Saliva levels of caspase-1, TNF-α, and IFN-γ in primary Sjögren’s syndrome: oral mucosal abnormalities revisited

Abstract

Background/aim: Abnormalities in oral mucosal immunity contribute to complex pathogenesis of primary Sjögren's syndrome (pSjS). We aimed to measure saliva and serum levels of caspase-1, tumor necrosis factor-alpha (TNF-α) and interferon gamma (IFN-γ) in patients with pSjS. Materials and methods: We studied 43 pSjS patients fulfilling the AECG criteria and 30 age/sex-matched healthy controls, as well as 39 rheumatoid arthritis (RA) patients as a disease control group. ESSDAI scores were less than seven in all patients with pSjS, indicating low disease activity. Quantitative analyses were made in serum and whole saliva samples. The statistical analysis was performed using SPSS 19.0. Results: While no significant difference was found in serum measurements, saliva levels of TNF-α and caspase-1 were significantly higher in pSjS patients versus healthy controls when using the Mann-Whitney U test. On the other hand, in the pSjS group, saliva levels of TNF-α and caspase-1 were also significantly higher compared to the RA group using Student's t-test. In the pSjS group, those parameters did not show any correlation with disease duration, seropositivity, and smoking. Conclusion: Despite low disease activity, saliva TNF-α and caspase-1 levels were found to be significantly higher in the pSjS group, which may suggest a possible advantage of local anticytokine treatments in selected cases.