Mechanism of Nickel and Chromium-Induced Immunotoxicity and Oxidative Stress: A Comparative Study

Introduction: Chromium (Cr) and Nickel (Ni) are examples of commonly used industrial substances with negative long time exposure on human health. One mechanism whereby metals can alter health is through modulation of immune homeostasis. They are capable of producing oxidative stress and it is possible that this oxidative stress contributes to the carcinogenic response of these metals. Aim of the Work: The aim of this study is to highlight the possible immunotoxic potential of both Cr and Ni in occupa-tionally exposed workers, to investigate the oxidative stress and their potential effects on glutathione peroxidase (GPx) among workers exposed to both metals during electroplating process. Material and methods: The study was carried out in a hot oven factory in electroplating sector in 6th October city. The studied population included randomly selected 28 workers exposed to chromium, 12 workers exposed tonickel and 20 workers not exposed to any metal as controls. Thorough present and past history were taken. Full clinical examination was performed. Both groups were matched as regards the age and smoking habits. Results: All workers were males with age ranging from 19 to 44 years with a mean value of 29.95±7.25. The duration of exposure of workers ranged from 1 to 15 years with a mean of 6.05±4.06 years. Both Ni and Cr-exposed workers had statistically significant high levels of tumor necrosis factor (TNF-a) and IL-6 and in terleukin-6 (IL-6). Statistically significant differences were found in CD3 and CD4 levels but with higher CD8 level. As regards the oxidative stress markers, serum malondialdehyde (MDA) was significantly higher in exposed groups when compared to the control group; while the serum glutathione peroxidase (GPx) was significantly lower in exposed groups. Conclusion and Recommendations: Our study shows that chromium and nickel cause significant deviations in various immune parameters with evidence of oxidative stress in occupationally exposed workers.