This study is designed to further define the dynamics and the mechanisms of the CD4 cell rise seen following administration of potent antiretroviral therapy. It will ascertain if treatment regimens containing nucleoside reverse transcriptase inhibitors (NRTIs) with a nonnucleoside reverse transcriptase inhibitor (NNRTI) have different effects on CD4 dynamics than regimens composed of a protease inhibitor with an NNRTI.

Patients are randomized to one of the two treatment arms listed below. They are stratified based on CD4 count and whether they choose to participate in substudy A5036s. Arm A (protease inhibitor plus NNRTI regimen): At Day 0 (entry), patients begin taking LPV/RTV. At Day 3, patients add NVP, once daily for 2 weeks and then twice daily for the remainder of the study. Arm B (triple reverse transcriptase inhibitors plus NNRTI regimen): At Day 0 (entry), patients begin taking 3TC plus d4T plus ABC. At Day 3, patients add NVP, once daily for 2 weeks and then twice daily for the remainder of the study.

HIV RNA analysis is performed at Weeks 4 and 5. If the mean is at least 1.0 log10 lower than the baseline HIV RNA, the patient may continue on study treatment. If the mean is not at least 1.0 log10 lower, however, patients are discontinued from the study by no later than Week 8. After 8 weeks of treatment, patients may change antiretroviral medications with permission of the protocol chair or vice chairs. Regular clinical evaluations are conducted. Blood is drawn to determine HIV RNA quantification, absolute CD4 and CD8 counts, immunological evaluations, telomere assays, and part is stored for future testing. Skin testing and return visits for delayed-type hypersensitivity to standard recall antigens are done on three occasions.

Patients remain on the study for 48 weeks. Substudy A5036s evaluates viral dynamics during study treatment. Serial plasma samples are collected during the first 24 hours of treatment and at Day 3 and Week 4. Plasma HIV measurements are performed to differentiate between infectious and non-infectious particle production.