Red blood cell alloimmunisation after platelet transfusion (excluding ABO blood group system).

Red blood cell alloimmunisation after transfusion of red blood cell concentrates carries a risk for every recipient. This risk is particularly high for patients with conditions such as sickle cell disease. However, red blood cell alloimmunisation can also occur after platelet concentrate transfusion. All blood group systems other than ABO are affected, and there are several mechanisms responsible for this alloimmunisation. The practical implications of this are a need to match red blood cell concentrates in all alloimmunised patients and, in pregnant women, recongnition of the risk of developing haemolytic disease of the foetus and newborn. Several measures can be taken to prevent alloimmunisation: in the case of the D antigen, for example, anti-RhD immunoglobulins can be infused before transfusing platelet concentrates from an RhD-positive donor in a RhD-negative recipient.