Effect of a Treatment Switch from Protease Inhibitor to Raltegravir-based ART on Myeloid Cell Inflammation in HIV-infected Patients.

Human immunodeficiency virus (HIV) infection damages body defence mainly by affecting two important white blood cells called cluster of differentiation (CD4) T cells and monocytes. This immune dysfunction leads to persistent inflammation, which is partially resolved with long-term anti-HIV therapy. Importantly, such inflammation increases risk for cardiovascular, diabetes, and kidney diseases. The causes of this inflammation are largely unknown and include HIV itself, presence of other infections, lifestyle characteristics like increased cholesterol levels, obesity, smoking and alcohol abuse. In addition, inflammation can be driven by certain type of anti-HIV therapy called protease inhibitor (PI). PI has been associated with an increase of cholesterol and may contribute to inflammation. A new class of medication that is now available in Canada called integrase inhibitor (II) may have a lesser or no effect on cholesterol levels. Therefore, it is important to study the effect of II on cholesterol levels and inflammation.

The purpose of this study is to assess the inflammatory changes, in the blood of persons treated with PI that will switch to the II or may remain on their PI-containing regimen. By comparing persons continuing their current PI-based regimen with those who switch to II-based regimen, we will know if the change from PI to raltegravir (Isentress), a type of II, decreases lipids and inflammatory markers.

The adult persons living with HIV, who are on PI-based therapy for more than a year, with any CD4 T cell count and plasma viral load below level of detection, will be invited to participate in the study. 40 study participants will be selected by randomization (like a toss of a coin) to either continue PI-based regimen (20 participants) or switch to raltegravir-based regimen (20 participants) for a period of 12 months. Blood samples of the study participants will be drawn before, during and at the end of study to evaluate changes in markers of inflammation, cholesterol level and CD4 T cell and monocyte function. No experimental anti-HIV medication will be used; change of therapy will include raltegravir which is one of currently recommended medications to treat HIV in Canada.

This study will be able to answer this important question whether inflammation can be decreased by switching therapy from PI-based therapy to raltegravir-based therapy. Ultimately, information provided by this study will contribute to the health of persons living with HIV.