Background/Aims: The Korean guidelines for Helicobacter pylori treatment were revised in 2020, however, the extent of adherence to these guidelines in clinical practice remains unclear. Herein, we initiated a prospective, nationwide, multicenter registry study in 2021 to evaluate the current management of H.pylori infection in Korea. Methods: This interim report describes the adherence to the revised guidelines and their impact on firstline eradication rates. Data on patient demographics, diagnoses, treatments, and eradication outcomes were collected using a web-based electronic case report form. Results: A total of 7,261 patients from 66 hospitals who received first-line treatment were analyzed.The modified intention-to-treat eradication rate for first-line treatment was 81.0%, with 80.4% of the prescriptions adhering to the revised guidelines. The most commonly prescribed regimen was the 14-day clarithromycin-based triple therapy (CTT; 42.0%), followed by tailored therapy (TT; 21.2%), 7-day CTT (14.1%), and 10-day concomitant therapy (CT; 10.1%). Time-trend analysis demonstrated significant increases in guideline adherence and the use of 10-day CT and TT, along with a decrease in the use of 7-day CTT (all p<0.001). Multivariate logistic regression analysis revealed that guideline adherence was significantly associated with first-line eradication success (odds ratio, 2.03; 95% confidence interval, 1.61 to 2.56; p<0.001). Conclusions The revised guidelines for the treatment of H. pylori infection have been increasingly adopted in routine clinical practice in Korea, which may have contributed to improved first-line eradication rates. Notably, the 14-day CTT, 10-day CT, and TT regimens are emerging as the preferred first-line treatment options among Korean physicians.

Background/Aims: The Korean guidelines for Helicobacter pylori treatment were revised in 2020, however, the extent of adherence to these guidelines in clinical practice remains unclear. Herein, we initiated a prospective, nationwide, multicenter registry study in 2021 to evaluate the current management of H.pylori infection in Korea. Methods: This interim report describes the adherence to the revised guidelines and their impact on firstline eradication rates. Data on patient demographics, diagnoses, treatments, and eradication outcomes were collected using a web-based electronic case report form. Results: A total of 7,261 patients from 66 hospitals who received first-line treatment were analyzed.The modified intention-to-treat eradication rate for first-line treatment was 81.0%, with 80.4% of the prescriptions adhering to the revised guidelines. The most commonly prescribed regimen was the 14-day clarithromycin-based triple therapy (CTT; 42.0%), followed by tailored therapy (TT; 21.2%), 7-day CTT (14.1%), and 10-day concomitant therapy (CT; 10.1%). Time-trend analysis demonstrated significant increases in guideline adherence and the use of 10-day CT and TT, along with a decrease in the use of 7-day CTT (all p<0.001). Multivariate logistic regression analysis revealed that guideline adherence was significantly associated with first-line eradication success (odds ratio, 2.03; 95% confidence interval, 1.61 to 2.56; p<0.001). Conclusions The revised guidelines for the treatment of H. pylori infection have been increasingly adopted in routine clinical practice in Korea, which may have contributed to improved first-line eradication rates. Notably, the 14-day CTT, 10-day CT, and TT regimens are emerging as the preferred first-line treatment options among Korean physicians.

Background/Aims: The Korean guidelines for Helicobacter pylori treatment were revised in 2020, however, the extent of adherence to these guidelines in clinical practice remains unclear. Herein, we initiated a prospective, nationwide, multicenter registry study in 2021 to evaluate the current management of H.pylori infection in Korea. Methods: This interim report describes the adherence to the revised guidelines and their impact on firstline eradication rates. Data on patient demographics, diagnoses, treatments, and eradication outcomes were collected using a web-based electronic case report form. Results: A total of 7,261 patients from 66 hospitals who received first-line treatment were analyzed.The modified intention-to-treat eradication rate for first-line treatment was 81.0%, with 80.4% of the prescriptions adhering to the revised guidelines. The most commonly prescribed regimen was the 14-day clarithromycin-based triple therapy (CTT; 42.0%), followed by tailored therapy (TT; 21.2%), 7-day CTT (14.1%), and 10-day concomitant therapy (CT; 10.1%). Time-trend analysis demonstrated significant increases in guideline adherence and the use of 10-day CT and TT, along with a decrease in the use of 7-day CTT (all p<0.001). Multivariate logistic regression analysis revealed that guideline adherence was significantly associated with first-line eradication success (odds ratio, 2.03; 95% confidence interval, 1.61 to 2.56; p<0.001). Conclusions The revised guidelines for the treatment of H. pylori infection have been increasingly adopted in routine clinical practice in Korea, which may have contributed to improved first-line eradication rates. Notably, the 14-day CTT, 10-day CT, and TT regimens are emerging as the preferred first-line treatment options among Korean physicians.

Background/Aims: The Korean guidelines for Helicobacter pylori treatment were revised in 2020, however, the extent of adherence to these guidelines in clinical practice remains unclear. Herein, we initiated a prospective, nationwide, multicenter registry study in 2021 to evaluate the current management of H.pylori infection in Korea. Methods: This interim report describes the adherence to the revised guidelines and their impact on firstline eradication rates. Data on patient demographics, diagnoses, treatments, and eradication outcomes were collected using a web-based electronic case report form. Results: A total of 7,261 patients from 66 hospitals who received first-line treatment were analyzed.The modified intention-to-treat eradication rate for first-line treatment was 81.0%, with 80.4% of the prescriptions adhering to the revised guidelines. The most commonly prescribed regimen was the 14-day clarithromycin-based triple therapy (CTT; 42.0%), followed by tailored therapy (TT; 21.2%), 7-day CTT (14.1%), and 10-day concomitant therapy (CT; 10.1%). Time-trend analysis demonstrated significant increases in guideline adherence and the use of 10-day CT and TT, along with a decrease in the use of 7-day CTT (all p<0.001). Multivariate logistic regression analysis revealed that guideline adherence was significantly associated with first-line eradication success (odds ratio, 2.03; 95% confidence interval, 1.61 to 2.56; p<0.001). Conclusions The revised guidelines for the treatment of H. pylori infection have been increasingly adopted in routine clinical practice in Korea, which may have contributed to improved first-line eradication rates. Notably, the 14-day CTT, 10-day CT, and TT regimens are emerging as the preferred first-line treatment options among Korean physicians.

Background/Aims: The programmed death 1 (PD-1)/programmed death-ligand 1 (PD-L1) pathway has not been fully evaluated in inflammatory bowel disease. We evaluated PD-1/PD-L1 levels in patients with ulcerative colitis (UC) and their significance in tonsil-derived mesenchymal stem cells (TMSCs) treatment. Methods: Using acute and chronic murine colitis model, we measured the PD-1 and PD-L1 levels in inflamed colonic tissues pre- and post-treatment with TMSCs. We also measured PD-1 and PD-L1 levels in colonic tissues from UC patients, compared to normal controls. Results: In the analysis using human colonic tissues, a significant increase in the levels of PD-1 and PD-L1 was observed in the colonic mucosa of patients with UC compared with normal controls (p < 0.001 and p = 0.005, respectively). When comparing the maximal disease extent, PD-L1 levels were highest in patients with proctitis (38.5 ± 46.7), followed by left-side colitis (17.5 ± 23.1) and extensive colitis (5.2 ± 8.2) (p < 0.001). In the chronic colitis model, the level of PD-L1 was decreased (p = 0.040) and the level of PD-1 increased more than in normal controls (p = 0.047). After treatment with TMSC, significant improvements were observed in body weight, disease activity index, and colon length recovery. Additionally, the levels of PD-1 and PD-L1 were recovered; PD-L1 significantly increased (p = 0.031), while the level of PD-1 decreased (p = 0.310). Conclusions The altered expression of PD-1 and PD-L1 in colonic mucosa may be a possible mechanism of UC, and T-MSC-derived PD-L1 could help suppress colitis.

Background: This study aimed to investigate the epidemiological characteristics and outcomes of myocarditis/pericarditis after BNT162b2 vaccination in Korean adolescents. Methods: This was a retrospective cohort analysis of adolescents aged 12–19 years old diagnosed with myocarditis/pericarditis within 42 days of BNT162b2 mRNA vaccination. All reported cases were investigated by city or government epidemiologists and the diagnostic certainty and causality was determined by the Korea Disease Control and Prevention Agency’s Adverse Event Following Immunization Expert Advisory Committee according to the modified version of Brighton Collaboration Myocarditis/Pericarditis Working group’s case definitions. Results: A total 3,709,063 adolescents aged 12–19 received 8,135,240 doses of the BNT162b2 vaccine in South Korea, and 184 cases met the Brighton criteria for the case definition of myocarditis and pericarditis with diagnostic certainty of possible and above. The median age was 17 years old (interquartile range [IQR], 15–18) and boys accounted for 81.5% (n = 150/184) of the cases. The overall incidence was 2.25 (95% confidence interval [CI], 1.94–2.60) cases per 100,000 doses and severe cases was 0.25 (95% CI, 0.15–3.80) cases per 100,000 doses.The highest incidence rate was observed in boys after the second dose, with 5.01 (95% CI, 4.12–6.17) cases per 100,000 doses. A total 89.1% (164/184) were classified as mild, and no deaths were reported. Conclusion The highest incidence of myocarditis/pericarditis after BNT162b2 immunization was observed in male adolescents after the second dose, with majority of the cases presenting with a mild clinical course and favorable outcome.

Background: This study aimed to investigate the epidemiological characteristics and outcomes of myocarditis/pericarditis after BNT162b2 vaccination in Korean adolescents. Methods: This was a retrospective cohort analysis of adolescents aged 12–19 years old diagnosed with myocarditis/pericarditis within 42 days of BNT162b2 mRNA vaccination. All reported cases were investigated by city or government epidemiologists and the diagnostic certainty and causality was determined by the Korea Disease Control and Prevention Agency’s Adverse Event Following Immunization Expert Advisory Committee according to the modified version of Brighton Collaboration Myocarditis/Pericarditis Working group’s case definitions. Results: A total 3,709,063 adolescents aged 12–19 received 8,135,240 doses of the BNT162b2 vaccine in South Korea, and 184 cases met the Brighton criteria for the case definition of myocarditis and pericarditis with diagnostic certainty of possible and above. The median age was 17 years old (interquartile range [IQR], 15–18) and boys accounted for 81.5% (n = 150/184) of the cases. The overall incidence was 2.25 (95% confidence interval [CI], 1.94–2.60) cases per 100,000 doses and severe cases was 0.25 (95% CI, 0.15–3.80) cases per 100,000 doses.The highest incidence rate was observed in boys after the second dose, with 5.01 (95% CI, 4.12–6.17) cases per 100,000 doses. A total 89.1% (164/184) were classified as mild, and no deaths were reported. Conclusion The highest incidence of myocarditis/pericarditis after BNT162b2 immunization was observed in male adolescents after the second dose, with majority of the cases presenting with a mild clinical course and favorable outcome.

Background: This study aimed to investigate the epidemiological characteristics and outcomes of myocarditis/pericarditis after BNT162b2 vaccination in Korean adolescents. Methods: This was a retrospective cohort analysis of adolescents aged 12–19 years old diagnosed with myocarditis/pericarditis within 42 days of BNT162b2 mRNA vaccination. All reported cases were investigated by city or government epidemiologists and the diagnostic certainty and causality was determined by the Korea Disease Control and Prevention Agency’s Adverse Event Following Immunization Expert Advisory Committee according to the modified version of Brighton Collaboration Myocarditis/Pericarditis Working group’s case definitions. Results: A total 3,709,063 adolescents aged 12–19 received 8,135,240 doses of the BNT162b2 vaccine in South Korea, and 184 cases met the Brighton criteria for the case definition of myocarditis and pericarditis with diagnostic certainty of possible and above. The median age was 17 years old (interquartile range [IQR], 15–18) and boys accounted for 81.5% (n = 150/184) of the cases. The overall incidence was 2.25 (95% confidence interval [CI], 1.94–2.60) cases per 100,000 doses and severe cases was 0.25 (95% CI, 0.15–3.80) cases per 100,000 doses.The highest incidence rate was observed in boys after the second dose, with 5.01 (95% CI, 4.12–6.17) cases per 100,000 doses. A total 89.1% (164/184) were classified as mild, and no deaths were reported. Conclusion The highest incidence of myocarditis/pericarditis after BNT162b2 immunization was observed in male adolescents after the second dose, with majority of the cases presenting with a mild clinical course and favorable outcome.

Background: This study aimed to investigate the epidemiological characteristics and outcomes of myocarditis/pericarditis after BNT162b2 vaccination in Korean adolescents. Methods: This was a retrospective cohort analysis of adolescents aged 12–19 years old diagnosed with myocarditis/pericarditis within 42 days of BNT162b2 mRNA vaccination. All reported cases were investigated by city or government epidemiologists and the diagnostic certainty and causality was determined by the Korea Disease Control and Prevention Agency’s Adverse Event Following Immunization Expert Advisory Committee according to the modified version of Brighton Collaboration Myocarditis/Pericarditis Working group’s case definitions. Results: A total 3,709,063 adolescents aged 12–19 received 8,135,240 doses of the BNT162b2 vaccine in South Korea, and 184 cases met the Brighton criteria for the case definition of myocarditis and pericarditis with diagnostic certainty of possible and above. The median age was 17 years old (interquartile range [IQR], 15–18) and boys accounted for 81.5% (n = 150/184) of the cases. The overall incidence was 2.25 (95% confidence interval [CI], 1.94–2.60) cases per 100,000 doses and severe cases was 0.25 (95% CI, 0.15–3.80) cases per 100,000 doses.The highest incidence rate was observed in boys after the second dose, with 5.01 (95% CI, 4.12–6.17) cases per 100,000 doses. A total 89.1% (164/184) were classified as mild, and no deaths were reported. Conclusion The highest incidence of myocarditis/pericarditis after BNT162b2 immunization was observed in male adolescents after the second dose, with majority of the cases presenting with a mild clinical course and favorable outcome.

Background/Aims: Sedation has become a standard practice for patients undergoing gastrointestinal (GI) endoscopy. However, considering the serious cardiopulmonary adverse events associated with sedatives, it is important to identify patients at high risk. Machine learning can generate reasonable prediction for a wide range of medical conditions. This study aimed to evaluate the risk factors associated with sedation during GI endoscopy and develop a predictive model for hypoxia during endoscopy under sedation. Methods: This prospective observational study enrolled 446 patients who underwent sedative endoscopy at the Korea University Ansan Hospital. Clinical data were used as predictor variables to construct predictive models using the random forest method that is a machine learning algorithm. Results: Seventy-two of the 446 patients (16.1%) experienced life-threatening hypoxia requiring immediate medical intervention. Patients who developed hypoxia had higher body weight, body mass index (BMI), neck circumference, and Mallampati scores. Propofol alone and higher initial and total dose of propofol were significantly associated with hypoxia during sedative endoscopy. Among these variables, high BMI, neck circumference, and Mallampati score were independent risk factors for hypoxia. The area under the receiver operating characteristic curve for the random forest-based predictive model for hypoxia during sedative endoscopy was 0.82 (95% confidence interval, 0.79–0.86) and displayed a moderate discriminatory power. Conclusions High BMI, neck circumference, and Mallampati score were independently associated with hypoxia during sedative endoscopy. We constructed a model with acceptable performance for predicting hypoxia during sedative endoscopy.