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Background The standard therapy for acute severe ulcerative colitis (ASUC) is intravenous corticosteroids; however, 30% of ulcerative colitis (UC) patients do not recover with corticosteroids alone. Few studies have reported the efficacy and safety of tofacitinib for ASUC with steroid resistance. We report a case series of successful first-line treatment consisting of tofacitinib (20 mg/day) administered to ASUC patients with steroid resistance. Methods Patients diagnosed with ASUC at our institution between October 2018 and February 2020 were retrospectively evaluated. They were administered a high dose of tofacitinib (20 mg) after showing no response to steroid therapy in a dose of 1-1.5 mg/kg/day. Results Eight patients with ASUC, 4 (50%) men, median age 47.1 (range 19-65) years, were included. Four patients were newly diagnosed, and the median UC duration was 4 (range 0-20) years. Six of the 8 patients were able to avoid colectomy. One patient (patient 2) had no response; however, remission was achieved after switching from tofacitinib to infliximab. One patient (patient 6) with no response to tofacitinib underwent total colectomy. Only one patient (patient 4) experienced an adverse event, local herpes zoster, treated with acyclovir without tofacitinib discontinuation. Conclusions Clinical remission without serious adverse events can be achieved with high probability and colectomy can be avoided by first administering high-dose tofacitinib to steroid-resistant ASUC patients. Tofacitinib may be one of the first-line treatment options for steroid-resistant ASUC. [ABSTRACT FROM AUTHOR]

In previous studies, we found that human IgG4-related autoimmune pancreatitis (AIP) and murine AIP are driven by activation of plasmacytoid dendritic cells (pDCs) producing IFN-α. In the present studies we examined additional roles of pDC-related mechanisms in AIP pathogenesis, particularly those responsible for induction of fibrosis. We found that in murine AIP (MRL/Mp mice treated with polyinosinic-polycytidylic acid) not only the pancreatic infiltration of immune cells but also the development of fibrosis were markedly reduced by the depletion of pDCs or blockade of type I IFN signaling; moreover, such treatment was accompanied by a marked reduction of pancreatic expression of IL-33. Conversely, polyinosinic-polycytidylic acid-induced inflamed pancreatic tissue in murine AIP exhibited increased expression of type I IFNs and IL-33 (and downstream IL-33 cytokines such as IL-13 and TGF-β1). pDCs stimulated by type I IFN were the source of the IL-33 because purified populations of these cells isolated from the inflamed pancreas produced a large amount of IL-33 upon activation by TLR9 ligands, and such production was abrogated by the neutralization of type I IFN. The role of IL-33 in murine AIP pathogenesis was surprisingly important because blockade of IL-33 signaling by anti-ST2 Ab attenuated both pancreatic inflammation and accompanying fibrosis. Finally, whereas patients with both conventional pancreatitis and IgG4-related AIP exhibited increased numbers of acinar cells expressing IL-33, only the latter also exhibited pDCs producing this cytokine. These data thus suggest that pDCs producing IFN-&3945; and IL-33 play a pivotal role in the chronic fibro-inflammatory responses underlying murine AIP and human IgG4-related AIP. [ABSTRACT FROM AUTHOR]

Colitis-associated cancer (CAC) is caused by chronic intestinal inflammation and is reported to be associated with refractory inflammatory bowel disease (IBD). Defective apoptosis of inflammatory cell populations seems to be a relevant pathogenetic mechanism in refractory IBD. We assessed the involvement of stress response protein cold-inducible RNA-binding protein (Cirp) in the development of intestinal inflammation and CAC. In the colonic mucosa of patients with ulcerative colitis, expression of Cirp correlated significantly with the expression of TNFα, IL23/IL17, antiapoptotic proteins Bcl-2 and Bcl-xL, and stem cell markers such as Sox2, Bmi1, and Lgr5. The expression of Cirp and Sox2 was enhanced in the colonic mucosae of refractory ulcerative colitis, suggesting that Cirp expression might be related to increased cancer risk. In human CAC specimens, inflammatory cells expressed Cirp protein. Cirp-/- mice given dextran sodium sulfate exhibited decreased susceptibility to colonic inflammation through decreased expression of TNFα, IL23, Bcl-2, and Bcl-xL in colonic lamina propria cells compared with similarly treated wild-type (WT) mice. In the murine CAC model, Cirp deficiency decreased the expression of TNFα, IL23/IL17, Bcl-2, Bcl-xL, and Sox2 and the number of Dclk1+ cells, leading to attenuated tumorigenic potential. Transplantation of Cirp-/- bone marrow into WT mice reduced tumorigenesis, indicating the importance of Cirp in hematopoietic cells. Cirp promotes the development of intestinal inflammation and colorectal tumors through regulating apoptosis and production of TNFα and IL23 in inflammatory cells. [ABSTRACT FROM AUTHOR]