The Rh Antigen D: Partial D Antigens and Associated Low Incidence Antigens

Open Access
Publisher Website
Google Scholar
Abstract
The expression of the Rh antigen D varies quantitatively and qualitatively (partial D); published information and 15 years' work studying D variants are discussed in this review. D epitopes correspond to the reaction patterns of monoclonal anti‐D with partial D antigens. Partial D antigens can be reported in terms of their D epitopes but the epitope profile of cells with a quantitative variant of D (weak D) is difficult to determine reliably by haemagglutination tests. Nine partial D antigens, categories II‐VII, DFR and two not previously reported, are identified by their epitope profiles and by association with low incidence antigens. Monoclonal anti‐D recognize 16 D epitopes and more epitopes are anticipated. The specificities of polyclonal anti‐D made by people with partial D antigens are considered in terms of possible D epitope specificities: recognized epitope specificities, or combination thereof, were not able to account for all observed reaction patterns of anti‐D made by immunized individuals with partial D pheno‐types. An attempt is made to understand partial D antigens and their associated low incidence antigens in terms of the molecular genetic information available.