ELANE and bronchiectasis: Consistent with this observation, human leukocyte elastase (NE) also binds to soluble high-Mr heparin sulfate proteoglycans (including syndecans-1 and -4) shed into bronchial secretions from patients with bronchiectasis [23] and NE bound to these syndecans retains its catalytic activity against extracellular matrix substrates and is protected from α-1-antitrypsin [23].