Purpose: To investigate ocular manifestation of immune reconstitution inflammatory syndrome (IRIS) in HIV patients after starting highly active antiretroviral therapy (HAART) and its relationship to T cell immunity. Methods: HIV patients with ocular IRIS after HAART were retrospectively reviewed. Clinical presentations with previous opportunistic infection, duration from initiation of HAART to IRIS, blood CD4+, CD8+ T cell count, and HIV RNA copies before HAART and at IRIS were analyzed. Results: Among 19 patients (27 eyes) included, the most common previous opportunistic infection was cytomegalovirus (17 patients, 89.5%) followed by tuberculosis choroiditis (2 patients, 10.5%). The clinical manifestations included vitritis (20 eyes, 74.0%), retinitis (14 eyes, 51.9%), and anterior uveitis (5 eyes, 18.5%). The median duration from initiation of HAART to IRIS was 70 days. CD4+ T cell count before HAART increased at IRIS (p < 0.001). CD8+ T cell count before HAART was negatively correlated with duration from HAART to IRIS (p < 0.001). The cutoff value of CD8+ T cell count for discerning early or late onset of ocular IRIS was 258/mm3 (p = 0.001). When divided into two groups by CD8+ T cell count of 258/mm3, 90% patients with CD8+ T cell count higher than 258/mm3 before HAART developed ocular IRIS within 70 days. Conclusions There was a negative relationship between CD8+ T cell count before HAART and duration from HAART to ocular IRIS. Ocular IRIS with higher CD8+ T cell count before HAART developed earlier after HAART initiation compared to those with lower CD8+ T cell count.

Background: Complete revascularization has demonstrated better outcomes in patients with acute myocardial infarction (AMI) and multivessel disease. However, in the case of left main (LM) culprit lesion AMI with multivessel disease, there is limited evidence to suggest that complete revascularization is better. Methods: We reviewed 16,831 patients in the Korea Acute Myocardial Infarction Registry who were treated from July 2016 to June 2020, and 399 patients were enrolled with LM culprit lesion AMI treated with percutaneous coronary intervention. We categorized the patients as those treated with complete revascularization (n=295) or incomplete revascularization (n=104). The study endpoint was major adverse cardiac and cerebrovascular events (MACCE), a composite of all-cause death, myocardial infarction, ischemia-driven revascularization, stent thrombosis, and stroke. We performed propensity score matching (PSM) and analyzed the incidence of MACCE at 1 year. Results: After PSM, the two groups were well balanced. There was no significant difference between the two groups in MACCE at 1 year (12.1% vs. 15.2%; hazard ratio, 1.28; 95% confidence interval, 0.60–2.74; p=0.524) after PSM. The components of MACCE and major bleeding were also not significantly different. Conclusion There was no significant difference in clinical outcomes between the groups treated with complete or incomplete revascularization for LM culprit lesion AMI with multivessel disease.

Background and Objectives: Cigarette smoking is a major risk factor for atherosclerosis.Nicotine, a crucial constituent of tobacco, contributes to atherosclerosis development and progression. However, evidence of the association between nicotine and neointima formation is limited. We aimed to evaluate whether nicotine enhances neointimal hyperplasia in the native epicardial coronary arteries of pigs after percutaneous coronary intervention (PCI) with drug-eluting stents (DES). Methods: After coronary angiography (CAG) and quantitative coronary angiography (QCA), we implanted 20 DES into 20 pigs allocated to 2 groups: no-nicotine (n=10) and nicotine (n=10) groups. Post-PCI CAG and QCA were performed immediately. Follow-up CAG, QCA, optical coherence tomography (OCT), and histopathological analyses were performed 2 months post-PCI. Results: Despite intergroup similarities in the baseline QCA findings, OCT analysis showed that the nicotine group had a smaller mean stent and lumen areas, a larger mean neointimal area, greater percent area stenosis, and higher peri-strut fibrin and inflammation scores than the no-nicotine group. In immunofluorescence analysis, the nicotine group displayed higher expression of CD68 and α-smooth muscle actin but lower CD31 expression than the no-nicotine group. Conclusions Nicotine inhibited re-endothelialization and promoted inflammation and NIH after PCI with DES in a porcine model.

Background/Aims: We investigated the clinical practice patterns of Korean endoscopists for the endoscopic resection of colorectal polyps. Methods: From September to November 2021, an online survey was conducted regarding the preferred resection methods for colorectal polyps, and responses were compared with the international guidelines. Results: Among 246 respondents, those with <4 years, 4–9 years, and ≥10 years of experiencein colonoscopy practices accounted for 25.6%, 34.1%, and 40.2% of endoscopists, respectively. The most preferred resection methods for non-pedunculated lesions were cold forceps polypectomy for ≤3 mm lesions (81.7%), cold snare polypectomy for 4–5 mm (61.0%) and 6–9 mm (43.5%) lesions, hot endoscopic mucosal resection (EMR) for 10–19 mm lesions (72.0%), precut EMR for 20–25 mm lesions (22.0%), and endoscopic submucosal dissection (ESD) for ≥26 mm lesions (29.3%). Hot EMR was favored for pedunculated lesions with a head size <20 mm and stalk size <10 mm (75.6%) and for those with a head size ≥20 mm or stalk size ≥10 mm (58.5%). For suspected superficial and deep submucosal lesions measuring 10–19 mm and ≥20 mm, ESD (26.0% and 38.6%) and surgery (36.6% and 46.3%) were preferred, respectively. The adherence rate to the guidelines ranged from 11.2% to 96.9%, depending on the size, shape, and histology of the lesions. Conclusions Adherence to the guidelines for endoscopic resection techniques varied depend-ing on the characteristics of colorectal polyps. Thus, an individualized approach is required to increase adherence to the guidelines.

Background/Aims: Although gastrointestinal endoscopy (GIE) is a major contributor to the carbon footprint of national healthcare, the amount of medical waste generated by GIE procedures is not reported in South Korea. This study aimed to measure the amount of medical waste generated from GIE procedures in South Korea. Methods: We conducted a 5-day audit of medical waste generated during GIEs at seven hospitals. During the study period, medical waste in the endoscopy examination rooms was measured twice daily and documented as mass (kg). To calculate the mean mass of disposable waste generated during one esophagogastroduodenoscopy (EGD) and one colonoscopy, the mean mass of medical waste generated from seven examinations was calculated. The mean mass of medical waste generated during GIEs was calculated by dividing the total mass of medical waste generated by the number of GIE procedures. Results: Overall, 3,922 endoscopies were performed and 4,558 kg of waste was generated. The mean weight of medical waste generated per endoscopy was 1.34 kg. Each EGD and colonoscopy generated a mean of 0.24 kg and 0.43 kg of disposable waste, respectively. Applying the mean waste estimates from this study to annual GIE procedures performed in South Korea in 2022 showed that the total medical waste produced from GIE was 13,704,453 kg. In addition, the total masses of medical waste produced during EGD and colonoscopy procedures were 819,766 kg and 2,889,478 kg, respectively. Conclusions Our quantitative measurement showed that a large amount of medical waste is generated from GIE procedures. However, further research is warranted to reduce medical waste generated during GIE, which is an urgent unmet need.

Background/Aims: Early diagnosis of esophageal cancer (EC) remains challenging despite the increasing frequency of endoscopic screenings globally. The rapidly increasing number of endoscopic screenings performed over a certain period might influence diagnostic performance. This study evaluated the association between the number of endoscopic screenings and EC detection rates in a nationwide cohort. Methods: This retrospective population-based study used the Korean National Cancer Screening Program database, comprising 32,774,742 males and females aged ≥40 years between 2015and 2019. Negative binomial regression model and least-squares mean evaluation were used to assess the association between month of the year and EC detection rates. Results: This study enrolled 28,032,590 participants who underwent upper endoscopy. The number of participants in the fourth quarter (October to December: 10,923,142 [39.0%]) was 2.1 times higher than that in the first quarter (January to March: 5,085,087 [18.1%]); this trend continued for all 5 years. Contrarily, detection rates for EC in the fourth quarter (0.08/1,000 person) were half that in the first quarter (0.15/1,000 person). The odds of detecting EC were lowest in November; in 2015 the odds were 0.57 (95% confidence interval, 0.41 to 0.79; p=0.001) times lower and in 2016, they were 0.51 (95% confidence interval, 0.37 to 0.68; p<0.001) times lower compared to January. The predicted detection rates showed a decreasing trend toward the end of the year (p>0.05 for all). Conclusions The workload of endoscopists increased excessively with the rising number of endoscopies toward the end of the year, which was reflected by the decreased EC detection rates during this period.

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: Although the urea breath test (UBT) is widely used as a representative monitoring test after Helicobacter pylori eradication, false-negative results can occur because of the gray zone related to its cutoff value. This study aimed to compare the diagnostic performances of the rapid urease test (RUT), the RUT with sweeping method, and the UBT, and to investigate the role of the sweeping method in the gray zone of UBT values. Methods: We retrospectively reviewed 216 patients who received standard first-line H. pylori eradication treatments (n=216). All participants underwent to testing using the sweeping method and UBT on the same day. The sensitivity, specificity, and accuracy were analyzed to compare the two methods. Results: The sensitivity (0.537 vs 0.806, p=0.002) and accuracy (0.843 vs 0.870, p=0.026) of the UBT were inferior to those of the sweeping method. A total of 31 individuals tested positive for H. pylori according to the UBT, whereas 54 individuals tested positive according to the sweeping method. In the group for which the gold standard definition indicated H. pylori positivity but UBT results were negative (n=31), all individuals had a UBT value under 2.5‰. In the multivariate logistic regression model, a UBT value of 1.4‰ to 2.5‰ increased the risk of false-negative results by 6.5 times (odds ratio, 6.5; 95% confidence interval, 2.077 to 20.288; p=0.001). Conclusions After H. pylori eradication, false-negative results can occur for individuals undergoing the UBT, primarily for values below the UBT cutoff. The RUT with the sweeping method can potentially help detect H. pylori in the gray zone of the UBT, improving diagnostic accuracy.

Purpose: We aimed to evaluate health-related quality of life (HRQoL) in intestinal failure (IF) patients after different modes of intestinal rehabilitation. Methods: HRQoL was assessed using the generic 36-item Short Form Survey (SF-36, ver. 2) and visual analogue scale (VAS) in 6 different areas: diet, sleep, gastrointestinal (GI) symptoms, diarrhea, musculoskeletal pain, and other symptoms. Results: Twenty-two patients completed the questionnaires, of which 7 had received intestinal transplant (ITx), 9 were continuing home total parenteral nutrition (HPN), and 6 had tapered off total parenteral nutrition (TPN). SF-36 physical component summary scores were highest in the ITx group (median, 65.6; interquartile range [IQR], 31.6–80.3) compared to the HPN (median, 48.4; IQR, 44.7–66.3) or tapered group (median, 54.2; IQR, 45.2–61.6). Mental component summary scores were lowest in the ITx group (median, 48.8; IQR, 37.1–63.6), compared to the TPN (median, 60.2; IQR, 41.6–78.5) or tapered group (median, 51.0; IQR, 48.8–56.0). Differences were not significant in all items of the SF-36. VAS scores showed that patients in the ITx group showed the best results in diet (0.9), gastrointestinal (GI) symptoms (1.4), and musculoskeletal pain (2.4). There was a significant difference in sleep (P = 0.036), with the ITx (1.43) and HPN groups (1.33) showing better outcomes compared with the tapered group (4.67). Patients in the tapered group showed the least favorable results in all performance areas, except GI symptoms. Conclusion SF-36 did not show a significant difference between the ITx, HPN, and tapered groups, but VAS showed a significant difference in sleep between groups. Further studies, including serial data, will allow a better understanding of the effects of different modes of intestinal rehabilitation.

Purpose: To investigate ocular manifestation of immune reconstitution inflammatory syndrome (IRIS) in HIV patients after starting highly active antiretroviral therapy (HAART) and its relationship to T cell immunity. Methods: HIV patients with ocular IRIS after HAART were retrospectively reviewed. Clinical presentations with previous opportunistic infection, duration from initiation of HAART to IRIS, blood CD4+, CD8+ T cell count, and HIV RNA copies before HAART and at IRIS were analyzed. Results: Among 19 patients (27 eyes) included, the most common previous opportunistic infection was cytomegalovirus (17 patients, 89.5%) followed by tuberculosis choroiditis (2 patients, 10.5%). The clinical manifestations included vitritis (20 eyes, 74.0%), retinitis (14 eyes, 51.9%), and anterior uveitis (5 eyes, 18.5%). The median duration from initiation of HAART to IRIS was 70 days. CD4+ T cell count before HAART increased at IRIS (p < 0.001). CD8+ T cell count before HAART was negatively correlated with duration from HAART to IRIS (p < 0.001). The cutoff value of CD8+ T cell count for discerning early or late onset of ocular IRIS was 258/mm3 (p = 0.001). When divided into two groups by CD8+ T cell count of 258/mm3, 90% patients with CD8+ T cell count higher than 258/mm3 before HAART developed ocular IRIS within 70 days. Conclusions There was a negative relationship between CD8+ T cell count before HAART and duration from HAART to ocular IRIS. Ocular IRIS with higher CD8+ T cell count before HAART developed earlier after HAART initiation compared to those with lower CD8+ T cell count.