Human papillomavirus (HPV) viral load and HPV type in the clinical outcome of HIV-positive patients treated with imiquimod for anogenital warts and anal intraepithelial neoplasia.

OBJECTIVE: To evaluate the efficacy of 5% imiquimod in HIV-positive male patients with anogenital warts or anal intraepithelial neoplasia (AIN), and to elucidate whether human papillomavirus (HPV) type and viral load were important for clinical outcome and recurrences.

METHODS: Thirty-seven patients with histologically proven anogenital warts or AIN were enrolled. Topical 5% imiquimod was applied three times per week for more than 8 h overnight for 16 weeks, although patients were allowed to continue therapy for 4 more weeks if they did not have complete clearance of lesions.

RESULTS: Mean age was 34 years. The perianal area was the main lesion location. Thirty-three patients had CD4 counts of < 500 cells/mm(3). Eighteen patients had a histopathological diagnosis of AIN-1. Main HPV types detected corresponded to low-risk HPV types. At 20 weeks of therapy, 46% patients achieved total clearance whereas 14 patients had > 50% clearance. Recurrence was observed in 5 of 17 patients who cleared. Clearance was not influenced by patients' CD4 counts, wart location, HIV viral load or HPV viral load.

CONCLUSIONS: The assumption that visible perianal warts are benign lesions in HIV-positive patients has to be reevaluated since an important number of such lesions could correspond to low-grade anal disease, which in turn could progress to high-grade anal disease or cancer. In addition, our results in this preliminary study indicate that imiquimod appears to be effective in treating AIN in HIV-positive patients. Further studies are needed to document its utility to prevent high-grade dysplasia and/or anal cancer.