Prenatal Exposure to Perfluoroalkyl Substances and Isomers Link to Depressed Toxoid Antibody Responses in Early Childhood: Guangzhou Birth Cohort Study

Abstract

Background/Aim: Perfluoroalkyl and polyfluoroalkyl substances (PFASs) are ubiquitous and persistent environmental chemicals and are suggested to have immunosuppressive effects. Studies indicate that prenatal exposure to PFAS may lead to suppressed immune responses in early life. However, human studies of immune effects are inconsistent. In this study, we aim to assess the association between prenatal exposure of PFASs with isomers and serum antibody concentrations against measles, coxsackievirus A 16 (CA16) and enterovirus 71 (EV71) toxoids in newborn and infant at 3 months. Methods: We recruited 295 pairs of mothers and their infants in Guangzhou Birth Cohort Study, China from July to October 2013. Measles IgG antibody was examined using ELISA assay, neutralizing antibodies titers against CA16, EV71 toxoids were performed in cord blood serum and infant aged 3 months, respectively. A PFAS isomer-specific analysis method based on high performance liquid chromatography-mass spectrometry (HPLC-MS/MS) was applied to determine the PFASs and isomers concentration in cord blood serum. Results: For measles antibody, PFOA showed the strongest negative correlations with toxoid antibody concentration in newborn and 3-month infant. A doubling of lnPFOA level (ng/ml) increasing among newborn and 3-m infant was associated with a difference of -24.4% (95% CI: -30.7, -17.5) and -33.3% (95% CI: --43.9, -20.6) in measles antibody concentration, respectively. A doubling ln-unit (ng/ml) increase in total branch PFOS isomers in 3-month infant was associated with higher odds ratio of 1.70 (95%: 1.03, 2.79) and 2.49 (95%, 1.45, 4.28) than that with linear PFOS for falling below a clinically protection level (<1_8 titers) for CA16 and EV71 antibody, respectively. This association was more obvious in boys than in girls. Interestingly, we observed that long-chain PFASs, such as perflouorotetradodecanoic acid (PFDoDA) and perfluoroundecanoic acid (PFUnDA) exposure were negatively associated with measles, CA16 and EV71 antibody level in both newborn and 3-month infant. Conclusions: Elevated prenatal exposures to PFASs, including long-chain PFASs were associated with depressed toxoid antibody response in newborn and infant. Branch isomer shows higher impact on CA16 and EV71 antibody level in 3-month infant for bellowing clinical protection.