The Role of Vitamin D and Its Metabolic Pathways in Behçet's Disease

Abstract

Behçet's Disease (BD) is a complex multisystem inflammatory disorder characterized by recurrent oral and genital ulcers, skin lesions, and uveitis, among other systemic manifestations. Despite extensive research, the etiopathogenesis of BD remains elusive, with genetic, epigenetic, immunological, and environmental factors contributing to its pathogenesis. This study aimed to investigate the role of vitamin D and its related enzymes in BD, focusing on their correlation with disease activity and phenotype. This study conducted a comprehensive analysis involving 79 BD patients and 29 healthy controls, assessing serum 25-hydroxyvitamin D levels using an ELISA kit, and measured the vitamin D receptor (VDR) expression and the relative levels of enzymes involved in vitamin D metabolism (CYP27A1, CYP2R1, CYP27B1, and CYP24A1). The study findings reveal significant differences in serum vitamin D levels between BD patients and healthy controls, with BD patients exhibiting higher median levels. Additionally, VDR expression and the relative levels of CYP27B1 showed significant variations, suggesting a potential role in the disease's inflammatory processes. Correlation analysis indicated strong positive interactions among VDR and several vitamin D-related enzymes, specifically CYP27A1, underscoring the complex regulatory mechanisms influencing immune responses in BD. This study also highlights the impact of vitamin D on inflammatory markers such as C-reactive protein (CRP) and calcium levels, reinforcing the hypothesis of vitamin D's anti-inflammatory properties. Furthermore, this study observed significant associations between disease activity, measured by the BDCAF score, and vitamin D levels, suggesting a potential modulatory effect of vitamin D on disease severity. Overall, this research underscores the importance of vitamin D and its metabolic pathways in the pathogenesis of BD, providing new insights into the disease understanding. Future studies should explore these interactions further to develop effective interventions for managing BD.