This research is being done to study how the immune system in the small intestine improves after taking antiretroviral (anti-HIV) medications. The main purpose is to measure the increase in the numbers of immune cells in the intestine to see if one type of HIV medication gives different results than other types of HIV medications.

While the world-wide AIDS epidemic continues to impact millions of individuals, effective anti-HIV medications have substantially reduced morbidity and mortality for those patients able to adhere to combination regimens. Despite improved survival, durable virologic suppression, and increases in peripheral CD4+T-cell counts in patients receiving potent antiretroviral therapy (ART), immune reconstitution remains incomplete as measured by a number of additional surrogate markers. Perhaps critically important among areas of apparent incomplete immune recovery is the gastrointestinal-associated lymphoid tissue (GALT), where CD4+T-cells repopulate very slowly, if at all. Raltegravir is a new ART agent from a novel class of HIV inhibitors, integrase inhibitors, that results in rapid suppression of HIV and recovery of peripheral CD4+T-cells. This project proposes to examine whether volunteers receiving raltegravir recover GALT immune cells more completely than those taking comparator ART.

Inclusion Criteria:

• willing to sign consent form
• no known GI pathology
• no anticipated antiretroviral therapy adjustments or changes
• males & females between the ages of 18 & 50 years
• no active opportunistic infections (OI) or therapy for OI within 30 days of entry
• can be on secondary prophylaxis with a history of AIDS defining illness
• per standard of care requirements, all females of child-bearing potential must agree to use barrier methods to prevent pregnancy or be abstinent from activity while on study

Exclusion Criteria:

• abnormal coagulation parameters (PT > or equal to 1.2 ULN)
• thrombocytopenia (platelet count < 50,000 within 6 weeks)
• contra-indications to upper endoscopy or conscious sedation
• anemia (> or equal to grade 1)
• aspirin, ibuprofen, warfarin or other agents that interfere with the coagulation cascade are prohibited within 1 week of endoscopy

Limitations of the study include small numbers of subjects over all - Several subjects dropped out due to moving out of the region and lost to follow up.