[In vitro study on the immune effects of the exposure to palladium nanoparticles]

Pd allergic contact dermatitis is increasing in the general population; aim of this preliminary study was to determine, in women with Pd sensitization, the cytokine release from PBMC exposed to Pd nanoparticles similar to those emitted from catalytic converters. PBMC of 8 non-atopic and of 5 Pd sensitized women were incubated with LPS stimulation in presence of Pd nanoparticles (5-10 nm) or potassium hexa-chloropalladate 10(-5) and 10(-6) M. This Pd salt inhibited IFN-gamma, TNF-alpha, IL-10 and IL-17 release from PBMC of non-atopic women, whereas Pd nanoparticles enhanced the release of IFN-gamma and inhibited that of TNF-alpha and IL-17. In the Pd-sensitized women, with high basal values of cytokine release, the 10(-5) M Pd salt (but not Pd nanoparticles) inhibited IL-10 and IL-17 release. In conclusion, Pd salt inhibits the cytokine release from PBMC, whereas Pd nanoparticles exert modulatory effects enhancing release of IFN-gamma which plays an important role in autoimmune diseases.