Absence of neutralizing antibodies to interferon in condyloma acuminata and cancer patients treated with natural human leukocyte interferon.

Human leukocyte-derived interferon-alpha (IFN-alpha n3) was used to treat condyloma acuminata patients in a double-blind placebo-controlled clinical study. The incidence of antibody formation to IFN-alpha was evaluated in matched patient sera from the control placebo and the IFN-alpha n3 treatment groups. Sera from IFN-alpha n3-treated phase I cancer patients and untreated healthy donors were also evaluated. Three sensitive assay methods (ELISA, competitive immunoradiometric, and antiviral neutralization) were used in these evaluations. The overall levels of detectable binding anti-IFN-alpha antibodies in the patients were similar to those of the normal donors. No neutralizing antibodies were generated in the patients after repeated treatment with natural IFN-alpha n3.