Cross-sectional analysis of Toll-like receptor variants and bacterial vaginosis in African-American women with pelvic inflammatory disease

Objective Bacterial vaginosis (BV) is a common condition associated with serious complications including pelvic inflammatory disease (PID). However, the pathogenesis of BV is poorly understood. Toll-like receptors (TLR) are responsible for microbial recognition and elimination through inflammatory responses. TLR variants have been implicated in infectious and inflammatory diseases and may be involved in BV pathogenesis. We conducted a cross-sectional study to determine if TLR variants are associated with BV. Methods Logistic regression was used to test associations between 14 variants assayed in 6 genes (TLR1, TLR2, TLR4, TLR6, TIRAP and MyD88) and BV/intermediate flora among 192 African-American women with clinical PID from the PID Evaluation and Clinical Health (PEACH) Study. Additionally, we examined associations between variants and endometrial BV-associated anaerobes. To account for multiple comparisons a permutated p< 0.003 was used to determine statistical significance. Results African-American women with PID carrying the AA genotype for TLR2 SNP rs1898830 had a threefold increased rate of BV/intermediate flora (OR 2.9, 95% CI 1.2 to 7.3). This was not significant after accounting for multiple comparisons (p= 0.0201). TLR2 variants rs1898830, rs11938228 and rs3804099 were associated with increased endometrial anaerobic gram-negative rods (p= 0.0107, p= 0.0076 p= 0.0121), anaerobic non-pigmented Gram-negative rods (p= 0.0231, p= 0.0083, p= 0.0044), and anaerobic Gram-positive cocci (p= 0.0596, p= 0.0640, p= 0.1459). Conclusions Among African-American women with PID, we observed trends between TLR2 variants, BV/intermediate flora, and BV-associated microbes. This provides some insight into BV pathogenesis. As not all BV-associated microbes may lead to pathology, future studies should focus on associations between TLR variants and individual BV-associated microbes.