Successful combination therapy with ustekinumab and intensive granulocyte and monocyte adsorptive apheresis in highly refractory pediatric ulcerative colitis: pathophysiological rationale and clinical outcome.

Pediatric-onset ulcerative colitis (UC) is characterized by an aggressive phenotype, with higher rates of pancolitis and more rapid progression to a medically refractory state. After failure of conventional therapies and multiple biologic agents, treatment options are limited and often require surgery. We report the case of a 15-year-old girl with a 5-year history of highly refractory pancolitis-type UC. Previous treatments included mesalazine, salazosulfapyridine, tacrolimus, and three biologic agents (infliximab, vedolizumab, and adalimumab), all of which failed to maintain remission. After ustekinumab initiation, she initially experienced mild improvement but subsequently developed a severe clinical relapse (Pediatric Ulcerative Colitis Activity Index score: 40-50) triggered by Edwardsiella tarda infection. Despite infection resolution and treatment with systemic corticosteroids, her condition remained critical. As adjunctive therapy, intensive granulocyte and monocyte adsorptive apheresis (GMA) was administered twice weekly for 10 sessions, followed by twice monthly for 7 sessions, resulting in rapid symptomatic improvement. Follow-up colonoscopy confirmed complete mucosal healing (Mayo Endoscopic Subscore, 0). Intensive GMA may be a safe and effective adjunct to ustekinumab before its full therapeutic effect is achieved, potentially complementing the anti-inflammatory effects of ustekinumab in refractory pediatric UC and may help avoid colectomy even when multiple drug therapies have failed.