Elevated Levels of α-Defensins in Plasma and BAL Fluid of Patients With Active Pulmonary Tuberculosis

To investigate the role of neutrophil peptides named α-defensins in patients with pulmonary tuberculosis (TB). Thirty-seven patients with TB and 25 healthy subjects. Concentrations of α-defensins (human neutrophil peptide [HNP]-1, HNP-2, and HNP-3) were measured by radioimmunoassay in plasma and BAL fluid (BALF). Concentrations of α-defensins were significantly higher in plasma and BALF of patients with TB than in healthy subjects. In BALF of patients with TB, the concentration of α-defensins correlated positively with the levels of interleukin 8, and higher concentrations of α-defensins in BALF were also detected in patients with cavitary lesions. There was an inverse relationship between plasma α-defensins and FEV1/FVC ratio before treatment, and between plasma concentrations of α-defensins before treatment and the improvement in percentage of vital capacity after treatment. Plasma α-defensin concentrations returned to the normal range after treatment. Our data suggest that α-defensins released from neutrophils may play an important role in the pathogenesis of TB, and that plasma α-defensin concentration may be a useful marker of disease severity and deterioration of pulmonary function.