Immune response to nickel and some clinical observations after stainless steel miniplate osteosynthesis.

Fifteen patients undergoing internal fixation for mandibular fractures were examined for delayed type hypersensitivity (DTH) reaction to nickel before and after implantation of stainless steel miniplates. A lymphocyte transformation test (LTT) was used to measure the immune response before implantation and at removal of plates and screws. The clinical complications during fracture healing were also recorded. The results show that the in vitro LTT may be useful in nickel hypersensitivity testing. A significant increase in lymphocyte transformation was found as a response to nickel stimulation (0.5 microgram Ni/ml) at removal of the implants. We conclude that, despite an increase in LTT after stainless steel implantation, no adverse clinical complications related to DTH could be recorded after short-time observation.