When to start antiretroviral therapy in children with TB?

The initiation of antiretroviral therapy (ART) after starting TB treatment is complex, involving many variables including treatment tolerance, drug co-toxicities, pharmacokinetic drug interactions and polypharmacy impacts on adherence. Delayed ART potentially allows better determination of a specific cause for a drug side effect, decreasing the severity of paradoxical reactions and adherence difficulties. However, of overriding importance is mortality associated with delayed ART initiation versus mortality associated with immune restoration disease with early ART. While results of adult randomized trials addressing this question are becoming available, there are little data to inform the 'when to start' question for children.