Topical treatment with human leukocyte interferon of HPV 16 infections associated with cervical and vaginal intraepithelial neoplasias

Abstract The present placebo-controlled, double-blind trial was designed to determine the effect of potent human leukocyte interferon cream (IFN) on genital HPV 16 (high-risk-type) infections associated with cervical intraepithelial neoplasia (CIN) and/or vaginal intraepithelial neoplasia (VAIN). Twenty women were treated with either IFN or placebo cream. The daily dose of IFN was 9 × 10 6 IU. The patients applied the cream deep into the vagina every night for 2-week courses 1 week apart. The entire treatment period was 12 months. On the basis of colposcopical, cytological, and histological examinations, 4 of 9 patients in the IFN group and 7 of 10 patients in the placebo group showed clinical remissions at the end of the trial. However, the virological studies gave a different picture. After treatment, 6 of 9 in the IFN group and 3 of 10 in the placebo group were HPV 16 DNA negative ( in situ hybridization). All four patients in remission after IFN were HPV 16 DNA negative, whereas 4 of 7 patients in remission after placebo were still HPV 16 DNA positive. One patient treated with placebo showed progression; no patient in the IFN group showed progression. During the post-treatment follow-up of 16 months, no recurrences were noted in the IFN group, as compared with 2 of 10 in the placebo group. These results showed a marked discrepancy between clinical evaluation (colposcopy, Pap smear, biopsy) and virological findings. Further studies are needed to clarify the prognostic value of the different evaluation criteria. It is encouraging that the high-risk HPV 16 infection was eradicated in two-thirds of the patients treated with topical IFN.