Background
Disseminated tuberculosis is strictly defined as isolation of Mycobacterium tuberculosis from blood or bone marrow, liver biopsy, or from specimens from ≥2 noncontiguous organs. Disseminated tuberculosis is associated with compromised cell-mediated immunity and the bacteremic form is rapidly fatal in a large proportion of HIV-infected patients. Early recognition and treatment are likely to be important in improving patient outcomes. Although research has identified a number of clinical and laboratory features that may assist with recognition of patients with bacteremic disseminated tuberculosis, non-specific clinical findings and lack of typical features of pulmonary tuberculosis complicate diagnosis. Randomized trials have confirmed that early initiation of antiretroviral therapy (ART) is associated with improved outcomes for HIV and tuberculosis co-infected patients. However, these studies have focused primarily on pulmonary tuberculosis, leaving unanswered questions about the timing and impact of ART in patients with confirmed disseminated tuberculosis. Research suggests that patients with disseminated and extra-pulmonary forms of tuberculosis may represent a special group that may experience worse outcomes, including greater risk for the tuberculosis immune reconstitution inflammatory syndrome (IRIS).
In order to strengthen data on clinical predictors of M. tuberculosis bacteremia and to assess the effect of M. tuberculosis bacteremia on ART treatment outcomes and toxicities, we conducted a planned analysis of patients enrolled in the AIDS Clinical Trials Group (ACTG) A5221 strategy study of early versus later initiation of antiretroviral therapy for HIV-infected persons treated for tuberculosis with CD4 < 250 cells/mm (STRIDE), who received a mycobacterial blood culture as part of their baseline evaluation. Participants with and without bacteremic disseminated tuberculosis were compared.