Effect of lead on the levels of some immunoregulatory cytokines in occupationally exposed workers

Abstract

<jats:p> Lead (Pb) may affect humoral and cellular immunity, acting on lymphocytes as well as on granulocytes and monocytes. Cytokines and nitric oxide (NO) play a central role in the immune balance. In this study, plasma levels of nitrites and nitrates (NOx), IL2, IL4, IL6, IL10, TNF-α and INF-γ, were measured in healthy workers with very low (Pb-B =3.2 -18.0 μg/dL) and low (Pb-B = 9.1 -46.0 μg/dL) Pb-exposure compared to non-exposed workers. Low Pb-exposed workers (Pb-B =9.1 -46.0 μg/ dL) were found to have significantly higher plasma IL-10 levels, and tendentially higher plasma TNF-α levels compared to non-exposed workers. This is the first report of a significant increase of plasma IL-10 levels in Pb-exposed workers. Plasma IL-10 increase was influenced by blood Pb levels even after correction for main confounding factors. No difference was found in plasma NOx levels between Pb-exposed and non-exposed workers, which is in agreement with previous findings exclusively regarding groups in the general population. Low Pb-exposure can induce an increase of pro-inflammatory cytokines, such as TNF-α, with a consequent increase of other cytokines, such as IL-10, considered a T cell cross-regulatory factor, suggesting possible interference of Pb in the system of immunophlogosis. Human &amp; Experimental Toxicology (2007) 26, 551 - 556 </jats:p>

Alteration of Th1/Th2/Th17 cytokine profile and humoral immune responses associated with chromate exposure

“…In addition, this system is one of the most sensitive targets for environmental pollutants or hazards and is regulated by many immune factors 7–9. Cytokines in this system are important immune response modulators but can be affected by metal exposure 10. Most cytokines are secreted by T helper (Th) cells and their measurement can provide feedback on differentiation regulation 11.…”

Ubiquitous hazardous metal lead induces TNF-α in human phagocytic THP-1 cells: Primary role of ERK 1/2

“…TNF-␣ is one of the principal mediators of the inflammatory responses in mammals, transuding deferential signals that regulate activation, proliferation and apoptosis at cellular levels [7]. Earlier studies identified the capacity of Pb to increase production of various pro-inflammatory cytokine mainly TNF-␣ among phagocytic cells of both animal and human [8][9][10][11][12], While the production of TNF-␣ can be elevated following exposure to lead, the expression of the receptor for TNF-␣ was also increased during the in vitro exposure of human blood monocytes to PbCl 2 [13]. Therefore, the combined effect of elevated cytokine production by macrophages and of increased receptor expression would be expected to contribute to problematic inflammatory responses.…”

Endoplasmic Reticulum Stress and Apoptosis Triggered by Sub-Chronic Lead Exposure in Mice Spleen: a Histopathological Study

“…If MZ does not work properly, inflammatory responses and auto-immune disorders may occur [65,66]. Finally, abnormal pro-inflammatory cytokines have been documented in Pb occupationally exposed workers [67].…”