Risk of first-line antiretroviral therapy failure in HIV-infected Thai children and adolescents.

BACKGROUND: Adolescence may affect adherence and response to highly active antiretroviral therapy (HAART). Limited data are available regarding the long-term treatment outcomes of perinatal HIV-infected adolescents.
METHODS: Data from perinatally acquired HIV-infected Thai children who started first-line nonnucleoside analog-based HAART before 18 years of age and treated for ≥24 weeks were analyzed. Children were categorized by age at HAART initiation; age<3 years, 3-9 years, early adolescence (10-13 years) and middle adolescence (14-16 years). CD4 and HIV-RNA were monitored every 6-12 months. Virologic failure (VF) was defined as HIV-RNA≥1000 copies/mL after ≥24 weeks of HAART.
RESULTS: Of 840 children, 68% were in pre-adolescence. Median baseline CD4% was 7.9%. Use of nevirapine versus efavirenz was 77:23%. Median duration of nonnucleoside reverse transcriptase inhibitor-based HAART was 5.6 years. No differences between groups were observed for rate of HIV-RNA<50 copies/mL (68%, P=0.18) and rate of VF (28%, P=0.82), median time to VF (22 months, P=0.13). Incidence of VF per 100 child-year in children age<3 years, 3-9 years, early adolescence and middle adolescence were 7.9, 4.7, 7.4 and 10.8, respectively (P=0.012). Median adherence by pill count was 97.3% (P=0.23). By multivariate analysis, predictors for VF were age at HAART initiation of <3 years (HR: 1.73, 95% CI: 1.18-2.55), age 10-16 years (HR: 1.47, 95% CI: 1.09-1.97), and nevirapine use (HR: 1.63, 95% CI: 1.14-2.32).
CONCLUSIONS: VF rates were observed in one-third of long-term treated Thai children on first-line HAART. Age 3-9 years at HAART initiation was associated with less VF compared with those younger or older, whereas children who used nevirapine had higher VF.