Abnormal anal cytology on antiretroviral therapy

The Study to Understand the Natural History of HIV/AIDS in the Era of Effective Therapy (SUN)1 looked at the incidence and predictors of abnormal anal cytology in patients established on antiretroviral therapy. Seven hundred HIV-positive participants in four cities in the USA were followed up for a median of 2.1 years. Baseline anal swab collection for cytology and human papilloma virus (HPV) detection was undertaken, and annually thereafter, and participants also completed a behavioural questionnaire. A total of 243/700 participants had negative baseline cytology, and of these, 37% developed abnormalities using the Bethesda system, with an incidence rate of 13.9/100 person-years of follow-up, 95% CI (11.3 to 16.9). Incidence rates were almost twice as high in men who have sex with men (MSM); 17.9 cases/100 person-years (95% CI 13.9 to 22.7) compared 9.4 cases/person-years (95% CI 5.6 to 14.9) for women and 8.9 cases/person-years (95% CI 4.8 to 15.6) for heterosexual men. The group found that persistent HPV 16 or 18 infection …