Tuberculosis and the risk of opportunistic infections and cancers in HIV-infected patients starting ART in Southern Africa

Abstract

Objectives: To investigate the incidence of selected opportunistic infections (OIs) and cancers and the role of a history of tuberculosis (TB) as a risk factor for developing these conditions in HIV-infected patients starting antiretroviral treatment (ART) in Southern Africa.

Methods: Five ART programmes from Zimbabwe, Zambia and South Africa participated. Outcomes were extrapulmonary cryptococcal disease (CM), pneumonia due to Pneumocystis jirovecii (PCP), Kaposi's sarcoma and Non-Hodgkin lymphoma. A history of TB was defined as a TB diagnosis before or at the start of ART. We used Cox models adjusted for age, sex, CD4 cell count at ART start and treatment site, presenting results as adjusted hazard ratios (aHR) with 95% confidence intervals (CI).

Results: We analysed data from 175,212 patients enrolled between 2000 and 2010 and identified 702 patients with incident CM (including 205 with a TB history) and 487 with incident PCP (including 179 with a TB history). The incidence per 100 person-years over the first year of ART was 0.48 (95% CI 0.44-0.52) for CM, 0.35 (95% CI 0.32-0.38) for PCP, 0.31 (95% CI 0.29-0.35) for Kaposi's sarcoma and 0.02 (95% CI 0.01-0.03) for Non-Hodgkin lymphoma. A history of TB was associated with cryptococcal disease (aHR 1.28, 95% CI 1.05-1.55) and Pneumocystis jirovecii pneumonia (aHR 1.61, 95% CI 1.27-2.04), but not with Non-Hodgkin lymphoma (aHR 1.09, 95% CI 0.45-2.65) or Kaposi's sarcoma (aHR 1.02, 95% CI 0.81-1.27).

Conclusions: Our study suggests that there may be interactions between different OIs in HIV-infected patients.