Polychlorinated biphenyls, mercury, and antinuclear antibody positivity, NHANES 2003–2004

Serum antinuclear antibody positivity (ANA) has been associated with elevated serum polychlorinated biphenyls (PCBs) among residents in PCB-polluted areas; however, associations in general populations have not been reported by congener type or with adjustment for mercury. Cross-sectional data on serum PCBs, total blood mercury, ANA, and potential confounders age, race, body mass index, menopausal status, and dietary eicosapentaenoic acid (EPA) were obtained from the 2003–2004 National Health and Nutrition Examination Survey (NHANES) for males and females aged 12–85. PCB congeners were summed separately for dioxin-like and nondioxin-like PCBs; the former were weighted for toxic equivalent factors. Total PCBs by congener type and mercury were analyzed as both continuous log-transformed variables and as categorical quintiles. Logistic regression models were stratified by sex. There were no associations between nondioxin-like PCBs or mercury and ANA among males or females. Among females (n = 114 affected and 518 unaffected), adjusting for potential confounders, the prevalence odds for ANA positivity were significantly elevated per incremental increase in log-transformed dioxin-like PCBs (odds ratio {OR} = 1.66; 95% confidence interval {CI} = 1.24, 2.23); the highest dioxin-like PCB quintile (>0.00425–0.04339 ng/g) was significantly associated with 4.04 (95% CI = 2.43, 6.70) greater prevalence odds for ANA positivity relative to the lowest quintile (Ptrend < 0.001). We present novel findings of an association between low-level dioxin-like PCBs and ANA among women. No associations were observed between mercury and ANA at mercury levels common to the U.S. population.