Protease inhibitor therapy in children with perinatally acquired HIV infection

Objective: To review the short-term response and safety of protease inhibitor therapy in HIV-infected children. Design: Retrospective chart review of open-label protease inhibitor-containing combination therapy. Setting: Two urban pediatric HIV centers. Patients: Twenty-eight HIV-infected children were prescribed 30 protease inhibitor-containing antiretroviral therapy combinations. The median age at initiation of protease inhibitor antiretroviral therapy was 79 months. Patients had been on previous antiretroviral therapy for a mean of 45.5 months. Results: Of the 28 children who completed at least 1 month of therapy, 26 experienced marked virologic and immunologic improvement (mean maximal decrease in viral load 1.90 log(10) copies/ml; SD, 0.8; mean maximal rise in CD4+ lymphocytes of 279x10(6)/l; SD, 300 x10(6)/l). Eleven patients achieved a viral nadir of < 400 copies/ml, and seven sustained this level of viral suppression for a mean of 6 months. Indinavir use was associated with a high incidence of renal side-effects, including two patients who developed interstitial nephritis. Two patients on ritonavir experienced a significant elevation of liver enzymes. Conclusions: Protease inhibitor therapy was associated with substantial short-term virologic and immunologic improvement in this primarily heavily pretreated cohort, with 25% maintaining a viral load of < 400 copies/ml after 6 months of therapy. There was a significant rate of adverse events. Pharmacokinetic and safety data are needed to guide aggressive antiretroviral therapy in HIV-infected children, and further treatment options are required for those failing or intolerant to the available protease inhibitors.