The study to understand the natural history of HIV and AIDS in the era of effective therapy (SUN Study).

Treatment of human immunodeficiency virus (HIV) infection with highly active combination antiretroviral therapy has increased survival and shifted the spectrum of HIV-associated morbidity and mortality from opportunistic infections toward a variety of other medical conditions. The prospective cohort Study to Understand the Natural History of HIV and AIDS in the Era of Effective Therapy (SUN Study) monitors the clinical course of HIV-infected individuals treated with combination antiretroviral therapy in 4 US cities. Every 6 months, clinical assessments, medical record abstraction, audio computer-assisted self-interview, and neurocognitive measurements are completed and blood and urine specimens are banked centrally. At enrollment and periodically thereafter, additional techniques such as anal cytology, dual energy x-ray absorptiometry, carotid ultrasonography, echocardiography, and abdominal and cardiac computed tomography are performed. From March 2004 through June 2006, 700 participants were enrolled; median age was 41 years, 76% were men, 58% were non-Hispanic white, 62% were men who have sex with men, 78% were taking combination antiretroviral therapy (of whom 86% had an HIV viral load of <400 copies/mL), and median CD4+ T-lymphocyte count was 459 cells/mm(3) (interquartile range: 324-660). The SUN Study provides a wealth of data that will inform and improve the clinical management of HIV-infected individuals in the modern era.