Background: Systemic sclerosis (SSc) is a rare chronic inflammatory disorder characterized by diffuse fibrosis and vascular abnormalities in the skin and internal organs. Interleukin-23 (IL-23) is a pro-inflammatory cytokine that can enhance the expansion of T helper 17 (Th17) cells and thus plays a critical role in many inflammatory autoimmune diseases. This study aims to assess the salivary IL-23 levels in Iranian patients with SSc in comparison to healthy individuals.
Methods: In this cross-sectional study, unstimulated saliva samples (5 cc) were collected from 88 SSc patients and 88 age- and sex- matched healthy individuals. The salivary levels of IL-23 in the saliva samples were measured using a commercially available enzyme–linked immunosorbent assay (ELISA) kit.
Results: The mean salivary levels of IL-23 in the patient group were significantly higher than those in the control subjects (164.5±22.1 ng/L vs. 95.8±15.7 ng/L, p<0.0001). In SSc patients, the salivary IL-23 levels were significantly elevated in ACA-positive participants compared to ACA-negative ones (179.8±11.2 ng/L vs. 144.3±15.7 ng/L, p<0.0001). However, IL-23 was not associated with gender or age (p>0.05).
Conclusion: The results suggest that IL-23 is associated with the pathogenesis of SSc; therefore, this pro-inflammatory cytokine is not only a valuable supportive biomarker for monitoring the disease progression but also blocking IL-23 could be considered a potential therapeutic target, especially in early SSc. Further comprehensive studies are needed to confirm our findings.