Determination of Red Cell Indices

The red cell indices consist of Mean Corpuscular Volume (MCV), Mean Corpuscular Hemoglobin (MCH) and Mean Corpuscular Hemoglobin Concentration (MCHC). These are the parts of Complete Blood Count (Complete Hemogram) and calculated from Hemoglobin concentration, Packed cell volume and Total erythrocyte count. These values give quantitative information about the volume of red cells and concentration of hemoglobin in the red blood cells.

Clinical Significance :

Mean Corpuscular Volume (MCV), Mean Corpuscular Hemoglobin (MCH) and Mean Corpuscular Hemoglobin Concentration (MCHC) are ‘Absolute’ values calculated from hemoglobin concentration, packed cell volume and total erythrocyte count are used in classification of anaemias.

 Normal Values :

• Mean Corpuscular Volume (MCV) : 82 – 92 fl or 92 ± 9 fl
• Mean Corpuscular Hemoglobin (MCH) : 27-32 pg or 29.5 ± 2.5 pg
• Mean Corpuscular Hemoglobin Concentration (MCHC) : 32 – 36 % (gm/dl) or  32.5 ± 2 % (gm/dl)

Procedure :

By using blood specimen determine – Hemoglobin concentration, Packed cell volume and Total erythrocyte count. Calculated the Mean Corpuscular Volume (MCV), Mean Corpuscular Hemoglobin (MCH) and Mean Corpuscular Hemoglobin Concentration (MCHC) values by applying following formulas.

Mean Corpuscular Volume (MCV)

MCV is the average volume of an erythrocyte. It’s measures the average size of erythrocytes and expressed in Cubic micron (µ³) or Femtoliter (fl). MCV increases in megaloblastic anaemia (macrocytosis) due to malnutrition where deficiency of Vitamin-B₁₂, deficiency of Folic acid and/or others types of Vitamin B and also it’s may be due to some liver diseases or hypothyroidism. MCV decreases microcytic anaemia (microcytosis) due to Iron deficiency or by thalasaemia. The normal value of MCV is 82 – 92 fl.

Mean Corpuscular Hemoglobin (MCH)

   It is the average amount of hemoglobin present in each red blood cell. It is expressed in Picogram (Pg). MCH level decreases in several condition like Malnutrition, Iron deficiency anaemia, Celiac disease, Gastric sugary, Women with excessive menstruation etc. MCH is also increase in Malnutrition dueto deficiency of Vitamin B₁₂ & Folic acid. In microcytic anaemia MCH will be higher than in other anaemias. It gives the absolute amount of hemoglobin in each cell on an average but does not consider the amount of hemoglobin in relation to the size of RBC. The normal value of MCH is 26 – 34 Pg.

Mean Corpuscular Hemoglobin Concentration (MCHC)

It is the amount of hemoglobin present in 100 ml RBC. It is expressed as gm/dl or percentage (%). The normal value of MCHC is 32 – 36 %. MCHC is lower in hypochromic anaemia and higher in spherocytosis but it is never higher than normal.