[One-way matching of HLA antigens between recipient and donor as a risk factor of transfusion-associated GVHD]

Clinical aspects, pathogenesis and risk factors of transfusion-associated graft versus host disease(TA-GVHD) are summarized. TA-GVHD should be suspected when fever, rashes, diarrhea, liver dysfunction and marrow aplasia occurred 14-30 days after blood transfusion. Almost all the patients suffering from this complication died from severe pancytopenia and grave infection in spite of intensive treatments. Although TA-GVHD have been thought as a rare disease which occurs only in immunosuppressed patients, it is clear now that TA-GVHD may also occur even in immunocompetent patients, in case of so called one-way matching pair of HLA antigens between recipient and donor. When they receive blood without any different HLA antigens from their own, they can neither recognize it non-self nor reject it and at last they may suffer from TA-GVHD. One-way matching of HLA antigens between recipient and donor is important as a risk factor of TA-GVHD especially in immunocompetent patients. Though there is no effective treatment after the onset of this complication, both autologous transfusion and irradiation of blood before transfusion are known to be clearly effective to prevent this complication.