Purpose: The long-term efficacy and safety of infliximab (IFX) in Japanese children with inflammatory bowel disease (IBD) remain unclear. This study aimed to examine the longterm outcomes of IFX treatment in Japanese children with IBD. Methods: We retrospectively recruited patients aged <16 years who were diagnosed with ulcerative colitis (UC) or Crohn’s disease (CD) at Kurume University Hospital in Japan between 2011 and 2022 and examined the effectiveness and safety of IFX. We characterized the responses to IFX as primary response, primary nonresponse (PNR), secondary loss of response (sLOR), or still receiving IFX. Results: Among the 77 enrolled patients with UC (median age, 10 years) and 48 with CD (median age, 12 years), 55 (27 with UC and 28 with CD) received IFX treatment. IFX treatment was significantly more common in patients with CD (58.3%) than in those with UC (35.1%;p=0.016). The PNR was significantly greater in patients with UC (18.5%) than in those with CD (0.0%; p=0.023), as was the sLOR (UC, 51.9%; CD, 21.4%; p=0.026). The likelihood of continuing IFX treatment during follow-up (median, 38 months) was significantly higher in patients with CD (71.4%) than in those with UC (29.6%; p=0.003). Adverse events resulting in the discontinuation of IFX occurred in 3.6% of the patients; one patient with CD developed leukemia, and the other had a serious infusion reaction. Conclusion The long-term durability of IFX in Japanese pediatric patients with IBD was inadequate in UC compared with CD. Serious adverse events in 3.6% of patients required discontinuation.

Purpose: The long-term efficacy and safety of infliximab (IFX) in Japanese children with inflammatory bowel disease (IBD) remain unclear. This study aimed to examine the longterm outcomes of IFX treatment in Japanese children with IBD. Methods: We retrospectively recruited patients aged <16 years who were diagnosed with ulcerative colitis (UC) or Crohn’s disease (CD) at Kurume University Hospital in Japan between 2011 and 2022 and examined the effectiveness and safety of IFX. We characterized the responses to IFX as primary response, primary nonresponse (PNR), secondary loss of response (sLOR), or still receiving IFX. Results: Among the 77 enrolled patients with UC (median age, 10 years) and 48 with CD (median age, 12 years), 55 (27 with UC and 28 with CD) received IFX treatment. IFX treatment was significantly more common in patients with CD (58.3%) than in those with UC (35.1%;p=0.016). The PNR was significantly greater in patients with UC (18.5%) than in those with CD (0.0%; p=0.023), as was the sLOR (UC, 51.9%; CD, 21.4%; p=0.026). The likelihood of continuing IFX treatment during follow-up (median, 38 months) was significantly higher in patients with CD (71.4%) than in those with UC (29.6%; p=0.003). Adverse events resulting in the discontinuation of IFX occurred in 3.6% of the patients; one patient with CD developed leukemia, and the other had a serious infusion reaction. Conclusion The long-term durability of IFX in Japanese pediatric patients with IBD was inadequate in UC compared with CD. Serious adverse events in 3.6% of patients required discontinuation.

Purpose: The long-term efficacy and safety of infliximab (IFX) in Japanese children with inflammatory bowel disease (IBD) remain unclear. This study aimed to examine the longterm outcomes of IFX treatment in Japanese children with IBD. Methods: We retrospectively recruited patients aged <16 years who were diagnosed with ulcerative colitis (UC) or Crohn’s disease (CD) at Kurume University Hospital in Japan between 2011 and 2022 and examined the effectiveness and safety of IFX. We characterized the responses to IFX as primary response, primary nonresponse (PNR), secondary loss of response (sLOR), or still receiving IFX. Results: Among the 77 enrolled patients with UC (median age, 10 years) and 48 with CD (median age, 12 years), 55 (27 with UC and 28 with CD) received IFX treatment. IFX treatment was significantly more common in patients with CD (58.3%) than in those with UC (35.1%;p=0.016). The PNR was significantly greater in patients with UC (18.5%) than in those with CD (0.0%; p=0.023), as was the sLOR (UC, 51.9%; CD, 21.4%; p=0.026). The likelihood of continuing IFX treatment during follow-up (median, 38 months) was significantly higher in patients with CD (71.4%) than in those with UC (29.6%; p=0.003). Adverse events resulting in the discontinuation of IFX occurred in 3.6% of the patients; one patient with CD developed leukemia, and the other had a serious infusion reaction. Conclusion The long-term durability of IFX in Japanese pediatric patients with IBD was inadequate in UC compared with CD. Serious adverse events in 3.6% of patients required discontinuation.

Purpose: The long-term efficacy and safety of infliximab (IFX) in Japanese children with inflammatory bowel disease (IBD) remain unclear. This study aimed to examine the longterm outcomes of IFX treatment in Japanese children with IBD. Methods: We retrospectively recruited patients aged <16 years who were diagnosed with ulcerative colitis (UC) or Crohn’s disease (CD) at Kurume University Hospital in Japan between 2011 and 2022 and examined the effectiveness and safety of IFX. We characterized the responses to IFX as primary response, primary nonresponse (PNR), secondary loss of response (sLOR), or still receiving IFX. Results: Among the 77 enrolled patients with UC (median age, 10 years) and 48 with CD (median age, 12 years), 55 (27 with UC and 28 with CD) received IFX treatment. IFX treatment was significantly more common in patients with CD (58.3%) than in those with UC (35.1%;p=0.016). The PNR was significantly greater in patients with UC (18.5%) than in those with CD (0.0%; p=0.023), as was the sLOR (UC, 51.9%; CD, 21.4%; p=0.026). The likelihood of continuing IFX treatment during follow-up (median, 38 months) was significantly higher in patients with CD (71.4%) than in those with UC (29.6%; p=0.003). Adverse events resulting in the discontinuation of IFX occurred in 3.6% of the patients; one patient with CD developed leukemia, and the other had a serious infusion reaction. Conclusion The long-term durability of IFX in Japanese pediatric patients with IBD was inadequate in UC compared with CD. Serious adverse events in 3.6% of patients required discontinuation.

Purpose: The long-term efficacy and safety of infliximab (IFX) in Japanese children with inflammatory bowel disease (IBD) remain unclear. This study aimed to examine the longterm outcomes of IFX treatment in Japanese children with IBD. Methods: We retrospectively recruited patients aged <16 years who were diagnosed with ulcerative colitis (UC) or Crohn’s disease (CD) at Kurume University Hospital in Japan between 2011 and 2022 and examined the effectiveness and safety of IFX. We characterized the responses to IFX as primary response, primary nonresponse (PNR), secondary loss of response (sLOR), or still receiving IFX. Results: Among the 77 enrolled patients with UC (median age, 10 years) and 48 with CD (median age, 12 years), 55 (27 with UC and 28 with CD) received IFX treatment. IFX treatment was significantly more common in patients with CD (58.3%) than in those with UC (35.1%;p=0.016). The PNR was significantly greater in patients with UC (18.5%) than in those with CD (0.0%; p=0.023), as was the sLOR (UC, 51.9%; CD, 21.4%; p=0.026). The likelihood of continuing IFX treatment during follow-up (median, 38 months) was significantly higher in patients with CD (71.4%) than in those with UC (29.6%; p=0.003). Adverse events resulting in the discontinuation of IFX occurred in 3.6% of the patients; one patient with CD developed leukemia, and the other had a serious infusion reaction. Conclusion The long-term durability of IFX in Japanese pediatric patients with IBD was inadequate in UC compared with CD. Serious adverse events in 3.6% of patients required discontinuation.

Background/Aims: Proteinase 3 antineutrophil cytoplasmic antibody (PR3-ANCA) is a serologic marker for granulomatosis with polyangiitis. However, recent studies have also shown their role as diagnostic markers for ulcerative colitis (UC). This study was performed to investigate the clinical roles of PR3-ANCAs in the disease severity, disease extension, and clinical course of UC. Methods: Serum PR3-ANCAs were measured in 173 UC patients including 77 patients with new-onset patients UC diagnosed within 1 month, 110 patients with Crohn’s disease, 48 patients with other intestinal diseases, and 71 healthy controls. Associations between the PR3-ANCA titer and clinical data, such as disease severity, disease extension, and clinical course, were assessed. The clinical utility of PR3-ANCA measurement was evaluated by receiver operating characteristic (ROC) analysis. Results: PR3-ANCA ≥3.5 U/mL demonstrated 44.5% sensitivity and 95.6% specificity for thediagnosis of UC in all patients. PR3-ANCA positivity was more prevalent in the 77 new-onset UC patients (58.4%). In this group, the disease severity and extension were more severe in PR3-ANCA positive patients than in PR3-ANCA negative group (p<0.001). After treatment, the partial Mayo scores were significantly decreased with the PR3-ANCA titers. The proportion of patients who required steroids for induction therapy was significantly higher among PR3-ANCA positive than negative group. ROC analysis revealed that PR3-ANCA ≥3.5 U/mL had 75% sensitivity and 69.0% specificity for steroid requirement in new-onset UC patients. Conclusions Our results indicate that PR3-ANCA measurement is useful not only for diagnosing UC but also for evaluating disease severity and extension and predicting the clinical course.