Inclusion Criteria:  HIV-positive patients Solid transplanted recipients Crohn's disease patients under immunosuppression: steroids, thiopurines, biologics Patients with lupus under immunosuppression Women with a previous history of genital neoplasia (high-grade lesions or cancer) in the cervix, vagina or vulva.  Exclusion Criteria:  Previous anal/perianal cancer history Previous known history of anal/perianal intraepithelial neoplasia Pelvic radiation