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.