There are no official guidelines regarding anal cytology as screening for ASIL.  The following is based on the approach used by the Palefsky  group at USCF, the group spearheading the clinical research on anal dysplasia.

1). HIV negative men with h/o receptive anal intercourse or anal warts.  If the first anal PAP is negative, it should be repeated in 6 months.  If the second PAP is negative, then repeat PAP should be obtained in 3 to 5 years.

2). HIV positive men with h/o anal intercourse or anal warts. If the first anal PAP is negative, it should be repeated in 6 months.  If the second PAP is negative, then repeat cytology should be obtained in one year.  Some clinicians screen patients with CD4 counts <500 mm more frequently.

3). HIV negative women with history of anal warts, high grade CSIL , vulvar SIL, or invasive cervical cancer.   If the first anal PAP is negative, it should be repeated in 6 months.  If the second PAP is negative, then repeat PAP should be obtained in 3 to 5 years.

4). HIV positive women.    If the first anal PAP is negative, it should be repeated in 6 months.  If the second PAP is negative, then repeat cytology should be obtained in one year.  Some clinicians screen patients with CD4 counts <500 mm more frequently.

5). Consider screening patients with organ transplants on chronic immunosuppressive agents [1,6].