Human antibody response following multiple injections of bovine collagen

The enzyme-linked immunosorbent assay (ELISA) was selected to further characterize the human antibody response to Zyderm (ZCI). Our studies have involved both patients and volunteers. Five patients with delayed cutaneous hypersensitivity reactions to Zyderm were positive for anti-Zyderm antibody. Six of nine patients treated with Zyderm who never displayed cutaneous reactions did develop significant levels of anti-Zyderm serum antibody. Some of these patients progressively increased their antibody levels. None of the volunteers who received multiple skin-test doses (0.1 cc) of Zyderm developed significant levels of anti-Zyderm antibody. Polyvalent anti-Zyderm antibody titers among patients with positive ELISA absorbance ranged from 1:16 to greater than 1:128. All were positive for antibodies of the IgG subtype; half were positive for the IgA subtype. None was positive for IgM or IgE subtype. We did not observe cross-reactivity between patient anti-bovine collagen sera and commercially prepared antibodies to human anti-collagen types I, II, and III. Given the frequency of current Zyderm use, it seems evident that for most patients, biologic exposure to collagen does not pose a health hazard. Nevertheless, because of the scarcity of data pertaining to the long-term significance of humoral anti-Zyderm antibodies, physicians and patients should be aware that unanswered questions remain whenever clinical use of injectable collagen is recommended.