Secretory leukoprotease inhibitor: Partnering alpha(1)-proteinase inhibitor to combat pulmonary inflammation

Secretory leukoprotease inhibitor (SLPI) is a low molecular weight serine proteinase inhibitor, notably of neutrophil elastase (NE), which is synthesised and secreted by the pulmonary epithelium. SLPI plays an important role in limiting NE-induced pulmonary inflammation and, significantly, it also possesses anti-HIV activity. SLPI is a significant component of the anti-NE shield in the lung which has different reactivity from, and is therefore complementary to, the anti-NE action of alpha(1)-proteinase inhibitor (alpha(1)-PI). Inhaled recombinant SLPI (rSLPI) could prove beneficial in partnership with alpha(1)-PI in the treatment of a number of inflammatory lung disorders including emphysema, chronic bronchitis, cystic fibrosis, and adult respiratory distress syndrome.