August 7, 2008
A growing area of concern in the health of people living with HIV is the role that the human papillomavirus (HPV) plays in causing cervical and anal cancers. Expanding research over the past two years has helped bring this concern closer to the forefront of the community's attention. Research is showing higher rates of HPV infection and disease in HIV-positive people than originally believed.
HPV is easily passed through sex, and about 130 types have been discovered. Most do not cause symptoms, while nearly 40 low-risk types can cause genital warts and another dozen or so high-risk types can cause cancer. People living with HIV are at higher risk for getting HPV infection and disease.
A Venezuelan study presented at the International AIDS Conference in Mexico City investigated the rate of high-risk HPV and high-grade anal intraepithelial neoplasia (AIN) in HIV-positive men who have sex with men. AIN is an abnormal growth of cells found in surface anal tissue. It is not cancer, but it can lead to other health consequences, including cancerous cells, invasive anal cancer and surgery.
AIN is more common in MSM than other populations, as is anal cancer. This is likely due to a higher rate of anal sex in this population, which means HPV is passed more often among individuals. However, anal HPV and AIN can still develop in any man or woman with HIV, even if they haven't engaged in anal sex. In fact, one study found higher rates of anal HPV in women than in men.
The study followed 188 men in a private medical center. Blood tests provided CD4 counts and viral loads along with detection of low-risk types (6, 11) and high-risk types of HPV (16/18/31/33/35). Average age was 40, average CD4 count was 354, and average viral load was 3.21 +/- 16 log copies HIV RNA.
Each volunteer also had an anal exam, which included the swabbing and collecting of surface anal tissue and mucous for examination. If the exam uncovered an abnormal condition, then an anal biopsy (surgical removal of tissue) was performed. All anal samples were evaluated for low-grade and high-grade AIN.
HPV was found in 56% of the volunteers, though it was found in 75% of those with lesions in surface anal tissue. About 42% of the volunteers showed high-grade AIN, another 42% were normal, and only 0.5% showed low-grade AIN.
Both high- and low-risk HPV were detected in the samples. Nearly every volunteer had some type of anal HPV and often had more than one. Additionally, high-grade AIN was also identified in the presence of high-risk HPV. The high rate of AIN found in this population may eventually lead to high rates of other cancerous conditions.
Studies like this one demonstrate the need for standard screening and treatment protocols, especially for MSM and others at high risk for AIN. The growing rate of HPV disease in people living with HIV needs assertive attention by medical providers to proactively identify these possible health risks. These study results will help contribute to creating a standard of care that is not yet in place to properly address these conditions.