Treatment of severe combined immunodeficiency with bone-marrow from an unrelated, mixed-leucocyte-culture-non-reactive donor.

A 7-month-old boy with severe combined immunodeficiency had no relative who was a suitable bone-marrow donor as determined by mixed-leucocyte-culture (M.L.C.) testing. In the general population an M.L.C.-nonreactive, unrelated donor was found among individuals who were identical with our patient at the Four locus. Following a bone-marrow transplant this child showed signs of rapid immunological reconstitution and only a mild graft-versus-host reaction. Unfortunately, the child died 31 days post-transplantation of cytomegalovirus infection. The findings support the hypothesis that matching for lymphocyte-defined antigens among unrelated individuals will permit successful immunological reconstitution.