BASIC HEMATOLOGY A BREIF DISCUSSION.pptx

HAEMATOLOGY

1. Clinical Hematological Tests And Interpretation Of Test Results 1 Dr. Ajil Antony MBBS, MS, MRCS( Edin .), FIAGES

2. CBC ? Complete blood count (CBC ) D etermine whether or not the patient is anaemic . If anaemia is present the MCV is likely to provide clues as to the cause of the anaemia. The white cells are often raised in infection neutrophilia in bacterial infections and lymphocytosis in viral (but not always so). Platelets (size or number) may be abnormal either as a direct effect of underlying hematological disorder . 2

3. Dr S P srinivas Nayak, Clinical Pharmacy LAB D A T A INTE R PRE T A TI O N 3 HAEMATOLOGICAL TESTS Main parameters measured 1. Hb concentration. 2. Red blood cell count . 3. MCV (Mean cell volume) 4. MCH (Mean corpuscular hemoglobin ) . 5. MCHC (Mean corpuscular hemoglobin concentration) . 6. Haematocrit (Hct) or PCV. 7. Red cell distribution width (RDW). 8. White cell count. 9. WBC differential count . 10.Platelet count .

4. 1. HAEMOGLOBIN CONCENTRATION (HB) 4 HEMOGLOBIN Hemoglobin is the protein molecule in red blood cells C arries oxygen from the lungs to the body's tissues R eturns carbon dioxide from the tissues back to the lungs . Hemoglobin is made up of four protein molecules (globulin chains) that are connected together . Normal values : Male : 14 – 18 g/dl Female: 12 - 16 g/dl Values differ between males and females since androgens drive RBC production and H ence adult males has higher Hb, PCV and RCC than adult females.

5. 5 2. RED CELL COUNT (RCC). Normal values: M ale : 4.5 – 5.5 × 10 12 /L or 4.5 – 5.5 × 10 6 /ml Female: 4 – 5 × 10 12 /L or 4 – 5 × 10 6 /ml Us eful in the diagnosis of polycythaemic disorders and thalassaemias

6. 6 ABNORMALITIES IN RBC COUNT CAUSES OF A LOW RED CELL COUNT INCLUDE HYPOPROLIFERATIVE ANAEMIAS , e.g. iron, vitamin B12 and folate deficiencies. APLASIAS e.g . idiopathic or drug-induced (chemotherapy ). PARVOVIRUS B19 INFECTION- induced red cell aplasia resulting in transient marked anaemia. CAUSES OF HIGH RED CELL COUNT INCLUDE PRV ( Polycythaemia Rubra Vera) Thalassaemia.

7. 7 3. MCV . (MEAN CELL VOLUME) Mean cell volume or Mean corpuscular volume (MCV ) is the average volume of red cells in a specimen . MCV is elevated or decreased in accordance with average red cell size A normal MCV range is roughly 80–100 fl LOW MCV indicates microcytic (small average RBC size), NORMAL MCV indicates normocytic (normal average RBC size), HIGH MCV indicates macrocytic (large average RBC size).

8. 8 The normal range for MCH is 27 to 31 picograms per cell.

9. Mean cell haemoglobin concentration (MCHC) MCHC is High in Severe prolonged dehydration. Hereditary spherocytosis. Cold agglutinin disease. MCHC is Low in Iron deficiency anaemia. Thalassaemia. 9

10. 6. HAEMATOCRIT (HCT) OR PCV. Measuring the proportion of red blood cells in whole sample of anticoagulated blood centrifuged. Hct = 3 X Hb There are two methods for estimation of PCV: M acro method (Wintrobe method) and M icro method (microhematocrit method). Micro method is preferred because it is rapid, convenient, requires only a small amount of blood, capillary blood from skin puncture can be used, and a large number of samples can be tested at one time High PCV is seen in Polycythaemia (any cause). Low PCV is seen in Anaemia (any cause). 10

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12. 7. RED CELL DISTRIBUTION WIDTH (RDW). Measures the range of red cell size in a sample of blood, providing information about the degree of red cell anisocytosis, i.e. how much variation there is between the size of the red cells. Of value in some anaemias: EXAMPLE : Low MCV with normal RDW suggests Thalassaemia trait . Low MCV with high RDW suggests iron deficiency. 12

13. 8. WHITE CELL COUNT. Quantitative estimation of total WBC in human - by manual method - using Hemocytometer. Total WBC count is increased (Leukocytosis ) transiently in bacterial, viral, protozoal infections parasitic infections such as Filaria, and also in severe hemorrahage . The degree of leukocytosis depends on the severity and type of infection . Leukopenia (decrease in leukocyte count) occurs in certain V iral infections such as Hepatitis, Influenza and Measles, Protozoal infections such as Malaria and B acterial infections such as Typhoid fever 13

14. WHITE CELL COUNT. REFERENCE RANGE Adults : 4, 00 – 1 1000 cells/cu.mm The 5 main white cell subtypes in peripheral blood which include: 14 2. Lymphocytes. 4. Eosinophils. 1. Neutrophils. 3. Monocytes. 5. Basophils

15. 1. Neutrophils : ( 40–75% of white blood cells ) INCREASED IN (IE. NEUTROPHILIA) DECREASED IN (IE NEUTROPENIA) Bacterial infections. Inflammation, eg: myocardial infarction, polyarteritis nodosa. Myeloproliferative disorders. Drugs (steroids). Disseminated malignancy. Stress, eg trauma, surgery, burns, haemorrhage, seizure 15 Viral infections. Drugs, eg post chemotherapy, cytotoxic agents, carbimazole, sulfonamides. Severe sepsis. Neutrophil antibodies (SLE, haemolytic anaemia) INCREASED destruction. Hypersplenism eg Felty’s syndrome Bone marrow failure REDUCED production

16. 2. LYMPHOCYTES . Normal range : ( 20–45%) 16 Increased (lymphocytosis) in: Acute viral infections . Chronic infections, eg TB, Brucella, hepatitis, syphilis. Leukaemias and lymphomas, especially chronic lymphocytic leukaemia. Decrease (lymphopenia) in: Steroid therapy, Uraemia, SLE; Legionnaire’s disease; HIV infection, marrow infiltration po s t chemo t he r a p y o r r adi o the r a p y .

17. MONOCYTES: Monocytosis is the state of excess monocytes in the peripheral blood. It may be indicative of various disease states. Examples of processes that can increase a monocyte count include: chronic inflammation diabetes stress response Cushing's syndrome (hyperadrenocorticism) immune-mediated disease granulomatous disease atherosclerosis necrosis red blood cell regeneration viral fever sarcoidosis chronic myelomonocytic leukemia (CMML) 17

18. EOSINOPHILS 18 In normal individuals, eosinophils make up about 1–3% of white blood cells, and are about 12–17 micrometres in size with bilobed nuclei Along with mast cells and basophils, they also control mechanisms associated with allergy and asthma. In normal individuals, eosinophils make up about 1–3% of white blood cells

19. EOSINOPHILIC DISORDERS EOSINOPHILIA An increase in eosinophils, i.e., the presence of more than 500 eosinophils/microlitre of blood is called an eosinophilia, IT IS TYPICALLY SEEN IN PEOPLE WITH A parasitic infestation of the intestines; Autoimmune and collagen vascular disease (such as rheumatoid arthritis) and Systemic lupus erythematosus; malignant diseases such as eosinophilic leukemia, clonal hypereosinophilia, and Hodgkin's disease; lymphocyte-variant hypereosinophilia. 19 EOSINOPENIA Eosinopenia is a form of agranulocytosis where the number of eosinophil granulocytes is lower than NORMAL RANGE Leukocytosis with eosinopenia can be a predictor of bacterial infection. It can be induced by stress reactions,Cushing's syndrome, or the use of steroids. Pathological causes include burns and acute infections.

20. 20 BASOPHILS Basophils are responsible for inflammatory reactions during immune response, as well as in the formation of acute and chronic allergic diseases, including anaphylaxis, asthma, atopic dermatitis and hay fever. They also produce compounds that co-ordinate immune responses, including histamine and serotonin that induce inflammation, heparin that prevents blood clotting .

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