Tobacco Smoking Impairs Immune System in HIV-Infected People

This article was reported by Digital Journal.

Digital Journal reported on a study of the effects of smoking in HIV-infected individuals. Researchers from the University of Miami analyzed the effect of HIV and smoking on the immune system of infected smokers on antiretroviral therapy (ART). The researchers studied four groups of participants: 25 HIV-infected smokers, 25 HIV-infected nonsmokers, 15 HIV-uninfected smokers, and 15 HIV-uninfected nonsmokers. The HIV-infected participants were on ART and had achieved viral suppression. Participants completed questionnaires on drug, tobacco, and alcohol use as well as past and present history, and received physical and laboratory tests.

HIV-infected and -uninfected smokers had significantly higher CD4+ and CD8+ or "helper" T cells, with a greater number in HIV-infected smokers. Microbial translocation was higher in both groups of smokers and correlated with T-cell activation. Also, markers for immune exhaustion were higher in smokers.

Results suggest that smoking in HIV-positive individuals causes increased immune activation, microbial translocation, and impairment of T-cell functions that could influence disease progression and management. Findings also confirmed that T-cell function was reduced in smokers regardless of HIV status, which means that HIV-infected smokers are at higher risk of bronchitis and bacterial pneumonia due to higher immune defects. This finding agreed with that of previous studies on altered immunity in smokers. The researchers suggest additional studies to further evaluate the effect of smoking on immune system impairment and increased disease progression.

The full report, "Tobacco Smoking Increases Immune Activation and Impairs T-Cell Function in HIV Infected Patients on Antiretrovirals: A Cross-Sectional Pilot Study," was published online in the journal PLoS ONE (2014; doi: 10.1371/journal.pone.0097698).