Susceptible perinatal windows to arsenic exposure and serum antibody levels in children

Several cohorts have documented potential immunotoxic effects of arsenic in pediatric populations, however, the identification of susceptible windows to arsenic exposure remains poorly investigated in relation to vaccine-specific antibody responses. The present study examines perinatal windows of susceptibility to arsenic exposure associated with antibody levels against MMR (measles, mumps, rubella) and DTP (diphtheria, tetanus, pertussis) vaccine antigens. Weekly arsenic exposure from the 16 weeks before birth through age 14 weeks postnatally was retrospectively quantified in the deciduous teeth of 289 PROGRESS Mexican children. Serum antigen-specific immunoglobulin G (IgG) antibody levels to MMR and DTP were assessed via a multiplexed Luminex bead-based immunoassay at the 5-year follow-up visit. Time-varying associations between log2-transformed dentine arsenic concentrations and log2-transformed antibody levels were modeled using Distributed Lag Non-linear Models (DLNMs) adjusted for age, maternal education, parity, child sex. Additional analyses included effect modification by child sex and breastfeeding status at 1 month postpartum. DLNMs identified a statistically significant adverse window of susceptibility around birth: a doubling arsenic exposure in the period from one week before to six weeks after birth for anti-measles antibody levels (-5.62; 95% CI: -8.39; -0.83) and anti-rubella antibody concentrations (-3.85; 95% CI: -6.99; -0.63). Associations between perinatal arsenic exposure and antibody levels against mumps, diphtheria, tetanus, or pertussis were not observed. We did not find any heterogeneity by sex or breastfeeding status. Around birth, a critical window of arsenic exposure was significantly associated with decreased anti-measles and anti-rubella antibody levels at the 4-year visit.