4. MCH IF HIGH = HYPERCHROMASIA
MCH IF LOW =HYPOCHROMASIA
5. VARIATIONS IN MCH
MCH DECREASES IN
• MICROCYTIC ANEMIA
• NORMOCYTIC ANEMIA
MCH INCREASES IN
• MACROCYTIC ANEMIA
• INFANTS
• NEWBORNS
6. INTERFERENCES IN MCH
• LIPEMIA
• MARKED LEUKOCYTOSIS ( >50000/microlitre)
• COLD AGGLUTININ
• IN VIVO HEMOLYSIS
• MONOCLONAL PROTEIN IN BLOOD
• HIGH HEPARIN CONCENTRATION
7. MEAN CORPUSCULAR HEMOGLOBIN
CONCENTRATION (MCHC)
• DEFINITION – The average hemoglobin
concentration per unit volume of packed red
cells.
• In contrast to MCH,MCHC correlates the
hemoglobin content with the volume of the
cell.
• It is expressed as g/dl of red blood cells.
8. NORMAL RANGE – 32-36 gm/dl
MCHC = (HEMOGLOBIN/HEMATOCRIT) X 10
9. MCHC DECREASED CONDITIONS
• HYPOCHROMIC MICROCYTIC ANEMIA.
• BUT NORMAL VALUE DOES NOT RULE OUT
ANY OF THESE ANEMIA.
10. MCHC INCREASED CONDITIONS
• HEREDITARY SPHEROCYTOSIS
• IN HS MCHC IS INCREASED DUE TO LOSS OF
MEMBRANE AND THE CONSEQUENT
PHERICAL SHAPE ASSUMED BY TE CELL.
• INFANT AND NEWBORN.
• AUTOAGGLUTINATION
• ARTEFACTUAL
11. INTERFERENCES WITH MCHC
MCHC DECREASES
• Marked leukocytosis
(>50,000/microlitre)
MCHC INCREASED
• HEMOLYSIS (sickle cell anemia
, hereditary spherocytosis ,
autoimmune hemolytic
anemia ) with shrinkage of
RBC makes them hyperdence
• COLD AGGLUTININS
• LIPEMIA
• ROULEAX OR RBC
AGGLUTINATES
• HIGH HEPARIN
CONCENTRATES.
12. RED CELL DISTRIBUTION WIDTH(RDW)
• RDW Is the quantitative measure or numerical
expression of anisocytosis.
• It is the coefficient of variation of the
distribution of individual RBC volume.
13. contd
• RDW reflects size variability in red cell.
• High RDW values mirror a large range in red cell
size.
• It provides an insight into the basis of anemia
because some process increases its value while
others donot.
• MICROCYTOSIS , for instance exists with iron
deficiency or thallasemia. The former condition
increases the RDW while the latter does
not.therefore marked microcytosis with a normal
RDW suggests THALLASEMIA early in workup.
14. THE SIX POSSIBLE COMBINATIONS
CLASSIFY ALMOST ALL MAJOR
POSSIBLE CAUSES OF ANEMIA
• LOWMCV WITH NORMALRDW OR HIGHRDW
• NORMALMCV WITH NORMALRDW OR
HIGHRDW
• HIGHMCV WITH NORMALRDW OR HIGHRDW
15. NORMAL RDW
• MCV NORMAL (NORMOCYTIC)
1. Anemia of chronic disease
2. Acute blood loss
3. Hemolysis
4. Chronic lymphocytic leukaemia
5. Chronic myelogenous leukaemia
6. Hemoglobinopathies
7. Normal variant.
16. NORMAL RDW
• MCV HIGH (MACROCYTIC)
1. Aplastic anemia
2. Preleukaemia
3. Myelodysplastic syndrome
17. NORMAL RDW
• MCV LOW (MICROCYTIC)
1. Anemia of chronic disease
2. thallasemia
18. HIGH RDW
• MCV NORMAL (NORMOCYTIC)
1. RDW increases before mcv become abnormal
in early iron deficiency anemia B12
DEFICIENCY and early folate deficiency
2. Anemia globinopathy like sickle cell anemia.
19. HIGH RDW
• MCV HIGH (MACROCYTIC)
1. VIT B12 deficiency
2. Folate deficiency
3. Liver disease
4. Cold agglutinins
5. alcoholism
21. Low RDW
• Low RDW is not possible theoratically only
seen at marrow level when rbc produced by
marrow have less heterogenicity then
accepted normal.
