Prevention of transfusion-associated graft-vs-host disease.

Transfusion-associated graft-vs-host disease (GVHD) occurs in certain immunocompromised recipients receiving viable lymphocytes in blood and components. Transfusion-associated GVHD affects the skin, liver, gastrointestinal tract, and most importantly, the bone marrow, and results in death in more than 90% of affected patients. The best means to prevent transfusion-associated GVHD is prophylactic irradiation of blood and components to inactivate contained lymphocytes. A dose of 15 Gy delivered by a self-contained cesium 137 irradiator is sufficient to prevent transfusion-associated GVHD. Engraftment of transfused lymphocytes may occur because of HLA similarity between donor and recipient. The HLA differences, however, then facilitate rejection of the host by the engrafted lymphocytes and thus make easier the development of transfusion-associated GVHD or the Japanese equivalent, postoperative erythroderma.