Salivary Cystatin C and the imbalance between cysteine proteases and their inhibitors in Churg Strauss Syndrome.

Cystatin C is a major constitutive secretory product of alveolar macrophages and a potent regulator involved in the remodeling associated with lung inflammatory processes. Debatable data have been reported on serum Cystatin C levels in asthmatic patients. Recently, serum Cystatin C has been also associated with small vessel vasculitis such as Henoch Schonlein purpura and Kawasaki disease. No data are available on Cystatin C and Churg Strauss Syndrome (CSS), a challenging small vessel vasculitis which combines both vascular inflammatory damage and asthma. This preliminary study demonstrated a peculiar pattern in the proteolytic profile of cysteine proteases and their inhibitors in CSS patients with respect to healthy volunteers. Additiopnal studies are required in order to clarify whether the apparent decrease of Cystatin C has a pathogenetic role in CSS or it might be considered as an epiphenomenon of the concomitant asthma.