Observation of HIV-Infected Children Receiving Protease Inhibitor and Reverse Transcriptase Inhibitor

INCLUSION CRITERIA Age greater than 1 year and less than 21 years. Diagnosis of HIV-1 infection as defined by the Centers for Disease Control (CDC). Currently on at least a three drug combination that includes a protease inhibitor (PI) and reverse transcriptase inhibitor (RTI) therapy for at least 6 months. Patient must have received initial protease inhibitor treatment in studies in the HIV and AIDS Malignancy Branch but need not be enrolled on another NIH study to be eligible for this protocol. Age-adjusted CD4+ T lymphocytes greater than 200 cells/ml. Measurements of CD4+45RA+ and CD4+45RO+ T lymphocytes taken within 9 weeks of the time of initiation of protease-inhibitor therapy. Availability of a parent or guardian to provide informed consent. EXCLUSION CRITERIA Critically ill or clinically unstable child. Patients receiving treatment for an infection that requires prolonged treatment must have been stable on therapy for at least 14 days prior to study entry. Administration of chemotherapeutic agents or use of immunomodulating agents such as high dose corticosteroids, interferons, pentoxifylline, G-CSF/GM-CSF, erythropoietin, growth hormone and other growth factors within one month of enrollment. However, patients on anti-inflammatory drugs or stable doses of immunoglobulins (including hyperimmune immunoglobulin) will be eligible unless the latter are directed at a T-cell specific antigen. Sexually active post-menarchal female unwilling to use a barrier method of contraception or unwilling to remain sexually abstinent. Patients who, in the opinion of the Protocol Chairperson or Principal Investigator: may not be likely to benefit from this study, may be put at undue risk by participation in this study, are unlikely to comply with the study requirements.