Salivary CXCL13 in relation to scintigraphy in early detection of secondary Sjogren’s syndrome

Abstract

Background Sjogren’s syndrome (SS) is a systemic autoimmune disease in which immune cells attack and destroy the exocrine glands. CXCL13 directs B-cell chemotaxis and is elevated in several autoimmune diseases. Objective To assess the role of salivary CXCL13 level as a screening tool in early detection of secondary SS patients. Patients and methods Salivary CXCL13 levels using ELISA technique, Schirmer paper test and/or Lissamine green staining, and quantitative salivary scintigraphy excretion fraction were measured in 45 selected patients with primitive connective tissue disease (rheumatoid arthritis, systemic lupus erythematosus, or systemic sclerosis) and according to the American-European Consensus Group criteria, they were classified to three equal groups: group I were having SS; group II were having dryness manifestations but not completing the criteria for SS diagnosis (suspected SS); group III were having no SS, and 15 age-matched and sex-matched apparently healthy controls. Results A significantly higher salivary CXCL13 level on comparing SS patients to suspected, non-SS groups and controls (P<0.001). Salivary CXCL13 had a significant negative correlation with scintigraphy (P<0.01), a significant positive correlation with eye dryness signs (P<0.01), cutoff value of CXCL13 to diagnose SS was more than 40 pg/ml and a cutoff value of salivary scintigraphy excretion fraction to diagnose SS was less than 33.1%. Conclusion Salivary CXCL13 is a sensitive biomarker for early detection of secondary SS.

Keywords

• CXCL13
• salivary
• scintigraphy
• Sjogren’
• s syndrome