Impact of tobacco use on the development of opportunistic respiratory infections in HIV seropositive patients on antiretroviral therapy

The increased risk of developing lung diseases in cigarette smokers has been well recognized. The association between smoking and the risk of developing pulmonary infections in HIV-1-infected patients, however, which has not been established, was evaluated in the present study. Twenty-seven cases with lower respiratory infections (15 Pneumocystis carinii pneumonia (PCP), 12 TB cases) were compared with 27 age, gender, socio-economic and HIV status-matched patients, without history of respiratory diseases. Medical history and physical examinations were obtained every 6 months. Blood was drawn for CD4 and viral load measurements. A substantial number of HIV + smokers who developed PCP (one-third) had been on highly active retroviral therapy (HAART) for more than 6 months and prophylaxis had been discontinued. Multivariate analyses indicated that in HIV-infected people, after controlling for HIV status and antiretrovirals, cigarette smoking doubled the risk for developing PCP (p = 0.01). Multivariate analyses demonstrated that long-term smoking also increased the risk (2 x) of developing tuberculosis (p = 0.04). Moreover, daily tobacco use seemed to attenuate by 40% the immune and virological response to antiretroviral therapies. These findings indicate that tobacco use significantly increases the risk of pulmonary diseases in HIV infected subjects and has a potential deleterious impact on antiretroviral treatment.