Sensitization against non-HLA antigens following bone marrow graft rejection.

A patient with severe aplastic anemia rejected consecutive bone marrow transplants from two HLA-identical sibling donors. Following rejection, the patient developed antibodies that reacted strongly against donor lymphocytes in the complement-dependent cytotoxicity assay. Whereas the reactivity was initially directed specifically against the first marrow donor, cells of both donors and most unrelated individuals were killed by sera obtained after the second injection. These sera were also cytotoxic to the patient's own pre-transplant cells but not to her autologous post-transplant lymphocytes.