Yu Bin Kim's research while affiliated with Ajou University Medical Center and other places

Background and aims Favourable clinical data were published on the efficacy of CT-P13, the first biosimilar of infliximab (IFX), in pediatric inflammatory bowel disease (IBD); however, few studies have compared the effect on endoscopic healing (EH) and drug retention rate between the IFX originator and CT-P13. Therefore, we aimed to compare EH and the drug retention rate between the IFX originator and CT-P13. Methods Children with Crohn’s disease (CD) and ulcerative colitis (UC)/IBD-unclassified (IBD-U) at 22 medical centers were enrolled, with a retrospective review conducted at 1-year and last follow-up. Clinical remission, EH and drug retention rate were evaluated. Results We studied 416 pediatric patients with IBD: 77.4% had CD and 22.6% had UC/IBD-U. Among them, 255 (61.3%) received the IFX originator and 161 (38.7%) received CT-P13. No statistically significant differences were found between the IFX originator and CT-P13 in terms of corticosteroid-free remission and adverse events. At 1-year follow-up, EH rates were comparable between them (CD: P=0.902, UC: P=0.860). The estimated cumulative cessation rates were not significantly different between the two groups. In patients with CD, the drug retention rates were 66.1% in the IFX originator and 71.6% in the CT-P13 group at the maximum follow-up period (P >0.05). In patients with UC, the drug retention rates were 49.8% in the IFX originator and 56.3% in the CT-P13 group at the maximum follow-up period (P >0.05). Conclusions The IFX originator and CT-P13 demonstrated comparable therapeutic response including EH, clinical remission, drug retention rate and safety in pediatric IBD.

Background Several cases of pediatric acute hepatitis of unknown etiology related to adenoviral infections have been reported in Europe since January 2022. The aim of this study was to compare the incidence, severity, possible etiology, and prognosis of the disease with those in the past in Korea. Methods The surveillance group collected data between May and November 2022 using a surveillance system. Acute hepatitis of unknown etiology was defined in patients aged < 16 years with a serum transaminase level > 500 IU/L, not due to hepatitis A-E or other underlying causes. For comparison, data from 18 university hospitals were retrospectively collected as a control group between January 2021 and April 2022. Results We enrolled 270 patients (mean age, 5 years). The most common symptom was fever. However, the incidence was similar between 2021 and 2022. Liver function test results, number of patients with acute liver failure (ALF), liver transplantation (LT), death, and adenovirus detection rates did not differ between the two groups. None of the adenovirus-positive patients in either group experienced ALF, LT, or death. In the surveillance group, adenovirus-associated virus-2 was detected in four patients, one of whom underwent LT. Patients with an unknown etiology showed significantly higher bilirubin levels, a lower platelet count, and a higher LT rate than patients with a possible etiology. Conclusion The incidence of pediatric acute hepatitis of unknown etiology and adenovirus detection rate have not increased in Korea.

Background/aims: : The recent update on Selecting Therapeutic Targets in Inflammatory Bowel Disease initiative has added a decrease in fecal calprotectin (FC) to an acceptable range as an intermediate target for Crohn's disease (CD). We aimed to investigate whether postinduction FC could predict future persistent remission (PR) and endoscopic healing (EH) after 1 year of treatment with infliximab (IFX) in pediatric patients with CD. Methods: : This multicenter retrospective observational study included pediatric patients with CD who were followed up for at least 1 year after starting IFX. The association of postinduction FC with PR and EH was investigated. Results: : A total of 132 patients were included in this study. PR and EH were observed in 71.2% (94/132) and 73.9% (82/111) of the patients, respectively. In multivariate logistic regression analysis, only the postinduction FC level was associated with PR (odds ratio [OR], 0.26; 95% confidence interval [CI], 0.08 to 0.66; p=0.009). The FC levels at initiation of IFX and postinduction were significantly associated with EH (OR, 0.73; 95% CI, 0.53 to 0.99; p=0.044 and OR, 0.20; 95% CI, 0.06 to 0.49; p=0.002, respectively). According to the receiver operating characteristic curve analysis, the optimal cutoff level for postinduction FC associated with PR was 122 mg/kg, and that associated with EH was 377 mg/kg. Conclusions: : Postinduction FC was associated with PR and EH after 1 year of treatment with IFX in pediatric patients with CD. Our findings emphasize the importance of FC as an intermediate target in the treat-to-target era.

Purpose: We aimed to investigate factors that correlate with fecal calprotectin (FC) levels in children and adolescents with colorectal polyps. Methods: Pediatric patients aged <19 years who underwent colonoscopic polypectomy for a juvenile polyps (JPs) and FC tests were simultaneously conducted in a multicenter, retrospective study. Baseline demographics, colonoscopic and histological findings, and laboratory tests, including FC levels, were investigated. Correlations between the factors were investigated, and linear regression analysis revealed factors that correlated with FC levels. FC levels measured after polypectomies were investigated and the FC levels pre- and post-polypectomies were compared. Results: A total of 33 patients were included in the study. According to Pearson correlation analysis, the polyp size was the only factor that showed a statistically significant correlation with FC levels (r=0.75, p<0.001). Furthermore, according to the multivariate linear regression analysis, polyp size was the only factor that showed a statistically significant correlation with FC levels (adjusted R2 =0.5718, β=73.62, p<0.001). The median FC level was 400 mg/kg (interquartile range [IQR], 141.6-1,000 mg/kg), and the median polyp size was 14 mm (IQR, 9-20 mm). Nineteen patients underwent post-polypectomy FC tests. FC levels showed a significant decrease after polypectomy from a median of 445.2 mg/kg (IQR, 225-1,000) to 26.5 mg/kg (11.5-51) (p<0.001). Conclusion: FC levels significantly correlated with polyp size in children and adolescents with JPs.

Background and Objectives: The coronavirus disease 2019 (COVID-19) pandemic has affected medical practice in diverse ways. We aimed to investigate the change in trends of lower gastrointestinal (LGI) endoscopy conducted in children and adolescents after the COVID-19 outbreak in Korea. Material and Methods: This was a multicenter, retrospective study conducted in Korea. We included children and adolescents aged <19 years who had undergone their first LGI endoscopy between 2016 and 2020. We compared clinicodemographic and endoscopic factors between groups divided according to the pre- and postCOVID-19 era in Korea. Results: We included 1307 patients in this study. Colonoscopies, instead of sigmoidoscopies, were conducted in most patients in the postCOVID-19 era compared to those in the preCOVID-19 era (86.9% vs. 78.5%, p = 0.007). The diagnosis of inflammatory bowel disease (IBD) was also significantly higher in the postCOVID-19 era compared to the preCOVID-19 era (47.2% vs. 28.5%, p < 0.001). According to multivariate logistic regression analysis, age at LGI endoscopy, LGI bleeding indication, and IBD diagnosis were independently associated with the use of a colonoscopy over a sigmoidoscopy (odds ratio (OR) 1.19, 95% confidence interval (CI) 1.12–1.27, p < 0.001; OR 0.56, 95% CI 0.37–0.83, p = 0.005; OR 1.80, 95% CI 1.20–2.77, p = 0.006, respectively). Conclusions: The COVID-19 pandemic has changed LGI endoscopy practice trends of pediatric gastroenterologists in Korea, who tended to perform lesser LGI endoscopies compared to previous years while conducting significantly more colonoscopies than sigmoidoscopies in the postCOVID-19 era. Furthermore, these colonoscopies were significantly associated with the diagnosis of IBD, as well as a significant increase in IBD diagnosis in the postCOVID-19 era.

Background: Studies on how the coronavirus pandemic has affected pediatric inflammatory bowel disease (PIBD) are lacking. We aimed to investigate the trends in epidemiology, characteristics, initial management, and short-term outcomes of PIBD in South Korea over the recent three years including the era of coronavirus disease 2019 (COVID-19). Methods: This multicenter study retrospectively investigated temporal trends in the epidemiology of PIBD in Korea. Annual occurrences, disease phenotypes, and initial management at diagnosis were analyzed from January 2018 to June 2021. Results: A total of 486 patients from 17 institutions were included in this epidemiological evaluation. Analysis of the occurrence trend confirmed a significant increase in PIBD, regardless of the COVID-19 pandemic. In Crohn's disease, patients with post-coronavirus outbreaks had significantly higher fecal calprotectin levels than those with previous onset (1,339.4 ± 717.04 vs. 1,595.5 ± 703.94, P = 0.001). Patients with post-coronavirus-onset ulcerative colitis had significantly higher Pediatric Ulcerative Colitis Activity Index scores than those with previous outbreaks (48 ± 17 vs. 36 ± 15, P = 0.004). In the initial treatment of Crohn's disease, the use of 5-aminosalicylic acid (5-ASA) and steroids significantly decreased (P = 0.006 and 0.001, respectively), and enteral nutrition and the use of infliximab increased significantly (P = 0.045 and 0.009, respectively). There was a significant increase in azathioprine use during the initial treatment of ulcerative colitis (P = 0.020). Conclusion: Regardless of the COVID-19 pandemic, the number of patients with PIBD is increasing significantly annually in Korea. The initial management trends for PIBD have also changed. More research is needed to establish appropriate treatment guidelines considering the epidemiological and clinical characteristics of Korean PIBD.

Background/aims: A full colonoscopy is currently required in children and adolescents with colorectal polyps, because of their potential of neoplastic transformation and complications such as intussusception. We aimed to analyze the associations of polyp characteristics in children and adolescents with colorectal polyps. Based on these findings, we also aimed to reevaluate the necessity of conducting a full colonoscopy. Methods: Pediatric patients <18 years of age who had undergone a colonoscopic polypectomy and those with <5 colorectal polyps were included in this multicenter, retrospective study. Baseline clinicodemographics, colonoscopic and histologic findings were investigated. Results: A total of 91 patients were included. Multivariate logistic regression analysis showed that polyp size was the only factor associated with the presence of any polyps located proximal to the splenic flexure (odds ratio [OR], 2.25; 95% confidence interval [CI], 1.28 to 4.28; p=0.007). Furthermore, polyp location proximal to the splenic flexure and sessile morphology were associated with the presence of any adenomatous polyp (OR, 8.51; 95% CI, 1.43 to 68.65; p=0.023; OR, 18.41; 95% CI, 3.45 to 173.81; p=0.002, respectively). Conclusions: In children and adolescents presenting with <5 colorectal polyps, polyp size and the presence of any adenomatous polyp were positively associated with polyp location proximal to the splenic flexure. This finding supports the necessity of a full colonoscopic exam in pediatric patients with colorectal polyps for the detection of polyps before the occurrence of complications such as intussusception or neoplastic transformation.

Background: Colorectal polyps are the most common cause of isolated hematochezia in children, which requires a colonoscopy for diagnosis. We aimed to investigate the potential utility of fecal calprotectin (FC) in assessing colorectal polyps detected by colonoscopy among children presenting with isolated hematochezia. Methods: Pediatric patients of the age of < 18 years who had undergone both colonoscopy and FC tests for isolated hematochezia from June 2016 to May 2020 were included in the present multicenter, retrospective, cross-sectional study. Comparative analysis was conducted between major causes of isolated hematochezia and FC cut-offs for discriminating colorectal polyps were explored. Results: A total 127 patients were included. Thirty-five patients (27.6%) had colorectal polyps, followed by anal fissure (14.2%), ulcerative colitis (UC; 12.6%), and others. A significant difference in FC levels was observed between patients with colorectal polyps (median, 278.7 mg/kg), anal fissures (median, 42.2 mg/kg), and UC (median, 981 mg/kg) (P < 0.001). According to receiver operating characteristic curve analysis, among patients diagnosed with colorectal polyp or anal fissure, the most accurate FC cut-off for discriminating colorectal polyps from anal fissures on colonoscopy was 225 mg/kg (sensitivity, 59.4%; specificity, 94.4%; positive predictive value [PPV], 95.0%; negative predictive value [NPV], 56.7%; area under the curve [AUC], 0.8; 95% confidence interval [CI], 0.678-0.923; P < 0.001), while among patients diagnosed with colorectal polyp or UC, the most accurate FC cut-off for discriminating colorectal polyps from UC on colonoscopy was 879 mg/kg (sensitivity, 81.2%; specificity, 56.2%; PPV, 78.8%; NPV, 60.0%; AUC, 0.687; 95% CI, 0.521-0.852; P < 0.001). Conclusion: FC may assist in assessing the cause of lower gastrointestinal tract bleeding in children who present with isolated hematochezia.

Background: The occurrences of infection-related systematic diseases, such as Henoch-Schönlein Purpura (HSP), intussusception, and mucocutaneous lymph node syndrome (MCLS) may have decreased, similarly to the decreased occurrence of infectious diseases following the Coronavirus disease 2019 (COVID-19) pandemic. We aimed to investigate whether there was a change in the occurrence of these diseases in South Korea after the spread of the COVID-19 pandemic. Methods: In this multicenter, retrospective study conducted in 16 medical centers in South Korea patients diagnosed with HSP, intussusception, and MCLS at the age of <18 years between January 2016 and December 2020 were included. New occurrences of these three diseases were investigated monthly and annually, while to compare between the pre- and post-COVID-19 era cases, new occurrences between 2017-2019 and 2020 were compared. Additionally, the total annual occurrence rate was calculated by dividing each center's occurrence into the annual population per 100,000 of the population <18 years in each region that the center covers. Results: A total 6,857 patients were included in this study. From 2017 to 2020, the number of patients diagnosed with HSP, intussusception, MCLS at the age of <18 years were 1,301, 1,693, and 3,863 patients, respectively. The average number of patients during the three years before the COVID-19 pandemic were each 379.7, 505.3, and 1,112.0 for HSP, intussusception, MCLS, respectively, which each decreased by 57.3%, 65.0%, 52.6% to 162, 177, 527 in 2020, respectively. Furthermore, the total annual occurrence rate showed a significant decrease in 2020 compared to 2017 to 2019 in all three diseases (2017-2020; HSP: 11.85, 12.96, 10.52, and 5.48; intussusception: 13.94, 16.97, 16.31, and 5.98; MCLS: 33.89, 35.11, 34.69, and 17.82, respectively). Conclusions: We revealed that the occurrence of HSP, intussusception, and MCLS, which are representative of infection-related systemic diseases in the pediatric population, decreased significantly after the spread of the COVID-19 pandemic.

Background: Sedative upper endoscopy is similar in pediatrics and adults, but it is characteristically more likely to lead to respiratory failure. Although recommended guidelines for pediatric procedural sedation are available within South Korea and internationally, Korean pediatric endoscopists use different drugs, either alone or in combination, in practice. Efforts are being made to minimize the risk of sedation while avoiding procedural challenges. The purpose of this study was to collect and analyze data on the sedation methods used by Korean pediatric endoscopists to help physicians perform pediatric sedative upper endoscopy (PSUE). Methods: The PSUE procedures performed in 15 Korean pediatric gastrointestinal endoscopic units within a year were analyzed. Drugs used for sedation were grouped according to the method of use, and the depth of sedation was evaluated based on the Ramsay scores. The procedures and their complications were also assessed. Results: In total, 734 patients who underwent PSUE were included. Sedation and monitoring were performed by an anesthesiologist at one of the institutions. The sedative procedures were performed by a pediatric endoscopist at the other 14 institutions. Regarding the number of assistants present during the procedures, 36.6% of procedures had one assistant, 38.8% had 2 assistants, and 24.5% had 3 assistants. The average age of the patients was 11.6 years old. Of the patients, 19.8% had underlying diseases, 10.0% were taking medications such as epilepsy drugs, and 1.0% had snoring or sleep apnea history. The average duration of the procedures was 5.2 minutes. The subjects were divided into 5 groups as follows: 1) midazolam + propofol + ketamine (M + P + K): n = 18, average dose of 0.03 + 2.4 + 0.5 mg/kg; 2) M + P: n = 206, average dose of 0.06 + 2.1 mg/kg; 3) M + K: n = 267, average dose of 0.09 + 0.69 mg/kg; 4) continuous P infusion for 20 minutes: n = 15, average dose of 6.6 mg/kg; 5) M: n = 228, average dose of 0.11 mg/kg. The average Ramsay score for the five groups was 3.7, with significant differences between the groups (P < 0.001). Regarding the adverse effects, desaturation and increased oxygen supply were most prevalent in the M + K group. Decreases and increases in blood pressure were most prevalent in the M + P + K group, and bag-mask ventilation was most used in the M + K group. There were no reported incidents of intubation or cardiopulmonary resuscitation. A decrease in oxygen saturation was observed in 37 of 734 patients, and it significantly increased in young patients (P = 0.001) and when ketamine was used (P = 0.014). Oxygen saturation was also correlated with dosage (P = 0.037). The use of ketamine (P < 0.001) and propofol (P < 0.001) were identified as factors affecting the Ramsay score in the logistic regression analysis. Conclusion: Although the drug use by Korean pediatric endoscopists followed the recommended guidelines to an extent, it was apparent that they combined the drugs or reduced the doses depending on the patient characteristics to reduce the likelihood of respiratory failure. Inducing deep sedation facilitates comfort during the procedure, but it also leads to a higher risk of complications.