Cystatins S and C in Human Whole Saliva and in Glandular Salivas in Periodontal Health and Disease

Cystatins are inhibitors of cysteine proteinases and could play a protective and regulatory role under inflammatory conditions. Since total cystatin activity of whole saliva was increased in periodontal patients (Henskens et al., 1993), we wanted to investigate the types or origins of cystatins involved in this increase. Distinct types of cystatins were identified by isoelectric focusing and immunoblotting with specific antibodies against one of the salivary acidic isoforms, cystatin S, and the widely distributed basic cystatin C. Clarified human whole saliva (CHWS) of healthy subjects contained cystatin S, whereas cystatin C was barely detectable. In contrast, in CHWS of gingivitis and periodontitis patients, both cystatin C and S levels were higher. The origin of cystatin activity was investigated by collecting submandibular (SM), sublingual (SL), and parotid (PAR) saliva from seven subjects with mild gingivitis. Total cystatin activity was about five times higher in SM saliva than in PAR saliva. In SM ...