Granulocyte and monocyte adsorptive apheresis for ulcerative colitis: mechanisms, clinical evidence, and future...

Ulcerative colitis (UC) is a chronic, idiopathic inflammatory bowel disease characterized by continuous mucosal erosions and ulcers in the colon. In recent years, biologics and small-molecule agents have revolutionized UC management; however, these therapies may be limited by risks such as infections, secondary loss of response, or intolerance. Granulocyte and monocyte adsorptive apheresis (GMA), developed in Japan, offers a non-pharmacologic and selective immunomodulatory approach by removing activated myeloid cells and modulating the inflammatory milieu. In this review, we summarize the mechanisms of action of GMA, including its effects on proinflammatory cytokines and regulatory T-cell responses. We also examine the clinical evidence, from randomized controlled trials and observational studies, that supports its efficacy, particularly in steroid-dependent and elderly patients. While mucosal healing rates with GMA may be lower than those achieved with biologics, its favorable safety profile may support its use as an adjunctive or bridging strategy in selected patients. However, evidence supporting these roles remains limited and is derived mainly from observational studies. Future directions include integration with personalized medicine, biomarker development and global expansion. GMA remains a viable option in the therapeutic landscape of UC.