Immune Reconstitution of Lopinavir/Ritonavir-Based vs Efavirenz-based HAART in Advanced HIV Disease

The ideal anti-HIV medications for patients with advanced HIV disease is unknown. There is evidence that anti-HIV regimens that contain protease inhibitors can enhance immune function better than regimens that do not contain protease inhibitors. This is a study that will determine the difference in immune enhancement capabilities between an anti-HIV regimen that contains the protease inhibitor - lopinavir-ritonavir, and a regimen that contains efavirenz. Both medications are recommended as first line treatments for HIV-infected patients. This study will recruit HIV-positive patients that need to start anti-HIV treatment because their CD4+ T-cells are below 200. The usual threshold for starting treatment is a CD4+ T-cell less than 350. Subjects will be randomized to treatment with either an anti-HIV regimen that contains lopinavir-ritonavir or a regimen that contains efavirenz. The study will determine the difference in immune reconstitution over 24 weeks of treatment with study medications. Among the immune parameters that will be measured is the ability of each subject to respond to vaccination with the tetanus-diphtheria vaccine and the 23-valent pneumococcal vaccine. Both vaccines are also recommended for HIV-positive patients but HIV-positive patients tend to have a lower response rate to these vaccines.