A serologic study of red cells and sera from 18 Rh:32,-46 (RN/RN) persons.

The red cells (RBCs) and sera from 18 RN/RN persons were studied. The study confirmed the Rh type D+C+E-c-e+Cw-, which is characterized by an increased expression of the D antigen; a markedly decreased expression of the C and e antigens; the presence of a low-incidence antigen, Rh32; and the absence of a high-incidence antigen, Rh46, which is associated with an epitope recognized by a murine monoclonal antibody (MR432). Other Rh antigens of low and high incidence were investigated, and the presence of Rh17 and Rh44 on the RBCs was confirmed. Three persons exposed to Rh:46 cells by pregnancy or transfusion (or both) had anti-Rh46. This antibody gave positive reactions with all RBCs of common and rare Rh phenotype except Rhnull, and those of D--, D.., DCw-, and RN homozygotes. This antibody is considered to be of clinical significance in case of transfusion or pregnancy.