Blood doping in athletes--detection of allogeneic blood transfusions by flow cytofluorometry.

Athletes may undergo blood transfusion to increase their red cell mass and the oxygen carrying capacity of their blood in order to confer a competitive advantage. Allogeneic transfusions are normally mismatched at one or more minor blood group antigens. The most sensitive and accurate method known to detect this form of blood doping is flow cytometry. Low percentages of antigen-positive and antigen-negative red blood cells (RBCs) can be quantitated using suitable specific alloantibodies and careful analysis. By testing blood samples taken at various times, a reduction in the percentage of a minor population of RBCs will indicate transfusion has occurred.