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Decreased salivary matrix metalloproteinase-8 reflecting a defensive potential in juvenile parotitis
Riitta Saarinen1, Anne Pitkäranta1, Kaija-Leena Kolho2
1Department of Otorhinolaryngology, Head and Neck Surgery, Helsinki University Hospital and University of Helsinki, Helsinki, Finland; Department of Clinical Medicine, Helsinki University Hospital and University of Helsinki, Helsinki, Finland.
Objective:
Matrix metalloproteinases MMP-2 and MMP-9 have been associated with juvenile parotitis. However, the role of MMP-8 has not been addressed previously. This work focuses on salivary MMP-8 and -9 levels in juvenile parotitis.
Methods:
During a five-year period at Helsinki University Hospital, a tertiary care hospital, 41 patients aged 17 or under, were identified as having parotitis; from 36 of these patients, saliva samples were collected for MMP-8 IFMA (time-resolved immunofluorometric assay) analyses. Control saliva samples were collected from 34 age- and gender-matched children admitted for an elective surgery who had no history of parotitis. For comparison, salivary levels of MMP-9, tissue inhibitor of matrix metalloproteinase (TIMP-1), MMP-8/TIMP-1 ratio, human neutrophil elastase (HNE), and myeloperoxidase (MPO) were analyzed by ELISA. Additionally, salivary MMP-8 levels were compared to historical saliva samples from 18 adult gingivitis patients as well as to 10 healthy adult controls.
Results:
The median (25%, 75% percentile) MMP-8 concentration in saliva of parotitis patients was significantly lower than MMP-8 concentration in saliva of their controls [50.4ng/ml (37.5, 72.9) vs. 148.5ng/ml (101.2, 178.5) p<0.0001] and lower than in patients with gingivitis [347.9ng/ml (242.6, 383.2) p<0.0001] or healthy adult controls [257.2ng/ml (164.9, 320.7) p<0.0001]. The MMP-8/TIMP-1 ratio was lower than in controls [0.13 (0.05-0.02) vs. 0.3 (0.17-0.46) p<0.0001]. The median MMP-9 concentration in saliva of parotitis patients was significantly higher than in controls [143.9ng/m (68.8-189.0) vs. 34.9ng/ml (16.3-87.6) p<0.0001]. Neither HNE, MPO, nor TIMP-1 alone separated the patients from the control groups.
Conclusions:
MMP-9 was up-regulated in juvenile parotitis saliva, suggesting that MMP-9 may play a destructive role in juvenile parotitis, as others have suggested. The present novel findings reveal a decreased salivary MMP-8 concentration, suggesting that MMP-8 may reflect in juvenile parotitis down-regulated or anti-inflammatory immune characteristics.
Insights
Salivary matrix metalloproteinase-9 (MMP-9) was elevated in juvenile parotitis, indicating a potential destructive role. Conversely, matrix metalloproteinase-8 (MMP-8) levels were significantly decreased, suggesting anti-inflammatory characteristics in this condition.
Area of Science:
- Oral Medicine
- Biochemistry
- Immunology
Background:
- Matrix metalloproteinases (MMPs) are implicated in inflammatory conditions.
- MMP-2 and MMP-9 are associated with juvenile parotitis.
- The specific role of MMP-8 in juvenile parotitis remains uninvestigated.
Purpose of the Study:
- To investigate salivary MMP-8 and MMP-9 levels in children with parotitis.
- To compare these levels with those in control groups.
Main Methods:
- Saliva samples were collected from 41 children with parotitis and 34 age/gender-matched controls.
- MMP-8 was analyzed using IFMA, and MMP-9, TIMP-1, HNE, and MPO were analyzed by ELISA.
- MMP-8 levels were also compared to historical samples from adult gingivitis patients and healthy adults.
Main Results:
- Salivary MMP-8 concentrations were significantly lower in parotitis patients compared to controls, gingivitis patients, and healthy adults.
- The MMP-8/TIMP-1 ratio was also significantly lower in parotitis patients.
- Salivary MMP-9 concentrations were significantly higher in parotitis patients than in controls.
Conclusions:
- Elevated MMP-9 in juvenile parotitis saliva suggests a potential destructive role.
- Decreased salivary MMP-8 levels indicate possible down-regulated or anti-inflammatory immune responses in juvenile parotitis.
