Immuno-allergological properties of aluminium oxide (Al2O3) ceramics and nickel sulfate in humans

For more than 30 years aluminium oxide (Al2O3) ceramics have been used for implants in maxillofacial and orthopaedic surgery. Up to now, there are no reports and also no investigations on hypersensitivity reactions. In order to evaluate the aspects of immuno-allergological reactivity to aluminium oxide ceramics, skin testing and in vitro lymphocyte activation studies were performed. The patch test reactivity to a standard series of contact allergens and to an aluminium oxide (Al2O3) disk was examined in a consecutive series of 250 patients frequenting a University Dermatology Clinic. Furthermore, peripheral blood mononuclear cells (PBMC) of 15 nickel-allergic and 15 non-allergic individuals were cultured with medium alone, with the pan T-cell mitogen phytohemagglutinine (PHA) or with nickel sulfate (NiSO4). By additional presence/absence of Al2O3 disk its influence on the cytokine secretion pattern and proliferative response was investigated. The results show that in contrast to a high frequency of delayed-type hypersensitivity to standard contact allergens, no allergic skin reactions to Al2O3 ceramics occured. The IL-4 and IFN-γ production in vitro remained almost unchanged by the presence of Al2O3 disk as well as the proliferative response of PBMC of non-allergic individuals. Cellular reactivity of nickel allergic and non-allergic donors was partly enhanced upon contact to Al2O3 disks.