Maternal CD46H*2 and IL1B-511*1 homozygosity in T helper 1-type immunity to trophoblast antigens in recurrent pregnancy loss

BACKGROUND: Women with recurrent pregnancy loss (RPL) and T-helper (Th)1-type immunity to trophoblast antigens have an increased frequency of the IL1B-511*1 promoter variant. Since CD46 gene products also regulate maternal immune responses including Th1 immunity, we investigated whether CD46 gene polymorphisms are also associated with RPL in women with and without Th1 immunity to trophoblast, and the possibility of a synergistic effect with the IL1B-511*1 promoter variant. METHODS: A case-controlled study was performed to document HindIII site polymorphism in intron 1 of the CD46 gene in 131 women with RPL and 72 fertile controls. Clinical information, Th1-type immune responsiveness to trophoblast in women with RPL history, and IL1B promoter allelo-types for this cohort were documented in a previous study. RESULTS: The frequency of the CD46H*2 allele and CD46H*2 homozygosity were significantly increased in women with RPL compared with fertile controls (P