HLA sharing in couples with recurrent abortion.

To investigate the interactions between HLA region and recurrent abortion we examined the HLA-A and HLA-B antigen frequencies, the degree of HLA sharing, and the incidence of anti-HLA antibodies in 18 recurrent abortion and in 23 control couples. HLA antigens with low distribution (less than 25% of phenotype frequencies in the general population) represent 38.5% of the HLA antigens shared between recurrent abortion partners. No antibodies against partners' HLA antigens were detected in recurrent abortion women, while such antibodies were present in 39.1% of control women (p = 0.002).