Academic journal article Environmental Health Perspectives

Humoral Immunity in Arsenic-Exposed Children in Rural Bangladesh: Total Immunoglobulins and Vaccine-Specific Antibodies

Academic journal article Environmental Health Perspectives

Humoral Immunity in Arsenic-Exposed Children in Rural Bangladesh: Total Immunoglobulins and Vaccine-Specific Antibodies

Article excerpt

Introduction

Exposure to inorganic arsenic through drinking water and certain food is a global public health concern. The arsenic problem is, perhaps, the most devastating in Bangladesh, where millions of hand-pumped tube wells yield drinking water with arsenic concentrations above the World Health Organization drinking water guideline value of 10 [micro]g/L (WHO 2004). Chronic exposure to arsenic, a well-documented carcinogen (IARC 2012), has been associated with numerous noncancer effects, including immunotoxicity (Dangleben et al. 2013; Ferrario et al. 2016). In particular, arsenic seems to inhibit the proliferation of peripheral blood mononuclear cells as well as separated pan T cells, particularly T-regulatory cells, in response to specific mitogens as shown in both children and adults (Biswas et al. 2008; Hernandez-Castro et al. 2009; Soto-Pena et al. 2006). We have also shown that prenatal arsenic exposure is inversely associated with placental T cells and thymic function in newborns (Ahmed et al. 2011; Ahmed et al. 2012; Raqib et al. 2009), and that childhood arsenic exposure is negatively associated with cell-mediated immune function (Ahmed et al. 2014), indicating arsenic-induced developmental immunotoxicity. Arsenic exposure may also impair the maturation, differentiation, and phagocytic function of macrophages as shown in arsenic-exposed adults with skin lesions compared to unexposed individuals (Banerjee et al. 2009). All these findings contribute to the growing evidence of increased risks of infectious diseases in relation to arsenic exposure, even at fairly low exposure levels (Farzan et al. 2016; Heaney et al. 2015; Rahman et al. 2010; Raqib et al. 2009; Smith et al. 2013).

Both T lymphocytes and macrophages are involved in the initiation of the humoral immune response by B lymphocytes (Abbas et al. 2012). Experimental studies on rodent splenocytes have shown that arsenic suppresses T-cell dependent antibody responses, as reviewed by Dangleben et al. (2013). Human data concerning the potential effects of arsenic on B cell-associated humoral immune function is, however, limited and inconclusive. Elevated concentrations of serum tIgG, tIgE, and tIgA were observed in arsenic-exposed Bangladeshi adults with skin lesions, compared to unexposed individuals (Islam et al. 2007), whereas no difference in cholera vaccine-specific IgG concentrations was found in children (2-5 years) living in high and low arsenic-exposed areas in Bangladesh (Saha et al. 2013). In this study we have followed up children born in a prospective mother-child cohort in Matlab, a rural area of Bangladesh with a wide range of arsenic exposure (Ahmed et al. 2014; Gardner et al. 2011). The aim was to evaluate whether prenatal and childhood arsenic exposure was associated with humoral immune function by measuring total plasma IgG, IgE, and IgA and measles, mumps, and rubella vaccine-specific plasma IgG concentrations following MMR vaccination in children at 9 years of age.

Materials and Methods

Study Area

The study was carried out in Matlab, a rural area of Bangladesh, where icddr,b has a health research and training center with a hospital and four subcenters. Here, icddr,b has been operating a health and demographic surveillance system (HDSS), covering a population of about 220,000 since 1966. Community health research workers update demographic and selected health information every 2 months.

The arsenic studies were initiated when it became apparent that elevated arsenic concentrations in groundwater were common in the study area (Rahman et al. 2006). More than 95% of the population use groundwater, retrieved from hand-pumped tube wells, as their main source of drinking water (icddr,b 2006). Screening of arsenic in all the functioning tube wells showed that 70% of the wells exceeded 10 [micro]g/L and 30% exceeded 200 [micro]g/L (Rahman et al. 2006; Vahter et al. 2006).

Study Design and Participants

The present study is part of our ongoing research in Matlab concerning the effects of arsenic and other contaminants in food and drinking water on pregnancy outcomes and child health and development (Ahmed et al. …

Search by... Author
Show... All Results Primary Sources Peer-reviewed

Oops!

An unknown error has occurred. Please click the button below to reload the page. If the problem persists, please try again in a little while.