Association between sputum smear status and local immune responses at the site of disease in HIV-infected patients with pulmonary tuberculosis

SummaryInfection with human immunodeficiency virus (HIV) may affect the clinical presentation of pulmonary tuberculosis (TB). To investigate the association between sputum smear status at presentation and local pulmonary immune responses in HIV-infected patients with pulmonary TB, we compared the cellular and cytokine profiles in bronchoalveolar lavage (BAL) fluid obtained from the site of lung disease in 22 sputum smear- and culture-positive, and 17 sputum smear-negative but culture-positive pulmonary TB patients. Smear-positive patients had significantly higher BAL fluid concentrations of IL-6 (p=0.007), IL-8 (p=0.02), IL-10 (p=0.03) and IFN-γ (p=0.008) than smear-negative patients. No significant differences in the proportions of examined BAL cells were found. We concluded that sputum smear-positive TB was associated with greater pro-inflammatory and immunomodulatory cytokine responses at the site of lung disease than sputum smear-negative disease. The local immune responses may affect the clinical presentation of active pulmonary TB in HIV-infected patients.