Hy. Chen et al., CATHEPSIN-B, ALPHA(2)-MACROGLOBULIN AND CYSTATIN LEVELS IN GINGIVAL CREVICULAR FLUID FROM CHRONIC PERIODONTITIS PATIENTS, Journal of clinical periodontology, 25(1), 1998, pp. 34-41
Gingival crevicular fluid (GCF) was collected from 16 molar and premol
ar sites in each of 20 chronic periodontitis patients before and after
periodontal therapy using filter paper strips. These were eluted indi
vidually into buffer for determination of cathepsin B and its endogeno
us inhibitors, alpha(2)-macroglobulin and cystatin, Cathepsin B activi
ty was assayed with a fluorogenic peptide substrate, alpha(2)-macroglo
bulin by enzyme-linked immunosorbent assay and cystatin activity by in
hibition of papain, Total amounts of enzyme and inhibitor per GCF samp
le decreased after treatment and correlated positively with pocket dep
th and gingival, bleeding and plaque indices, These comparisons were n
early always statistically significant for pooled site data and someti
mes so for mean patient values, The amounts of alpha(2)-macroglobulin
and cystatin were greater than those of cathepsin B and surprisingly,
enzyme and inhibitor levels correlated positively with each other. Exp
eriments with purified reagents. however, demonstrated that the cathep
sin B: alpha(2)-macroglobulin complex was still active against the low
molecular weight substrate and that cystatin levels In GCF are probab
ly insufficient to inhibit the enzyme substantially These factors may
explain why GCF cathepsin B activity reflects the clinical status of p
eriodontal lesions and has been identified in another study as a promi
sing indicator of disease progression.