Unstimulated salivary flow, pH, proteins and oral health in patients with Juvenile Idiopathic Arthritis

Background: There have been inconsistent conclusions regarding salivary abnormalities and their effect on oral health of Juvenile Idiopathic Arthritis (JIA) patients. The purpose of the study was to evaluate the flow rate and selected biochemical parameters of unstimulated whole saliva in correlation to oral health in JIA children. Methods: Thirty-four JIA patients and 34 age-and sex-matched controls not affected by JIA (C) were divided into two groups: with mixed and permanent dentition. DMFT/dmft, gingival and simplified oral hygiene indices were evaluated. Salivary flow rate, pH, lysozyme, lactoferrin, salivary protein concentrations and peroxidase activity were assessed. Results: The salivary flow rate was significantly lower in the total JIA group (0.41 ml/min) as compared with the C (0.51 ml/min) and in the permanent dentition of JIA children (0.43 ml/min) as compared with the C (0.61 ml/min). A significantly lower pH was observed in total (6.74), mixed (6.7) and permanent (6.76) dentition of JIA groups in comparison to the C (7.25, 7.21, 7.28 respectively). The specific activity of peroxidase was significantly higher in JIA patients (total 112.72 IU/l, mixed dentition 112.98 IU/l, permanent dentition 112.5 IU/l) than in the C group (total 70.03 IU/l, mixed dentition 71.83 IU/l, permanent dentition 68.61 IU/l). The lysozyme concentration in JIA patients (total and permanent dentition groups) was significantly higher than in the C group. There were no significant differences in lactoferrin and salivary protein concentrations. There were no statistically significant differences in oral status between JIA patients and C, respectively: DMFT = 5.71, dmft = 3.73, OHI-S = 0.95, GI = 0.25 and DMFT 5.71, dmft = 3.73, OHI-S = 0.85, GI = 0.24. The specific activity of peroxidase in the unstimulated whole saliva was inversely correlated with the GI index, whereas the salivary lysozyme concentration was inversely correlated with the dmft index in JIA patients. Conclusion: In the course of JIA occur a reduction of the resting salivary flow rate and a decrease of saliva pH. In spite of this, no differences in the clinical oral status between the JIA children population and the control group were found. The mobilisation of salivary peroxidase and lysozyme contributes to the maintenance of healthy oral tissues.