Levels of interferon-γ and interleukin-2 receptor-α for bronchoalveolar lavage fluid and serum were correlated with clinical grade and treatment of pulmonary tuberculosis

OBJECTIVE: We investigated possible correlations for interferon-γ (IFN-γ) and soluble interleukin-2 receptor-α (sIL-2R-α) levels in bronchoalveolar lavage fluid (BALF), and clinical grade of pulmonary tuberculosis (TB), which is determined by factors such as extent of pulmonary involvement, fever and loss of body weight. DESIGN: In order to explore these correlations and address associated questions, BALF was collected from 45 patients presenting with active pulmonary TB and 14 healthy controls. Repetitive BALF was collected in 17 patients after 3 months of anti-tuberculosis chemotherapy. The epithelial lining fluid (ELF) levels for IFN-γ and sIL-2R-α were measured using enzyme-linked immunosorbent assay (ELISA) after standardization with urea. RESULTS: Patients with higher-grade pulmonary TB (i.e., with more advanced pulmonary involvement, fever or body weight loss), revealed significantly higher ELF levels for IFN-γ and sIL-2R-α compared to those with lower grade pulmonary TB. Similar results were also determined for sIL-2R-α serum levels, but not for IFN-γ serum levels. After anti-tuberculosis chemotherapy the elevated cytokine levels for ELF and serum significantly decreased in accordance with radiographic improvement. CONCLUSIONS: ELF levels of IFN-γ and sIL-2R-α were correlated with disease grading of pulmonary TB and decreased after anti-tuberculosis chemotherapy.