Alterations in humoral immune responses associated with recurrent pregnancy loss

Objective: To investigate the reactivity of maternal antibodies with endometrium-derived antigens and to correlate their association with recurrent pregnancy loss (RPL). Design: Prevalence study. Setting: Academic research center. Patient(s): Nulliparous women (n = 10), women with RPL (n = 15), pregnant women (n = 8), and multiparous women with a normal obstetric history (n = 20). Intervention(s): None. Main Outcome Measure(s): Reactive antibodies were analyzed by Western immunoblot techniques and quantitated by densitometry. Result(s): Antibodies from women with RPL and multiparous women recognized antigens ranging from 10-120 kd on normal endometrium and endometrial tumors. Antibodies from most women with RPL (10/15) and from multiparous women (15/20) recognized 65-kd and 80-kd proteins in normal endometrium. Antibodies from women with RPL recognized 21-kd and 28-kd antigens (12/15 and 13/15, respectively) in endometrial tumors at a significantly greater rate (than did antibodies from multiparous women (5/20 and 8/20, respectively). Women with RPL had significantly lower levels of asymmetric IgG compared with controls. Conclusion(s): Recurrent pregnancy loss may be linked with the failure to elicit asymmetric IgG and a unique immunologic recognition of endometrial antigens. (Fertil Steril(R) 2000;73:305-13. (C) 2000 by American Society for Reproductive Medicine.)