[Beta-defensins in plasma and bronchoalveolar lavage fluid in patients with non-tuberculous mycobacterium infection]

We measured the levels of beta-defensin 1 and 2 (HBD-1, 2), novel antimicrobial peptides in plasma and in bronchoalveolar lavage fluid (BALF) from patients with with non-tuberculous mycobacterium infection (NTM). Plasma HBD-2 levels in NTM patients before treatment were higher than those in the controls, while the HBD-1 levels were similar to the control levels. High levels of HBD-2, but not of HBD-1, in BALF were also observed in NTM patients. In NTM, a positive correlation was found between HBD-2 levels in BALF and plasma, and also between HBD-2 and IL-1 beta levels in BALF. NTM patients with cavities or ectasia on chest radiography had higher HBD-2 levels in BALF than those without. Plasma HBD-2 levels in NTM patients were markedly decreased after successful treatment, while those of patients with an intractable mycobacterium infection maintained the same high plasma HBD-2 levels as those before treatment. These findings suggest that HBD-2 may participate in the host defense and plasma HBD-2 levels may reflect disease activity in pulmonary NTM.