Relationship between levels of aspartate aminotransferase in gingival crevicular fluid and conventional measures of periodontal status assessed using PocketWatch: a cross-sectional study

A Prototype Antibody-based Biosensor for Measurement of Salivary MMP-8 in Periodontitis using Surface Acoustic Wave Technology

Periodontitis is an economically important disease which is highly prevalent worldwide. Current diagnostic approaches are time-consuming and require interpretation of multiple aspects of clinical and radiographic assessment. Chair-side monitoring of inflammatory mediators of periodontitis could provide immediate information about disease activity, which can inform patient management. We aimed to develop a novel prototype biosensor to measure salivary matrix metalloproteinase-8 (MMP-8) using specific antibodies and surface acoustic wave (SAW) technology. The analytical performance of the prototype biosensor was compared to standard enzyme-linked immunosorbent assay (ELISA) using unstimulated saliva samples obtained from patients with periodontitis before and after non-surgical treatment (N = 58), patients with gingivitis (N = 54) and periodontally healthy volunteers (N = 65). Receiver operator characteristic (ROC) analysis for distinguishing periodontitis from health revealed an almost identical performance between the sensor and ELISA assays (area under curve values (AUC): ELISA 0.93; SAW 0.89). Furthermore, both analytical approaches yielded readouts which distinguished between heath, gingivitis and periodontitis, correlated identically with clinical measures of periodontal disease and recorded similar post-treatment decreases in salivary MMP-8 in periodontitis. The assay time for our prototype device is 20 minutes. The prototype SAW biosensor is a novel and rapid method of monitoring periodontitis which delivers similar analytical performance to conventional laboratory assays.

Presence of Aspartate Aminotransferase in Peri-Implant Crevicular Fluid With and Without Mucositis

The aim of this study was to assess the presence of aspartate aminotransferase (AST) in peri-implant crevicular fluid, with or without clinical signs of mucositis, to determine its predictive diagnostic value, sensitivity, and specificity. The AST levels were determined (at a threshold of 1200 µIU/mL) for 60 clinically successful implants in 25 patients with or without peri-implant mucositis. Samples were taken prior (AST1) to peri-implant probing with a manual constant-pressure probe (0.2 N) and 15 minutes after probing (AST2). Clinical assessments included radiographic determination of preexisting bone loss, probing, and the evaluation of mucositis, plaque, and bleeding upon probing. Analysis was performed at both the level of the implant and the patient as a unit. We detected a significant difference between AST1 and AST2 at both levels. A significant difference was observed at AST1 between implants that bled upon probing and those that did not. However, when we considered the patient as a unit, there were no significant differences. The plaque index was not significant at either level. AST1 had high specificity and positive predictive diagnostic value (80%) for bleeding upon probing. Probing induces a greater release of AST from inflamed tissues compared with healthy tissues in situ but not at the systemic level. At the implant level, the implant position could be responsible for this difference. Aspartate aminotransferase was a reliable predictor of patients with mucositis.

Current developments in salivary diagnostics

Salivary diagnostics is an emerging field that has progressed through several important developments in the past decade, including the publication of the human salivary proteome and the infusion of federal funds to integrate nanotechnologies and microfluidic engineering concepts into developing compact point-of-care devices for rapid analysis of this secretion. In this article, we discuss some of these developments and their relevance to the prognosis, diagnosis and management of periodontitis, as an oral target, and cardiovascular disease, as a systemic example for the potential of these biodiagnostics. Our findings suggest that several biomarkers are associated with distinct biological stages of these diseases and demonstrate promise as practical biomarkers in identifying and managing periodontal disease, and acute myocardial infarction. The majority of these studies have progressed through biomarker discovery, with the identified molecules requiring more robust clinical studies to enable substantive validation for disease diagnosis. It is predicted that with continued advances in this field the use of a combination of biomarkers in multiplex panels is likely to yield accurate screening tools for these diagnoses in the near future.

Arginine and glutamate levels in the gingival crevicular fluid from patients with chronic periodontitis

The objectives of this study were to determine arginine and glutamate levels in the gingival crevicular fluid (GCF) of adult chronic periodontitis patients versus periodontally healthy controls, and to compare two kinds of microdialysis probes: normal and U-shaped probes. The analysis of GCF components was developed to improve the diagnosis of periodontal disease (PD). Proteolysis in the periodontal tissues increases the concentration of amino acids (aa) in the GCF and the levels of these aa may reveal PD features and stages. GCF samples were collected by microdialysis in situ from 5 periodontally affected sites (probing depth >or=5 mm, clinical attachment loss >or=3 mm) in 14 adult chronic periodontitis patients and from 14 adult periodontally healthy controls. Capillary zone electrophoresis coupled to laser induced fluorescence detection was used to measure concentration of arginine and glutamate in the GCF. Data were analyzed statistically by ANOVA and Tukey's post-hoc tests (á=0.05). Arginine concentration was increased (p<0.001) and glutamate concentration was decreased (p<0.001) in chronic periodontitis patients as compared to controls. There were no significant differences (p=0.069) between the normal and U-shaped probes. In conclusion, the increase of arginine and decrease of glutamate concentration in GCF were associated to the presence of periodontitis, and might be used as markers to recognize periodontally susceptible subjects as well as to evaluate the treatment course.

Association of gingival crevicular fluid and serum intracytoplasmic enzyme levels in periodontally healthy homozygous (major) beta-thalassemia patients

OBJECTIVE

To assess tissue necrosis in beta-thalassemia major patients, as in other areas of medicine, lactate dehydrogenase (LDH), aspartate aminotransferase (AST) and alanine aminotransferase (ALT) have been widely used. These markers of tissue degradation have also been studied in the gingival crevicular fluid (GCF) in relation to periodontal disease status. The purpose of this study was to investigate whether periodontal diagnostic tests based on these markers of tissue degradation are influenced from the enzymes' levels in serum and, therefore, could be used in the assessment of the patient's periodontal status.

MATERIAL AND METHODS

Forty-four periodontally healthy, homozygous beta-thalassemia patients were enrolled in the study. GCF and serum samples were obtained and the levels of AST, ALT and LDH were determined; the measurements took place in an automated analyzer (Hitachi 777) using the kits of Roche Company.

RESULTS

Lack of correlations between serum and GCF enzyme levels was demonstrated. Serum LDH and serum AST, serum AST and serum ALT are significantly positively correlated. Concerning the GCF, AST and ALT were proved to be significantly positively correlated.

CONCLUSIONS

Elevated values of LDH, ALT and AST in serum do not constitute a confounding factor in GCF measurements of the respective enzymes.

Levels of aspartate aminotransferase (AST) in saliva of patients with different periodontal conditions

OBJECTIVES

The purpose of this study was to evaluate the relationship between aspartate aminotransferase (AST) levels in saliva measured by Reflotron trade mark System of Diagnosis and periodontal condition indicated by Community Periodontal Index of Treatment Needs (CPITN).

MATERIAL AND METHODS

Fifteen patients were assigned to one of four groups C0, C1, C3 and C4, based on their largest CPITN code among the examined sites, totaling 60 participants. About 1.0 ml of non-stimulated saliva was collected from the individuals after a mouth rinse with water. Biochemical analyses of saliva samples were carried out using the proposed system in order to quantify their AST concentration.

RESULTS

There were no significant differences between levels (U/ml) of AST (median; interquartile range) from groups C0 (30.9; 14.7-41.7), C1 (30.3; 19.5-39.4) and C3 (35.1; 27.0-63.5). However, group C4 (106.2; 84.4-129.7) differed statistically from the others (p<0.001) and presented AST levels as high as 284.2 U/ml. Gingival bleeding and suppuration were observed in three individuals with concentrations higher than 125.0 U/ml.

CONCLUSION

Levels of AST in saliva from patients presenting CPITN code 4 were higher than from patients coded lower and could be detected by the evaluated diagnostic system. Periodontal destruction such as periodontal pockets, gingival bleeding and suppuration seems to be related to higher AST levels in saliva.