Arsenic exposure and hepatitis E virus infection during pregnancy

Abstract

Background: Arsenic has immunomodulatory properties and may have the potential to alter susceptibility to infection in humans.

Objectives: We aimed to assess the relation of arsenic exposure during pregnancy with immune function and hepatitis E virus (HEV) infection, defined as seroconversion during pregnancy and postpartum.

Methods: We assessed IgG seroconversion to HEV between 1st and 3rd trimester (TM) and 3 months postpartum (PP) among 1100 pregnancies in a multiple micronutrient supplementation trial in rural Bangladesh. Forty women seroconverted to HEV and were matched with 40 non-seroconverting women (controls) by age, parity and intervention. We assessed urinary inorganic arsenic plus methylated species (∑As) (µg/L) at 1st and 3rd TM and plasma cytokines (pg/mL) at 1st and 3rd TM and 3 months PP.

Results: HEV seroconverters' urinary ∑As was elevated throughout pregnancy. Non-seroconverters' urinary ∑As was similar to HEV seroconverters at 1st TM but declined at 3rd TM. The adjusted odds ratio (95% confidence interval) of HEV seroconversion was 2.17 (1.07, 4.39) per interquartile range (IQR) increase in average-pregnancy urinary ∑As. Increased urinary ∑As was associated with increased concentrations of IL-2 during the 1st and 3rd TM and 3 months PP among HEV seroconverters but not non-seroconverters.

Conclusions: The relation of urinary arsenic during pregnancy with incident HEV seroconversion and with IL-2 levels among HEV-seroconverting pregnant women suggests arsenic exposure during pregnancy may enhance susceptibility to HEV infection.

Trial registration: ClinicalTrials.gov NCT00860470.

Keywords: Arsenic; Cytokines; Hepatitis E virus; Immunotoxicity; Infection; Pregnancy.

Conflict of interest statement

Competing interests

All authors report no competing or conflict of interest.

Copyright © 2015 Elsevier Inc. All rights reserved.

Figures

Fig. 1

Trends of inorganic arsenic plus methylated species (∑As) concentration (µg/L) in urine during the 1st and 3rd trimester (TM) of pregnancy among: A. HEV seroconverting (n = 40) and B. non-seroconverting (n = 39) women. Gray lines depict individual trajectories for each pregnant woman and the black line denotes the median trajectory within each group. Note. The p-value shown compares 1st and 3rd TM urinary ∑As derived from Fisher's exact test of the equality of medians. The beta (standard error), p-value from a linear mixed model of the temporal association between trimester (3rd vs 1st) and ln-transformed ∑As concentration (µg/L) was −0.27 (0.13), p < 0.04 among HEV seroconverters and −0.34 (0.11), p < 0.003 among non-seroconverters.