Effect of periodontal treatment on the protein composition of whole and parotid saliva
Cystatins are physiological inhibitors of cysteine proteinases and are 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 as compared with healthy subjects, suggesting a response of the salivary glands to an inflammatory condition of the oral cavity.
Based on these results, investigators studied a possible change in the concentration of cystatin S, cystatin C, albumin, IgA, amylase activity, and cystatin activity in whole and parotid saliva of 20 periodontitis patients as a consequence of periodontal treatment. Saliva samples were qualified 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 toward papain. The clinical condition of the subjects improved significantly after six 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 sources of cystatins other 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. [P.W.]
Henskens,Y., F. van der Weijden, P. van der Keijbus, E. Veerman, M. Timmerman, U. van der Velden, and A. Nieuw Amerongen, J Periodont, 67:205, 1996