Considerations for the evaluation of antiretroviral agents in infants and children infected with human immunodeficiency virus: a perspective from the National Cancer Institute.

Human immunodeficiency virus (HIV) infection in infants and young children differs in a number of ways from that in adults. In most HIV-infected children the infection is acquired perinatally and the course of infection is more accelerated than in adults. Diseases related to B cell defects and dysgammaglobulinemia (e.g., multiple or recurrent bacterial infections) predominate early in the disease, and children can be symptomatic before their CD4+ count decreases. Lymphoid interstitial pneumonitis occurs frequently and almost exclusively in children, and a number of the opportunistic infections (e.g., cryptococcosis, toxoplasmosis) or malignancies (e.g., Kaposi's sarcoma) occur infrequently in children. A major disease manifestation in the pediatric population is HIV encephalopathy, which results in impairment in neurologic development that can lead to loss or lack of developmental milestones and to diminished intellectual function. The methodology and design of clinical trials for the study of pediatric HIV infection should consider these clinical and laboratory manifestations as well as the developmental differences that reflect the disease in infants and young children.