Sung Hoon Jung

Background Limited reports exist regarding invasive fungal diseases (IFDs) in inflammatory bowel disease (IBD) patients. Objectives This study aims to investigate the incidence and risk factors of IFDs, specifically invasive candidiasis, aspergillosis and pneumocystosis, in IBD patients in South Korea using nationwide data. Patients/Methods A population‐based retrospective cohort of 42,913 IBD patients between January 2010 and December 2018 was evaluated using the Health Insurance Review and Assessment database. The primary outcome was the incidence of IFDs, including invasive candidiasis, aspergillosis and pneumocystosis, while the secondary outcome involved analysing the risk factors associated with each specific infection. Results The study included a total of 42,913 IBD patients, with 29,909 (69.7%) diagnosed with ulcerative colitis (UC) and 13,004 (30.3%) diagnosed with Crohn's disease (CD). IFDs occurred in 166 IBD patients (0.4%), with 93 cases in UC patients and 73 cases in CD patients. The incidence rates of invasive candidiasis, aspergillosis and pneumocystosis in IBD patients were 0.71 per 1000 person‐years (PYs), 0.15 per 1000 PYs and 0.12 per 1000 PYs, respectively. The cumulative incidence of invasive candidiasis (adjusted p ‐value <.001) and Pneumocystosis (adjusted p ‐value = .012) was found to be higher in CD patients than in UC patients. Each IFD had different risk factors, including IBD subtypes, age at diagnosis, anti‐tumour necrotic factor agents or the Charlson comorbidity index. Conclusion Based on nationwide data in South Korea, this study shows that IFDs occur consistently in patients with IBD, albeit with a low frequency.

Background: Biologics play an important role in the treatment of moderate to severe Crohn’s disease (CD). Ustekinumab was approved for such patients in the Republic of Korea on 1 December 2018. Therefore, we need to compare the efficacy of ustekinumab and anti-TNF inhibitors. Methods: We compared one-year persistence rates between anti-TNF inhibitors and ustekinumab in moderate-to-severe CD patients using Korean National Health Insurance Service data from 1 December 2016 to 30 November 2021. We also analysed the risk factors for the non-persistence of biologics. Results: The one-year persistence rates with index therapy in bio-naïve and bio-experienced patients were 87.7% and 69.7% for infliximab (p < 0.001), 85.1% and 72.8% for adalimumab (p < 0.001), and 92.1% and 89.8% for ustekinumab (p = 0.333), respectively. The risk factors for non-persistence were older age, non-use of an immune modulator, and previous biologic exposure in both the infliximab and adalimumab groups. The one-year persistence rate of ustekinumab was higher than that of anti-TNF inhibitors in bio-naïve patients (hazard ratio [HR] 0.53; 95% confidence interval [CI] 0.35–0.81; p = 0.003) and bio-experienced patients (HR 0.32; 95% CI 0.22–0.45; p < 0.001). Conclusions: Ustekinumab was superior in bio-naïve CD patients compared to anti-TNF inhibitors. However, the follow-up time was relatively short; further studies should continuously collect and analyse data.