The carriage of pro-inflammatory cytokine gene polymorphisms in recurrent pregnancy loss

PROBLEM: Recurrent pregnancy loss (RPL) affects 2-4% of couples, and remain s largely unexplained. Recent studies have examined the role of cytokines i n the maintenance of normal pregnancy, which is linked with an increased ex pression of Th2 cytokines. Overexpression of Th1 cytokines is associated wi th RPL. Knowing that functional polymorphisms exist for certain cytokines, it has therefore been suggested that women with RPL may have a genetic pred isposition to overexpress Th1 cytokines. METHOD OF STUDY: The genes for interleukin-1 beta (IL-1 beta) and tumor nec rosis factor alpha (TNF-alpha) carry functional gene polymorphisms. In both cases these are biallelic polymorphisms that can be detected by polymerase chain reaction followed by restriction fragment length polymorphism. The a im of this pilot study was to assess whether carriage of the rarer alleles (TNF*2 and IL-1B*2) could act as independent risk factors in recurrent misc arriage. RESULTS: We found an increased incidence in the carriage of TNF*2, more pro nounced in those women with two or more miscarriages. Carriage of the IL-1B *2 either alone or in association with TNF*2 was not associated with recurr ent miscarriage. CONCLUSION: There may be a role for these cytokine gene polymorphisms in RP L.