Getting to know… the CBC It’s about time!

Components of the CBC Hemoglobin (Hgb) Hematocrit (Hct) Mean Corpuscular hemoglobin (MCH) MCH concentration (MCHC) Mean corpuscular volume (MCV) Erythrocyte count (RBC) Red cell distribution width (RDW) Leukocyte count Platelet count

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

What is anemia? Measured Hgb > 2 SD below the mean for age AgeMean-2SD 1 mo mo mo y y y M F M F1412

Evaluating Anemia Role of MCV –measures the average volume of a red blood cell –categorizes red blood cells by size. 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

Evaluating Anemia MCH (Mean Corpuscular Hb) –average weight of hemoglobin in a red blood cell MCHC (Mean Corpuscular Hb conc) –average concentration of hemoglobin in a red blood cell -normo/hypo chromic -Used in -iron deficiency - -Spherocytosis -

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

answer LL: 77 fL UL: 88.2 fL

RETICULOCYTE COUNT -Measures erythrocyte production -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

RETICULOCYTE COUNT Provide crucial info on RATE of red cell production 2 broad classes of anemias 1.2 red cell loss or destruction – inc retic - e.g. hemolysis, blood loss 2.Dec red cell production – dec retic e.g. aplastic, iron deficiency

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

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

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

Answer 45,000 retics / uL

Anemia based on MCV and retic Increased MCV –High retic –Low retic Decreased MCV –High retic –Low retic Normal MCV –High retic –Low retic

Increased MCV Increased Retic –Acute blood loss –Hemolysis > Increased MCV - caused by inc # retics  retics have a large cellular volume

Anemia based on MCV and retic Increased MCV –High retic –Low retic Decreased MCV –High retic –Low retic Normal MCV –High retic –Low retic

Inc MCV, low retic 1.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 > Compute for corrected retic count % absolute retic

Answer Corrected retic: 0.33 % ( 0.5 – 1.5 %) You got it!  Absolute Retic Count: 17,300 /uL (40, ,000)

Bone Marrow Failure  MCV inc bec of production of stress rbc’s  Examples of bone marrow failure oAplastic Anemia oFanconi’s Anemia oDiamond-Blackfan anemia (Congenital hypoplastic anemia) oTransient Erythroblastopenia of Childhood (TEC)

TEC vs DBA  Diamond Blackfan Anemia - Congenital hypoplastic anemia - 90% cases < 6 mos - some recover by 7 years old -Macrocytosis with reticuloyctopenia -- ADA increased Transient erythroblastopenia of childhood –Acquired –90% cases in > 1 y.o. –Recovery within 2 mos –In recovery phase, inc MCV bec inc retics –ADA normal

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

Inc MCV, dec retic 4.Anti-metabolites a.Methotrexate (folic acid anti-metabolite) b.Co-trimoxazole 5.Hypothyroidism a. Causes red cell hypoplasia b.Usually normocytic/normochromic c.Macrocytosis may develop

Anemia based on MCV and retic Increased MCV –High retic –Low retic Decreased MCV –High retic –Low retic Normal MCV –High retic –Low retic

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

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

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

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

Iron deficiency Common cause in 1-3 years of age As iron stores become depleted: –R DW  serum F e  M CV  anemia First manifestation : RDW

Iron deficiency Reasonable approach: Oral iron replacement (+) response: Hb by in 1 month PRESUMPTIVE DX MADE !

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

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

Anemia based on MCV and retic Increased MCV –High retic –Low retic Decreased MCV –High retic –Low retic Normal MCV –High retic –Low retic

MCV NORMAL INC RETIC 1.HEMOLYSIS 2.BLOOD LOSS DEC RETIC N OR DEC RETIC

MCV NORMAL INC RETICDEC RETIC 1.BALANCED 2.PRCA/TEC 3.APLASTIC 4.HYPOTHYROIDISM 5.REPLACEMENT OF MARROW N OR DEC RETIC

MCV NORMAL INC RETICDEC RETICN OR DEC RETIC 1.CHRONIC INFECTION 2.RENAL DISEASE 3.HYPERPARATHYROID 4.LIVER DISEASE

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

Hyperparathyroidism Fibrosis in marrow cavity Decreased erythropoeisis

Liver disease Anemia is due to –H–Hypersplenism –V–Vitamin-nutritional deficiencies –B–Blood loss

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

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

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 !

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

RBC abnormalities Anisocytosis –Microcytes –Macrocytes –Normocytes Poikilocytosis –Different shapes

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

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

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

Abn RBC Shapes Envelope forms –Thalassemia –Liver disease Burr cells –Hemolytic anemias –Iron deficiency –Megaloblastic anemia –Thalassemia –Hypersplenism Stomatocytes –Hereditary stomatocytosis –Artefact –Acute leukemia, treated –Alcoholics with liver disease

Abn RBC shapes Spherocytes –Hereditary spherocytosis –ABO incompatibility –Hemolytic anemia –Hypersplenism –Malaria –Hemoglobinopathies –Post-transfusion ! –Liver disease Acanthocytes –Abetalipoproteinemia –Hemolytic anemias –Thalassemia –Liver disease –Severe burns –Post splenectomy –Renal disease –Enzyme deficiencies

RBC Inclusions Howell-Jolly bodies –Nuclear remnants not extruded from mature erythrocytes –Indicate splenic hypofunction –Seen in Post-splenectomy Leukemia Hemolytic thalassemia

RBC Inclusions Basophilic stippling –Caused by aggregated ribosomes in rbc –Seen in Thalassemia Lead intoxication /heavy metal

WBC abnormalities Toxic changes –Toxic granules –Dohle bodies Dark blue cytoplasmic inclusions Seen in neutrophils Seen in : infection, burns, pregnancy –Vacuolations

WBC abnormalities Leukopenia Viral illness (1-2 days of infection, persists for several weeks) Salmonella Staphylococcal Mycobacterial –Neutropenia NC < 1500/mm3) –Viral infections

WBC abnormalities –Leukocytosis Body’s response to : –Infections –Stresses –Eosinophilia Usually associated with: –Rashes, wheezes, parasites, allergies, malignancies –Lymphocytosis –Viral infections: IM, EBV, CMV, rubella, mumps, hep –Pertussis

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 What is most likely diagnosis ? a.Fe deficiency b.Megaloblastic anemia c.Diamond Blackfan Anemia d.Hemolytic anemia

Answer B MEGALOBLASTIC ANEMIA (Prob 2 folate def)

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

ANSWER C Iron deficiency anemia

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

ANSWER 24,000 / uL

4/4 Quiz show Which presents as a microcytic anemia A.B-thalassemia B.Hemolytic Anemia C.Aplastic Anemia D.Anemia 2 blood loss

ANSWER A B- Thalassemia