What Is Macrocytosis?

[dropcap]M[/dropcap]acrocytosis is a blood cell disorder characterized by altered blood cell formation that results in abnormally large erythrocytes (red blood cells) circulating in the bloodstream.

The mean corpuscular volume (MCV), which is a measure of the size of red blood cells in the bloodstream, is greater than 100 fL as shown in a complete blood count (CBC) laboratory analysis report.

Macrocytosis produces macrocytic anemias that are classified as megaloblastic or non-megaloblastic:

1. Megaloblastic anemias result from disorders of DNA synthesis of red blood cell precursors (megaloblasts) in bone marrow due to B vitamin deficiency demonstrated by macro-ovalocytes and hypersegmented neutrophils.¹
2. Non-megaloblastic anemias are or those caused primarily by alcoholism, liver disease and hypothyroidism.²

What Is Macrocytosis In Celiac Disease and/or Gluten Sensitivity?

1. Kaferle J, Strzoda CE.Evaluation of macrocytosis. Am Fam Physician. 2009 Feb 1;79(3):203-8. [↩]
2. Davenport J. Macrocytic anemia. Am Fam Physician. 1996 Jan;53(1):155-62. [↩]