β-Defensins and panbronchiolitis

Human β-defensins (HBD) are now recognised as important antimicrobial peptides forming part of the innate immune system. In this month’s issue of Thorax Hiratsuka and colleagues describe a study of HBD-1 and HBD-2 in plasma and bronchoalveolar lavage (BAL) fluid in patients with diffuse panbronchiolitis (DPB) and compare the findings with human volunteers (HV). DPB is a condition associated with chronic airway inflammation and airway infection. They show that HBD-1 and HBD-2 levels are increased in the BAL fluid of patients with DPB and, in the case of HBD-2, relationships were found with inflammatory cells in the BAL fluid. Macrolide antibiotics are useful as treatment in DPB and this study shows that, after 6 months’ treatment with macrolides, HBD-2 levels in the BAL fluid are reduced. The authors discuss some mechanisms for the airway inflammation in DPB and suggest …