HLA status following fetal liver transplantation in aplastic anaemia and acute myeloid leukaemia.

Fetal liver infusion (FLI) was tried as an alternate mode of therapy in 40 patients with aplastic anaemia and in 16 patients with acute myeloid leukaemia. The fetal HLA typing carried out on spleen and thymus cells revealed that, while it was more difficult to HLA type the thymus than the spleen cells, 'full house' antigens could be determined only in fetuses of 18 weeks or older. No special effort was made to transfuse HLA- matched or partially matched donor cells into the recipient. The recipients were HLA typed at varying time intervals following FLI in an attempt to document a possible chimerism. None of the patients revealed a 'shift' in their HLA antigen profile and there was no evidence of any donor cell engraftment. No relationship between the HLA match of donor and recipient, and the general condition, the prognosis or the total survival of the patient was evidenced. These data indicate that, even though fetal liver cells express HLA antigens, these cells are functionally incompetent to cause an apparent graft-versus-host disease in the host.