The immunogenicity of injectable collagen. II. A retrospective review of seventy-two tested and treated patients.

Sera were collected from seventy-two patients who had been exposed to a preparation of a bovine collagen implant in widespread clinical use for correction of dermal defects ( Zyderm Collagen Implant [hereafter referred to as "the implant"]; Collagen Corporation, Palo Alto, CA). Thirty-one of these patients had reported implant site reactions alone, thirty-five had reported generalized symptoms without implant site involvement, and six had reported implant site reactions accompanied by generalized symptoms. Results of a radioimmunoassay performed on these sera showed that elevated levels of anti-implant antibodies correlated significantly with localized responses at injection sites. Conversely, systemic complaints could not be correlated with either skin reactions or antibody titers. In previous clinical studies, increasing numbers of exposure to this material were not shown to increase the likelihood of an immune response developing at implant sites. Therefore, immune responses to this implant are typically localized reactions that manifest within the first two exposures to the implant material.