From the Guidelines
MCH (Mean Corpuscular Hemoglobin) and MCHC (Mean Corpuscular Hemoglobin Concentration) are crucial red blood cell indices used to diagnose and differentiate various types of anemias, with MCH measuring the average amount of hemoglobin per red blood cell and MCHC measuring the average concentration of hemoglobin within a single red blood cell. MCH and MCHC provide different information about hemoglobin content in red blood cells. MCH measures the average amount of hemoglobin per red blood cell, expressed in picograms (pg), with normal values typically ranging from 27-31 pg, as seen in studies on iron deficiency anaemia 1. MCHC, on the other hand, measures the average concentration of hemoglobin within a single red blood cell, expressed as a percentage or in g/dL, with normal values typically between 32-36 g/dL. The key difference between MCH and MCHC is that MCH tells us the absolute amount of hemoglobin in each cell, while MCHC tells us how concentrated that hemoglobin is within the cell volume. Some key points to consider when interpreting MCH and MCHC values include:
- Low MCH and MCHC values suggest microcytic anemias like iron deficiency, as noted in the british society of gastroenterology guidelines for the management of iron deficiency anaemia in adults 1.
- MCH is probably a more reliable marker of iron deficiency as it is less dependent on storage and the counting machine used, and a reduction is seen in both absolute and functional iron deficiency (FID) 1.
- MCH may also be more sensitive for iron deficiency than MCV, as it is less affected by other factors such as chronic disease, thalassaemia or vitamin B12/folate deficiency 1. These measurements help diagnose different types of anemias and understanding these indices helps clinicians determine not just if anemia is present, but also its potential underlying cause.
From the Research
Definition of MCH and MCHC
- MCH (Mean Cell Hemoglobin) is the average amount of hemoglobin in a single red blood cell [ 2 ].
- MCHC (Mean Cell Hemoglobin Concentration) is the average concentration of hemoglobin in a single red blood cell, calculated as MCH divided by MCV (Mean Cell Volume) [ 2 ].
Difference between MCH and MCHC
- MCH measures the total amount of hemoglobin in a red blood cell, while MCHC measures the concentration of hemoglobin in a red blood cell [ 3 ].
- A low MCH value indicates that the red blood cells have less hemoglobin than normal, while a low MCHC value indicates that the red blood cells have a lower concentration of hemoglobin than normal [ 4 ].
Clinical Significance of MCH and MCHC
- MCH and MCHC are used to diagnose and differentiate between various types of anemia, such as iron deficiency anemia and thalassemia [ 3 ].
- Abnormal MCH and MCHC values can also be associated with other conditions, such as cardiovascular disease [ 5 ].
- The ratio of platelet count to MCH can be used to distinguish between combined iron and vitamin B12 deficiency and uncomplicated iron deficiency [ 4 ].