Differences in Antigenic Specificity of Human Normal Adult, Fetal, and Sickle Cell Anemia Hemoglobin

1. Small differences in the antigenic structures of human normal adult hemoglobin and sickle cell anemia hemoglobin were found to exist. A difference in the serologic behavior of these two hemoglobins attributable to a factor other than that of antigenic specificity was also demonstrated. This factor is thought to pertain to differences in the physicochemical properties of the 2 hemoglobins.

2. Rabbit antiserums failed to show a difference in antigenic specificity, but with chicken antiserums a difference was clearly demonstrated when the in vitro reactions were performed under conditions which produced maximal precipitation. Results suggest that these 2 hemoglobins have a predominance of common antigenic determinants but a small number that are unique for each of the types.

3. Relatively large differences in specificity were found to exist between fetal hemoglobin and adult hemoglobin which suggest that only a few antigenic groups are shared in common by the 2 types.

4. The second, minor hemoglobin in patients with sickle cell anemia was shown to have an antigenic specificity that was either identical with or very similar to that of fetal hemoglobin.