Long-Term Effects of HAART in Youth With Stronger Immune Systems Versus Youth With Weaker Immune Systems

Recent adult clinical trials involving combination HAART, including a protease inhibitor (PI), have demonstrated improvements in somatic immune system functioning. [AS PER AMENDMENT 2/27/01: More recently, similar success has been demonstrated with a PI-sparing regimen, zidovudine, lamivudine, and efavirenz.] Not all individuals, however, experience the same level of immune reconstitution, and oftentimes any improvement is short-lived. Adolescent patients may have a greater potential for immune restoration because of residual thymic tissue and therefore may experience greater long-term virus-free states as compared to adult patients. This study examines the duration of virologic efficacy HAART has on the adolescent HIV-positive population.

Patients begin study by initiating a HAART regimen of a minimum of 3 drugs, at least 1 of which must be a PI [AS PER AMENDMENT 2/27/01: or efavirenz (EFV)]. A variety of drug combinations are used; therefore, patients are grouped according to the classes of drugs in their respective regimen (e.g., 2 nucleoside reverse transcriptase inhibitors [NRTIs] plus 1 PI; 2 NRTIs plus 2 PIs; 1 or 2 NRTIs plus 1 PI plus 1 nonnucleoside reverse transcriptase inhibitor [NNRTI] [AS PER AMENDMENT 2/27/01: ; and 2 NRTIs plus EFV]). At the time of HAART initiation, patients undergo immunologic and virologic assessments in order to determine baseline values. Then, to determine the virologic success or failure of HAART, HIV-1 RNA measurements are taken and compared to initial baseline values. Virologic success equals undetectable HIV-1 RNA at Week 12 [AS PER AMENDMENT 2/27/01: and confirmed at Week 16] or a significant (greater than 1 log) decrease in HIV-1 RNA from baseline to Week 12 [AS PER AMENDMENT 2/27/01: and confirmed undetectable HIV-1 RNA before the next scheduled visit (Week 24)]. Patients are followed for a minimum of 3 years of maintained viral suppression or until they have demonstrated virologic failure. From these values, any correlation that may exist between HIV-1 RNA values and HAART can be deduced. Patients with virologic failure on the initial HAART regimen may be allowed to change to a second HAART regimen. [AS PER AMENDMENT 2/27/01: Patients with virologic success on the second HAART regimen are followed for a minimum of 3 years.] Patients with virologic failure on the second HAART regimen or who voluntarily discontinue HAART are followed using an abbreviated schedule for 3 years.

Inclusion criteria

Children may be eligible for this study if they:

• Are HIV-positive.
• Are between 8 and 22 years old (consent of parent or guardian required if under 18).
• Have detectable levels of HIV in the blood within 30 days prior to study entry.
• Expect to be on the study for at least 1 year. (This study has been changed by adding this requirement.)
• Are pregnant and are not taking didanosine/stavudine (ddI/d4T) or EFV as part of their HAART regimen. (This study has been changed so that pregnant patients may be eligible if they are not taking ddI/d4T or EFV.)

Exclusion criteria

Children will not be eligible for this study if they:

• Are taking HAART or more than 1 anti-HIV drug.
• Were infected with HIV before birth, at the time of delivery, or by a blood transfusion during birth.
• Have taken part in the study before.
• Have not responded well to HAART in the past.
• Have taken drugs to boost the immune system such as HIV vaccines, IVIG, or cytokine therapy.
• Have AIDS-related (opportunistic) infection at the time of screening. (This study has been changed so that patients with an AIDS-related infection are ineligible.)
• Are pregnant and are taking ddI/d4T or EFV as part of their HAART regimen. (This study has been changed so that pregnant patients are ineligible if they are taking ddI/d4T or EFV.)