Long-term responses to treatment including ritonavir or nelfinavir in HIV-1-infected children

Background: Knowledge concerning the long-term antiretroviral and immunolog ical efficacy of protease inhibitors in children is limited. Patients and Methods: An open-label, prospective, multicenter clinical tria l was conducted over a period of 72 weeks in Switzerland. 60 HIV-1 infected children (aged 0.3-16.9 years) naive to protease inhibitors were enrolled. Ritonavir or nelfinavir and at least one new nucleoside reverse transcript ase inhibitor were introduced into the current treatment regimen. HIV-1 RNA levels and CD4 cell counts were monitored after introducing the protease i nhibitor, and the tolerability and safety of the drugs were assessed. Results: Dictated by chronological availability, 37 children received riton avir and 23 nelfinavir,At baseline, children given ritonavir had higher mea n plasma HIV-1 RNA levels (5.03 vs 4.63 log(10) copies/ml; p = 0.001) and l ower mean CD4 cell counts (277 vs 555 cells/mu l; p = 0.009) than children given nelfinavir. Antiretroviral treatment (ART) naive children showed high er mean plasma HIV-1 RNA levels than non-naive (5.18 vs 4.64 log(10) copies /ml; p = 0.02). The decline in plasma HIV-1 RNA levels 72 weeks after treat ment with ritonavir and nelfinavir was -2.17 and -1.30 log(10) copies/ml, r espectively (p = 0.006) and in ART-naive vs non-naive patients -2.70 vs -1. 39 log(10) copies/ml (p less than or equal to 0.01), 69% of ART-naive patie nts and 32% of non-naive patients achieved sustained plasma HIV-l RNA level s < 400 copies/ml. Increases in CD4 cells were higher in ART-naive compared to non-naive patients (p < 0.04), Conclusion: The antiretroviral and immunologic benefits of protease inhibit ors are more profound in ART-naive than in non-naive children.