DNA-BASED HLA TYPING OF NONHEMATOPOIETIC TISSUE USED TO SELECT THE MARROW TRANSPLANT DONOR FOR SUCCESSFUL TREATMENT OF TRANSFUSION-ASSOCIATED GRAFT-VERSUS-HOST DISEASE

Transfusion-associated graft-versus-host disease (TAGVHD) is a rare an d usually fatal complication of blood transfusion which can arise when immunocompetent lymphocytes from the donor of a cellular blood produc t are transfused into a severely immunocompromised recipient. We descr ibe the case of an 8-month-old male with a severe combined immunodefic iency syndrome who developed TAGVHD after receiving an unirradiated tr ansfusion. Serologic HLA typing of the parents, the patient, and the b lood donor demonstrated the foreign origin of circulating lymphocytes, confirming the diagnosis of TAGVHD. The manifestations of TAGVHD did not respond to medical immunosuppressive therapy, and bone marrow tran splantation was planned to treat the underlying immunodeficiency as we ll as the TAGVHD. By using DNA-based class I and class II HLA typing, the child's HLA type was determined from nonhematopoietic tissues. Thi s information proved critical in selecting the bone marrow donor. The child received immunosuppression, myeloablation, and a T-depleted, mat ernal bone marrow graft mismatched at one HLA class II allele. Triline age hematopoietic engraftment occurred within 3 weeks, and the child r emains clinically stable with no evidence of TAGVHD more than 2 years after the transplant. This case illustrates that TAGVHD can be success fully treated by allogeneic bone marrow transplantation and that DNA-b ased HLA typing can play a unique role in the diagnosis and management of TAGVHD.