From the Guidelines
Elevated MCV, even in asymptomatic individuals, warrants further evaluation to rule out underlying conditions that may impact morbidity, mortality, and quality of life. The initial workup should include a complete blood count with peripheral smear, reticulocyte count, vitamin B12, folate, thyroid function tests, liver function tests, and serum creatinine, as these tests can help identify common causes of macrocytosis, such as vitamin B12 or folate deficiency, alcoholism, liver disease, hypothyroidism, and certain medications 1. Some key points to consider when evaluating elevated MCV include:
- The degree of elevation, as an MCV >110 fL may require more urgent evaluation than borderline elevations (100-110 fL)
- The presence of other laboratory abnormalities, such as low serum ferritin, which may indicate iron deficiency or other underlying conditions 1
- The patient's age and medical history, as certain conditions, such as myelodysplastic syndrome, are more common in older adults
- The potential for irreversible neurological damage if underlying conditions, such as B12 deficiency, are left untreated Further investigation, including bone marrow examination, may be necessary if initial testing does not reveal a cause, especially in older adults where myelodysplastic syndrome is a concern. Early identification and treatment of the underlying cause can prevent progression to symptomatic disease and improve patient outcomes.
From the Research
Elevated MCV Evaluation
Elevated Mean Corpuscular Volume (MCV) is a condition where the average size of red blood cells is larger than normal. The need for further evaluation of elevated MCV in asymptomatic individuals depends on various factors.
- Alcohol Abuse: Studies have shown that alcohol abuse is a common cause of macrocytosis, which is characterized by an elevated MCV 2. In fact, one study found that 80.2% of male patients with macrocytosis were alcohol abusers 2.
- Folate and Vitamin B12 Deficiency: While folate and vitamin B12 deficiency can cause macrocytosis, not all cases of elevated MCV are due to these deficiencies 3, 4. In some cases, the MCV may be elevated even in the absence of folate or vitamin B12 deficiency 2.
- Underlying Conditions: Elevated MCV can be a sign of underlying conditions such as liver disease, hypothyroidism, or myelodysplastic syndrome 5. Therefore, further evaluation may be necessary to rule out these conditions.
- Laboratory Tests: Laboratory tests such as serum gamma-glutamyltransferase measurement can be useful in identifying alcohol abuse as the cause of macrocytosis 2. Other tests such as folate and vitamin B12 levels, liver function tests, and thyroid function tests may also be necessary to evaluate the underlying cause of elevated MCV.
In summary, while asymptomatic individuals with elevated MCV may not require immediate attention, further evaluation may be necessary to rule out underlying conditions such as alcohol abuse, liver disease, or vitamin deficiencies 3, 2, 4, 5, 6.