Management of pregnancy complicated by anti-hr^B/anti-Hr^B

Anti-hr^B and anti-Hr^B are rare alloantibodies found predominantly in people of Black African descent. It has been assumed that strongly reacting examples of anti-hr^B may cause hemolytic transfusion reactions, but precise information is limited. Anti-Hr^B 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-Hr^B, 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-hr^B, anti-Ce, and anti-D; the other, with anti-hr^B and anti-D, who later formed anti-Hr^B. 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-hr^B or anti-Hr^B. Further information and publications are warranted to gain more knowledge of these rare antibodies. Immunohematology2007;23:143–5.