Proteases and inhibitors in the plasma of patients with periodontal disease

Detection of stable and active periodontitis sites by clinical assessment and gingival crevicular acute-phase protein levels

The aim of the present study was to investigate whether incipient periodontal disease breakdown could be associated with changes in gingival crevicular fluid (GCF) acute-phase protein levels. In addition, the potential of clinical indices to act as predictors of significant attachment level (AL) change was investigated. AL measurements were taken at baseline and 3 months using the Florida Probe stent handpiece from a total of 384 sites in 38 patients. The average standard deviation of duplicate AL measurements was 0.423. When the tolerance method was used to detect significant AL change, 3.9% of the sites lost attachment. When a less stringent criterion of AL change of > or = 1 mm was used 9.9% of the sites lost attachment during the 3-month period. With the exception of probing depth, baseline clinical parameters failed to predict AL change. Fourteen active periodontitis sites that demonstrated significant attachment loss were paired to stable periodontitis sites within the same patient. The levels of four acute-phase proteins, namely alpha 2-macroglobulin (alpha 2-M), alpha 1-antitrypsin (alpha 1-AT), transferrin (TF) and lactoferrin (LF), and also albumin (Alb) were assessed in the same gingival crevicular fluid sample using sandwich ELISAs. Results were expressed either as ng/30 s and ng/microgram Alb. Acute-phase protein levels in GCF failed to differentiate between active and stable periodontitis sites at baseline. In conclusion, the degree of gingival inflammation of the tissues adjacent to the crevice/pocket seems to influence the levels of protease inhibitors and iron-binding proteins in GCF to a greater extent than probing attachment loss.

Neutrophil lysosomal nonoxidative microbicidal proteins in early-onset periodontitis

The purpose of this study was to evaluate whether the reduced microbicidal activity of polymorphonuclear leukocytes (neutrophils) in patients with early-onset periodontitis is associated with a deficiency of nonoxidative microbicidal proteins. Neutrophils from 10 patients with early-onset periodontitis and 8 healthy control subjects were assessed for elastase isozymes 1 through 4, cathepsin G isozymes 1 through 4 and defensins (HNP-1, HNP-2 and HNP-3) using cationic and acid urea polyacrylamide gel electrophoresis. The results showed that both the total content and the relative distribution of elastase and cathepsin G isozymes was normal in neutrophils of patients with early-onset periodontitis. However, the HNP-3 content was significantly reduced in neutrophils from patients with generalized early-onset periodontitis. These findings indicate that the impaired microbicidal activities of neutrophils in patients with early-onset periodontitis does not appear to be based on an elastase or cathepsin G abnormality in neutrophils. Due to the high variability of HNP-1 + 2 and HNP-3 in neutrophils of control subjects, the reduced HNP-3 content in neutrophils probably plays a minor role in the pathogenesis of generalized early-onset periodontitis.

Elastase release from gingival crevicular and peripheral neutrophils in periodontitis and health

The activity of elastase increases significantly in the gingival sulcus during inflammation. The release of this enzyme from crevicular and peripheral polymorphonuclear leucocytes (PMNs) was studied in seven patients with gingivitis, six with adult periodontitis, seven with rapidly progressive periodontitis and in nine healthy subjects. Peripheral PMNs were isolated from blood and crevicular PMNs from gingival washings. After preincubation with cytochalasin B, the same numbers of crevicular and peripheral cells were incubated either in phosphate-buffered saline (spontaneous release) or in the same buffer containing formyl methionyl-leucyl-phenyl-alanine (stimulated release). Elastase activity was measured in the supernatant by a fluorimetric technique. The results confirm that compared to peripheral PMNs, crevicular cells show a higher spontaneous release of elastase and a lower stimulated release. The activity of elastase released either spontaneously or after stimulation of crevicular cells was significantly lower in the controls as compared with cells obtained from patients with gingivitis or periodontitis. Crevicular PMNs collected from patients with deeper pockets appear to release larger amounts of elastase than those from controls.

Gingival crevicular fluid elastase-inhibitor complex: correlation with clinical indices and subgingival flora

This investigation analyzed, in a cross-sectional study, the possible relationship between gingival crevicular fluid (GCF) elastase-like protease (ELP) levels and the periodontal clinical parameters or the presence of specific bacteria in subgingival plaque. A total of 388 periodontal sites from 8 adult periodontitis patients were examined for plaque index (PII), gingival index (GI), pocket depth (PD) and alveolar bone loss (ABL). GCF ELP levels were determined as ELP alpha-1 protease inhibitor (ELP-alpha 1-PI) complex levels with a commercially available ELISA. Subgingival plaque samples were tested for the presence of Bacteroides gingivalis, B. intermedius and Actinobacillus actinomycetemcomitans by indirect immunofluorescence (IF) microscopy. GCF ELP-alpha 1-PI levels were then correlated with clinical periodontal indices and proportions of IF-positive bacteria per site. Statistically significant positive correlations were found between GCF ELP-alpha 1-PI concentrations and subgingival Bacteroides proportions. When the sites examined were analyzed depending on the level of each clinical parameter, the levels of these correlations changed. A. actinomycetemcomitans correlated highly (r = 0.716) with ABL for sites with low GI score. The correlations between GCF ELP-alpha 1-PI and B. gingivalis (r = 0.642) or B. intermedius (r = 0.774) were the highest for ABL less than or equal to 20% and PD less than or equal to 3 mm, respectively. The strong association between GCF ELP-alpha 1-PI concentrations and subgingival bacteria previously associated with advancing periodontitis indicates that measurement of GCF ELP-alpha 1-PI concentrations may be useful in the evaluation of periodontal sites, especially those with very little or no tissue destruction.

Enhanced superoxide production with no change of the antioxidant activity in gingival fluid of patients with chronic adult periodontitis

In the gingival crevicular fluid (GCF) of control and chronic adult periodontitis (CAP) patients there is a spontaneous release of O2- radicals from polymorphonuclear leukocytes (PMN). The addition of the exogenous stimuli phorbol myristate acetate (PMA) decreased the O2-. formation in control GCF, while in CAP patients produced a marked enhancement of O2-. generation. The circulating PMN of control subjects did not show a spontaneous O2-. formation, differently from CAP patients. On the contrary, a similar O2-. production was measured when the circulating PMN were stimulated with PMA. Moreover, the antioxidant activity measured in 10 microliters of cell free gingival supernatant (GS) of control and CAP patients had the same values by inhibiting 12.6% and 18.9% respectively of the O2- formation supported by a xanthine/xanthine oxidase system. Probably, the protective or destructive effect of PMN in GCF of CAP patients depends on the variations of the rate of O2- formation in respect to the intrinsic antioxidant property of GS.