Site of Disease and Opportunistic Infection Predict Survival in HIV-associated Tuberculosis

Objective: Infection with HIV adversely affects survival in patients with tuberculosis (TB), even when TB is effectively treated. The aim of this study was to identify the determinants of survival in HIV-associated TB.

Design: Retrospective cohort study.

Setting: Four US academic medical centers.

Patients: An inception cohort of 112 HIV-infected patients (mean age 41 years, 96% men, 46% African American) with their first episode of culture-proven TB.

Outcomes Measures: Observed survival from the date of diagnosis of TB to the date of death or censoring. Independent variables included demographics, HIV-related conditions, risk behavior for HIV, absolute CD4+ counts, and site of disease with Mycobacterium tuberculosis.

Results: Of the 112 patients, 54 (48%) had pulmonary TB alone, 36 (32%) had both pulmonary and extra-pulmonary TB and 22 (20%) had extrapulmonary TB alone. Median CD4+ count was 95 x 10(6)/l (range, 2-767 x 10(6)/l). During follow-up, 45 patients (40%) died. Median survival was shortest in patients with both pulmonary and extrapulmonary disease (8.4 months), followed by extrapulmonary disease alone (15.6 months), then pulmonary disease (30.4 months; P < 0.001, log-rank test). Median survival was also reduced in patients with previous opportunistic infection and in those with CD4+ < 200 x 10(6)/l. In a proportional hazards regression analysis, which adjusted for CD4+ count, extrapulmonary disease and previous opportunistic infection were the only factors independently associated with shorter survival. Of the extrapulmonary sites of disease, TB meningitis was associated with the greatest risk of death.

Conclusion: The site of culture-proven TB at presentation and the history of previous opportunistic infection are important predictors of survival in HIV-infected patients with TB.