Improved Classification of Anemias by MCV and RDW

TLDR

Automated blood cell analyzers now provide RDW and histogram displays of red cell volume distribution. The authors developed a classification of red cell disorders based on MCV, heterogeneity, and histograms to guide peripheral blood diagnosis. Red cell volume distribution histograms identify fragmentation, agglutination, dimorphic populations, and artifactual lymphocyte counting, forming the basis of the classification. This method improves differentiation of iron deficiency anemia from heterozygous thalassemia and anemia of chronic disease, detects early iron and folate deficiency, and is recommended for initial anemia classification by clinicians.

Abstract

New automated blood cell analyzers provide an index of red cell volume distribution width (RDW) or heterogeneity and a histogram display of red cell volume distribution. We have developed a classification of red cell disorders, based on mean corpuscular volume (MCV) or red cell size, heterogeneity, and histograms, to guide diagnosis from the peripheral blood analysis. The distinction of iron deficiency anemia from heterozygous thalassemia or the anemia of chronic disease and the detection of early iron and folate deficiency is improved. Red cell volume distribution histograms identify red cell fragmentation or agglutination, dimorphic populations, and artifactual counting of lymphocytes as red cells. We recommend the use of these new variables in the initial classification of anemia by the practicing physician.