FcγRIIB polymorphisms, periodontitis and preterm birth in Japanese pregnant women

Recently, numerous studies have investigated the association of preterm birth with periodontitis. FcγRIIb is a human low-affinity receptor for immunoglobulin G (IgG). We have previously demonstrated single nucleotide polymorphisms (SNPs) of FcγRIIb to be associated with periodontitis and the serum-specific IgG level against periodontopathic bacteria. In this study, we investigated whether FcγRIIB gene polymorphisms were associated with periodontitis and/or pregnancy outcome.

We assessed the periodontal conditions of 122 Japanese pregnant women within 5 d of delivery, and polymorphisms in FcγRIIB and in other Fcγ receptors were detected from the genomic DNA. Using clinical and genomic data, we analyzed the relationship between periodontitis, preterm birth and Fcγ receptor polymorphisms.

A significant difference was observed in the distribution of FcγRIIB-nt645+25A/G (rs2125685) between preterm and term birth groups, with a higher prevalence of nt645+25AA in the preterm birth group (p = 0.032). Additionally, the FcγRIIB-nt645+25GG carrier showed significantly higher results for the prevalence of periodontitis (p = 0.048), mean pocket depth (p = 0.021), mean clinical attachment level (p = 0.010), percentage of sites with pocket depth ≥ 4 mm (p = 0.005) and percentage of sites with clinical attachment level ≥ 3 mm (p = 0.007) than the AA carrier. An association between preterm birth and periodontitis was not observed in this study.

These findings suggest that FcγRIIB-nt645+25AA carriers are more likely to experience preterm birth than FcγRIIB-nt645+25AG and GG carriers. Also, women with FcγRIIB-nt645+25G exhibited a greater tendency to have periodontitis than those with nt645+25A.