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CBC interpretation

CBC interpretation. Do you know :. How to evaluate anemia using MCV, RDW and RETIC count How to assess different RBC shapes reported in the PBS How to deal with leukocyte abnormalities seen on PBS The causes of thrombocytosis and thrombocytopenia. Evaluating Anemia. Role of MCV

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CBC interpretation

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  1. CBC interpretation

  2. Do you know : • How to evaluate anemia using MCV, RDW and RETIC count • How to assess different RBC shapes reported in the PBS • How to deal with leukocyte abnormalities seen on PBS • The causes of thrombocytosis and thrombocytopenia

  3. Evaluating Anemia • Role of MCV • mean corpuscular volume • Formula (2-10 yrs old) • Lower limit: 70 fL + age in years • Upper limit: 84 fL + ( age in yrs x 0.6 ), until upper limit of 96 is reached

  4. Evaluating Anemia • MCH (Mean Corpuscular Hb) • MCHC (Mean Corpuscular Hb conc) • normo/hyper/hypo chromic • Used in • iron deficiency - • Spherocytosis -

  5. What’s the MCV range? Give LL and UL • 7 year old

  6. answer LL: 77 fL UL: 88.2 fL

  7. RETICULOCYTE COUNT • Expressed as % of circulating rbc’s • Take up reticulin stain (supravital): • bec of inc RNA • N = 0.5 % to 1.5 % • or = .005 to .015

  8. RETICULOCYTE COUNT • Provide crucial info on RATE of red cell production • 2 broad classes of anemias • 2 red cell loss or destruction – inc retic - e.g. hemolysis, blood loss • Dec red cell production – dec retic e.g. aplastic, iron deficiency

  9. Reticulocyte index Example: Hb 50 Hct 0.15 Retic count=.045= 4.5 % Corrected retic = 4.5% x .15/.45 = 1.5 %( N = 0.5-1.5%) • Anemic patient --> increased retic • so have to correct: retic observed x px Hct / 0.45

  10. Absolute Retic Count • More accurate • Compute as ff: RBC (in n x 1012 ) x # retic/1000 rbc x 1000 • Normal = 40,000 – 100,000/uL

  11. Quiz • Compute for absolute retic count : Hb 90 RBC 3 x 1012 /L Retic .015

  12. Answer 45,000 retics / uL

  13. Anemia based on MCV and retic • Increased MCV • High retic • Low retic • Decreased MCV • High retic • Low retic • Normal MCV • High retic • Low retic

  14. Increased MCV • Increased Retic • Acute blood loss • Hemolysis > Increased MCV - cased by inc # retics  retics have a large cellular volume

  15. Anemia based on MCV and retic • Increased MCV • High retic • Low retic • Decreased MCV • High retic • Low retic • Normal MCV • High retic • Low retic

  16. Inc MCV, low retic • Bone Marrow Failure • Retic count greatly dec for degree of anemia ----------------------------------------------------------------- E.g. Known case of Aplastic anemia RBC 1.73 Hb 52 Hct 0.15 Retic = 1 % or 0.010 > Compute for corrected retic count % absolute retic

  17. Inc MCV, Dec Retic 2. Megaloblastic disorders • Folate and Vit B 12 deficiency • Other things seen : • Hypersegmentation of PMN’s • Macroovalocytosis • Megaloblastic changes in BM 3. Alcohol • direct toxic effect on BM

  18. Inc MCV, dec retic • Anti-metabolites • Methotrexate (folic acid anti-metabolite) • Co-trimoxazole • Hypothyroidism a. Causes red cell hypoplasia • Usually normocytic/normochromic • Macrocytosis may develop

  19. Decreased MCV • Caused by insufficient Hb synthesis • Mostly caused by: • Iron deficiency • Inability to use iron • Chronic disease • Thalassemia • Lead poisoning • Sideroblastic anemia

  20. Decreased MCV • Increased retic • Thalassemia • Normal /decreased retic • Fe deficiency • Anemia of Chronic Disease • Thalassemia trait • Sideroblastic anemia hardest differentials !

  21. Iron deficiency • Common cause in 1-3 years of age • As iron stores become depleted: • RDW serum Fe  MCV  anemia • First manifestation : RDW

  22. Iron deficiency • Reasonable approach: Oral iron replacement • (+) response: Hb by 15-20 in 1 month PRESUMPTIVE DX MADE !

  23. RED CELL DISTRIBUTION WIDTH • Quantitative measure of anisocytosis • The greater the # of sizes of rbc’s, the higher the RDW • Normal = 11.5-14.5 • No subnormal values have been reported

  24. RDW • HIGH ( FGHI- C ) • Iron deficiency • Hb H disease • Fragmentation • G-6PD • Chronic disease

  25. Decreased MCV • Increased retic • Thalassemia • Normal /decreased retic • Fe deficiency • Anemia of Chronic Disease • Thalassemia trait • Sideroblastic anemia hardest differentials !

  26. Anemia of Chronic Disease • Mild to moderate anemia (Hb 100 – 110) • Slight inc RDW; dec Fe, inc Ferritin • Px has chronic INFLAMMATION • Disturbs iron recycling  iron left trapped in RES • Cytokines IL-1, IL-6  inc ferritin syn  empty ferritin shells provide excess iron storage capacity  iron sequestered in RES

  27. MCV NORMAL

  28. MCV NORMAL

  29. MCV NORMAL

  30. Renal Disease • Cause: • erythropoeitin insufficiency • Serum inhibitors of erythropoeisis accumulate in uremic patients • Acanthocytosis • Shortened rbc life span When BUN > 150 mg/dL

  31. PLATELETS • Cytoplasmic fragments ; no nucleus • Life span = 7-10 days • 1/3 in spleen, 2/3 in circulation • Size= 1 – 4 um • Large • Young • 2 peripheral destruction • Small or normal • Production defect

  32. THROMBOCYTOSIS • Platelet count > 600,000 • Rarely causes complications ! • Therefore, antiplatelet tx is rarely indicated • Kawasaki is an exception

  33. THROMBOCYTOSIS • Hemolytic anemia • Hemorrhage • Infection • Iron def anemia • Vit E deficiency • Vascular Collagen disorders • Post-splenectomy • Post-op • Inflammatory Bowel Dis • Trauma • Tumors • Syndrome, kawasaki • Syndrome, nephrotic • Syndrome, myeloprolif HIV is the PITS !

  34. THROMBOCYTOPENIA • Immune Platelet Destruction • Infections • Platelet clumping - falsely low - 2 inadequate coagulation

  35. RBC abnormalities • Anisocytosis • Microcytes • Macrocytes • Normocytes • Poikilocytosis • Different shapes

  36. RBC abnormalities • Severe hemolysis • Nucleated rbc’s • Schistocytes: helmet cells, triangle cells, bite cells • Spherocytes (immune mediated) • acanthocytes

  37. Spherocytes / acanthocytes

  38. schistocytes

  39. Abn RBC shapes • Normochrom ovalocyte • Ovalocytosis • Thalassemia • Hypochrom ovalocyte • Iron deficiency • Macrocytic ovalocyte • Megaloblastic anemia • Target cells • Liver disease • Thalassemia • Iron deficiency • Post-splenectomy • Elliptocyte • Elliptocytosis • Megaloblastic anemia • Myelofibrosis • Thalassemia

  40. Target cells/ elliptocytes

  41. Abn RBC shapes • Schistocytes • hemolytic anemia • Hypersplenism • Megaloblastic anemia • Thalassemia • Acute Leukemia • Post severe burns • Blister cell • Microangiopathic hemolytic anemia • Tailed RBC • Megaloblastic anemias • Iron deficiency • Tear drop • Hypersplenism • Thalassemia • Hemolytic Anemia

  42. 1/4 point quiz show • 10 year old with Hb 80, WBC 9 plt 350. On co-tri for repeated UTI. MCV 102 MCH 340 Retic ct 0.002 • What is most likely diagnosis ? • Fe deficiency • Megaloblastic anemia • Diamond Blackfan Anemia • Hemolytic anemia

  43. Answer B MEGALOBLASTIC ANEMIA (Prob 2 folate def)

  44. 2/4 Quiz show The ff is a cause of thrombocytosis A. Immune thrombocytopenic purpura B. Pregnancy C. Iron deficiency anemia D. Renal failure

  45. ANSWER C Iron deficiency anemia

  46. ¾ QUIZ show • Compute absolute retic count Hb 45 RBC 1.5 x 1012 / L Retic count: 0.016

  47. ANSWER 24,000 / uL

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