Association between Chronic Environmental Lead (Pb) Exposure and Cytokines in Males and Females of Reproductive Age from Kabwe, Zambia

Abstract

Lead (Pb) poisoning remains a great public health challenge globally known to induce a wide range of ailments in both children and adults. The current study investigated the association of chronic environmental Pb exposure and immunomodulatory cytokines tumor necrosis factor alpha (TNF-α) and interleukin-8 (IL-8) in adult males and females living in Kabwe, Zambia. The standard human cytokine/chemokine Milliplex assay was used to quantify plasma cytokines from four groups categorized as low (<10 μg/dL) and high (>10 μg/dL) blood lead level (BLL) groups, namely, low BLL female (n = 47; BLL = 3.76 μg/dL), low BLL Male (n = 43; BLL = 4.13 μg/dL), high BLL female (n = 21; BLL = 23.5 μg/dL), and high BLL male (n = 18; BLL = 23.7 μg/dL), respectively. The low BLL group was associated with increased TNF-α levels, and the high BLL group was associated with reduced TNF-α levels in female subjects. No associations between BLL and the levels of IL-8 and TNF-α cytokines were observed in either females or males, respectively. A negative correlation between BLL and TNF-α was found in female subjects, suggesting that an increase in BLL accompanied by a reduction in TNF-α. The reduced levels of circulating TNF-α in female subjects suggest that chronic Pb exposure could predispose females to immune and inflammation-related disorders than their male counterparts. Further studies are recommended to ascertain the impact of chronic Pb exposure on immunomodulatory cytokines, especially in females.