[Anti-RH1 (anti-D) alloimmunization after transfusion of platelet concentrates from RH :1 donors]

Anti-erythrocyte alloimmunization may occur following the transfusion of platelet concentrates, in response to the presence of residual erythrocytes. Immunization against RH1 (D) antigen is the most frequent, but transfusion of RH1 compatible platelet concentrates is not always possible because of supply constraints. We report here three cases of anti-RH1 (anti-D) alloimmunization in RH :-1 patients after transfusion of platelet concentrates from RH :1 donors. Criteria for selection of platelet concentrates are numerous and difficult to achieve in practice. Respect of RH1 compatibility is not obligatory, but in case of transfusion of RH1 incompatible platelet concentrates, anti-RH1 immunoprophylaxis must be made for RH :-1 women of child-bearing age and without profound immunosuppression, as recommended by Afssaps (Agence française de sécurité sanitaire des produits de santé). These data point out the need to perform post-transfusional screening test for irregular erythrocyte antibodies as part of the transfusion of platelet concentrates.