Objectives To establish the safety and efficacy of programmed treatment interruption (PTI) in HIV infected children. To iidentify parameters that could define for whom this strategy is safe.

Methods A prospective study since October 2005. Eligible patients were HIV infected children with prolonged and sustained control of virological and immunological response to antiretroviral treatment (ART).

Results Ten patients underwent PTI. The median age of HIV diagnosis was 4.6 months (category A 40%, B 50%, C 10%). The average on ART regimens was 46.3 months (four under a second treatment pattern and two on a third). Median age at start of interruption was 120 months (range 79–169). Significant decreases of CD4 (CD4<25%) were seen in two patients during the first month (6.1 and 21% total CD4) and five patients during the third month (range 13–24% total CD4); two of them recovered (>25%) in the next months. HIV viral loads increased from the first month. None of the patients had changes in their clinical status. Six children have remained for a median time of 21.6 months (range 1 to 60 months) on PTI. Four of the patients continued with PTI. During monitoring there were two immunological failures, one acute retroviral rebound syndrome, one clinical failure, one with a significant decrease in CD4 (14%) and one who restarted ART following the protocol of a PENTA clinical trial.

Conclusions PTI may represent a safe therapeutic strategy in a selective group of HIV infected children, despite initial decrease in CD4 (close follow up is warranted).