Donor-specific transfusion with diminished sensitization.

: Fourteen mixed lymphocyte culture (MLC)-reactive haploidentical recipients have received donor specific transfusions (DSTs) with diminished sensitization to HLA antigens. A single unit of donor blood was obtained in CPD-A anticoagulant, packed, and transfused in three aliquots at 1-week intervals when the blood was 1, 3, and 5 weeks old. Transplantation, performed 22 to 149 days after the last DST, has been successful in all patients for 3 to 26 months except for one experiencing hyperacute rejection despite a negative crossmatch. In vitro studies suggest that blood storage results in the loss of T lymphocytes, which are presumably responsible for the sensitization, and preservation of B cells and monocytes, which remain capable of stimulating a cellular immune response in vitro throughout the 30-day storage period. Apparently this change in the cellular characteristics of blood with storage produces the salutory effects of blood transfusion without the undesirable sensitization to HLA antigens. The mechanisms remain under study.