Interruption of cART in clinical practice is associated with an increase in the long-term risk of subsequent immunosuppression in HIV-1-infected children.

Background: Antiretroviral treatment interruption (TI) is not recommended in HIV-infected children. We aimed to evaluate the context and consequences of TI in clinical practice.
Methods: We investigated the probability and risk factors of a first TI in the 483 children treated with combined ART (cART) in the ANRS French national pediatric cohort. Immunologic and virologic outcomes were compared between patients with TI (TI group) and those on continuous treatment (matched control group), from a baseline defined as the age at first interruption for the TI child and the corresponding age for the control child.
Results: At least one TI ≥ 3 months occurred in 42.4% of patients, at a median age of 8.0 years, for a median duration of 12.1 months. After cART initiation, the risk of TI was 7.0% (5.0-9.6) at 1 year and 30.3% (26.1-35.0) at 5 years and was higher for children starting treatment before 2000 and for children starting cART before 6 months of age. AIDS-free survival was similar, but severe immunosuppression occurred earlier in the TI group than in the control group (adjusted HR = 3.1; 1.0-9.1; P = 0.04). Four years after baseline, the proportion of patients with CD4% ≥ 25% was lower in the TI group than in the control group (52.0% vs. 72.0%; P < 0.01), even among children restarting cART at least 6 months earlier (aRR = 0.5; 0.3-0.9; P = 0.03).
Conclusions: The risk of TI in clinical practice has decreased but remains high. In intent-to-treat analysis, TI was associated with a greater risk of subsequent immunosuppression, even after cART resumption.