THE EFFECTIVENESS OF ALLOGENEIC LEUKOCYTE IMMUNIZATION IN UNEXPLAINEDPRIMARY RECURRENT SPONTANEOUS-ABORTION

PROBLEM: Unexplained primary recurrent spontaneous abortion (RSA) can be viewed as a partner-specific problem for which immunization with al logeneic leukocytes is being offered as therapy. Published data from r andomized controlled trials have produced conflicting results regardin g treatment effectiveness. The aim of this study was to perform a subg roup analysis of the data from a recent worldwide collaborative meta-a nalysis using the raw data for patients with primary RSA entered into randomized controlled trials of immunotherapy. METHODS: Data from rand omized controlled trials in eight centers were included in this analys is. Individual patients were included only if they had had three or mo re spontaneous abortions, no previous pregnancy beyond 20 weeks' gesta tion, no identifiable cause for the abortions, and no evidence of anti paternal antibodies. Meta-analysis by centre and logistic regression a nalysis were performed to determine the overall effect of treatment in achieving live birth and to identify variables that affect the progno sis for a successful outcome. RESULTS: In the meta-analysis by center, immunotherapy significantly improved the live birth rate (common odds ratio = 1.94, 95% confidence interval (CI) = 1.20 to 3.12). In the an alysis by patient, the likelihood of a successful outcome was also sig nificantly better with treatment (relative risk = 1.46, 95% CI 1.19 to 1.69). The absolute treatment effect was 16.3% producing a number nee ded to treat of 6. The number of previous abortions had a significant negative correlation with live birth rate, such that for each addition al pregnancy loss beyond three, the likelihood of live birth was reduc ed by 23%. CONCLUSION: Allogeneic leukocyte immunization is an effecti ve treatment for unexplained primary RSA when pretreatment antipaterna l antibodies are absent. Better diagnostic tests are required to ident ify patients who may derive maximal benefit from this therapeutic appr oach.