Management of pregnancy complicated by anti-hrB/anti-HrB

Anti-hrB and anti-HrB are rare alloantibodies found predominantly in people of Black African descent. It has been assumed that strongly reacting examples of anti-hrB may cause hemolytic transfusion reactions, but precise information is limited. Anti-HrB is a clinically significant antibody and may cause hemolytic transfusion reactions and HDN. Selection of blood for transfusion support for patients with these alloantibodies, and especially with anti-HrB, imposes a special challenge in the United Kingdom. We report two antenatal patients (both patients were of the partial D phenotype DIII), one with anti-hrB, anti-Ce, and anti-D; the other,with anti-hrB and anti-D, who later formed anti-HrB. Transfusion support and the outcome of the pregnancies are discussed. A literature search confirms that,apart from some publications in abstract form,there is not much detailed clinical information available for either anti-hrB or anti-HrB. Further information and publications are warranted to gain more knowledge of these rare antibodies.