Red Cell Indices

UNIT II

Red Cell Indices

2.1 Red Cell Indices – Expand MCV, MCH, MCHC.

2.2 Definition, reference range, calculation and interpretation

Red cell indices

Red cell indices are also called erythrocyte indices or haematological indices. These are the numerical value that provides information about the characteristics and size of red blood cells (Erythrocytes). There are following three main red cell indices:

1. Mean Corpuscular Volume (MCV)

2. Mean Corpuscular Hemoglobin (MCH)

3. Mean Corpuscular Hemoglobin Concentration (MCHC)

1. Mean Corpuscular Volume (MCV):

The average volume or size of the individual red blood cells is called Mean corpuscular volume (MCV). It is calculated by dividing the total volume of packed red blood cells (hematocrit) by the total volume of red blood cells. MCV is reported in femtolitres (fL.).

Reference range of MCV: Upper limit: 80fL

Lower limit: 100 fL.

Interpretation: The following are the general interpretations of MCV

• · Microlytic Anaemia: Anaemia with MCV below the reference range indicates microlytic anaemia. It is characterised by abnormally small red blood cells.

• · Normocytic anaemia: Anaemia with normal MCV indicates normocytic anaemia. In normocytic anaemia, red blood cell size remains normal.

• · Macrocytic Anaemia: Anaemia with MCV above normal range indicates Macrocytic anaemia. In macrocytic anaemia, red blood cell size is larger than normal RBC cells.

2. Mean Corpuscular Hemoglobin (MCH):

The average amount of haemoglobin in each red blood cell is called Mean Corpuscular Hemoglobin (MCH). It is calculated by dividing the total amount of haemoglobin by the total number of red blood cells. MCH is reported in the picogram (pg).

Reference range: Lower limit: 27 pg.

Upper limit: 33 pg.

Interpretation: The following are the general interpretations of MCH

• · Hypochromic Anaemia: Anaemia with MCV below the reference range indicates hypochromic anaemia. In hypochromic anaemia, red blood cells have a reduced amount of haemoglobin.

• · Normochromic anaemia: Anaemia with MCH within the reference range indicates normochromic anaemia. In normochromic anaemia, haemoglobin content in RBC is normal.

• · Hyperchromic anaemia: Anaemia with MCH above reference indicates hyperchromic anaemia. In hyperchromic anaemia, red blood cells have an increased amount of haemoglobin.

3. Mean Corpuscular Hemoglobin Concentration (MCHC):

The average concentration of haemoglobin in each red blood cell is called Mean Corpuscular Hemoglobin Concentration (MCHC). It is calculated by dividing the total amount of haemoglobin by the total volume of packed red blood cells and multiplying by 100. It is reported in grams per decilitre (g/dL).

Reference range: Lower limit: 32 g/dL.

Upper limit: 36 g/dL.

Interpretation: The following are the general interpretations of MCH

• · Hypochromic: MCHC below the reference range indicates hypochromic red blood cells. It means a decrease in haemoglobin concentration in RBCs.

• · Normochromic: MCHC within the reference range indicates normochromic red blood cells. It means haemoglobin concentration in red blood cells is normal.

• · Hyperchromic: MCHC above normal range indicates hyperchromic red blood cells. It means increased haemoglobin concentration in red blood cells.