Erythrocyte indices

RBC indices
reference - wintrobe , kawthalkar

1. ERYTHROCYTE INDICES Presented by – Dr. Pritika Nehra Moderator – Dr. Vinod Mam

2. Used for determining the size, content, and Hb concentration of red cells . Useful in the morphologic characterization of anemias . They may be calculated from the red cell count, Hb concentration, and Hct .

3. Mean cell volume ( MCV ) Mean cell hemoglobin ( MCH ) Mean cell hemoglobin concentration( MCHC ) Red cell distribution width ( RDW )

4. average size of the red cells. measured directly by automated instruments from the measurement of volume of each red cell. With semiautomated instruments and by manual method, it is obtained by MCV = PCV in% × 10 Red cell count in million/ cmm Mean Cell Volume

5. MCV is expressed in femtoliters or fl (10–15 of a liter ). It corresponds with red cell diameter on blood smear. Normal MCV is 80-100 fl .

6. Normal peripheral smear . Erythrocytes appear as circular, homogeneous disks of nearly uniform size, ranging from 6 to 8 μ m in diameter, with central pallor not exceeding more than one third of the cell. On average, the red cells are approximately the same size as the nucleus of a small lymphocyte

7. Microcytic red cells in iron deficiency anemia . Red cells are hypochromic—the amount of hemoglobin per cell is decreased, and the central pale area becomes larger

8. Macrocytes . Red cells are larger and thicker, stain deeply, and lack central pallor

9. Dimorphic anemia . Anisocytosis and anisochromia characterized by the presence of microcytic cells, normocytic cells, and few macrocytes characteristic of sideroblastic anemias also found some weeks after iron therapy for iron deficiency anemia in a hypochromic anemia after transfusion with normal cells.

10. Average amount of hemoglobin in a single red cell. MCH = Hemoglobin in grams/dl × 10 Red cell count in millions/ cmm MCH is expressed in picograms or pg Reference range is 27-32 pg. Decreased in microcytic hypochromic anemia Increased in macrocytic anemia & in newborns MEAN CELL HEMOGLOBIN (MCH)

11. concentration of hemoglobin in 1 dl or 1 liter of packed red cells. expressed in grams/dl or grams/ liter MCHC = Hemoglobin in grams/dl × 100 PCV in % Reference range is 30-35 grams/dl. MEAN CELL HEMOGLOBIN Concentration ( mchc )

12. MCHC corresponds with degree of hemoglobinization of red cells on a blood smear If MCHC is normal, red cell is normochromic If low, red cell is hypochromic MCHC is raised in hereditary spherocytosis and is decreased in hypochromic anemia

13. Hypochromic red cells Red cells are hypochromic—the amount of hemoglobin per cell is decreased, and the central pale area becomes larger MCH is decreased MCHC is decreased

14. Hereditary spherocytosis Spherocytes are nearly perfectly round in shape, smaller than normal red cells, and lack central pallor ( hyperchromic ) MCH is normal MCHC is usually increased because of a reduced surface/volume ratio

15. quantitative measure of the variation in red cell size ( anisocytosis ) higher the value, the more heterogeneous the RBC population size. Normal RDW is 11.0 to 14.5. increased in iron deficiency, and this often is useful in distinguishing iron deficiency from thalassemia trait conditions in which the RDW is normal Red Cell Distribution Width (RDW)