P34 Management of Pregnancy Complicated by Anti‐hrB and/or Anti‐HrB.

Abstract

Anti‐hrB and anti‐HrB are rare alloantibodies, so far found exclusively in people of Black African descent. There is no data available regarding haemolytic transfusion reactions in association with anti‐hrB, and precise information is limited. Anti‐HrB may cause transfusion reactions, but no data is available. Selection of blood for transfusion support for patients with these alloantibodies imposes a special challenge in the UK, as, in the case of anti‐hrB (if accompanied with anti‐D) it is difficult to locate suitable antigen negative blood, whilst HrB‐ blood is almost unknown amongst the UK donor population. Two antenatal cases are reported, one with anti‐hrB, and one with anti‐HrB. Weak anti‐D was also identified in the serum in both cases. For the former case, r“r” ( dcE/dcE) units were provided to cover the delivery. The baby was delivered by vaginal route. Cord sample DAT was negative, with no evidence of haemolytic disease of the newborn (HDN). The patient did not require transfusion. The patient was known to have anti‐hrB in her previous pregnancy, and there was no evidence of HDN in that pregnancy. Anti‐HrB may cause haemolytic transfusion reaction. In the latter case, there are two options: either to import extremely rare D‐, HrB blood from South Africa or to provide rare Rhnull units. The patient received two Rhnull units to cover for Caesarean Section and transfusion was uneventful. Although the cord sample DAT was positive (Anti‐IgG 2+, ‐C3d1+) the infant's delivery Hb level was 15.2 g dL‐1 and bilirubin was within the normal range. No therapy was required. A literature search confirms that there is not much data available regarding the clinical significance of anti‐hrB and anti‐HrB. The few previous reports indicate that both anti‐hrB and anti‐HrB appear not to cause HDN. Our cases supported that HDN is not associated with both anti‐hrB and anti‐HrB. The cases reported here illustrate the complexity in providing transfusion support for these patients. Further case reports are warranted to establish the clinical relevance of these rare antibodies.