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Background: The primary barrier to curing HIV infection is the pool of intact HIV proviruses integrated into host cell DNA throughout the bodies of people living with HIV (PLHIV), called the HIV reservoir. Reservoir size is impacted by the duration of HIV infection, delay in starting antiretroviral therapy (ART), and breakthrough viremia during ART. The leading infectious cause of death worldwide for PLHIV is TB, but we don't know how TB impacts the HIV reservoir. Methods: We designed a case-control study to compare HIV provirus-containing CD4 in PLHIV with vs. without a history of active TB disease. Study participants in the pilot and confirmatory cohort were enrolled at GHESKIO Centers in Port au Prince, Haiti. Intact and non-intact proviral DNA were quantified using droplet digital PCR of PBMC-derived CD4 cells. For a subset, Th1 and Th2 cytokines were assayed in plasma. Kruskal-Wallis tests were used to compare medians with tobit regression for censoring. Results: In the pilot cohort, we found that PLHIV with history of active pulmonary TB (n=20) had higher intact provirus than PLHIV without history of active TB (n=47) (794 vs 117 copies per million CD4, respectively; p<0.0001). In the confirmatory cohort, the quantity of intact provirus was higher in the TB group (n=13) compared with the non-TB group (n=18) (median 102 vs. 0 intact provirus per million CD4, respectively p=0.03). Additionally, we found that the frequencies of CD4+ T cells with any detectable proviral fragment was directly proportional to the levels of IL1B (p= 0.0025) and IL2 (p=0.0002). Conclusions: This is the first assessment of HIV provirus using IPDA in a clinical cohort from a resource limited setting, and the finding of larger reservoir in PLHIV with history of TB has significant implications for our understanding of TB-HIV coinfection and HIV cure efforts in TB-endemic settings.
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INTRODUCTION: Long-term mortality among TB survivors appears to be higher than control populations without TB in many settings. However, data are limited among persons with HIV (PWH). We assessed the association between cured TB and long-term mortality among persons with PWH in Haiti. METHODS: A prospective cohort of PWH from the CIPRA HT-001 trial was followed from study enrolment (August 2005 to July 2008) to study closure (December 2018) to compare mortality between participants with and without TB. The index date for the survival analysis was defined as 240 days after TB diagnosis or randomization date. Time to death was described using Kaplan-Meier curves, and log-rank tests were used to compare time to death between the TB and no-TB cohorts. The association between TB and long-term mortality was estimated with multivariable Cox models. RESULTS: Of the 816 participants in the CIPRA HT-001 trial, 77 were excluded for a history of TB prior to study enrolment and 31 were excluded due to death or attrition prior to the index date, leaving 574 in the no-TB and 134 in the TB cohort. Twenty-four (17.9%) participants in the TB and 48 (8.4%) in the no-TB cohort died during follow-up. Five and 10-year mortality rates were 14.2% and 17.9% respectively, in the TB cohort, and 6.1% and 8.4% in the no-TB cohort. In Kaplan-Meier analysis, participants in the TB cohort had a significantly shorter time to death (log-rank p < 0.001). In multivariable analysis, TB treatment was the only predictor of mortality (HR: 2.78; 95% CI: 1.61, 4.79). Sensitivity analyses, which included only baseline TB cases, an index date of two years after TB diagnosis, and study enrolment and case-control matching yielded results that were consistent with primary analyses. CONCLUSIONS: PWH who are successfully treated for TB have higher long-term mortality than those who are never diagnosed with TB, even after accounting for acute TB-related mortality. A better understanding of the underlying mechanisms associated with TB sequelae is critically needed to guide specific interventions. Until then, more aggressive measures for health promotion and disease prevention are essential to improve long-term survival for PWH after TB treatment.