Successful transition to mirikizumab following hepatic abscess during adalimumab therapy in a patient with ulcerative colitis.

Ulcerative colitis (UC) is associated with an increased risk of infectious complications, particularly during anti-tumor necrosis factor (anti-TNF) therapy. Pyogenic hepatic abscess is a rare but potentially life-threatening extraintestinal complication of UC. Optimal biologic management following deep infection during anti-TNF therapy remains unclear. Mirikizumab, a selective interleukin-23 p19 inhibitor, may have a more favorable infectious safety profile than anti-TNF agents. We report the case of a 19-year-old woman with pancolitis-type UC who developed persistent fever, worsening diarrhea, hematochezia, and subsequent right upper quadrant abdominal pain during maintenance therapy with adalimumab. Contrast-enhanced computed tomography revealed active colitis complicated by hepatic abscess. Adalimumab was discontinued, and intravenous ceftriaxone plus metronidazole therapy was initiated. After confirmation of infection control and abscess regression, induction therapy with mirikizumab was initiated for active UC. Clinical symptoms rapidly improved, and the patient achieved sustained clinical and endoscopic remission without recurrence of the hepatic abscess during long-term follow-up. This case suggests that mirikizumab can be successfully administered after adequate infection control in a patient with UC complicated by hepatic abscess during anti-TNF therapy. However, larger studies are needed to determine the optimal biologic option as a second-line treatment for patients requiring treatment reintroduction after deep infection.