Influence of histocompatibility antigens in recurrent spontaneous abortion and its relevance to leukocyte immunotherapy.

A total of 108 couples with recurrent spontaneous abortion (RSA) were studied to investigate the possible influence of histocompatibility antigens (HLA) on their condition and its management. HLA-B18 was shown to be at a higher frequency in RSA women, but not significantly so after statistical correction. Just over half the RSA women shared two or more HLA-A, B or DR antigens with their partners (P < 0.01), but this group did not differ from the others in clinical or laboratory features, nor in subsequent pregnancy success rate. Leukocyte immunotherapy in which the donor shared at least one HLA-DR antigen with his partner was not associated with a significant improvement in subsequent pregnancy outcome compared with HLA-DR mismatched immunotherapy. HLA antibody production following leukocyte immunotherapy was influenced by both inoculum size and degree of HLA incompatibility, but had no effect on birthweight. Tissue-typing investigations are not indicated for individual RSA patients seeking advice or treatment.