Cystatins S and C in human whole saliva and in glandular salivas in periodontal health and disease
Cystatins are physiological inhibitors of cysteine proteinases and are widely distributed in human tissues and body fluids. Cystatins can be classified into three families on the basis of structural and functional characteristics. Family 1 cystatins (stefins A and B) are mainly found intracellularly and have molecular weights of 12kD. Family 2 cystatins (S, SA, SN, C) are essentially found extracellularly and have a molecular weight of 14kD. Family 3 cystatins are high molecular-weight kininogens. One objective of the present study was to investigate which of the cystatins of family 2 had been increased in subjects with gingivitis or periodontitis. Another objective was to determine the origin of the increased cystatin activity in whole saliva by analysis of glandular saliva samples from various subjects.
The relative contributions of cystatin S and C to the cystatin activity in whole saliva were investigated in seven healthy subjects, five gingivitis subjects, and four periodontitis patients. The healthy subjects had no periodontal breakdown and a bleeding upon probing (BOP) score of < 0.2. The gingivitis subjects had no periodontal breakdown but a BOP score 21.2. The periodontitis patients had radiographic evidence of alveolar bone loss and at least 10 sites with a probing depth of 2 7 mm. Human whole saliva HWS), parotid (PAR) saliva, and submandibular (SM) and sublingual (SL) saliva samples were collected, and isoelectric focusing and immunological detection performed. Bands of the acidic cystatin S were detected in HWS samples from all subjects, but the most intense bands were seen in gingivitis and periodontitis subjects. Cystatin C bands were barely detected in HWS from healthy individuals. Cystatin C was clearly higher in all gingivitis and periodontitis patients. The mean total cystatin activity of SM was about five times as high as the mean value of PAR. The authors conclude that the previously observed increase of cystatin activity in whole saliva in inflammatory disease is partially due to an increased glandular output of both cystatin S and C. [M.J.D.]
Henskens,Y.M.C., E.C.I.Veerman, M.S. Mantel, U. van derVelden, and A.V. Nieuw Amerongen, J Dent Res, 73:1606, 1994