STUDIES ON BLOOD FACTORS RhA, RhB, AND RhC

Abstract

Observations are described of the incidence among Caucasians and Negroes of the blood factors Rh^A, Rh^B and Rh^C which occur associated with the Rh₀ factor in typical Rh-positive blood. The antiserums used for the tests were derived from Rh-positive patients who had had hemolytic transfusion reactions or erythroblastotic babies. Among a large series of individuals, it was found that only rarely is any of the blood factors Rh^A, Rh^B, or Rh^C lacking from "standard" Rh₀-positive blood. On the other hand, about half of the specimens of Rh₀ variant blood lack one or more of the factors Rh^A, Rh^B, and Rh^C, which, when present in such blood, are also almost always variants. Judging from the incidence of specimens lacking one or more of these factors, Rh^A, Rh^B, and Rh^B appear to be relatively independent of one another despite their association with blood factor Rh₀. Tests for factors Rh^A, Rh^B, and Rh^C distinguish new rare varieties of Rh and ℜh agglutinogens, each genetically determined by corresponding allelic genes.