Salivary Protease Activity in Children with Cystic Fibrosis

Objective: Patients with cystic fibrosis (CF) present with impaired protease-antiprotease balance in their lungs. However, salivary protease equilibrium in children with CF with poor oral health has not been reported. The current study investigated salivary matrix metalloproteinase-8 (MMP-8), tissue inhibitor of matrix metalloproteinases-1 (TIMP-1), neutrophil elastase (NE), and myeloperoxidase (MPO) levels in children with CF with or without gingivitis.Materials and Methods: Eleven CF and 11 systemically healthy children aged 3-12 years were evaluated. Clinical periodontal examinations including probing pocket depth (PPD), gingival index (GI), plaque index (PI), and bleeding on probing (BOP) were recorded and saliva samples were obtained. Salivary MMP-8, TIMP-1, NE, and MPO levels were analyzed by immunofluorometric assay and enzyme-linked immunosorbent assay.Results: Salivary levels of MMP-8, TIMP-1, NE, MPO, and MMP-8/TIMP-1 molar ratios were similar in CF and systemically healthy children (p>0.05). Levels of MMP-8, NE, and MPO were significantly higher in the saliva of children with gingivitis compared to periodontally healthy children in both CF and systemically healthy groups (p<0.05). MMP-8 and MMP-8/TIMP-1 levels were positively correlated with GI, PI, and BOP (p<0.05), while NE and MPO levels were related to all periodontal parameters (p<0.01).Conclusion: CF may not alter the activity of MMP-8, NE, and MPO. On the other hand, gingival inflammation had a pronounced effect on salivary levels of these enzymes and the MMP-8/TIMP-1 molar ratio in children, irrespective of CF. Further investigations in larger cohorts are needed to better clarify this issue.