Effect of periodontal treatment on the protein composition of whole and parotid saliva.

Cystatins are physiological inhibitors of cysteine proteinases and widely distributed in human tissues and fluids including saliva. Cystatins S, SA, SN, and D are only found in glandular saliva and tear fluid whereas cystatin C has been detected in all tested biological fluids. Previous studies demonstrated that total cystatin activity and cystatin C concentration were highest in whole and parotid saliva of periodontitis patients compared to healthy subjects suggesting a response of the salivary glands to an inflammatory condition of the oral cavity. Based on these results we studied a possible change in the concentration of cystatin S, cystatin C, albumin, IgA, amylase activity, and cystatin activity in a whole and parotid saliva of 20 periodontitis patients as a consequence of periodontal treatment. Saliva samples were quantified for cystatins S and C, albumin, and IgA by enzyme-linked immunosorbent assay. Amylase was determined in an activity assay and total cystatin activity was measured towards pa-pain. The clinical condition of the subjects improved significantly after 6 months of periodontal therapy whereas biochemical analyses of whole and parotid saliva indicated that significant changes in salivary protein composition occurred only in whole saliva. Total cystatin activity (P < 0.05) and cystatin C concentration (P < 0.05) of whole saliva samples collected after periodontal treatment decreased to normal healthy control values. Further, concentrations of cystatin S were unchanged during the periodontal treatment process. These results suggest that other sources of cystatins than the parotid gland i.e.; other salivary glands or crevicular fluid, are involved in the decrease of total cystatin activity in whole saliva after periodontal treatment.