Anal cancer and its precursor lesion, anal squamous intraepithelial lesions (SILs), are associated with human papillomavirus (HPV) infection.
Anal HPV infection and anal SIL are common in HIV-positive men who have sex with men. Receptive anal intercourse has been presumed to be the mode of acquisition of HPV.
|46% of the 50 heterosexual men studied had anal HPV infection.|
|Annals of Internal Medicine|
In this study, researchers from France and the United States assessed the prevalence and risk factors for anal HPV infection and anal SIL in HIV-positive men with no history of anal intercourse.
The research team studied 50 HIV-positive male injection drug users with no history of anal intercourse. They also assessed 67 HIV-infected men who had sex with men. Study subjects were evaluated using cytologic, histologic, and anal HPV DNA testing.
The researchers found that 46% of the 50 heterosexual men had anal HPV infection.
In addition, low-grade SIL (LSIL) was found in 16% of these patients and high-grade SIL (HSIL) in 18%.
The team also determined that of the 67 men who had sex with men, anal HPV infection was found in 85%, LSIL in 49%, and HSIL in 12 patients 18%.
They identified risk factors for abnormal anal cytologic or histologic findings in injection drug users using univariate analysis. Risks included CD4+ cell counts less than 250 × 106 cells/l (odds ratio (OR) 5.7), plasma HIV RNA viral load greater than 1.7 log copies/ml (OR 8.9), previous AIDS-defining event (OR 4.3), and anal HPV detection (OR 5.7).
Risk factors among men who had sex with men included having more than 10 lifetime receptive anal intercourse episodes (OR 5.6) and anal HPV detection (OR 8.7).
Dr Christophe Piketty's team concluded, "Anal HPV infection and anal SIL may be acquired in the absence of anal intercourse in HIV-positive men".
"The prevalence of HSIL is high among HIV-positive injection drug users."
"All HIV-positive men with CD4+ cell counts less than 500 × 106 cells/L, regardless of history of anal intercourse, should be considered for anal cytologic screening.
"However, additional studies are needed to determine the efficacy of this procedure to prevent anal cancer in these populations."