The clinical implications of platelet transfusions associated with ABO or Rh(D) incompatibility

Despite the time elapsed since their development, and substantial human and economical efforts searching for alternatives, platelet transfusion, continues to be the main therapeutic measure available for the management of patients suffering from quantitative and qualitative platelet disorders. However, there are still aspects of their use that are not completely established. One of these is ABO and/or Rh(D) compatibility. A major ABO group incompatibility appears to decrease the response to a platelet transfusion, whereas a minor ABO incompatibility can be associated with, sometimes lethal, acute hemolytic transfusion reactions in the recipient. Other detrimental effects on the recipient of a minor ABO incompatibility have also been reported. In contrast, the main problem associated to a Rh(D) incompatible platelet transfusion is the development of alloimmunization of a Rh(D)-negative woman in childbearing age or younger. Factors like degree of patient immunosuppression and red blood cell content in the platelet concentrate significantly modulate the risk of alloimmunization. New clinical studies are needed to define clearly the current risk associated to ABO- and/or Rh(D)-incompatible platelet transfusions, and such defined risks would help establish the most cost effective measures to prevent the appearance of the potential complications related to platelet use.