Quantitative anisocytosis as a discriminant between iron deficiency and thalassemia minor

Abstract

The coefficient of variation (CV) of red cell size, as measured by electronic red cell sizing (erythrography), was less than 14.0% in 20 normal subjects. In 22 of 25 patients with β-thalassemia minor and microcytosis (mean corpuscular volume [MCV] < 70 fl), CV was less than 14.0%; in the other 3, CV was 14.0% - 14.9%. In 53 patients with iron deficiency anemia and MCV < 70 fl CV always was > 14.0%. In 7 patients with α-thalassemia minor and MCV < 70 fl, CV was less than 14.0%, in all 7. Among patients with microcytosis, erythrography appears to be an excellent technique for rapidly distinguishing between iron deficiency and α or β thalassemia minor.