Prospective study of anticardiolipin antibodies in immunized and untreated women with recurrent spontaneous abortions

Abstract

Objective: To investigate whether active leukocyte immunization increases levels of anticardiolipin antibodies in women with recurrent spontaneous abortions. To assess the impact of anticardiolipin antibodies on pregnancy outcome in these women.

Design: Patients who had received various treatments in an ongoing randomized trial were studied prospectively.

Setting: A department of clinical immunology investigating women with recurrent spontaneous abortions from all over Denmark.

Patients: Eighty-nine patients with unexplained recurrent spontaneous abortions whose pregnancies had been completed during the course of the trial.

Interventions: After randomization, 44 patients were actively immunized with husband's or third party leukocytes, and 27 patients received placebo. Eighteen patients received anticoagulation therapy in pregnancy.

Main outcome measures: Changes in levels of immunoglobulin (Ig)M class and IgG class anticardiolipin antibodies after active immunization. Frequency of new miscarriages in patients who were positive or negative for anticardiolipin antibodies.

Results: Neither IgM nor IgG anticardiolipin antibodies changed significantly after active immunization (P greater than 0.2). The interim results of the immunization trial showed a success rate of 68% in the treated group versus 56% in the placebo group (not significantly different). Relative risk of miscarriage in anticardiolipin antibody-positive patients compared with anticardiolipin antibody-negative patients was 1.3 (95% confidence interval 0.7 to 2.2; P = 0.4) in the combined study groups.

Conclusions: Patients eligible for active immunization did not exhibit significant changes in anticardiolipin antibody levels subsequent to the treatment. The treatment did not seem to provide any overall benefit with respect to pregnancy outcome. Prospectively, the risk of miscarriage in patients positive for anticardiolipin antibodies was not significantly increased.