Rectal microbicides to prevent HIV transmission are currently being developed in the hope that someday they will be widely used to prevent sexually transmitted HIV. This study will examine variables in male rectal tissue; this information may be useful for future rectal microbicide safety and efficacy studies. The study will evaluate the differences in rectal tissue from HIV infected or uninfected males who either engage in anal-receptive sex (men who sleep with men, or MSM) or do not have anal-receptive sex.
The study will last approximately 7 months, with 6 weeks of follow-up. There are four groups in this study. Groups 1 and 2 will enroll HIV uninfected men; Groups 3 and 4 will enroll HIV infected men. Groups 1, 3, and 4 will comprise MSM who engage in anal-receptive sex; Group 2 will comprise men who do not. Patients will provide medical and medication history, undergo a complete physical exam, and receive HIV counseling at screening. An anoscopy (examination of the anus, anal canal, and lower rectum) and blood draw will be conducted at screening, study entry, and Weeks 2 and 4. Rectal secretions will be collected and a sigmoidoscopy (an internal examination of the rectum, distal sigmoid colon, and large bowel using a small camera) will be performed at study entry and Weeks 2 and 4.