Clinical spectrum and virologic characteristics of anal intraepithelial neoplasia in HIV infection.

BACKGROUND Anal intraepithelial neoplasia (AIN) represents a precursor lesion of invasive squamous cell carcinoma with a clear association to high-risk human papillomavirus (HPV) types. HIV infection is strongly associated with a higher prevalence of genital HPV infection, a higher incidence of AIN, and, consecutively, an increased risk for anal cancer. OBJECTIVE The aim of this study was to determine the clinical spectrum of AIN and lesional HPV colonization in a cohort of homosexual men who were HIV positive and had a history of receptive anal intercourse. METHODS In all, 103 men who were HIV-1 positive were screened by using clinical, proctologic, cytologic, histologic, and HPV DNA testing. RESULTS Of all patients, 86% had anal HPV infection at their first visit. HPV-16 (53%), HPV-18 (27%), HPV-58 (22%), and HPV-83 (22%) were the most frequently found HPV types. AIN was diagnosed in 20 of the 103 patients (19.4%). High-risk HPV types were present in all AIN cases with up to 7 different high-risk and up to 5 different low-risk types per lesion. Histologically, 7 (35%), 7 (35%), and 6 (30%) of the patients had AIN grade I, II, or III, respectively. Four different types of clinical presentation could be distinguished in the 20 patients with AIN: bowenoid (1 case, 5%); erythroplakic (2 cases, 10%); verrucous (6 cases, 30%); and leukoplakic (11 cases, 55%). All verrucous lesions were graded as high-grade intraepithelial lesions in cytology, whereas 6 of the 11 leukoplakic lesions (55%) were low grade. All verrucous AIN carried at least 4 different HPV types, always including HPV-16, and the mean number of HPV types was higher in verrucous lesions than in leukoplakic lesions (5.5 vs 3.8, respectively). CONCLUSION These data confirm the high incidence and prevalence of AIN in patients who are HPV positive with HIV infection. Four different clinical types of AIN can be distinguished that might have prognostic implications. Standardized screening programs for anal cancer prevention and treatment protocols for AIN in patients infected with HIV must be implemented.