Manganese is associated with increased plasma interleukin-1β during pregnancy, within a mixtures analysis framework of urinary trace metals.

• Multiple urinary trace metals were associated with immune biomarkers. • Manganese, barium, and nickel were positively associated with interleukin-1β. • Mixtures analysis identified manganese as most predictive of interleukin-1β. • Association between manganese and interleukin-1β was greater in women with a female fetus. Exposure to trace metals may impact reproductive health outcomes through perturbations in maternal immune signaling molecules. We conducted a cross-sectional study of 390 pregnant women from the LIFECODES birth cohort and investigated the associations between 17 urinary metals and five immune biomarkers measured in the 3rd trimester (median 26 weeks gestation). We used linear regression to estimate pair-wise associations and applied elastic net and Bayesian kernel machine regression to identify important contributing exposures analytes as well as non-linear effects. Maternal urinary manganese, nickel, and barium were positively associated with maternal plasma interleukin-1β (IL-1β). Elastic net and Bayesian kernel machine regression identified manganese as the dominant trace metal in association with IL-1β. An interquartile range difference in manganese (0.6 μg/L) was associated with a 29 % increase in IL-1β (95 % CI: 12.4–48.2). In conclusion, trace metal exposures were associated with biomarkers of immune perturbations, and this warrants further investigation. [ABSTRACT FROM AUTHOR]