Second-Line Antiretroviral Treatment Outcome in HIV-Infected Patients Coinfected with Tuberculosis in Pakistan

Abstract

Background. Tuberculosis (TB) coinfection in human immunodeficiency virus- (HIV-) infected patients is considered a risk of antiretroviral therapy (ART) failure. Coadministration of antitubercular therapy (ATT) with ART is another challenge for TB management. Objective. The study was aimed at investigating contributing factors affecting treatment outcomes in HIV-/TB-coinfected patients. Design. Cross-sectional. Setting. Samples were collected from the Pakistan Institute of Medical Sciences Hospital Islamabad. Subject and Methods. Clinicodemographic and immunovirological factors between the two groups were compared. The Student $t$ -test and chi-square test were applied to compare outcome variables, and logistic regression was applied to determine the effect of TB on virological failure (VF). Main Outcome Measures. TB coinfection did not increase VF even in univariate ( $p=0.974$ ) and multivariate analysis at 6 and 12 months of 2nd-line ART start. ARV switching was significant ( $p=0.033$ ) in TB-coinfected patients. VF was significantly high in ATT-coadministered patients along with a viral load of ≥1000 ( $p=0.000$ ). Sample Size and Characteristics. We recruited seventy-four HIV patients on 2nd-line ART; 33 coinfected with TB were followed for at least 12 months. Conclusion. In HIV-/TB-coinfected patients, CD4 count, CD4 gain, and VF remained comparable to HIV patients with no TB infection. ATT significantly affects the treatment outcome, suggesting drug-to-drug interactions. These factors are important to revisit the therapeutic guidelines to maximize the benefit of dual therapy in resource-limited settings.