Therapy insight: how the gut talks to the joints--inflammatory bowel disease and the spondyloarthropathies.

Axial and peripheral arthritis can occur in up to 30% of patients with inflammatory bowel disease. Likewise, the presence of gut inflammation in primary spondyloarthropathies is underappreciated, with subclinical gut inflammation documented in up to two-thirds of patients with this group of inflammatory disorders. Common genetic and immunologic mechanisms underlie the coincidence of inflammation in the joints and the intestine. New research highlights the critical role of innate and adaptive immune responses directed against components of the enteric microbial flora in driving gut and articular inflammation. Indeed, elucidation of genetic and serological immune markers will define clinically important subgroups of patients with these heterogeneous diseases. The treatment of inflammatory articular manifestations of inflammatory bowel disease is similar to the treatment of primary spondyloarthropathies. A notable exception is the use of NSAIDs, which can precipitate flares of inflammatory bowel disease and should be used with caution. Agents that target tumor necrosis factor have been a major advance in the treatment of both gut and joint inflammation in inflammatory bowel disease.