Correlates and Consequences of Increased Immune Activation in Injection Drug Users

The goal of this study is to learn how injection drug use may affect the immune system. One
way to measure this is by looking at the blood and the gut, or gastrointestinal tract at the
same time. It is thought that activating the immune system by injection drug use may
increase destruction of immune cells in the gut. To test this theory, the investigators are
enrolling HIV-negative injection drug users, HIV-negative people who do not use drugs and
HIV-negative former injection drug users.

Inclusion Criteria:

- Ability to give informed consent

- Between the ages of 18 and 55

- Absence of medical conditions that would preclude flexible sigmoidoscopy

- Absence of active opportunistic infection requiring active therapy including
antibiotics or antineoplastics (note this does not include prophylactic antibiotic
therapy)

Exclusion Criteria:

- History of bleeding disorder

- Platelet count below 70,000

- INR>1.5 or PTT>2X control

- Active use of anticoagulants or aspirin therapy that cannot be interrupted

- Comorbid diagnosis of inflammatory bowel disease

- Pregnancy, incarceration, mentally disabled individuals

- HIV-1 infection

- Currently on Hepatitis C treatment