Jussi Leppilahti

Detection of gingival crevicular fluid MMP‐8 levels with different laboratory and chair‐side methods

OBJECTIVE The aim of the study was to compare four methods for gingival crevicular fluid (GCF) matrix metalloproteinase (MMP)-8 detection. METHODS Matrix metalloproteinase-8 levels from 20 GCF samples from two periodontally healthy subjects, 18 samples from two patients with gingivitis and 45 samples from six patients with moderate to severe periodontitis, altogether 83 samples, were analysed using (1) a time-resolved immunofluorometric assay (IFMA), (2) an MMP-8 specific chair-side dip-stick test, (3) a dentoAnalyzer device and (4) the Amersham ELISA kit. Western immunoblot using same monoclonal anti-MMP-8 as in IFMA and dentoAnalyzer was used to identify molecular forms of MMP-8 in GCFs. RESULTS Correlation between IFMA and dentoAnalyzer results calculated with Spearmans correlation coefficient was 0.95 (P = 0.01). The chair-side dip-stick test results were well in line with these assays. Periodontitis sites with unstable characteristics were differentiated with these methods. The Amersham ELISA results were not in line with the findings by other methods. CONCLUSIONS Immunofluorometric assay and dentoAnalyzer can detect MMP-8 from GCF samples and these methods are comparable. Using Western immunoblot, it was confirmed that IFMA and dentoAnalyzer can detect activated 55 kDa MMP-8 species especially in periodontitis-affected GCF. dentoAnalyzer is among the first quantitative MMP-8 chair-side testing devices in periodontal and peri-implant diagnostics and research.

Collagenase-2 (MMP-8) as a point-of-care biomarker in periodontitis and cardiovascular diseases. Therapeutic response to non-antimicrobial properties of tetracyclines

Neutrophil collagenase or collagenase-2 (matrix metalloproteinase [MMP]-8) belongs to the collagenase subgroup of the MMP superfamily of calcium- and zinc-dependent neutral proteinases. MMP-8 is catalytically the most competent proteinase to initiate type I collagen and extracellular matrix degradation associated with periodontal and peri-implant tissue destruction leading to tooth and dental implant loss. Regarding cardiovascular diseases, pathologically excessive MMP-8 has been implicated in atherosclerotic plaque destabilization and rupture probably through its proteolytic ability to thin the protecting collagenous fibrous cap lining coronary and other arteries. During the initiation and course of inflammatory responses in periodontitis, peri-implantitis and cardiovascular diseases, proinflammatory mediators including especially MMP-8 are up-regulated not only in affected tissues but also in the secreted, disease-affected, oral fluids (gingival crevicular fluid [GCF], peri-implant sulcular fluid [PISF], mouthrinse and saliva) as well as in serum and plasma. Regarding periodontitis, peri-implantitis and cardiovascular diseases, the oral fluid and serum MMP-8 analysis has proven to be a sensitive and an objective biomarker as an indicator of health, pathologic processes and pharmacologic response to therapeutic intervention including doxycycline medication as an MMP inhibitor. Oral fluids, i.e., GCF, PISF, mouthrinse and saliva are easily and non-invasively collected for the site- and patient-specific diagnostic analysis in periodontitis and peri-implantitis, whereas serum and/or plasma sample collection is required for diagnosis and monitoring of cardiovascular diseases. Research in periodontology and cardiology has identified a need for the development of innovative point-of-care diagnostic tests for MMP-8. We summarize and review the recent studies on these topics.

Matrix metalloproteinases and myeloperoxidase in gingival crevicular fluid provide site‐specific diagnostic value for chronic periodontitis

AIM To identify the diagnostic accuracy of gingival crevicular fluid (GCF) candidate biomarkers to discriminate periodontitis from the inflamed and healthy sites, and to compare the performance of two independent matrix metalloproteinase (MMP)-8 immunoassays. MATERIALS AND METHODS Cross sectional study. GCF (N = 58 sites) was collected from healthy, gingivitis and chronic periodontitis volunteers and analysed for levels of azurocidin, chemokine ligand 5, MPO, TIMP-1 MMP-13 and MMP-14 by ELISA or activity assays. MMP-8 was assayed by immunofluorometric assay (IFMA) and ELISA. Statistical analysis was performed using linear mixed-effects models and Bayesian statistics in R and Stata V11. RESULTS MMP-8, MPO, azurocidin and total MMP-13 and MMP-14 were higher in periodontitis compared to gingivitis and healthy sites (p < 0.05). A very high correlation between MPO and MMP-8 was evident in the periodontitis group (r = 0.95, p < 0.0001). MPO, azurocidin and total levels of MMP-8, MMP-13 and MMP-14 showed high diagnostic accuracy (≥0.90), but only MMP-8 and MPO were significantly higher in the periodontitis versus gingivitis sites. MMP-8 determined by IFMA correlated more strongly with periodontal status and showed higher diagnostic accuracy than ELISA. CONCLUSIONS MPO and collagenolytic MMPs are highly discriminatory biomarkers for site-specific diagnosis of periodontitis. The comparison of two quantitative MMP-8 methods demonstrated IFMA to be more accurate than ELISA.

Analysis of matrix metalloproteinases, especially MMP-8, in gingival creviclular fluid, mouthrinse and saliva for monitoring periodontal diseases.

Matrix metalloproteinase-8 is a promising candidate biomarker for oral fluid (gingival crevicular fluid, peri-implant sulcular fluid and saliva) and mouthrinse chair-side/point-of-care diagnostics to predict, diagnose and determine the progressive phases of episodic periodontitis and peri-implantitis, as well as to monitor the treatments and medications. Matrix metalloproteinase-8 can be used alone or together with interleukin-1beta and Porphyromonas gingivalis to calculate cumulative risk score at the subject level as a successful diagnostic tool, especially in large-scale public health surveys, in which a thorough periodontal examination is not feasible.

Oral rinse MMP-8 point-of-care immuno test identifies patients with strong periodontal inflammatory burden

OBJECTIVE To determine whether oral rinse matrix metalloproteinase (MMP)-8 levels, measured by three different methods, tissue inhibitor of matrix metalloprotease-1 (TIMP-1) levels and elastase activity differentiate subjects with different periodontal condition; and second, to find out if MMP-8 levels were comparable among the methods used. METHODS MMP-8 levels were analysed with an immunofluorometric method (IFMA), dentoELISA and commercial ELISA. Also TIMP-1 levels and elastase activity were measured. For statistical analysis 214 study subjects were categorized into four groups, specified by the presence and number of moderate (4-5mm) and deep (≥6mm) periodontal pockets, and bleeding on probing percentage. RESULTS MMP-8 levels especially measured by dentoELISA and adjusted to the number of teeth per subject differentiated the study group with strong periodontal inflammatory burden from groups with lower levels. This was also verified with receiver operating characteristic (ROC) analysis. Elastase activity associated with higher IFMA and dentoELISA MMP-8 levels. IFMA MMP-8/TIMP and dentoELISA MMP-8/TIMP-1 tended to be higher with the increasing level of periodontal inflammatory burden. TIMP-1 levels decreased with increasing age. CONCLUSIONS Oral rinse MMP-8 together with TIMP-1 analysis may have potential in complementary periodontal diagnostics. dentoELISA can be applied in quantitative oral rinse chair side biomarker diagnostics.

Gingival crevicular fluid matrix metalloproteinase-8 levels predict treatment outcome among smokers with chronic periodontitis.

BACKGROUND Molecular biomarkers are needed for diagnostic use in periodontal diseases. The aim of this study is to explore different gingival crevicular fluid (GCF) matrix metalloproteinase-8 (MMP-8) patterns in smokers and non-smokers with chronic periodontitis (CP) and test the utility of baseline GCF MMP-8 levels in predicting categorically assessed treatment outcomes. METHODS The study population comprised 15 patients with CP (five non-smokers and 10 smokers). GCF sampling of five to seven periodontal sites per patient was done at baseline, post-treatment, and bimonthly during the maintenance period from 8 to 12 months. GCF MMP-8 levels were measured with an immunofluorometric assay. MMP-8 response patterns were explored by cluster analysis. The ability of baseline MMP-8 levels to predict categorical treatment outcomes was analyzed with receiver operating characteristic curves. RESULTS GCF MMP-8 response patterns could be clustered into two different site profiles among both smokers and non-smokers. Smoker site profiles 1 and 2 had significantly different clinical attachment level and gingival recession changes by the end of the maintenance period. In smoker sites, baseline MMP-8 levels significantly predicted the categorical treatment outcome. CONCLUSIONS Baseline GCF MMP-8 levels strongly predict how MMP-8 levels behave during the maintenance period. In smoker sites, high baseline MMP-8 levels indicate weak treatment response.

The Utility of Gingival Crevicular Fluid Matrix Metalloproteinase-8 Response Patterns in Prediction of Site-Level Clinical Treatment Outcome

BACKGROUND Different gingival crevicular fluid (GCF) matrix metalloproteinase (MMP)-8 response patterns were studied among non-smoking and smoking patients with chronic periodontitis (CP) and generalized aggressive periodontitis (GAgP) to test the utility of GCF MMP-8 levels predicting the site-level treatment outcome. METHODS Data from four independent longitudinal studies were combined. Altogether, the studies included 158 periodontal sites from 67 patients with CP and 32 patients with GAgP, and GCF samples were collected at baseline, after the treatment, and during the 6-month maintenance period. All GCF samples were analyzed by immunofluorometric assay for MMP-8. Different site-level MMP-8 response patterns were explored by the cluster analysis. Most optimal MMP-8 cutoff levels were searched with receiver operating characteristic analyses, and the predictive utility of defined levels was tested. RESULTS Distinct types of MMP-8 response patterns were found in both smokers and non-smokers. MMP-8 levels exceeding the optimal cutoff levels separately defined for smokers and non-smokers indicated increased risk for compromised treatment outcome at baseline and during the maintenance period. Seventy-one percent of non-smokers (positive likelihood ratio of 4.22) and 88% of smokers (positive likelihood ratio of 5.00) with positive test results at both baseline and the maintenance period had compromised treatment outcome. The double-positive result indicated 46% and 39% point risk increase for the compromised outcome, respectively. CONCLUSION GCF MMP-8 analysis with defined cutoff levels could be used to predict the site-level treatment outcome and for longitudinal monitoring of the disease status during the maintenance period.

Active Matrix Metalloproteinase-8: Contributor to Periodontitis and a Missing Link Between Genetics, Dentistry, and Medicine

Periodontitis is one of the most common infection-induced inflammatory tissue destructive diseases globally. According to the epidemiological studies in Western countries, about 30% of populations are affected by periodontitis [1]. The pathogenesis of periodontitis can be briefly described and summarized as follows: the dental plaque, a bacterial biofilm, induces an inflammatory and immune responses in the adjacent gingival and periodontal or peri-implant tissues. The cells of the immune and inflammatory system are together with resident gingival cells (including fibroblasts, cementoblasts, and epithelial cells, bone cells) triggered to express and release pro-inflammatory cytokines, reactive oxygen species, and matrix metalloproteinases (MMPs) [2–5]. MMPs are genetically distinct but structurally related proteinases that can degrade not only almost all extracellular matrix proteins but also non-matrix bioactive molecules such as growth factors, serpins, insulin receptor, apolipoprotein-1, complement components, and pro- and anti-inflammatory cytokines and chemokines [2–5]. Thus, MMPs can modify immune responses [2–5]. The active form of catalytically competent matrix metalloproteinase-8 (aMMP-8; neutrophil collagenase or collagenase-2) is the predominant MMP in periodontitis-affected gingiva, gingival crevicular fluid (GCF), peri-implant sulcular fluid (PISF), saliva, and mouthrinse [2–5]. MMP-8 cleaves preferably and efficiently the interstitial collagens, mainly type I fibers of the gingival and periodontal tissues, leading to irreversible soft and hard tissue destruction, i.e., the development of periodontal pockets and attachment loss, and eventually leading to tooth loss [2–5]. Physiological levels of MMP-8 in periodontal tissue also participate to protective and anti-inflammatory resolution of infection-induced tissue destruction [6, 7].

Diagnosis of Newly Delivered Mothers for Periodontitis with a Novel Oral-Rinse aMMP-8 Point-of-Care Test in a Rural Malawian Population

A novel qualitative point-of-care test of activated matrix metalloproteinase-8 (aMMP-8) using noninvasive oral rinse sampling procedures has been developed for the early detection of collagen breakdown indicating periodontal tissue destruction. The main object of this study was to assess the reliability of the test in a low-income setting to identify participants with history of periodontal destruction detected as alveolar bone loss (ABL) in radiographs. This cross-sectional study included 486 women who had recently delivered in rural Malawi. The aMMP-8 test and dental panoramic radiographs were taken within 48 h of delivery. The performance of the test in comparison to radiological examinations was tested by following the standards for reporting of diagnostic accuracy studies protocol (STARD) with respective statistical measures and 95% confidence intervals. From the 486 eligible participants, 461 mothers with complete data, aged from 15 to 46 years (mean 24.8, SD 6.0) were included in the analysis. ABL was identified in 116 of 461 participants. There was 56% agreement between the aMMP-8 test results and detected ABL (yes or no) in radiographs. Calculated sensitivity of the test was 80% (72–87%), specificity 48% (43–54%), positive predictive value 34% (31–37%), negative predictive value 88% (83–91%), positive likelihood ratio 1.55 (1.35–1.77), and negative likelihood ratio 0.41(0.28–0.60). The aMMP-8 test sensitivity and negative predictive value to identify the ABL cases were relatively high, but there was additionally a high rate of test-positive results in participants without ABL, especially in young mothers, leading to low overall agreement between the test results and radiological bone loss. Further longitudinal studies are needed to examine if the test positive subjects are in risk of future bone loss before the detectable signs of periodontitis in radiographs.

Topic: aMMP-8 Oral Fluid PoC Test

There is rising interest about influences of periodontal diseases on systemic health, while traditional measures cannot quantify periodontal inflammation. Confusing case definitions make the need to quantify periodontal inflammation greater than ever. Modern measures of periodontal inflammation depend on metabolism-mediated changes in salivary metabolites (salivary metabolomics)—an extra mile in salivary diagnostics.