Levels of Selected Matrix Metalloproteinases, Their Inhibitors in Saliva, and Oral Status in Juvenile Idiopathic
Agnieszka Kobus1, Joanna Bagińska1, Joanna Łapińska-Antończuk2
1Department of Dentistry Propaedeutics, Medical University of Bialystok, ul. Szpitalna 30, 15-295 Bialystok, Poland.
Aims:
Matrix metalloproteinases (MMPs) are a group of calcium-dependent zinc-containing proteinases acting both physiologically and in pathological conditions. The aim of this study was to evaluate the concentration of MMP-2, MMP-8, and MMP-9 and their inhibitors TIMP-1 and TIMP-2 of unstimulated whole saliva (UWS) in correlation with the oral health in juvenile idiopathic arthritis (JIA) children.
Methods:
The study population comprised 34 JIA patients and 34 age- and sex-matched controls (C). They were divided into two groups: with mixed dentition (MD) and with permanent dentition (PD). Dental caries (DMFT/dmft), unstimulated salivary flow rate (SF), and gingival inflammation (Gingival Index (GI) and Papilla Bleeding Index (PBI)) and oral hygiene (Simplified Oral Hygiene Index (OHI-S)) indices were evaluated. Saliva samples were tested with the enzyme-linked immunosorbent assay (ELISA) for MMP-2, MMP-8, MMP-9, TIMP-1, and TIMP-2. Data were statistically analysed with the Mann-Whitney U test and Spearman's rank correlation (p < 0.05).
Results:
There were no differences in dental hygiene or dental and periodontal status between the JIA and C groups. The MMP-9 concentration was higher in the whole JIA group compared with C (p=0.005) and JIA MD groups (p=0.038). A positive correlation of MMP-2 with the OHI-S index and a negative correlation of MMP-2 with SF were found in JIA. MMP-9 and its tissue inhibitor TIMP-1 had a positive mean correlation with the GI. A high correlation of MMP-8 with the number of decayed teeth (D) in JIA MD patients (p=0.037) was revealed. In the JIA-PD patients, there was a positive correlation of MMP-2, -8, and -9 levels with gingival inflammation indices and a negative correlation of MMP-2 and 8 with the SF.
Conclusions:
Despite a comparable clinical oral status of affected and unaffected children, in the JIA patients, a statistically significantly increased level of MMP-9 was found. In reference to the periodontal status, the role of MMPs increased in children with permanent dentition, whereas in reference to dental caries, the period of mixed dentition (MD) was critical.
Insights
Juvenile idiopathic arthritis (JIA) patients show elevated levels of matrix metalloproteinase-9 (MMP-9) in saliva, despite similar oral health compared to controls. MMPs play a role in periodontal health in permanent dentition and dental caries in mixed dentition JIA patients.
Area of Science:
- Biochemistry
- Immunology
- Pediatric Dentistry
Background:
- Matrix metalloproteinases (MMPs) are crucial enzymes involved in physiological and pathological processes.
- MMPs and their inhibitors are implicated in various inflammatory conditions, including those affecting oral health.
- Juvenile idiopathic arthritis (JIA) is a chronic inflammatory disease that can impact overall health, potentially including oral manifestations.
Purpose of the Study:
- To investigate the concentrations of MMP-2, MMP-8, MMP-9, and their inhibitors TIMP-1 and TIMP-2 in unstimulated whole saliva (UWS) of children with JIA.
- To correlate salivary MMP levels with various oral health parameters in JIA patients, including dental caries, gingival inflammation, and oral hygiene.
- To compare salivary MMP profiles between children with JIA and healthy controls.
Main Methods:
- A cohort of 34 JIA patients and 34 age- and sex-matched controls were recruited.
- Participants were categorized into mixed dentition (MD) and permanent dentition (PD) groups.
- Oral health assessments included DMFT/dmft, salivary flow rate (SF), Gingival Index (GI), Papilla Bleeding Index (PBI), and Simplified Oral Hygiene Index (OHI-S). Salivary MMPs and TIMPs were quantified using ELISA, with statistical analysis by Mann-Whitney U test and Spearman's rank correlation.
Main Results:
- No significant differences in oral hygiene or dental/periodontal status were observed between JIA patients and controls.
- MMP-9 concentration was significantly higher in the JIA group compared to controls and the JIA MD subgroup.
- Correlations were found between MMP levels and oral health indices: MMP-2 with OHI-S and SF (negative), MMP-9/TIMP-1 with GI (positive), MMP-8 with decayed teeth in JIA MD, and MMP-2, -8, -9 with gingival inflammation and SF (negative) in JIA-PD.
Conclusions:
- Children with JIA exhibit elevated salivary MMP-9 levels, irrespective of comparable clinical oral status to healthy children.
- MMPs play an increased role in periodontal status among JIA children with permanent dentition.
- The mixed dentition period is critical for the association between MMPs and dental caries in JIA patients.
