measurement of oxygen carrying capacity of Hb
3 Measurement of iron content of Hb
4 Specific gravity method
Hemoglobin (Hb)
Men: 14-17.4 grams per deciliter (g/dL) or 140-
174 grams per liter (g/L)
Women: 12-16 g/dL or 120-160 g/L
Children: 9.5-20.5 g/dL or 95-205 g/L
Newborn: 14.5-24.5 g/dL or 145-245 g/L
Hemoglobin interfering factors-
It increases at higher altitude in children
Low in excess fluid intake and in pregnancy
Gentamycin, methyldopa increases the values.
Causes of Increased Haemoglobin-
Primary :
Polycythemia vera (neoplastic)
Secondary :
Associated with hypoxia-Cardiovascular diseases, pulmonary diseases, High altitude, hypoventilation, Smoking, Methaemoglobinemia.
Increased erythropoietin production- Kidney diseases and tumours
liver tumours, Associated with adrenocortical steroids, testosterone supplements., Associated with chronic chemical exposure, nitrites, cobalt, alcohol
Relative:
*Stress
*Dehydration: vomiting, diarrhoea
*Plasma loss: burns.
Causes of Decreased haemoglobin level-
Blood loss
- Internal, External
Impaired red cell production
- Deficiency of iron, Vit B12
- Infection, renal failure, liver disease, chronic diseases.
- Aplastic, sideroblastic & dyserythroblastic anemia
- Bone marrow infiltrations with tumor cells
Increased destruction of RBC (Haemolysis)
Haemodilution
- Pregnancy, oedema
Increased destruction of RBC (Haemolysis)
Haemodilution
- Pregnancy, oedema
HEMATOCRIT (PCV)-
Hematocrit (HCT, packed cell volume, PCV). This test measures the amount of space (volume) red blood cells take up in the blood. The value is given as a percentage of red blood cells in a volume of blood. It is one of the most precise methods of determining the degree of anemia or polycythemia.
Normal Range: Male :- 40-55%
Female :-36-48%
Ratio of Hemoglobin to Hematocrit = 3: 1
Method for estimation-
Macro method ( Wintrobes method)
Micro haematocrit method
Electronic method.
Blood is collected in a hematocrit tube with anti coagulant and centrifuged for 30 min at 3000 rpm, the RBC’s settle down at bottom having a clear plasma at top. In between the plasma and RBC’s there is a thin layer of white buffy coat which is formed by white blood cells and platelets.
Increased PCV value-
Polycythemia
Dehydration due to severe diarrhoea & Vomitting
Burns
Spleen hyperfunction,
Decreased PCV value
Anaemia
Pregnancy
low thymus function.
RBC COUNT-
The scientific name for red blood cells is Erythrocytes.
The most numerous of all cells in the blood.(4-5million/cmm)
Produced at a rate of 4-5 billion every hour in an adult human!(Life span 120 days).
RBC- M: 4.7 to 6.1 x10^12 /L
F: 4.2 to 5.4 x10^12 /L
Biconcave disc shape with diameter of about 8 µm
Function: - transport hemoglobin which carries oxygen from the lung to the tissues.
Red blood cell (RBC) count
Men: 4.5-5.5 million RBCs per microliter (mcL) or 4.5-5.5 x 1012/liter (L)
Women: 4.0-5.0 million RBCs per mcL or 4.0-5.0 x 1012/L
Children: 3.8-6.0 million RBCs per mcL or 3.8-6.0 x 1012/L
Newborn: 4.1-6.1 million RBCs per mcL or 4.1-6.1 x 1012/L
METHOD- Visual haemacytometer method
Electronic method
RBC Interfering factors-
In lying position count is low.
Excitement and exercise raises the count.
Count is highest in morning then falls.
Count is high at high altitude.
Increased red blood cell count-
Increase in Red Cell production
Primary: Polycythemia vera (Neoplastic)
Secondary: To compensate for low oxygen levels (Poor heart / lung function, high altitude )
Erythropoietin (EPO)- Internal / External
Anabolic Steroids
Smoking, Alcohol, Carbon Monoxide
Liver disease, Kidney diseases,
Long term lung diseases, Heart diseases, Cancers Haemoglobinopathies
Decreased Red blood cell Count-
Decreased Production (Aplastic Anemia, deficiency of Iron / VitB12 / Folic acid etc) Blood loss. Internal / External, Haemolytic Anaemias, sickle cell anemia, Tumors, Addison's disease, Thalassemia, other haemoglobinopathies, Lead poisoning, stomach ulcers, Bowel diseases, Splenectomy.
Red blood cell indices-
There are three red blood cell indices:
Mean corpuscular volume (MCV), Mean corpuscular hemoglobin (MCH), and Mean corpuscular hemoglobin concentration (MCH
Red blood cell indices
Mean corpuscular volume (MCV): 80-100 cubic millimeters (mm3) or 80-
100 femtoliters (fL)
Mean corpuscular hemoglobin
(MCH): 26-34 picograms (pg) or 0.40-0.53
femtomoles (fmol)
Mean corpuscular hemoglobin
concentration (MCHC): 32-36 grams per deciliter (g/dL) or
320-360 grams per liter (g/L)
Absolute Values
Based on normal values of RBC,Hb, PCV red cell indices are derived which are of diagostic importance.
1 Mean corpuscular volume
= PCV in L/L
RBC count/L
2 Mean corpuscular haemoglobin MCH
= Hb/L
RBC count/ L
3 Mean corpuscular haemoglobin concentration MCHC
= Hb/dl
PCV IN L/L
Since MCHC is independent of red cell count and size, it is greater clinical importance as compared with other values.
SIGNIFICANCE OF RED CELL INDICIES
Decreased MCH, MCV, MCHC = Iron deficiency anemia & thalassaemia.
Increased MCV = Megaloblastic anemia
Normal MCV, MCH, MCHC = Anemia due to acute blood loss and haemolytic anaemia.
Mean Corpuscular Volume (MCV)-
The MCV relates to the average size of the red blood cell.
Abnormal MCV associated with changes in MCH is a significant finding for folic acid and/or B12 need (increase) or iron, copper or vitamin B6 need (decrease).
MCV and MCH are always be viewed together.
Optimum range is 80.0 to 100.0 femtolitres.
It indicates whether RBC’s are Microcytic, Normocytic or Microcytic
If MCV is less than 80fl then it is Microcytic
If MCV is More than 96fl then it is Macrocytic
If it is with in 80-96fl then it is Normocytic.
Macrocytosis-
- Hereditary anemia(s).
- Megaloblastic Anemias
- Reticulocytosis
- Liver disease .
- Hypothyroidism .
- Drugs (anti-convulsants).
- Zidovidune treatment (AIDS).
Alcoholism, sprue, def b12, folate
Microcytosis
Copper and iron deficiency
Low stomach acid (Hypochlorhydria).
Vitamin C and Vit B6 insufficiency.
Rheumatoid arthritis.
Lead poisoning.
Hereditary (thalassemias, sideroblastic anaemia)
After a splenectomy
Hemolytic anemia
Mean Corpuscular Hemoglobin (MCH)
The amount of hemoglobin in a single RBC
It is the ratio of Hb and the RBC count.
Optimum values: 28.0 to 32.0 picograms.
Increased & decreased in the same conditions as the MCV.
It is significantly less in when Microcytosis is associated with Hypochromia
Ex :- Iron Deficiency anaemia & Thalessemia minor
Mean Corpuscular Hemoglobin Concentration (MCHC)
The average hemoglobin concentration per unit volume(100 ml) of packed red cells. Optimum values: 32 to 36 %.
MCHC (32-36%)
Increased – spherocytosis
Decreased – IDA, microcytic anaemia, thalassemia, pyridoxine responsive, anaemia
Red cell Distribution Width (RDW)
The red blood cell distribution width (RDW or RCDW) is a measure of the variation of red blood cell (RBC) volume.
Usually red blood cells are of about 6-8 μm. Certain disorders, however, cause a significant variation in cell size.
Higher RDW values indicate greater variation in size. Normal reference range is 11–15%.
An elevated RDW (red blood cells of unequal sizes) is known as anisocytosis
RDW test results are often used together with mean corpuscular volume (MCV) results to determine the cause of the anemia. It is mainly used to differentiate an anemia of mixed causes from an anemia of a single cause.
Vitamin B12 deficiency produces a macrocytic anemia (large cell anemia) with a high RDW.
However, iron deficiency anemia initially presents with a varied size distribution of red blood cells, and as such shows an decreased RDW.
In the case of a mixed iron and B12 deficiency, there will normally be a mix of both large cells and small cells, causing the RDW to be elevated.
Mathematically the RDW is calculated with the following formula:
RDW = (Standard deviation of MCV ÷ mean MCV) × 100.
The RDW is often increased in:
^ Pernicious anemia
^ Folic acid anemia
^ Hemolytic anemia
^ Transfusions
^ Sideroblastic anemia
^ Alcohol abuse
^ Maturation defect anaemias
The RDW is often decreased in:
< Iron deficiency anemia (blood loss, parasites infection, poor iron absorption, etc.)
< Vitamin B6 anemia.
< Rheumatoid arthritis.
Peripheral smear- A blood film or peripheral blood smear is a thin layer of blood smeared on a microscope slide and then stained to examine various blood cells microscopically.
Blood films are usually examined to investigate hematological problems (disorders of the blood) and, occasionally, to look for parasites within the blood such as malaria and filaria.
The smear offers the functional status of the bone marrow. It is particularly important when assessing cytopenic states (eg, anemia, leukopenia, thrombocytopenia).
Analysers cannot indentify abnormalities of red cell shape and contents( howell- jolly bodies, basophilic stippling, malarial parasite) or fully defined abnormal white cells such as blasts.
Peripheral smear is especially important in,
Hemolytic anemia — Review of red cell morphology may identify the cause of erythrocyte destruction (eg, the presence of bite cells points to a Heinz body hemolytic anemia).
Thrombocytopenia — Distinguishing between increased platelet consumption and reduced platelet production can often be made through review of platelet size in blood smear.
White cell disorders — The disease classification rely upon evaluation of abnormal circulating cells (eg, the presence of Auer rods in a blast form in patients with acute myeloid leukemia)
Microcytosis ( reduced average cell size, MCV< 76 fl):
Iron deficiency Anemia, Thalassemia, Sideroblastic anaemia.
Macrocytosis ( increased average cell size, MCV> 100 fl):
Megaloblastic Anemia because of vit B12 & folic acid deficiency, liver disease, alcohol, hypothyroidism, drugs like zidovudine.
The presence of target cells may be due to:
Hemoglobin abnormalities (hemoglobinopathies)
Iron deficiency
Liver disease
Spleen removal
Thalassemia
The presence of sphere-shaped cells (spherocytes) may be due to:
Autoimmune hemolytic anemia
Hereditary spherocytosis
Post splenectomy
The presence of red cell fragmented (schistocytes) may be due to:
Artificial heart valve
Disseminated intravascular coagulation
Hemolytic uremic syndrome (HUS)
Microangiopathic hemolytic anemia
Thrombotic thrombocytopenic purpura (TTP)
The presence of a type of immature red blood cell called a normoblast ( nucleated RBC’s) may be due to:
Cancer that has spread to bone marrow infiltration
Erythroblastosis fetalis
Leukoerythroblastic anemia (myelophthisis process)
Miliary tuberculosis
Myelofibrosis
Removal of spleen
Severe hemolysis
Thalassemia
The presence of teardrop-shaped cells may indicate:
Leukoerythroblastic anemia
Myelofibrosis
Severe iron deficiency
Thalassemia major
The presence of Howell-Jolly bodies( small round nuclear remnants) may indicate:
Dyshaemopoiesis
Post-splenectomy
Sickle cell anemia
The presence of Heinz bodies may indicate:
Alpha thalassemia
Congenital hemolytic anemia
G6PD deficiency
Unstable form of hemoglobin
The presence of slightly immature red blood cells (reticulocytes) polychromasia may indicate:
Anemia with bone marrow recovery
Hemolytic anemia
Acute Hemorrhage
The presence of basophilic stippling( abnormal ribosomes appear as blue dots) may indicate:
Lead poisoning
Myelofibrosis
Dyshaemopoiesis
The presence of sickle cells may indicate sickle cell anemia.
PLATELETS (Thrombocytes)
Fragments of cells that participate in clotting.
Initiate repair of blood vessel walls.
Optimum values: 150,000 to 400,000/ mm3 of blood.
Small granular non-nucleated discs.
Diameter about 2-4 µm
Function; involved in coagulation and blood haemostasis.
Life span 7-10 days
METHOD
Visual haemacytometer method
Electronic method
Platelet (thrombocyte) count
Adults: 140,000-400,000 platelets per mm3 or
140-400 x 109/L
Children: 150,000-450,000 platelets per mm 3 or
150-450 x 109/L
Thrombocytosis(Platelets increased )
Infections
Acute blood loss
Disseminated carcinoma
Splenectomy
Thrombocythemia
Polycythemia Vera
Myeloproliferative Disorders
Chronic Granulocytic Leukemia
Hemolytic anemia(s)
Myelosclerosis
Essential (without known cause)
After sever injuries,
major surgery, parturation, haemorrhage.
Thrombocytopenia (Platelets decreased)
Decreased Production
Marrow depression/ infiltration
Megaloblastic anemia. Aplastic anaemia
Congenital
Increased Destruction
Immunologic (ITP, SLE), Infectious mononucleosis ,Rubella, EBV
Lymphoma, Multiple myeloma, Leukemia
Drugs-chemotherapy, Quinine, Sulphonamides, Rifampicin, heparin.
Hypersplenism ,Liver dysfunction (cirrhosis).
Dilution due to overhydration
Platelet aggregation or large platelets
Low platelet values can occur in pregnancy or idiopathic thrombocytopenic purpura (ITP)
A large spleen can lower the platelet count
Mean platelet volume (MPV)
Mean platelet volume (MPV) is a measurement that describes the average size of platelets in the blood. It is part of a complete blood count (CBC). The importance of mean platelet volume is that, it is an indicator as to whether the bone marrow is manufacturing them normally.
Elevated mean platelet volume is common in patients with certain forms of diabetes. If combined with a low Plt result, indicates a condition resulting in destruction of platelets such as immune thrombocytopenia, pre-eclampsia, sepsis, various hereditary conditions. High MPV with a normal Plt test result is a sign of chronic myeloid leukemia, hyperthyroidism. Accompanied by a high Plt result, it may indicate a bone marrow disorder that causes excessive cell production.
Conditions Associated with Low MPV
In association with a low Plt value, this indicates anemia, chemotherapy. If combined with a normal Plt, indicates chronic kidney failure. Accompanied by a high Plt, indicates an infection, inflammation or some form of cancer.
DLC (Differential Leucocyte Count):
Neutrophils (polys and bands)
Lymphocytes
Monocytes
Eosinophils
Basophils
White blood cell (WBC, leukocyte) count
Men and non pregnant women: 5,000-10,000 WBCs per cubic millimeter (mm3) or 5.0-10.0 x 109 WBCs per liter (L)
White blood cell types (WBC differential)
Neutrophils: 50%
Lymphocytes: 25%-40%
Monocytes: 3%-7%
Eosinophils: 0%-3%
Basophils: 0%-1%
When the total leucocyte count is increase above the normal level called Leucocytosis.
When the total leucocyte count is decrease below the normal level called Leucocytopenia.
Normal Range: Adult :- 4000- 11000 /mm3 of blood
New borns :- 10000-25000/mm3 of blood
Infants :- 6000-18000/mm3 of blood
Children :- 5000-15000/mm3 of blood
There is NO sex difference in value, as seen in RBC count.
METHOD
Visual haemacytometer method
Electronic method
Differential Leucocyte COUNT
Visual counting
Automated DLC counters have differential counting capacity of counting 3 or 5 part ( P,L,M,E,B)
Interfering Factors
In new born and infants count is high values reaches normal at puberty.
Physical activity, food, pain, emotional disturbance will slightly increase the count.
Chronic leukemia may decrease the count.
Early morning values are low during evening hours are high.
Leucocytosis
Physiological conditions
New borns & infants
Physical exercise
After food intake
Exposure to sun & increased environment temp.
Pregnancy
Parturition
Pain, nausea, vomiting
Menstruation
Emotion & Anxiety
Pathological conditions
Acute Bacterial infections Ex- pyogenic bacteria ,boils, abscess, pneumonia Chronic bacterial infection ,Tuberculosis, Tissue injury
Infarction, Burns, Surgery, Splenectomy
Haemorrhage, Neoplasia, Stress states & hyperactivity, Convulsions
Severe colic, Inflammatory disorders, Rheumatic fever, Metabolic disorders, Diabetic ketoacidosis, RA, Corticosteroid therapy, Leukemia, cancer,
Leucocytopenia-
Conditions that can lower WBC values include chemotherapy and reactions to other medicines, aplastic anemia, viral infections, malaria, alcoholism, AIDS, lupus, or Cushing's syndrome.
A large spleen can lower the WBC count.
Physiological
Exposure to severe cold
Pathological
Infections:-Typhoid fever, Paratyphoid fever
Viral infections(early phase :- infectious hepatitis )
Overwhelming sepsis
Replacement of haemopoietic tissue in the bone marrow by neoplastic infiltrative cells
Acute leukemia
Lymphoma
Multiple myeloma
Myelofibrosis
Aplastic anaemia
Cytotoxic therapy
Drugs
Chloramphenicol
Sulpha drugs
Aspirin
Hyperspleenism
Starvation & Malnutrition
Neutrophils (Granulocytes)
polymorphonuclear leukocytes
Nucleus 3-5 lobes.
Diameter 10-14 µm
50-70% WBC
Function: Phagocytosis of bacteria and cell debris
Numbers rise with all manner of stress, especially bacterial infections
Interfering factors-
In children neutrophilia develops more prominently in case of infection.
Weak debilitated people fail to respond with neutrophilia in infection.
ACTH, Myelosuppressive chemotherapy don’t allow proportionate neutrophilia in infection.
NEUTROPHILIA-
Physiological
Exercise
Pregnancy last week
Parturition
Food intake
Emotional stress
Exposure to cold & heat.
Emotional disturbance Infants during first days.
Pathological
Acute pyogenic infections
Pneumonia, tonsillitis,
Acute infective inflammatory conditions
Rheumatic fever
Non inflammatory conditions
Pulmonary embolism, MI
Acute haemorrhage
Trauma
Leukemia, Neoplasm
Metabolic diseases-uremia, gout, acidosis
Chronic myeloid leukemia
Toxic conditions
Uremia, hepatic coma
Corticosteroid therapy
Eosinophils-
A type of leukocyte with coarse orange red round granules of uniform size and bilobed nucleus.
Eosinophils are so named because their cytoplasmic granules stain red with the dye eosin.
Eosinophils constitute 1 to 3 % (350 to 650 /cmm).
Pathological conditions
Allergic conditions Parasitic infestations Bronchial asthama Hookworm
Urticaria Filariasis
Hay fever Hydatid disease
Psoriasis Collagen disease
Bronchial asthama Periarteritis nodosa
Skin diseases Hodgkins disease
Food allergy Addisons disease
Pemphigus Certain leukemias , Neoplasm
Pulmonary Drugs – Streptomycin, penicillin etc.
eosionophilia
EOSINOPENIA-
ACTH therapy, Adrenalin, Insulin
Cushings syndrome, Acromegaly
Acute pyogenic infection, Aplastic anaemia, SLE
Stress, sever shocks, sever burns
Interfering factors-
Eosinophil count is lowest in morning
Burns electric shock, post operative states will decrease the count
ACTH reduces the count.
Basophil-
Coarse bluish-black granules of uniform size and typically a bilobate nucleus.
Basophils are so named because their cytoplasmic granules stain with basic dyes.
Constitute 0.5 to 1% of the peripheral blood leukocytes.
Release histamine and serotonin
BASOPHILIA
Chronic myeloid leukemia
Polycythemia vera
Hypersensitivity, mylosclerosis, Hodgkins lymphoma, cirrhosis of liver, early stage of Hodgkins disease, Lead poisoning
BASOPENIA
Severe septicaemia
Aplastic anaemia
Hyperthyroidism
Corticosteroid
Lymphocytes
Lymphocytes are of large and small types.
Normal range is 20-45%.
No specific granules
20-40% of WBC
Diameter 8-10 µm
T cells: cellular (for viral infections)
B cells: humoral (antibody) Natural Killer Cells
LYMPHOCYTOSIS
Chronic infection
Tuberculosis, Brucellosis, syphills,
Infection mononucleosis, hepatitis, rubella, pertusis
Lymphatic leukemia
Lymphomas
Endocrine – Thyrotoxicosis, hypopituritism, neoplasm
LYMPHOCYTOPENIA
Immune suppressive therapy
ACTH
Hodgkins disease
Bone marrow failure, pancytopenia, CHF, AIDS
Monocytes-
Monocytes share the 'vacuum cleaner' function of neutrophils.(2-9%).
Present pieces of pathogens to T cells, so the pathogens may be recognized again and killed, thus an antibody response may be mounted.
Also known as macrophage after they leave the bloodstream
and enter tissues.
MONOCYTOSIS
Protozoan disease
Malaria
Kala-azar
Hodgkins disease, RA, SLE, Sarcoidosis, ulcerative colitis
Monocytic leukemia, lymphoma, multiple myeloma
ACTH therapy, Infection brucellosis, typhus, typhoid.
MONOCYTOPENIA
Bone marrow failure
Aplastic anaemia
Septicaemia
Steroid, low immunity
CONCLUSION-
The results of CBC shows how well the vital organs are functioning which is indicator of general state of health.
Reflects problems of blood loss & fluid volume (dehydration)
Shows any abnormalities in the production, destruction & life span of blood cells.
Reflects acute or chronic infection, allergies, and problems with clotting
Screening for high and low values before surgery.
Finds the cause of symptoms such as fatigue, weakness, fever, bruising, or weight loss.
Diagnosing diseases of the blood, such as Leukemia, Polycythemia, Thrombocytosis.
Checks how the body is dealing with some types of drug or radiation treatment.
n - by oxford dictionaries-
Red liquid that circulates in the arteries and veins of humans and other vertebrate animals, carrying oxygen to and carbon dioxide from the tissue of the body.
by CCM,- Blood is a biological red liquid circulating in the arteries and veins under the impulse of the heart. An individual contains 5-7 L of blood in his body, which represents about 8% of its total weight. Blood is made up of plasma, red blood cells, white blood cells and platelets. Its distributes oxygen, hormones and nutrients to all cells, all tissues and all organs of the body, then get rid of their waste. Blood also plays a role in immune defense.
COMPOSITION OF BLOOD-
Blood consists of 55% plasma (liquid portion) and 45% formed elements ( blood cells)
Formed elements are RBC(Erythrocytes), WBC( Leukocytes), Platelets (Thrombocytes)
Complete Blood Count (CBC)
Also known as: Complete blood picture(CBP), Haemogram
Red Blood Cells, Platelets , T Lymphocyte, Monocyte
as seen through a scanning electron microscope.
The CBC is the measurement of the number of circulating RBC’s, WBC’s, platelets, the concentration of haemoglobin and characteristics of RBC’s.
Anticoagulated blood is processed through automatic blood analysers which using variety of technologies ( particle sizing, radiofrequency, laser instrumentation) to measure different parameters.
These includes number of circulating cells, the proportion of red cells (haematocrit) and red cell indices which gives information about size of red cells (MCV), and amount of Hb present in RBC’s(MCH), and WBC’s and differential counts.
CBC includes
WBC (TLC) – Total leucocyte count
RBC – Red blood cell count
Hb - Haemoglobin
Hct - Haematocrit value
MCV – Mean corpuscular volume
MCH – Mean corpuscular Haemoglobin
MCHC – Mean corpuscular Haemoglobin concentration
Peripheral smear.
RDW – Red cell distribution width
Plt – Platelet count
Mean platelet volume (MPV)
DLC – Differential count
CBC is a screening test, used to diagnose numerous diseases.
HEMOGLOBIN-
The hemoglobin test measures the amount of hemoglobin in blood and is a good measure of the blood's ability to carry oxygen throughout the body.
Hb is measured in gram per deciliter (g/dL) of blood
Methods for estimation of Hb-
1 Colorimetric method
Cynamethaemoglobin method
Oxyhaemoglobin method
Electronic counter method
Direct reading electronic haemoglobinometer
Sahlis method
2 Measurement of oxygen carrying capacity of Hb
3 Measurement of iron content of Hb
4 Specific gravity method
Hemoglobin (Hb)
Men: 14-17.4 grams per deciliter (g/dL) or 140-
174 grams per liter (g/L)
Women: 12-16 g/dL or 120-160 g/L
Children: 9.5-20.5 g/dL or 95-205 g/L
Newborn: 14.5-24.5 g/dL or 145-245 g/L
Hemoglobin interfering factors-
It increases at higher altitude in children
Low in excess fluid intake and in pregnancy
Gentamycin, methyldopa increases the values.
Causes of Increased Haemoglobin-
Primary :
Polycythemia vera (neoplastic)
Secondary :
Associated with hypoxia-Cardiovascular diseases, pulmonary diseases, High altitude, hypoventilation, Smoking, Methaemoglobinemia.
Increased erythropoietin production- Kidney diseases and tumours
liver tumours, Associated with adrenocortical steroids, testosterone supplements., Associated with chronic chemical exposure, nitrites, cobalt, alcohol
Relative:
*Stress
*Dehydration: vomiting, diarrhoea
*Plasma loss: burns.
Causes of Decreased haemoglobin level-
Blood loss
- Internal, External
Impaired red cell production
- Deficiency of iron, Vit B12
- Infection, renal failure, liver disease, chronic diseases.
- Aplastic, sideroblastic & dyserythroblastic anemia
- Bone marrow infiltrations with tumor cells
Increased destruction of RBC (Haemolysis)
Haemodilution
- Pregnancy, oedema
Increased destruction of RBC (Haemolysis)
Haemodilution
- Pregnancy, oedema
HEMATOCRIT (PCV)-
Hematocrit (HCT, packed cell volume, PCV). This test measures the amount of space (volume) red blood cells take up in the blood. The value is given as a percentage of red blood cells in a volume of blood. It is one of the most precise methods of determining the degree of anemia or polycythemia.
Normal Range: Male :- 40-55%
Female :-36-48%
Ratio of Hemoglobin to Hematocrit = 3: 1
Method for estimation-
Macro method ( Wintrobes method)
Micro haematocrit method
Electronic method.
Blood is collected in a hematocrit tube with anti coagulant and centrifuged for 30 min at 3000 rpm, the RBC’s settle down at bottom having a clear plasma at top. In between the plasma and RBC’s there is a thin layer of white buffy coat which is formed by white blood cells and platelets.
Increased PCV value-
Polycythemia
Dehydration due to severe diarrhoea & Vomitting
Burns
Spleen hyperfunction,
Decreased PCV value
Anaemia
Pregnancy
low thymus function.
RBC COUNT-
The scientific name for red blood cells is Erythrocytes.
The most numerous of all cells in the blood.(4-5million/cmm)
Produced at a rate of 4-5 billion every hour in an adult human!(Life span 120 days).
RBC- M: 4.7 to 6.1 x10^12 /L
F: 4.2 to 5.4 x10^12 /L
Biconcave disc shape with diameter of about 8 µm
Function: - transport hemoglobin which carries oxygen from the lung to the tissues.
Red blood cell (RBC) count
Men: 4.5-5.5 million RBCs per microliter (mcL) or 4.5-5.5 x 1012/liter (L)
Women: 4.0-5.0 million RBCs per mcL or 4.0-5.0 x 1012/L
Children: 3.8-6.0 million RBCs per mcL or 3.8-6.0 x 1012/L
Newborn: 4.1-6.1 million RBCs per mcL or 4.1-6.1 x 1012/L
METHOD- Visual haemacytometer method
Electronic method
RBC Interfering factors-
In lying position count is low.
Excitement and exercise raises the count.
Count is highest in morning then falls.
Count is high at high altitude.
Increased red blood cell count-
Increase in Red Cell production
Primary: Polycythemia vera (Neoplastic)
Secondary: To compensate for low oxygen levels (Poor heart / lung function, high altitude )
Erythropoietin (EPO)- Internal / External
Anabolic Steroids
Smoking, Alcohol, Carbon Monoxide
Liver disease, Kidney diseases,
Long term lung diseases, Heart diseases, Cancers Haemoglobinopathies
Decreased Red blood cell Count-
Decreased Production (Aplastic Anemia, deficiency of Iron / VitB12 / Folic acid etc) Blood loss. Internal / External, Haemolytic Anaemias, sickle cell anemia, Tumors, Addison's disease, Thalassemia, other haemoglobinopathies, Lead poisoning, stomach ulcers, Bowel diseases, Splenectomy.
Red blood cell indices-
There are three red blood cell indices:
Mean corpuscular volume (MCV), Mean corpuscular hemoglobin (MCH), and Mean corpuscular hemoglobin concentration (MCH
Red blood cell indices
Mean corpuscular volume (MCV): 80-100 cubic millimeters (mm3) or 80-
100 femtoliters (fL)
Mean corpuscular hemoglobin
(MCH): 26-34 picograms (pg) or 0.40-0.53
femtomoles (fmol)
Mean corpuscular hemoglobin
concentration (MCHC): 32-36 grams per deciliter (g/dL) or
320-360 grams per liter (g/L)
Absolute Values
Based on normal values of RBC,Hb, PCV red cell indices are derived which are of diagostic importance.
1 Mean corpuscular volume
= PCV in L/L
RBC count/L
2 Mean corpuscular haemoglobin MCH
= Hb/L
RBC count/ L
3 Mean corpuscular haemoglobin concentration MCHC
= Hb/dl
PCV IN L/L
Since MCHC is independent of red cell count and size, it is greater clinical importance as compared with other values.
SIGNIFICANCE OF RED CELL INDICIES
Decreased MCH, MCV, MCHC = Iron deficiency anemia & thalassaemia.
Increased MCV = Megaloblastic anemia
Normal MCV, MCH, MCHC = Anemia due to acute blood loss and haemolytic anaemia.
Mean Corpuscular Volume (MCV)-
The MCV relates to the average size of the red blood cell.
Abnormal MCV associated with changes in MCH is a significant finding for folic acid and/or B12 need (increase) or iron, copper or vitamin B6 need (decrease).
MCV and MCH are always be viewed together.
Optimum range is 80.0 to 100.0 femtolitres.
It indicates whether RBC’s are Microcytic, Normocytic or Microcytic
If MCV is less than 80fl then it is Microcytic
If MCV is More than 96fl then it is Macrocytic
If it is with in 80-96fl then it is Normocytic.
Macrocytosis-
- Hereditary anemia(s).
- Megaloblastic Anemias
- Reticulocytosis
- Liver disease .
- Hypothyroidism .
- Drugs (anti-convulsants).
- Zidovidune treatment (AIDS).
Alcoholism, sprue, def b12, folate
Microcytosis
Copper and iron deficiency
Low stomach acid (Hypochlorhydria).
Vitamin C and Vit B6 insufficiency.
Rheumatoid arthritis.
Lead poisoning.
Hereditary (thalassemias, sideroblastic anaemia)
After a splenectomy
Hemolytic anemia
Mean Corpuscular Hemoglobin (MCH)
The amount of hemoglobin in a single RBC
It is the ratio of Hb and the RBC count.
Optimum values: 28.0 to 32.0 picograms.
Increased & decreased in the same conditions as the MCV.
It is significantly less in when Microcytosis is associated with Hypochromia
Ex :- Iron Deficiency anaemia & Thalessemia minor
Mean Corpuscular Hemoglobin Concentration (MCHC)
The average hemoglobin concentration per unit volume(100 ml) of packed red cells. Optimum values: 32 to 36 %.
MCHC (32-36%)
Increased – spherocytosis
Decreased – IDA, microcytic anaemia, thalassemia, pyridoxine responsive, anaemia
Red cell Distribution Width (RDW)
The red blood cell distribution width (RDW or RCDW) is a measure of the variation of red blood cell (RBC) volume.
Usually red blood cells are of about 6-8 μm. Certain disorders, however, cause a significant variation in cell size.
Higher RDW values indicate greater variation in size. Normal reference range is 11–15%.
An elevated RDW (red blood cells of unequal sizes) is known as anisocytosis
RDW test results are often used together with mean corpuscular volume (MCV) results to determine the cause of the anemia. It is mainly used to differentiate an anemia of mixed causes from an anemia of a single cause.
Vitamin B12 deficiency produces a macrocytic anemia (large cell anemia) with a high RDW.
However, iron deficiency anemia initially presents with a varied size distribution of red blood cells, and as such shows an decreased RDW.
In the case of a mixed iron and B12 deficiency, there will normally be a mix of both large cells and small cells, causing the RDW to be elevated.
Mathematically the RDW is calculated with the following formula:
RDW = (Standard deviation of MCV ÷ mean MCV) × 100.
The RDW is often increased in:
^ Pernicious anemia
^ Folic acid anemia
^ Hemolytic anemia
^ Transfusions
^ Sideroblastic anemia
^ Alcohol abuse
^ Maturation defect anaemias
The RDW is often decreased in:
< Iron deficiency anemia (blood loss, parasites infection, poor iron absorption, etc.)
< Vitamin B6 anemia.
< Rheumatoid arthritis.
Peripheral smear- A blood film or peripheral blood smear is a thin layer of blood smeared on a microscope slide and then stained to examine various blood cells microscopically.
Blood films are usually examined to investigate hematological problems (disorders of the blood) and, occasionally, to look for parasites within the blood such as malaria and filaria.
The smear offers the functional status of the bone marrow. It is particularly important when assessing cytopenic states (eg, anemia, leukopenia, thrombocytopenia).
Analysers cannot indentify abnormalities of red cell shape and contents( howell- jolly bodies, basophilic stippling, malarial parasite) or fully defined abnormal white cells such as blasts.
Peripheral smear is especially important in,
Hemolytic anemia — Review of red cell morphology may identify the cause of erythrocyte destruction (eg, the presence of bite cells points to a Heinz body hemolytic anemia).
Thrombocytopenia — Distinguishing between increased platelet consumption and reduced platelet production can often be made through review of platelet size in blood smear.
White cell disorders — The disease classification rely upon evaluation of abnormal circulating cells (eg, the presence of Auer rods in a blast form in patients with acute myeloid leukemia)
Microcytosis ( reduced average cell size, MCV< 76 fl):
Iron deficiency Anemia, Thalassemia, Sideroblastic anaemia.
Macrocytosis ( increased average cell size, MCV> 100 fl):
Megaloblastic Anemia because of vit B12 & folic acid deficiency, liver disease, alcohol, hypothyroidism, drugs like zidovudine.
The presence of target cells may be due to:
Hemoglobin abnormalities (hemoglobinopathies)
Iron deficiency
Liver disease
Spleen removal
Thalassemia
The presence of sphere-shaped cells (spherocytes) may be due to:
Autoimmune hemolytic anemia
Hereditary spherocytosis
Post splenectomy
The presence of red cell fragmented (schistocytes) may be due to:
Artificial heart valve
Disseminated intravascular coagulation
Hemolytic uremic syndrome (HUS)
Microangiopathic hemolytic anemia
Thrombotic thrombocytopenic purpura (TTP)
The presence of a type of immature red blood cell called a normoblast ( nucleated RBC’s) may be due to:
Cancer that has spread to bone marrow infiltration
Erythroblastosis fetalis
Leukoerythroblastic anemia (myelophthisis process)
Miliary tuberculosis
Myelofibrosis
Removal of spleen
Severe hemolysis
Thalassemia
The presence of teardrop-shaped cells may indicate:
Leukoerythroblastic anemia
Myelofibrosis
Severe iron deficiency
Thalassemia major
The presence of Howell-Jolly bodies( small round nuclear remnants) may indicate:
Dyshaemopoiesis
Post-splenectomy
Sickle cell anemia
The presence of Heinz bodies may indicate:
Alpha thalassemia
Congenital hemolytic anemia
G6PD deficiency
Unstable form of hemoglobin
The presence of slightly immature red blood cells (reticulocytes) polychromasia may indicate:
Anemia with bone marrow recovery
Hemolytic anemia
Acute Hemorrhage
The presence of basophilic stippling( abnormal ribosomes appear as blue dots) may indicate:
Lead poisoning
Myelofibrosis
Dyshaemopoiesis
The presence of sickle cells may indicate sickle cell anemia.
PLATELETS (Thrombocytes)
Fragments of cells that participate in clotting.
Initiate repair of blood vessel walls.
Optimum values: 150,000 to 400,000/ mm3 of blood.
Small granular non-nucleated discs.
Diameter about 2-4 µm
Function; involved in coagulation and blood haemostasis.
Life span 7-10 days
METHOD
Visual haemacytometer method
Electronic method
Platelet (thrombocyte) count
Adults: 140,000-400,000 platelets per mm3 or
140-400 x 109/L
Children: 150,000-450,000 platelets per mm 3 or
150-450 x 109/L
Thrombocytosis(Platelets increased )
Infections
Acute blood loss
Disseminated carcinoma
Splenectomy
Thrombocythemia
Polycythemia Vera
Myeloproliferative Disorders
Chronic Granulocytic Leukemia
Hemolytic anemia(s)
Myelosclerosis
Essential (without known cause)
After sever injuries,
major surgery, parturation, haemorrhage.
Thrombocytopenia (Platelets decreased)
Decreased Production
Marrow depression/ infiltration
Megaloblastic anemia. Aplastic anaemia
Congenital
Increased Destruction
Immunologic (ITP, SLE), Infectious mononucleosis ,Rubella, EBV
Lymphoma, Multiple myeloma, Leukemia
Drugs-chemotherapy, Quinine, Sulphonamides, Rifampicin, heparin.
Hypersplenism ,Liver dysfunction (cirrhosis).
Dilution due to overhydration
Platelet aggregation or large platelets
Low platelet values can occur in pregnancy or idiopathic thrombocytopenic purpura (ITP)
A large spleen can lower the platelet count
Mean platelet volume (MPV)
Mean platelet volume (MPV) is a measurement that describes the average size of platelets in the blood. It is part of a complete blood count (CBC). The importance of mean platelet volume is that, it is an indicator as to whether the bone marrow is manufacturing them normally.
Elevated mean platelet volume is common in patients with certain forms of diabetes. If combined with a low Plt result, indicates a condition resulting in destruction of platelets such as immune thrombocytopenia, pre-eclampsia, sepsis, various hereditary conditions. High MPV with a normal Plt test result is a sign of chronic myeloid leukemia, hyperthyroidism. Accompanied by a high Plt result, it may indicate a bone marrow disorder that causes excessive cell production.
Conditions Associated with Low MPV
In association with a low Plt value, this indicates anemia, chemotherapy. If combined with a normal Plt, indicates chronic kidney failure. Accompanied by a high Plt, indicates an infection, inflammation or some form of cancer.
DLC (Differential Leucocyte Count):
Neutrophils (polys and bands)
Lymphocytes
Monocytes
Eosinophils
Basophils
White blood cell (WBC, leukocyte) count
Men and non pregnant women: 5,000-10,000 WBCs per cubic millimeter (mm3) or 5.0-10.0 x 109 WBCs per liter (L)
White blood cell types (WBC differential)
Neutrophils: 50%
Lymphocytes: 25%-40%
Monocytes: 3%-7%
Eosinophils: 0%-3%
Basophils: 0%-1%
When the total leucocyte count is increase above the normal level called Leucocytosis.
When the total leucocyte count is decrease below the normal level called Leucocytopenia.
Normal Range: Adult :- 4000- 11000 /mm3 of blood
New borns :- 10000-25000/mm3 of blood
Infants :- 6000-18000/mm3 of blood
Children :- 5000-15000/mm3 of blood
There is NO sex difference in value, as seen in RBC count.
METHOD
Visual haemacytometer method
Electronic method
Differential Leucocyte COUNT
Visual counting
Automated DLC counters have differential counting capacity of counting 3 or 5 part ( P,L,M,E,B)
Interfering Factors
In new born and infants count is high values reaches normal at puberty.
Physical activity, food, pain, emotional disturbance will slightly increase the count.
Chronic leukemia may decrease the count.
Early morning values are low during evening hours are high.
Leucocytosis
Physiological conditions
New borns & infants
Physical exercise
After food intake
Exposure to sun & increased environment temp.
Pregnancy
Parturition
Pain, nausea, vomiting
Menstruation
Emotion & Anxiety
Pathological conditions
Acute Bacterial infections Ex- pyogenic bacteria ,boils, abscess, pneumonia Chronic bacterial infection ,Tuberculosis, Tissue injury
Infarction, Burns, Surgery, Splenectomy
Haemorrhage, Neoplasia, Stress states & hyperactivity, Convulsions
Severe colic, Inflammatory disorders, Rheumatic fever, Metabolic disorders, Diabetic ketoacidosis, RA, Corticosteroid therapy, Leukemia, cancer,
Leucocytopenia-
Conditions that can lower WBC values include chemotherapy and reactions to other medicines, aplastic anemia, viral infections, malaria, alcoholism, AIDS, lupus, or Cushing's syndrome.
A large spleen can lower the WBC count.
Physiological
Exposure to severe cold
Pathological
Infections:-Typhoid fever, Paratyphoid fever
Viral infections(early phase :- infectious hepatitis )
Overwhelming sepsis
Replacement of haemopoietic tissue in the bone marrow by neoplastic infiltrative cells
Acute leukemia
Lymphoma
Multiple myeloma
Myelofibrosis
Aplastic anaemia
Cytotoxic therapy
Drugs
Chloramphenicol
Sulpha drugs
Aspirin
Hyperspleenism
Starvation & Malnutrition
Neutrophils (Granulocytes)
polymorphonuclear leukocytes
Nucleus 3-5 lobes.
Diameter 10-14 µm
50-70% WBC
Function: Phagocytosis of bacteria and cell debris
Numbers rise with all manner of stress, especially bacterial infections
Interfering factors-
In children neutrophilia develops more prominently in case of infection.
Weak debilitated people fail to respond with neutrophilia in infection.
ACTH, Myelosuppressive chemotherapy don’t allow proportionate neutrophilia in infection.
NEUTROPHILIA-
Physiological
Exercise
Pregnancy last week
Parturition
Food intake
Emotional stress
Exposure to cold & heat.
Emotional disturbance Infants during first days.
Pathological
Acute pyogenic infections
Pneumonia, tonsillitis,
Acute infective inflammatory conditions
Rheumatic fever
Non inflammatory conditions
Pulmonary embolism, MI
Acute haemorrhage
Trauma
Leukemia, Neoplasm
Metabolic diseases-uremia, gout, acidosis
Chronic myeloid leukemia
Toxic conditions
Uremia, hepatic coma
Corticosteroid therapy
Eosinophils-
A type of leukocyte with coarse orange red round granules of uniform size and bilobed nucleus.
Eosinophils are so named because their cytoplasmic granules stain red with the dye eosin.
Eosinophils constitute 1 to 3 % (350 to 650 /cmm).
Pathological conditions
Allergic conditions Parasitic infestations Bronchial asthama Hookworm
Urticaria Filariasis
Hay fever Hydatid disease
Psoriasis Collagen disease
Bronchial asthama Periarteritis nodosa
Skin diseases Hodgkins disease
Food allergy Addisons disease
Pemphigus Certain leukemias , Neoplasm
Pulmonary Drugs – Streptomycin, penicillin etc.
eosionophilia
EOSINOPENIA-
ACTH therapy, Adrenalin, Insulin
Cushings syndrome, Acromegaly
Acute pyogenic infection, Aplastic anaemia, SLE
Stress, sever shocks, sever burns
Interfering factors-
Eosinophil count is lowest in morning
Burns electric shock, post operative states will decrease the count
ACTH reduces the count.
Basophil-
Coarse bluish-black granules of uniform size and typically a bilobate nucleus.
Basophils are so named because their cytoplasmic granules stain with basic dyes.
Constitute 0.5 to 1% of the peripheral blood leukocytes.
Release histamine and serotonin
BASOPHILIA
Chronic myeloid leukemia
Polycythemia vera
Hypersensitivity, mylosclerosis, Hodgkins lymphoma, cirrhosis of liver, early stage of Hodgkins disease, Lead poisoning
BASOPENIA
Severe septicaemia
Aplastic anaemia
Hyperthyroidism
Corticosteroid
Lymphocytes
Lymphocytes are of large and small types.
Normal range is 20-45%.
No specific granules
20-40% of WBC
Diameter 8-10 µm
T cells: cellular (for viral infections)
B cells: humoral (antibody) Natural Killer Cells
LYMPHOCYTOSIS
Chronic infection
Tuberculosis, Brucellosis, syphills,
Infection mononucleosis, hepatitis, rubella, pertusis
Lymphatic leukemia
Lymphomas
Endocrine – Thyrotoxicosis, hypopituritism, neoplasm
LYMPHOCYTOPENIA
Immune suppressive therapy
ACTH
Hodgkins disease
Bone marrow failure, pancytopenia, CHF, AIDS
Monocytes-
Monocytes share the 'vacuum cleaner' function of neutrophils.(2-9%).
Present pieces of pathogens to T cells, so the pathogens may be recognized again and killed, thus an antibody response may be mounted.
Also known as macrophage after they leave the bloodstream
and enter tissues.
MONOCYTOSIS
Protozoan disease
Malaria
Kala-azar
Hodgkins disease, RA, SLE, Sarcoidosis, ulcerative colitis
Monocytic leukemia, lymphoma, multiple myeloma
ACTH therapy, Infection brucellosis, typhus, typhoid.
MONOCYTOPENIA
Bone marrow failure
Aplastic anaemia
Septicaemia
Steroid, low immunity
CONCLUSION-
The results of CBC shows how well the vital organs are functioning which is indicator of general state of health.
Reflects problems of blood loss & fluid volume (dehydration)
Shows any abnormalities in the production, destruction & life span of blood cells.
Reflects acute or chronic infection, allergies, and problems with clotting
Screening for high and low values before surgery.
Finds the cause of symptoms such as fatigue, weakness, fever, bruising, or weight loss.
Diagnosing diseases of the blood, such as Leukemia, Polycythemia, Thrombocytosis.
Checks how the body is dealing with some types of drug or radiation treatment.
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