Observations on the Minor Basic Hemoglobin Component in the Blood of Normal Individuals and Patients with Thalassemia

Abstract

The minor hemoglobin component (A2) of normal blood was readily separated from the main hemoglobin fraction by various procedures of zone electrophoresis. In the isolated form it showed all the usual characteristics of a true hemoglobin. The shifts in the absorption spectrum obtained with various derivatives were similar to those obtained with hemoglobin A. A close resemblance in sedimentation coefficient, solubility, and immunological properties was found for these hemoglobins. A2 hemoglobin was in the blood of all of approximately 300 normal adult individuals but was absent or greatly reduced in newborn infants. A similar component was found in the blood, of certain other primates, but not in other animals. Quantitation of the A2 component revealed elevated levels only in individuals with thalassemia. A mean level of 5.11 [plus or minus] 1.36 % compared to the normal of 2.54 [plus or minus] 0.35 % was obtained for a series of 34 carriers of the thalassemia trait. The highest values were obtained in two patients classified as intermediate forms of thalassemia. Children with Cooley''s anemia showed considerable variation with most values falling in the normal range.