Modulation of Immune Activation by Aspirin

Since people started taking HIV medications, illness from AIDS has decreased, but other serious diseases like heart disease, cancer, and kidney, and liver disease have increased. HIV causes inflammation (irritation) inside the body that cannot be felt but can be measured by blood. Inflammation can lead to diseases that have become some of the leading causes of death in people with HIV. HIV therapy can partially lower levels of inflammation measured in blood, however, levels of inflammation in people who have HIV may remain high compared with people not infected with HIV. Aspirin is a drug that is commonly used for pain relief but is also approved by the Food and Drug Administration (FDA) for preventing heart attacks and stroke in those who are at increased risk for heart attack and stroke. Aspirin also is used (but is not approved by the FDA) to decrease the risk of some cancers in people who are at increased risk. Aspirin is thought to decrease risk of heart attack and stroke because it blocks the activation of platelets and prevents blood clots from clogging narrowed blood vessels, a disease called atherosclerosis. It is unknown how aspirin might decrease the chance of developing cancer in some people at higher risk, but aspirin has been shown to modulate (or change) the immune system. In HIV-infected people who have been taking antiretroviral therapy and have an undetectable HIV viral load it was recently shown that low-dose aspirin 81 mg (baby aspirin), given for one week, lowers platelet activation and reduces blood markers of inflammation which may improve the function of the immune system. The purpose of this study was to evaluate whether aspirin improves inflammation and immune activation when compared to a placebo (inactive medication like a dummy pill) and to determine if 12 weeks of aspirin 300 mg and aspirin 100 mg is safe for HIV-infected persons on antiretroviral therapy. Additionally, it studied whether a higher dose and longer duration of aspirin provides further anti-inflammatory and immune-modulating benefit. This was done using blood and urine tests that measure inflammation and also with a test that uses ultrasound to measure the flow of blood in your arm, called flow-mediated vasodilation (FMD) of the brachial artery (BART). This is a painless test that bounces sound waves off of a blood vessel in your arm.