Impact of tuberculosis on HIV disease progression in persons with well-documented time of HIV seroconversion

Tuberculosis (TB) enhances HIV replication in vitro, but its impact on HIV progression at the population level is not established. Studies from industrialized and nonindustrialized countries show contradictory results as to whether TB accelerates HIV progression, although no studies have been conducted in persons with well-documented seroconversion times. Data from HIV seroconverters from 19 cohorts were analyzed to examine the effect of TB on HIV progression comparing persons with TB and persons without TB infected by HIV for the same length of time. TB and other AIDS-defining conditions (ADCs) were fitted as time-dependent covariates, adjusting for age, sex, transmission category, calendar year at risk, and cohort, using Cox proportional hazards models and allowing for late entry. Of 4398 seroconverters, 1294 (29%) developed AIDS. TB accounted for 72 (5.6%) of initial ADCs and for 105 (5.7%) of all ADCs. Survival from HIV seroconversion shows that compared with AIDS-free subjects, the risk of death associated with TB as an initial ADC (hazard ratio [HR] = 23.23, 95% CI: 14.60-36.96) does not differ from that associated with Kaposi sarcoma (HR = 23.47, 95% CI: 16.66-33.05) or esophageal candidiasis (OC)/Pneumocystis carinii pneumonia (PCP) (HR = 30.97, 95% Cl: 24.38-39.34) but is lower than that for opportunistic infections other than TB, OC/PCP (HR = 46.83, 95% Cl: 37.86-47.94) and high-grade non-Hodgkin lymphomas/invasive cervical carcinoma (HR = 92.71, 95% CI: 60.83-141.3). The lowest risk of death was seen, as expected, in AIDS-free subjects. HIV progression is not inherently faster in subjects who develop TB compared with other individuals with AIDS who have been infected by HIV for the same length of time in countries where TB treatment is widely available.