Clinical features, pathogenesis, and treatment of inflammatory bowel disease-associated spondyloarthritis

Inflammatory bowel disease-associated spondyloarthritis (IBD-SpA) is a unique subtype of SpA that affects approximately 10-20 % of patients with IBD. It encompasses both peripheral arthritis and axial involvement, with enthesitis being increasingly recognized. Despite its clinical significance, there are currently no established screening tools, classification criteria, or standardized treatment guidelines specific to IBD-SpA. Management is typically guided by recommendations for IBD and SpA, requiring close collaboration between gastroenterologists and rheumatologists. Emerging evidence suggests that subclinical gut inflammation and IL-23-IL-17-TNFα signaling pathway play central roles in the pathogenesis of IBD-SpA. Among the available therapeutic options, TNF inhibitors and JAK inhibitors have demonstrated efficacy in both IBD and SpA, whereas IL-17 inhibitors may exacerbate intestinal inflammation. Additionally, vedolizumab, an α4β7 integrin inhibitor, while effective for IBD, has been implicated in triggering de novo SpA. These complexities highlight the need for a tailored treatment approach that balances efficacy for both gut and joint inflammation. This review provides an updated overview of the clinical features, diagnosis, pathogenesis, and treatment strategies for IBD-SpA, emphasizing recent advancements and future directions in the field.