Application of beta-interferon in virus-induced papillomas.

Eighty patients with bilateral common warts of the extremities were treated at weekly intervals with intralesional injections of either human fibroblast interferon or placebo. Lyophilized interferon (3 X 10(6) units) was diluted with 3 ml of normal sterile saline matched with identical vials of placebo. Eighty sets of three vials of human fibroblast interferon or placebo were labeled either A or B by a controller who maintained the code until the experiment was completed. Each patient received 0.1 X 10(6) units of interferon into the warts on one side and placebo injections into those on the matching extremity. Warts were measured each week and the progress or lack thereof was scored on a scale of -1 (worse) to 3 (cured). Therapy continued until either at least one extremity had cleared or the patient had received 10 weekly injections. A final evaluation was scored by measuring the total progress of each patient during the study. Sixty-four patients were treated to completion. More than 81% of the interferon-treated extremities were either cured or responded effectively to therapy. Only 17% of the placebo-treated lesions responded in this fashion. A statistical analysis of these data confirms the effectiveness of intralesional interferon therapy. The average number of interferon injections until cure was 5.9 +/- 1.7. No adverse effects were observed. The applications of interferon in patients with epidermodysplasia verruciformis and flat warts were also studied. Intralesional interferon beta was, to a certain degree, effective for benign lesions of epidermodysplasia verruciformis, but systemic treatments were not effective. Subcutaneous interferon beta was, in an uncontrolled study, effective in 45% of patients with flat warts.