If you have been using the automated hematology analyzer,I’m pretty sure you might have come across these MCV,MCH and MCHC.These parameters are very useful in automated and manual hematology.They are called Red Blood Cells indices and are useful blood tests that provide hematological information about haemoglobin and the size of red blood cells.
Red blood cells functions in the transportation of Oxygen and Carbon Dioxide in the blood stream or circulatory system.A deficiency or abnormalities of Red blood cells is a serious threat to life and an indication of the presence of Anemia.
The uses of Red blood cells indices provides information on Anemia and the types of Anaemia.
MCV (Mean Cells Volume)
- Also known as Mean Corpuscular Volume which is the average volume of a red blood cells and it is measured in femto litres (fl) where by a femto litres is 10-15of a Litres
- It has a reference range of 80 – 10 fl
- It is usually calculated by dividing the hematocrit(HCT) by the concentration of red blood cells OR determined from the PCV and the electronically obtained RBC count as follow
Clinical Significance of MCV
|Low MCV||Raised MCV|
|Microcytic anaemia||Macrocytic anaemias (Folate deficiency)|
|Iron deficiency Anaemia||Mark reticulocytosis|
|Anaemia of chronic disease||Chronic Alcoholism|
- MCV is low in children that is about 70 fl at 1 years of age
- MCV is raised in newborn babies
MCH (Mean Cells Haemoglobin)
Also known as Mean Corpuscular Haemoglobin and it is the average amount of haemoglobin (Hb) per RBC.
- It is obtained by dividing haemoglobin by RBC count.
- It is measured in picograms (pg) where by a pg is 10-12 of a gram
- It has a reference range of 27 – 32 pg/cell
Clinical Significance of MCH
|Low MCH||Raised MCH|
|Microcytic red cells||Macrocytic anaemias|
|hypochromic anaemia (Iron deficiency)||Macrocytic Normochromic anaemia (Folate deficiency anemia)|
|In Thalassaemia minor||MCH is also raised in newborn babies|
MCHC (Mean Cell Haemoglobin Concentration)
Also known as Mean Corpuscular Haemoglobin Concentration
- It is the average concentration of haemoglobin per unit volume of RBC
- It is usually calculated by dividing the haemoglobin by the hematocrit OR by diving the haemoglobin by PCV (Packed Cell Volume)
- It has a reference range of 32-36 g/dl
Clinical Significance of MCHC
|Low MCHC||Raised MCHC|
|Iron Deficiency Anemia||Marked spherocytosis but this is a rare condition|
|Microcytic hypochromic anaemia||Raised MCHC is mostly due to calculation error or an incorrect haemoglobin or PCV|
- Monica cheesbrough part 2 p.313