Immunohistochemical characterization of the perivascular infiltrate cells in tissues adjacent to stainless steel implants compared with titanium implants

Metallic orthopaedics implants are composed of elements that are known to b e skin sensitizers in the general population In this study, we analyzed the cells of perivascular infiltration in the tissue adjacent to titanium (n = 23) and steel (n = 8) implants after explantation of the metals by immunoh istochemical methods. The following panel of monoclonal antibodies were use d as parameters: CD la (Langerhans cells), CD 4 (T-helper cells), CD 8 (T-s uppressor cells), CD 11c (monocytes and macrophages), CD 45 RO (memory cell s), CD 45 RA (naive cells), eosinophil cationic proteins (ECP), neutrophil elastase, and HLA-DR. The number of perivascular total cells did not differ significantly. All cells were identified in both metal subgroups, but a st atistical difference was not seen in the above-mentioned parameters. We con clude that sensitization to metals is possible in the tissue adjacent to st eel and titanium implants, because all cells which play an important role i n allergic delayed-type hypersensitivity (type IV) reactions are present. T his phenomenon may be called a 'pre-sensitization' phase, because no sensit ization or allergic reactions were seen in our cases. Second, in the presen t study, a statistical difference was not seen in the number of infiltrate cells in the tissue adjacent to steel compared with titanium implants.