Successful upadacitinib treatment in anti-TNF-refractory intestinal Behçet’s disease: a case report and literature review

Background: Behçet's disease (BD) is a persistent inflammatory vasculitis affecting various vessel types across multiple organ systems. It clinically presents recurrent oral and genital ulcers, ocular inflammation, and various skin manifestations. Etiology remains multifactorial, involving genetic susceptibility, immune system dysregulation, and environmental triggers such as infections. Intestinal involvement represents a rare but particularly severe form of BD, whose clinical features frequently resemble those of inflammatory bowel diseases (IBD), complicating differential diagnosis and management. Case presentation: We report a case of a 23-year-old male with progressive postprandial abdominal pain, diarrhea, and marked weight loss. His clinical history was notable for recurrent oral aphthae, genital ulcers, and perianal infections. Colonoscopic examination revealed circumferential ulceration, mucosal edema, contact bleeding, and significant narrowing of the ileocecal lumen. Histopathological analysis indicated chronic active inflammation in the absence of granulomas or definitive vasculitis. Infectious and neoplastic causes were systematically excluded. The patient was diagnosed with intestinal BD. Although initial therapy with infliximab yielded partial clinical improvement, drug-level monitoring revealed suboptimal trough levels, indicating secondary loss of response. Subsequently, treatment was transitioned to the Janus kinase (JAK) inhibitor upadacitinib, which led to full symptom resolution and mucosal healing on follow-up endoscopy. Conclusion: This case underscores the diagnostic and therapeutic challenges associated with intestinal BD, especially in distinguishing it from Crohn's disease and addressing resistance to anti-TNF agents. Our findings suggest that JAK inhibitors like upadacitinib may offer a promising alternative for patients with refractory intestinal BD. Incorporating therapeutic drug monitoring into clinical practice allows for personalized, adaptive treatment adjustments, potentially improving long-term outcomes in complex cases.