The critical role of blood from HLA-homozygous donors in fatal transfusion-associated graft-versus-host disease in immunocompetent patients.

Fatal transfusion-associated graft-versus-host disease developed in a 69-year-old woman with colon cancer who underwent elective hemicolectomy. During the perioperative period, she was transfused with 4 units of nonirradiated fresh whole blood less than 6 hours after the blood was donated by family members. She was immunocompetent and was not treated with any immunosuppressive agents such as corticosteroids, chemotherapy, or irradiation therapy. The implicated donor was thought to be her daughter, who was homozygous for an HLA haplotype that was shared with the recipient: A24, Bw52, CBL, DR2. This is the most common haplotype in the Japanese population. This case and others in the Japanese literature indicate that the transfusion of fresh, nonirradiated blood that contains immunocompetent lymphocytes and peripheral hematopoietic precursor cells from HLA-homozygous donors can be lethal to the recipient.