Evaluation and Comparison of Salivary Interleukin-8 Levels and Dental Caries Severity in Pediatric and Adolescent Celiac Patients Versus Healthy Controls: A Cross-Sectional Observational Study

Background: Celiac disease (CD) is an immune-mediated disorder characterized by gluten-induced small intestinal mucosal injury and malabsorption, which may adversely affect oral and dental health. Interleukin-8 (IL-8), plays a central role in mucosal immune activation and has been implicated in both CD pathophysiology and caries susceptibility. This study investigated salivary IL-8 levels in pediatric and adolescent CD patients compared with healthy controls and examined their association with dental caries severity. Methods: A cross-sectional observational study was conducted on 45 biopsy- and serology-confirmed CD patients and 45 age- and sex-matched healthy controls. Dental caries status was recorded using the International Caries Detection and Assessment System (ICDAS) and Decayed, Missing and Filled Teeth (DMFT/dmft) indices. Unstimulated whole saliva samples were collected and IL-8 concentrations were quantified via ELISA. Between-group comparisons and correlation analyses were performed (p < 0.05). Results: CD patients demonstrated significantly higher DMFT scores and salivary IL-8 concentrations than controls (p = 0.005 and p < 0.001, respectively). No significant correlations emerged between IL-8 and DMFT/dmft indices. However, in the CD group, IL-8 levels were negatively correlated with ICDAS scores of primary teeth (r = − 0.60; p = 0.015). Anti-tTG-IgA levels correlated negatively with dmft and positively with ICDAS scores of permanent teeth. IL-8 concentrations showed no relationship with CD severity. Conclusions: Individuals with CD exhibited greater caries experience and elevated salivary IL-8 levels compared with healthy controls, suggesting that CD may influence oral health through immunological and nutritional mechanisms. Salivary IL-8 may serve as a promising noninvasive biomarker of mucosal immune activation and could support monitoring of disease activity and response to dietary management.