Clinical interpretation of cbc

quick look, informative.

1. CLINICAL INTERPRETATION OF CBP M HIMABINDU JR RESIDENT DEPT OF PAEDIATRICS

2. Blood components Plasma : 55% Formed elements : 45% Erythrocytes Leukocytes Thrombocytes

3. COMPLETE HEMOGRAM Qualitative and quantitative assessment of blood and its contents. C ontents : Red blood cells White blood cells – neutrophils , lymphocytes , eosinophils , monocytes, basophils Platelets

4. Importance Counts of each cell line and their relative content Morphology of each cell line . Distribution of the cell lines Gross characteristics – rouleaux formation of RBCs , clumping of platelets Presence of immature cells / dysmorphogenesis Presence of haemoparasites .

5. Contents Hemoglobin content Hemocrit Mean cell volume (MCV) Mean corpuscular haemoglobin (MCH) Mean corpuscular haemoglobin concentration (MCHC) RBC count – in millions /dl Total WBC count – in thousands /dl Differential count Platelet count – in lakhs /dl

6. Peripheral smear Red cell distribution width Reticulocyte count

7. Rule of 3s 3 times the RBC count in millions – haemoglobin in gms /dl 3 times the haemoglobin in gms /dl – hemocrit in % Deviation : Due to abnormal fragility of RBCs . Improper dilution

8. Hemoglobin concentration Method : Acid Hematin method. Instrument : Sahli’s Hemoglobinometer

9. Hemocrit Relative Percentage of formed elements in the blood. Method : Centrifugation and Sedimentation

10. RBC count Conventional measurement – by Neubeur’s Chamber Measured in millions /dl

11. RBC indices Mean corpuscular volume : Low MCV - microcytes High MCV – macrocytes . Drugs – valproate , zidovudine , immunosuppressive drugs.

12. Mean corpuscular haemoglobin : Low MCH - hypochromia

13. Mean corpuscular haemoglobin concentration : Indicates the hydration status of the RBC cell. Higher MCHC indicates – dehydrated RBC . Hereditary spherocytosis , sickle cell anemia .

14. Red cell distribution width Measure of range of variation of red blood cell volume Normal reference ranges of RCDW-CV in human RBC is 11.5 to 14.5% RDW-CV = SD of MCV / MCV X 100 Variations High RDW with low MCV iron deficiency anemia High RDW with high MCV – megaloblastic anemia High RDW with variable MCV- mixed deficiency High RDW with N MCV- recent hemorrhage

15. Reticulocyte count Normal reticulocyte count : 2-4 % Absolute reticulocyte count = retics /L = retics % X RBC count Normal 50 - 100 X 10 3 /dl - ARC >100,000/dl indicates increased marrow activity Corrected Reticulocyte % = Pt. PCV /0.45 X actual reticulocyte count

16. Reticulocyte production index (RPI ): the rate of increase in erythropoiesis. Maturation time of reticulocytes is : 1 day if PCV = 0.45 L/L 1.5 days if PCV = 0.35 L/L 2 days if PCV = 0.25 L/L 2.5 days if PCV = 0.15 L/L

17. Eg : RPI = reticulocyte (%) / maturation time e.g. If PCV = 0.25 L/L and retics are 20% RPI = 20/2 X 0.25/0.45 = 5.5

18. Total WBC count Both sensitivity and specificity of the test – very low. Marker of infection status . Usually take 1-2 days for the counts to be raised – in infections. Leukocytosis – bacterial infections, as an acute phase response >15,000 16% >20,000 25% >30,000 40% TLC Incidence of bacteremia

19. Band forms – important indicator of infections >500 band forms /mm3 – indicates infection - Vacuolisation , D ohle bodies , toxic granules – indicate infection Leukopenia – viral infections Hypoproliferative disorders Bone marrow failure Dohle bodies

20. Differential count Monocytosis Monocytic leukemia Ulcerative colitis Viral diseases – mononucleosis, herpes zoster Parasitic diseases – Rocky M ountain spotted fever Monopenia In some forms of leukemia Bone marrow failure or supression

21. Eosinophilia : Rashes ,wheezes and unusual diseases Parasitic infection Drug hypersensitivity, asthma All forms of allergy and anaphylaxis. Job syndrome , Malignancy Eosinopenia : Corticosteroid therapy , adreno cortical hyperfunction ,stress ,shock.

22. Lymphocytosis : Viral infections – IM , CMV , Rubella ,Mumps ,Hepatitis Leukemias , lymphoreticular neoplasias A deviation – WBC >30,000/mm3 with 60% lymphocytes – pertussis. Lymphopenia : Corticosteroid therapy , adreno cortical hyperfunction ,stress ,shock.

23. Basophilia : Chronic inflammatory and hypersensitivity reactions Leukemias Basopenia : Corticosteroid therapy , adreno cortical hyperfunction ,stress ,shock.

24. Platelet count Indication of hemostatic status of the body . Platelet size and number – important clue for the disease Mean platelet volume : 8.9+/- 1.5 fl Increased MPV – increased turnover / peripheral destruction - ITP, Bernard soulier synd , May Hegglin anomaly Low MPV – defective production process. W iskott - Aldrich syndrome Iron def anemia Storage pool disorders .

25. Thrombocytosis Primary : Polycythemia vera Essential thrombocythemia Reactive: IDA Hemolytic anemia Vit E def Hemorrhage Collagen vascular disorder

26. Kawasaki syndrome Nephrotic syndrome Inflammatory bowel disease Post splenectomy Post-op status Trauma Tumours Myeloproliferative syndromes Histiocytosis Drugs – epinephrine ,corticosteroids , vinka alkaloids

27. Thrombocytopenia Most common cause – immune platelet destruction False low counts – platelet clumps (automated analysers) Causes: Infections – esp viral Thrombocytopenia with no other abnormality – ITP. Acute leukemias can be ruled out.

28. Peripheral smear Details of each of the cell line- size , shape , relative distribution Presence of immature cells Presence of hemoparasites – P lasmodium , filarial worms .

29. Artifacts : Abnormal shapes,sizes of rbcs , relative size of pallor. WBC – due to delay in smear making They loose granulations , nuclear pyknosis , toxic granulations may develop

30. Importance of blood smear : Signs of hemolysis can be detected best by smear. Nucleated RBCs , Schistocytes , Spiculated erythrocytes Acanthocytes Poikilocytosis – bite / blister cells.

31. Target cells Thalassemia Hemoglobinopathies like – HbAC or CC , Hb SS ,SC Obstructive liver disease Post splenectomy Hyposplenic states Severe iron def . HbE LCAT def.

32. Spherocytes : Hereditary spherocytosis ABO incompatibility Autoimmune haemolytic anemia Microangiopathic haemolytic anemia SS disease Hypersplenism Burns Severe hypophosphatemia Post transfusion Pyruvate kinase def Water dilution hemolysis

33. Acanthocytes : Liver disease DIC Post splenectomy /hypo splenic disorder Vit E def Hypothyroidism Abetalipoprotenemia Malabsorption states

34. Schistocytes : DIC Hemolytic anemias ( immune , microangiopathic ,HUS, uremia ) Prosthetic valves Connective tissue disorders Kasabach Meritt Syndrome Purpura fulminans Renal vein thrombosis Burns, cirrhosis

35. Basophilic stippling : Hemolytic anemia Thalassemia Ineffective erythropoiesis Lead poisoning IDA Pyramidine 5’ nucleotidase def

36. Siderocytes : Post splenectomy Chronic infection Aplastic anemia Hemolytic anemia

37. Polychromasia : - Reticulocytosis - Hemolytic anemia -Acute haemorrhage -Response to hematinics in nutritional anemia Spiculated / crenated RBC Acute hepatic necrosis Uremia Abetalipoprotenemia Transiently after massive tansfusion of stored blood.

38. References Textbook of Paediatrics , Nelson’s ,20 th Edition Practical Pediatric Hematology , Anupam Sachdeva 2 nd edition Google images

39. THANK YOU