Interpretation of cbc

CBC, interpretation, hematology, red blood cells, pediatric

1. INTERPRETATION OF CBC DR. N. BAJAJ

2. TERMS Anisopokilocytosi s : variation in size and shape Cytometry : measurment of the cell either visual or automated Cluster analysis : analysis that is based upon the instrument’s ability to cluster different populations, together based upon size, staining, absorption or other parameter Contour grating: analysis where information is plotted three dimentionally , that can be separate subpopulation of cells Coulter principle (electrical impedence ): sizing and counting cells by detecting and measuring changes in electrical resistance when cell passes through small aperture. Dimorphic : two population of cells in single blood sample Forward angle light scatter : light from laser source is scatter in forward direction (0 degree) when it strike a cell or particle, larger object more forward light scatter Forward high angle light scatter : similar to forward angle light scatter, but angle is 5 to 15 degree variation Forward low angle light scatter : similar to forward angle light scatter, but angle is 2 to 3 degree variation

3. Introduction Haematology comprise of ‘ Haima ’ = blood in G reek ‘ Logos ’ = study Haematology is a unique super speciality in medicine which encompasses the fields of pathology, physiology, biochemistry, molecular biology, obstetrics and gynecology, medicine and paediatrics

4. CBC A complete blood count is a series of tests used to evaluate the composition and concentration of the various cellular component of the blood. Is a basic test Most informative single investigation Tests consists of Counts of RBC, WBC, Platelets Haemoglobin, haematocrit , and red cell indices TLC, DLC Platelet count, mean platelet volume, plateletcrit , PDW Histogram of RBC, WBC, Platelets

5. How important is CBC ? To know the importance of CBC we need to know….. What is CBC? Why CBC? What are various parameter of CBC? What are variation in parameter of CBC? What these variation can tell us? How these variations affect the assessesment and care of patients?

6. Why CBC? CBC is an inexpensive tool and powerful tool which provide information about Blood, also about Marrow, Health or disease state of other organ of body

7. CBC USES To diagnose Anemia Haemoglobinopathies Bone marrow aplasia Nutritional deficiencies Thrombocytopenia Autoimmune conditions Infections and Parasitemia Malignancies, response to drug, chemotherapy etc.

8. Red blood cells

9. RBC produced in marrow and requires Iron, copper, magnease, cobalt Vitamins; especially B12, folic acid Regulated by erythropoietin, thyroid hormone, androgens Counts depend upon age, sex, altitude, exercise, drug, tobacco use etc. Life span - 120 days

10. Clinical importance of assessment of RBC is to: measures oxygen carrying capacity of blood Normal values Newborn 4.1-6.1 million/mm3 Children 3.6-5.5 million/mm3 Adult (M) 4.6-6.0 million/mm3 Adult (F) 4.2-5.0 million/mm3

11. Decreased RBCs Blood loss Impaired production Increased destruction Trauma Surgery GI bleed Gynecological disturbance Pure red cell aplasia Pernicious anemia Megaloblastic anemia Iron deficiency anemia Thalassemia Anemia of prematurity Anemia of chronic disorder Intra-corpuscular Hereditary spherocytosis Sickle cell anemia Abetalipoprotienimia G6PD Pyruvate kinase deficiency PNH Extra-corpuscular Autoimmune Haemolytic disease of newborn Mismatch transfusion Microangiopathic haemolytic anemia TTP, HUS DIC infections

12. Increased RBCs Polycethemia vera High altitude chronic obstructive pulmonary disease(COPD, emphysema, chronic bronchitis), pulmonary hypertension, Hypoventilation syndrome, congestive heart failure obstructive sleep apnea, poor blood flow to the kidneys, and

13. Haemoglobin Oxygen carrying component of blood Synthesize in polychromatic normoblast stage of red cell development Values Newborn 15.5-24.5 g/L Adult male 13.5-16.5 g/L Adult female 12.0-15.5 g/L

14. Hb estimation Cynemethamoglobin Method : Recommended 20 microL blood + diluent (potassium cynide and potassium fericynide ) Mixed and read in photo colorimeter Photo colorimeter is used to determine the concentration Hb % =(test sample absorbance/ standard sample absorbance)x concentration of standard x dilution factor Advantage – haemoglobin, methamoglobin and carboxyhaemoglobin are used in measurment . Disadvantage – sulphamethamoglobin cannot be included in measurment , takes more time for estimation

15. Hb estimation: other method Sahli acid haematin Alkaline haematin method Sulphahaemoglobin method Oxyhaemoglobin method

16. Reticulocyte Normal value 0.5% - 1.5%. Hence 0.5% - 1.5% RBCs are replaced per day Uses To evaluate anemia Response to treatment of anemia Note If the disease causing the anemia is inside the marrow, the reticulocyte count is decreased If the disease causing the anemia is outside the marrow, the reticulocyte count is increased

17. Methods Manual reticulocyte count using supravital stain Automated reticulocyte count by flouroscent method - gives immature reticulocyte fraction (IRF) and removes errors like Howell-Jolly bodies, pappenheimer bodies Reticulocyte production index or corrected reticulocyte count: an index corrected according to level of anemia Reticulocyte index = reticulocyte count x patient’s haematocrit / normal haematocrit

18. Reticulocyte proliferation index : Index is used to determine if a person's bone marrow is properly responding to the body's need for red blood cells Shift correction factor: normal reticulocyte count survive 3.5 days in marrow and 1 day in peripheral circulation at normal PCV. In case of variation in PCV the survival time is increased which is termed as shift correction factor Reticulocyte proliferation index = reticulocyte index/ shift correction factor Shift correlation factor PCV% Maturation days = shift correction factor 45 1 35 1.5 25 2 15 2.5

19. Increased reticulocyte count Haemolytic anemia Recent haemorrhage Thalassemia Pregnancy Response to treatment Hypoxia Leukamia Decrease reticulocyte count Aplastic anemia Megaloblastic anemia Anemia of chronic disease Cirrhosis Radiation Decrease ACTH and pitutary hormones

20. Reticulocyte haemoglobin measurement (RET-He) Reticulocyte Hemoglobin (Ret-He) is a direct assessment of the incorporation of iron into erythrocyte hemoglobin . It is a direct estimate of the recent functional availability of iron (2–3 days). Traditional chemistry tests used for iron assessment (serum iron, Tsat, ferritin) are indirect measurements . As a direct measurement, Ret-He may identify iron deficiency earlier than traditional parameters. It is an established parameter used in KDOQI (Kidney Disease Outcome Quality Initiative) guidelines for assessing iron status

21. Haematocrit Ratio of the volume of erythrocytes to that of the whole blood in percentage Most precise method for determining the degree of anemia or polycythemia i.e. increase or decrease RBC concentration Normal values Newborn 42-68% Upto 1 year age 29-41% Adult Male 39-47% Adult female 36-44% Rule of 3:– RBC x 3 = Hb and Hb x 3 = Hct

22. High Polycythemia vera Dehydration Low oxygen in blood Congenital heart disease Cor pulmonale Smoking Haemoconcentration (Dengue) Low Anemia Blood loss Haemolysis Bone marrow aplasia Leukamia Malnutrition An elevated haematocrit may be due to spleen hyper function, and reduced haematocrit may indicate low thymus function

23. Mean corpuscular volume Measures average volume of RBC MCV = haematocrit / red cell count x100 Normal values Newborn 103-106fL Child upto 1 year 78 fL Adult 79-98fL Classified accordingly as Microcyte – MCV <79 Macrocytic – MCV >98 Presence of microcytic and macrocytic cells in same sample may result in normal MCV MCV <72 without heterogeneity, is a sensitive and specific predictor of thalassemia trait

24. Microcytic MCV Hypochromic Iron deficiency Thalessemia Lead poisoning Porphyria Normochromic Anemia of chronic disease haemoglobinopathies Macrocytic MCV Megaloblastic anemia Pernicious anemia Sprue Di Gulielmo disease MDS Post spleenectomy Alcoholism Liver disease Drugs ( anticonvulscents , anticancer etc ) Normocytic MCV Acute haemorrhage Diamorphic anemia Haemoglobinopathies Endocrinopathies

25. Interference in MCV Cold and warm antibodies Marked hyperglycemia Marked leukocytosis Marked reticulocytosis Methanol poisoning

26. Mean corpuscular haemoglobin MCH = haemoglobin/ red cell count x 100 Normal range Newborn 36-38 % Upto 1 year age 23-27% Adult 26.7-31.9%

27. MCH decreased in Microcytic and normocytic anemias MCH increased in Macrocytic anemias Infants and newborns Interference in MCH Lipemia Marked leukocytosis Cold agglutinin Monoclonal protein in blood

28. Mean corpuscular haemoglobin concentration MCHC = haemoglobin/ haematocrit x 10 Normal range Newborn 34-36 % Upto 1 year age 31-33% Adult 32-36%

29. MCHC decreased in Hypocromic microcytic anemia MCHC increased in Heridietery spherocytosis Infant and newborns Autoagglutinations Interference in MCHC Marked leukocytosis Haemolysis Cold aggutinins Rouleaux

30. Red cell distribution width (RDW) Red cell distribution is a quantative measure or numerical expression of anisocytosis. It is a coefficient of variation of the distribution of individual RBC volume In microcytes, RDW increased in iron deficiency anemia but in thalessemia it is not raised

31. RDW-CV:It is the ratio of standard deviation to the mean corpuscular volume RDW-CV = standard deviatiom of RBC volume/ mean MCV x 100 value 11.5%-14.5% RDW-SD: It is the actual measurnment of the width of the RBCdistribution curve Values 35-45 fL

32. RBCs on peripheral smear

33. Preparation The wedge slide (push slide) technique was developed by Maxwell Wintrobe as is a standard method The “zone of morphology” (area of optimal thickness for light microscopy examination) should be at least 2cm in length. The smear should occupy the central area of the slide and be margin free at the edges.

34. RBCs in peripheral smear Microcytic hypochromic Size smaller than the nucleus of small lymphocyte < 7 micron Markedly increase central pallor >1/3 of the diameter of RBC Causes Iron deficiency anemia Thalassemia Sideroblastic anemia Anemia of chronic disease Haemoglobinopathies

35. Macrocytic cells Size > 8.3 micron kin diameter Causes Vitamin B 12 and folic acid deficiency Alcoholism Liver disease Myleodysplastic syndrome Hypothyroidism Drug that impair DNA synthesis

36. Oval macrocytes Vitamin B 12 and folic acid deficiency Pernicious anemia Myleodysplastic syndrome Hypothyroidism Drug that impair DNA synthesis

37. Round hypochromic macrocytes Alcoholism Hypothyroidism Liver disease Post splenectomy Blue tinged macrocytes Neonate Response to anemic stress

38. Target or bell cell They have a characteristic ringed appearance. This is because of the “increase surface area to volume ratio” i.e. increase in red cell membrane which get pooled at the centre of cells Causes Thalessemia Haemoglobinopathies Hb AC or CC, HbSS,SC Liver disease Post spleenectomy Severe iron deficiency anemia abetalipoprotenimia

39. Schistocytes ‘ Schisto ’ = split or cleft Physical assault to erythrocytes with in the blood stream creates these cells which include Helmet cells Triangles Crescents Microspherocytes Horns Purse

40. Causes DIC Severe haemolytic anemia Microangiopathic haemolytic anemia HUS &TTP Prosthetic cardiac valves Connective tissue disorders Burns Acute tubular necrosis, glomerulonephritis Malignant hypertension

41. Tear drop cells( Dacrocytes ) Pear shape cells, usually microcytic and hypochromic Seen in Newborn Thalassemia major Myleoproliferative disorder Leukoerythroblastic reaction

42. Spherocytes Ball shaped red cells, decreased surface: volume ratio, hyperdense (> MCHC) Seen in Hereditary spherocytes ABO incompatibility Autoimmune haemolytic anemia Microangiopathic haemolytic anemia SS disease Hyperspleenism Burns Posttransfusion

43. Elliptocytes Elliptical and normochromic cells, seen normally in less than 1% of RBCs Causes Hereditary elliptocytosis Iron deficiency anemia (increased with severity) SS disease and SA trait Thalassemia Major Leukoerythroblastic reaction Malaria Megaloblastic anemia

44. Burr cells ( Echinocytes ) 10-30 spicules equal in size and evenly distributed over RBC surface; caused by alteration in extracellular environment Seen in Liver disease Renal failure Dehydration Pyruvate kinase deficiency Storage artefacts

45. Spur cell - Acanthocyte Acantho = thorn Cells with 5-10 specules of varying length, irregular in shape, thickness, with wide bases and appear smaller than normal cell because they assume spheroid shape Result from changes in membrane lipid content Seen in Spur cell anemia Alcoholism Hypothyroidism Abetalipoprotinemia Vitamin E deficiency Malsbsorption Postsplenectomy

46. Bite cell ( Degmacyte ) Appear as a cookie with a bite taken out Seen in G6PD When spleen removes the H einz bodies from RBCs

47. Stomatocyte When examined on dry smear, it has a central slit or stoma Seen in Few may be seen normally Various cardiovascular and pulmonary disorders Hereditary Alcoholism Liver disease Malignancies

48. Howell – Jolly bodies Small well defined, rounded, densely stained inclusions, 1 micron in diameter, ecentric , that represent DNA fragments Associated with rapid or abnormal RBC formation Seen in Post spleenectomy Newborns Megaloblastic anemia Dyserythopoietic anemias Hereditary spherocyosis

49. Heinz Bodies Inclusion of denatured haemoglobin caused by oxidation of globin portion of haemoglobin Removal of Heinz body leads to formation of ‘bite cells’ Causes Drugs Certain foods like fava beans and onion

50. Sideroblastic granules/ pappenheimer bodies Irregular dark blue iron containing granules occuring in small clusters, predominantly in periphery Seen in Sideroblastic anemia Spleenectomy Haemolytic anemia Myelodysplastic syndromes Lead poisoining Its presence can rule out iron deficiency anemia

51. Sickle cell Crescent shape cells develop in people homozygous for haemoglobin S Heterozygous HbS and either thallasemia or another Hb like Hb C

52. Nucleated red cells Cells have dense dark nucleus in the center of the cell Results from marked stimulation of the bone marrow Seen in New born (first 3-4 days) Acute bleeding severe haemolytic anemia Megaloblastic anemia Congenital infections (syphilis, CMV, rubella) Postspleenectomy Leukoerythroblastic reaction Fungal and mycobacterial infections Dyselectropoeitic anemia

53. Basophilic stippling Numerous small, purplish inclusions, which results from RNA and mitochrondrial remenants Seen in Lead toxicity Thalessemia Haemoglobinopathies Macrocytic anemia

54. Cabot ring These are delicate thread like inclusions, remenants of the nuclear membranes, in the RBC They can take any shape like purplish ring, figure of eight, incomplete ring Seen in Pernicious anemia Lead poisoning Alcoholic jaundice Severe anemia Leukamia

55. Roulex formation A stack like arrengment of red blood cells where the biconcave surdface of RBCs are next to each other. Seen in Increase in cathodal protien, such as immunoglobins and fibronegen Multiple myleoma Macroglobulimias Acute and cronic infections Connective tissue disease Diabetes mellitus Malignancies

56. Grading of inclusions Rare 0-1/hpf Few 1-2/hpf Mod 2-4/hpf Many >5/hpf Qualitative grading of abnormal RBC morphology Grade degree of abnormalities 1-5 cells /10fields slight 6-15cells /10fields moderate >15cells /10fields marked