Viral dynamics after starting first-line HAART in HIV-1-infected children.

BACKGROUND: After starting HAART, the plasma HIV-1 RNA (pVL) declines rapidly to undetectable levels in most treated adults and children. The viral dynamics in children are assumed to differ from those in adults. Therefore viral decay and time to reach a pVL of < 400 copies/ml during the first weeks after starting HAART were studied in a cohort of HIV-1-infected children. METHODS: Viral decay expressed as half-life and time to reach a pVL of < 400 copies/ml in 39 HIV-1-infected children starting HAART were calculated and correlated with age, pretreatment with antiretroviral mono- or duo-therapy, and baseline pVL. RESULTS: Baseline pVL correlated with age (r, -0.41; P = 0.01). Median half-life of the virus was 2.1 days (interquartile range, 1.8-3.0 days). No correlation was found between the half-life of the virus and the baseline pVL at the start of treatment, antiretroviral pretreatment or age. Eight children did not reach a pVL of < 400 copies/ml with the first allocated medication regimen. These children were significantly younger than those in whom HIV was successfully suppressed (P = 0.009). The remaining 31 children reached a pVL of < 400 copies/ml in a median of 8.1 weeks after the start of therapy; time to reach a pVL of < 400 copies/ml was only correlated with baseline pVL. CONCLUSIONS: These results suggest that pVL at baseline correlated with age. HAART was able to suppress pVL below the lower limit of detection in children with a viral decay rate of 2.1 days, similar to adults and irrespective of baseline pVL.