Estimation of lymphocyte subsets and cytokine levels in workers occupationally exposed to cadmium

Introduction: Occupational exposure to Cadmium (Cd) may have serious health effect on workers. However, little is known about its effect on immune system. Moreover, previous studies have been inconclusive in stating the effect of Cd on immune system. The aim of our study was to estimate immune parameters in workers occupationally exposed to Cd. Material and methods: 110 individuals occupationally exposed to Cd and 97 apparently healthy non-exposed individuals were recruited for this study. Blood Cadmium levels were determined by AAS. Lymphocyte subset were analyzed using flow cytometry and the cytokine levels were determined by ELISA. Results: Exposed group have significantly higher levels of B-Cd. % of CD8 cells were higher in exposed while % of CD4 cells showed a decreasing trend in the exposed group. Among the CD3CD4 T cell subsets Th1 (%) and Tregs (%) cells were lower while Th17 (%) were higher in exposed group. Increased levels of IL-4 (Th2), IL-6 (Th2) and TNF-alpha (Th1) and decreased levels of IL-2 (Th1) and IL-10 (Tregs) were observed in Cd exposed workers which is indicative of a predominant pro-inflammatory response in Cd exposed workers. IL-17 (Th17) levels did not show any significant difference between the two groups. Increased Th17/Tregs ratio in the exposed group is also suggestive of an increased pro-inflammatory immune response in exposed group. Conclusion: To conclude, even low level of exposure to Cd in occupational settings is associated with alterations in Th17 cells, which may further predispose an individual to other systemic abnormalities.