From the Guidelines
Elevated MCV and MCH typically indicate macrocytic anemia, a condition where red blood cells are larger than normal and contain more hemoglobin per cell, most commonly associated with vitamin B12 deficiency, folate deficiency, or alcohol abuse, as suggested by the most recent and highest quality study 1. This pattern is often seen in patients with liver disease, hypothyroidism, certain medications (like anticonvulsants or chemotherapy drugs), and myelodysplastic syndromes. Some key points to consider:
- The morphologic approach to evaluating anemia characterizes it based on the mean corpuscular volume (MCV), with macrocytic anemia being greater than 100 fL, as noted in 1.
- The kinetic approach focuses on the underlying mechanism of anemia, distinguishing among the production, destruction, and loss of RBCs, with a reticulocyte count corrected against the degree of anemia (reticulocyte index [RI]) being a key measurement, as discussed in 1.
- Treatment depends on the underlying cause, with B12 deficiency potentially requiring injections or oral supplements, and folate deficiency usually responding to oral supplements, as indicated in 1.
- Reducing alcohol consumption is essential if that's a contributing factor, and these abnormalities should not be ignored as some causes, if left untreated, can lead to progressive neurological damage or other complications, highlighting the importance of prompt evaluation and management, as emphasized in 1.
From the Research
Mean Corpuscular Volume (MCV) and Mean Corpuscular Hemoglobin (MCH) Elevation
- A slight elevation of MCV and MCH can indicate various conditions, including macrocytic anemia 2, 3.
- Macrocytic anemia is generally classified into megaloblastic or nonmegaloblastic anemia, with megaloblastic anemia caused by deficiency or impaired utilization of vitamin B12 and/or folate 3.
- Nonmegaloblastic macrocytic anemia can be caused by various diseases such as myelodysplastic syndrome (MDS), liver dysfunction, alcoholism, hypothyroidism, certain drugs, and less commonly inherited disorders of DNA synthesis 3.
- A study found that changes in MCV were observed in cancer patients, and a higher MCV was associated with an increased risk of secondary leukemia 4.
- Another study found that reticulocyte parameters, including MCV and MCH, can be useful in differentiating between iron deficiency anemia, vitamin B12 deficiency anemia, and mixed anemia 5.