Iron deficiency,
anemia of chronic disease, Shahidi-Nathan-Diamond syndrome, sideroblastic
anemia, thalassemias, and hemoglobinopathies.
Some causes of a high MCV include
Cobalamin (B12)
deficiency due to strict vegetarianism, impaired absorption due to numerous
conditions ( pernicious anemia, gastrectomy, celiac disease, scleroderma,
lymphoma, etc.), parasites,
hyperthyroidism, neoplastic disease, pancreatic disease, and enzyme
deficiencies.
Folate deficiency from alcoholism , lack of vegetables, celiac disease, anticonvulsanats,
oral contraceptives, hypothyroidism, infancy, neoplastic disease, exfoliative skin diseases, folic acid antagonists
(trimethoprim, methotrexate, etc. ), and hemodialysis .
Metabolic inhibitors such as methotreaxte, enzyme
deficiencies, Lesch-Nyhan syndrome and other inborn errors.
Mild macrocytosis can be seen during normal pregnancy in women who are not iron or folate deficient
References:
1. Lockitch G. Handbook of Diagnostic Biochemistry and
Hematology in Normal Pregnancy. Boca Raton:CRC, 1993.
2.
Abbassi-Ghanavati M, Greer LG, Cunningham FG. Pregnancy and laboratory
studies: a reference table for clinicians. Obstet Gynecol. 2009
Dec;114(6):1326-31. PMID:19935037
3. Fischbach FT, Dunning MB III, eds.
A Manual of Laboratory and Diagnostic Tests, 7th ed. Philadelphia,
Lippincott Williams and Wilkins,2004
4. Chanarin I, et al. The physiological macrocytosis of pregnancy.Br J
Obstet Gynaecol. 1977 Jul;84(7):504-8.PMID:911706
