Unsuccessful tuberculosis treatment outcomes—including death, treatment failure, losses to follow-up, and recurrence—not only contribute to individual morbidity and mortality, but also influence community transmission and drug resistance. With current tuberculosis treatment lasting at least 6 months, early treatment predictors are needed to identify patients with tuberculosis at greatest risk of unsuccessful outcomes to enable timely tailoring of treatment programs and interventions toward those who need it most.

In a prospective study published in The Journal of Infectious Diseases, my colleagues and I sought to examine, among 547 patients with culture-confirmed, drug-susceptible, pulmonary tuberculosis whether 1) HIV influences weight change during the first 2 months of treatment, and 2) whether HIV, weight change, or both impact tuberculosis treatment outcomes.

Results suggest that persons living with HIV (PLWHIV) gained a median of 1.3 kg less weight during the first 2 months of treatment than those who were HIV-negative. Differences between the groups were more pronounced among PLWH with low CD4 cell counts (CD4 ≤50μL) or high viral loads (viral load ≥400 copies/mL). Additionally, HIV and weight change were predictors of unsuccessful treatment outcomes after adjusting for relevant confounders.

We conducted mediation analysis to examine the extent to which HIV impacts tuberculosis treatment outcome if patients with and without HIV gained the same amount of weight. Results revealed that 35% of the effect of HIV on tuberculosis treatment outcome could be reduced if patients with and without HIV gained the same amount of weight during tuberculosis treatment, suggesting HIV alone additionally exerts direct influence on tuberculosis treatment outcome.

Because tuberculosis is a disease of wasting, nutritional improvement during treatment is an essential aspect of recovery. Our study proposes that weight gain during tuberculosis treatment can be used to monitor treatment efficacy and highlights that PLWHIV—especially those with more severe presentation—gain less weight during early tuberculosis treatment and are at greater risk of unsuccessful tuberculosis treatment than patients who are HIV-negative, suggesting they would likely benefit from more targeted treatment. However, additional research is needed to identify what types of interventions would best promote weight gain and recovery during tuberculosis treatment, particularly among PLWHIV.