|Year : 2016 | Volume
| Issue : 1 | Page : 21-24
Aspartate aminotransferase as a biomarker in periodontal disease: A comparative in vitro study
Sabin Siddique1, Ganesh Shenoy Panchmal1, Fawaz Pullishery2
1 Department of Public Health Dentistry, Yenepoya Dental College, Mangalore, Karnataka, India
2 Department of Public Health Dentistry, Educare Institute of Dental Sciences, Malapuram, Kerala, India
|Date of Web Publication||18-Jan-2016|
Department of Public Health Dentistry, Yenepoya Dental College, Mangalore - 575 018, Karnataka
Source of Support: None, Conflict of Interest: None
Background: Estimation of biomarkers in saliva could offer an attractive opportunity for the diagnosis of periodontal diseases. The aim of this study was to investigate the aspartate aminotransferase (AST) levels in the saliva of patients with periodontal disease.
Materials and Methods: Twenty patients were assigned to each of the three groups - C0, C3, and C4 based on their largest Community Periodontal Index of Treatment Needs (CPITN) code, totaling 60 participants. Immediately after a single mouth rinse with 15 mL of water to wash out exfoliated cells, about 1 mL of unstimulated saliva was collected in sterile plastic containers and transported to the biochemical laboratory for spectrophotometric analysis.
Results: There were significant differences between levels of AST from the groups C0, C3, and C4. There was a significant positive correlation between clinical parameters and AST concentration in the saliva of each group. There was no statistical significance between males and females in all three groups.
Conclusion: AST levels in the saliva increased with increase in the CPITN score. Group C0 had the least while group C4 had the highest AST level. High levels of AST are characteristic features of periodontitis affected subjects. Hence, monitoring the levels of AST in the saliva could be utilized as periodontal disease markers.
Keywords: Biomarker, periodontal disease, saliva
|How to cite this article:|
Siddique S, Panchmal GS, Pullishery F. Aspartate aminotransferase as a biomarker in periodontal disease: A comparative in vitro study. Saudi J Oral Sci 2016;3:21-4
|How to cite this URL:|
Siddique S, Panchmal GS, Pullishery F. Aspartate aminotransferase as a biomarker in periodontal disease: A comparative in vitro study. Saudi J Oral Sci [serial online] 2016 [cited 2020 Jan 18];3:21-4. Available from: http://www.saudijos.org/text.asp?2016/3/1/21/174294
| Introduction|| |
The goal of a periodontal diagnostic procedure is to provide useful information to the clinician regarding present periodontal disease location, type, and severity. Traditional diagnostic procedures used clinically include probing pocket depth and radiographic assessment of alveolar bone loss. Probing depth and attachment level measurements or evaluations from radiographs can only describe the past history of periodontal disease and do not reveal current or future disease activity.  Advances in oral and periodontal diagnostic research are moving toward methods by which periodontal disease can be identified and quantified by objective measures such as biomarkers.
Reports have suggested that several biochemical parameters could be used to detect periodontal disease activity. , Elevated levels of specific enzymes such as elastase, β-glucuronidase, collagenase, aspartate aminotransferase (AST), and alkaline phosphatase are known to be associated with future attachment loss. However, differences in experimental design among investigations have made it difficult to identify which parameter is the most appropriate in determining disease activity. 
The search for a resource that can be used to detect a broad range of diseases easily and reliably is akin to a search for the diagnostic Holy Grail. Indeed, the key to a library of biomarkers representing disease and health may lie inside our mouths. Saliva - the source of all this information - is the secretory product of glands located in or around the oral cavity. By cracking the saliva diagnostic codes, we may be able to explore a whole new world. The aim of this study is to assess and compare periodontal disease with salivary AST levels.
- To estimate the levels of AST in the saliva of patients with periodontal condition indicated by the Community Periodontal Index of Treatment Needs (CPITN) code.
- Comparison of the levels of AST in the saliva of patients with periodontal condition indicated by the CPITN.
| Materials and Methods|| |
The study was an institution-based cross-sectional study. Subjects were selected from the Outpatient Department of Public Health Dentistry in Yenepoya Dental College who gave informed consent to participate in the study and also an ethical clearance was obtained from the Yenepoya University. Patients of both genders between 20 years and 65 years of age were included in the study. A total of 210 people were selected initially for the study and out of this, 60 subjects (30 males and 30 females) were selected for the study as the minimum sample calculated for the study was 30 in each category by a systematic random sampling technique. Individuals who participated in the study were assigned to one of the following three groups based on their highest CPITN score found among all the examined sites as given by Ainamo et al. 
- Group C0: No periodontal disease (healthy periodontium).
- Group C3: Pathological pocket of depth 4-5 mm; gingival margin situated on the black band of the probe.
- Group C4: Pathological pocket of depth 6 mm or more; black band of the probe not visible.
- History of any systemic diseases.
- Periodontal therapy in the last 6 months.
- Tobacco users.
- Pregnant women.
- Subjects who had taken any antibiotics or anti-inflammatory agents in the last 3 months.
Analysis of AST
Unstimulated whole saliva of 1 mL was collected after a single mouth rinse with 15 mL of water to wash out exfoliated cells, by making the patient sit in an upright position. The saliva was allowed to accumulate for 2 min and then collected in sterile plastic containers. The saliva sample was then sent for biochemical analysis.
AST activity was determined using the spectrophotometric method. AST catalyzes the transfer of the amino group from L-aspartate and α-ketoglutarate to form oxaloacetate and L-glutamate. The oxaloacetate is reduced to L-malate in a reaction catalyzed by malate dehydrogenase (MDH). In this same reaction, an equivalent amount of nicotinamide adenine dinucleotide (NADH) is oxidized to nicotinamide adenine dinucleotide (NAD). The resulting decrease in absorbance at 340 nm is followed spectrophotometrically and is directly proportional to the activity of AST. Observations were tabulated and analyzed statistically. One-way analysis of variance (ANOVA) was used to analyze the data. Unpaired t-test was used to analyze AST levels between genders.
| Results|| |
The present study was aimed to estimate and compare periodontal disease with salivary AST in patients. The mean value of group C0 was found to be 61.33 ± 15.26 IU/mL with minimum value of 29 IU/mL and maximum value of 97 IU/mL. Group C3 showed a mean value of 176.88 ± 32.45 IU/mL and the group C4 showed a higher value of 277.23 ± 98.35 IU/mL. The P value was found to be statistically significant (P < 0.05) when the following groups were compared (C0 vs C3, CO vs C4, and C3 vs C4) [Table 1].
It was found that the AST levels were high in group C4 when groups C0, C3, and C4 were compared and the results were statistically significant (P ≤ 0.05). There was no statistical difference in the AST levels between males and females in each group [Table 2].
|Table 2: Comparison of aspartate aminotransferase levels within the groups between males and females|
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| Discussion|| |
Saliva is a unique fluid and interest in it as a diagnostic medium has advanced exponentially in the last 10 years. Advances in the use of saliva as a diagnostic fluid have been tremendously affected by current technological developments. The ability to measure and monitor a wide range of molecular components in the saliva, thus making it feasible to study microbes, immunological markers, and biochemical markers has been demonstrated previously.  The objective of the present study was to assess and compare periodontal disease with salivary AST levels.
AST is a cytoplasmic enzyme released upon cell death. Since cell death is an integral part of periodontal destruction, levels of this enzyme have been studied as a possible marker for disease activity. 
As loss of tooth-supporting tissue is characteristic of periodontitis, markers of tissue destruction have been examined for their potential application in diagnostic tests. The presence of lactate dehydrogenase and AST is indicative of cell death. 
The findings indicated higher levels of AST in patients with higher CPITN score. These results are in agreement with the findings of Persson et al., Eley and Cox et al., and Cesco et al. who have concluded that AST levels were significantly higher in patients with CPITN Code 4 when compared to patients coded lower than 4. ,, It has also been demonstrated that supporting tissues in the periodontium, i.e., the gingival epithelial cells, gingival fibroblasts, and periodontal ligament fibroblast cells contain significant levels of AST (100 KU/1,000 cells, 60 KU/1,000 cells, and 20 KU/1,000 cells, respectively).  Another study conducted by Magnusson et al. had also demonstrated high levels of AST in diseased sites than in healthy sites.  The possible reason could be due to the fact that AST is a cytoplasmic enzyme released upon cell death and cell death is an integral part of periodontal destruction. Chambers et al. suggested that increased AST levels in GCF could be as a short-term (3-month) marker for attachment loss.  A study conducted by Najafi et al. suggested that total serum AST activity might serve as a reliable biomarker and also reported that low molecular weight AST (LMV-AST) isoenzyme could be used as a more sensitive biomarker. 
From the observations in this study, the following conclusions were drawn:
- AST levels in the saliva increased with increase in the CPITN score.
- Group C0 had the least while group C4 had the highest AST level.
- There were significant differences between the levels of AST in groups C0, C3, and C4. There was a significant positive correlation between clinical parameters and AST concentration in the saliva of each group.
- There was no statistical significance between males and females in all the three groups.
| Conclusion|| |
The present study clearly demonstrated that high levels of AST are characteristic features of periodontitis-affected subjects. Hence, monitoring the levels of AST in the saliva could be utilized as periodontal disease markers.
While the future of periodontal disease diagnosis using salivary diagnostics looks promising, significant obstacles lie ahead before these approaches can be widely available in a clinical setting. Validation of novel periodontal diagnostics will need to be benchmarked with existing "gold standards" of disease such as alveolar bone levels and clinical attachment levels in large patient populations. Although many challenges lie ahead, the use of saliva-based oral fluid diagnostics appears promising for future application to diagnose and prognosticate periodontal treatment outcomes.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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[Table 1], [Table 2]