From the Guidelines
MCH in a CBC stands for Mean Corpuscular Hemoglobin, which measures the average amount of hemoglobin contained in each red blood cell, and is a crucial parameter in diagnosing iron deficiency anemia, with low MCH values indicating hypochromic red blood cells 1.
Importance of MCH in CBC
The normal range for MCH is typically between 27 to 33 picograms per cell. This value helps doctors evaluate the size and color of red blood cells, which is important for diagnosing different types of anemias.
Interpretation of MCH Values
Low MCH values indicate hypochromic (pale) red blood cells, often seen in iron deficiency anemia or thalassemia, while high MCH values suggest hyperchromic red blood cells, which may occur in conditions like vitamin B12 or folate deficiency.
Calculation and Interpretation
MCH is calculated by dividing the total hemoglobin by the red blood cell count. It's always interpreted alongside other CBC parameters like MCV (Mean Corpuscular Volume) and MCHC (Mean Corpuscular Hemoglobin Concentration) to provide a complete picture of red blood cell characteristics and help determine the underlying cause of blood disorders, as noted in recent guidelines for managing iron deficiency anemia 1.
Clinical Relevance
According to the British Society of Gastroenterology guidelines, automated cell counters provide measurements of changes in red cells that accompany iron deficiency, including reduced mean cell Hb (MCH), which is probably a more reliable marker of iron deficiency than MCV 1.
Key Points
- MCH measures the average amount of hemoglobin in each red blood cell
- Low MCH values indicate hypochromic red blood cells, often seen in iron deficiency anemia
- MCH is interpreted alongside other CBC parameters to diagnose blood disorders
- Recent guidelines emphasize the importance of MCH in managing iron deficiency anemia 1
From the Research
Definition of MCH in CBC
- MCH stands for Mean Corpuscular Hemoglobin, which is a measure of the average amount of hemoglobin in a red blood cell.
- It is an important parameter in a Complete Blood Count (CBC) test, used to diagnose and monitor various blood disorders, including anemia 2.
- MCH is calculated by dividing the total hemoglobin by the total number of red blood cells, and is typically expressed in units of picograms (pg) per cell.
Diagnostic Accuracy of MCH
- The diagnostic accuracy of MCH in diagnosing empty iron stores has been studied, and it has been found to be moderately accurate, with an area under the ROC curve of 0.73-0.96 2.
- MCH has been shown to be slightly more accurate than Mean Cell Volume (MCV) and Mean Cell Hemoglobin Concentration (MCHC) in diagnosing iron deficiency anemia 2.
- However, normal values of MCH do not exclude empty iron stores in anemic patients, and it should be used in conjunction with other diagnostic tests, such as serum ferritin levels 2.
Clinical Significance of MCH
- Abnormal MCH values can indicate various blood disorders, including iron deficiency anemia, vitamin deficiency anemia, and other conditions affecting red blood cell production or function 2, 3.
- MCH values can also be used to monitor response to treatment, such as iron supplementation, in patients with iron deficiency anemia 4, 3.
- In some cases, MCH values can help distinguish between different types of iron deficiency anemia, such as unexplained refractory iron deficiency anemia and iron-refractory iron deficiency anemia 3.