Immune Effects of Nickel

Abstract

Data on nickel immunomodulation are contradictory. The most consistent immune effects are suppression of immune responses. It has been show that T-lymphocytes and NK cells are more susceptible to nickel toxicity than are B lymphocytes or macrophages. Data reported about cytokine production in human and nickel reactive T-cell clones are also conflicting. Some authors studied cytokine production PBMC cultures of nickel allergic individuals after stimulation with NiSo₄. They showed a higher synthesis of IL4, IL5 and IL13 but not of IFN gamma and TNFα in Ni allergic subjects. We found that the addiction of NiSo₄ to the PBMC cultures of non sensitised subjects induces a reduction of release of IL5, IFN γ and TNFα. Our studies demonstrate a clear difference in NK cell activity between nickel-tolerant and intolerant individuals. In particular NK cell activity in reduced in sensitised patients respect to the normal subjects and the addition of Ni to the PBMC cultures induce a significant decrease of NK cell activity. The decrease was greater in cell derived from allergic subjects than non allergic. In conclusion, reported data show Ni has immunotoxic potential. Researches are in progress in an attempt to correlate the present data with other immune parameters and to measure the effects of a Ni free diet on the immune system of subjects with Ni intolerance. The comprehension of the mechanisms inducing these changes requires further studies in the uptake and intracellular distribution and binding of the metal.