Immune profile of women experiencing recurrent spontaneous abortions of unknown aetiology.

Immunological and immunogenetic investigations are described in a group of 28 women with a history of unexplained recurrent (greater than or equal to 3 consecutive) spontaneous abortions (RSA). Compared with female blood donor controls, recurrent aborters had significantly elevated mean serum complement C4 (p less than 0.05), but not C3, levels. Immunoglobulin levels and T4:T8 ratios showed a similar distribution to the controls. Mixed lymphocyte reactivities to partners' lymphocytes were low in some of the patients, but hyporesponsiveness correlated well with husband-wife HLA-DR compatibility. No individual HLA specificity was significantly increased in the RSA patients, but the combination A3, B7, DR2 was common (p less than 0.02), and general HLA antigen sharing with partners was significantly increased (p less than 0.004) relative to obstetrically normal couples. RSA women who shared two or more HLA antigens with spouses had higher mean serum immunoglobulin concentrations, which for IgM reached statistical significance (p less than 0.05).