Background: The clinical implications of myelin oligodendrocyte glycoprotein autoantibodies (MOG-Abs) are increasing. Establishing MOG-Ab assays is essential for effectively treating patients with MOG-Abs. We established an in-house cell-based assay (CBA) to detect MOG-Abs to identify correlations with patients’ clinical characteristics. Methods: We established the CBA using HEK 293 cells transiently overexpressing fulllength human MOG, tested it against 166 samples from a multicenter registry of central nervous system (CNS) inflammatory disorders, and compared the results with those of the Oxford MOG-Ab-based CBA and a commercial MOG-Ab CBA kit. We recruited additional patients with MOG-Abs and compared the clinical characteristics of MOG-Ab-associated disease (MOGAD) with those of neuromyelitis optica spectrum disorder (NMOSD). Results: Of 166 samples tested, 10 tested positive for MOG-Abs, with optic neuritis (ON) being the most common manifestation (4/15, 26.7%). The in-house and Oxford MOG-Ab CBAs agreed for 164/166 (98.8%) samples (κ = 0.883, P < 0.001); two patients (2/166, 1.2%) were only positive in our in-house CBA, and the CBA scores of the two laboratories correlated well (r = 0.663, P < 0.001). The commercial MOG-Ab CBA kit showed one falsenegative and three false-positive results. The clinical presentation at disease onset differed between MOGAD and NMOSD; ON was the most frequent manifestation in MOGAD, and transverse myelitis was most frequent in NMOSD. Conclusions The in-house CBA for MOG-Abs demonstrated reliable results and can potentially be used to evaluate CNS inflammatory disorders. A comprehensive, long-term study with a large patient population would clarify the clinical significance of MOG-Abs.

Despite the availability of direct-acting antivirals (DAAs) for chronic hepatitis C virus (HCV) infection in Korea, need remains for pangenotypic regimens that can be used in the presence of hepatic impairment, comorbidities, or prior treatment failure. We investigated the efficacy and safety of sofosbuvir–velpatasvir and sofosbuvir–velpatasvir–voxilaprevir for 12 weeks in HCV-infected Korean adults. Methods: This Phase 3b, multicenter, open-label study included 2 cohorts. In Cohort 1, participants with HCV genotype 1 or 2 and who were treatment-naive or treatment-experienced with interferon-based treatments, received sofosbuvir–velpatasvir 400/100 mg/day. In Cohort 2, HCV genotype 1 infected individuals who previously received an NS5A inhibitor-containing regimen ≥ 4 weeks received sofosbuvir–velpatasvir–voxilaprevir 400/100/100 mg/day. Decompensated cirrhosis was an exclusion criterion. The primary endpoint was SVR12, defined as HCV RNA < 15 IU/mL 12 weeks following treatment. Results: Of 53 participants receiving sofosbuvir–velpatasvir, 52 (98.1%) achieved SVR12. The single participant who did not achieve SVR12 experienced an asymptomatic Grade 3 ASL/ALT elevation on day 15 and discontinued treatment. The event resolved without intervention. All 33 participants (100%) treated with sofosbuvir–velpatasvir–voxilaprevir achieved SVR 12. Overall, sofosbuvir–velpatasvir and sofosbuvir–velpatasvir–voxilaprevir were safe and well tolerated. Three participants (5.6%) in Cohort 1 and 1 participant (3.0%) in Cohort 2 had serious adverse events, but none were considered treatment-related. No deaths or grade 4 laboratory abnormalities were reported. Conclusions: Treatment with sofosbuvir–velpatasvir or sofosbuvir–velpatasvir–voxilaprevir was safe and resulted in high SVR12 rates in Korean HCV patients.

Background: and Purpose Neuromyelitis optica spectrum disorder (NMOSD) is a rare demyelinating disease of the central nervous system (CNS). We investigated the medical behaviors of experts in Korea when they are diagnosing and treating NMOSD. Methods: An anonymous questionnaire on the diagnosis and treatment of NMOSD was distributed to experts in CNS demyelinating diseases. Results: Most respondents used the 2015 diagnostic criteria for NMOSD and applied a cerebrospinal fluid examination, magnetic resonance imaging (MRI) of the brain and spine, and anti-aquaporin-4 antibody testing to all suspected cases of NMOSD. All respondents prescribed steroid pulse therapy as an first-line therapy in the acute phase of NMOSD, and 67% prescribed azathioprine for maintenance therapy in NMOSD. However, details regarding monitoring, the tapering period of oral steroids, second-line therapy use in refractory cases, management during pregnancy, and schedule of follow-up MRI differed according to the circumstances of individual patients. We analyzed the differences in response rates between two groups of respondents according to the annual number of NMOSD patients that they treated.The group that had been treating ≥10 NMOSD patients annually preferred rituximab more often as the second-line therapy (p=0.011) and had more experience with rituximab treatment (p=0.015) compared with the group that had been treating <10 NMOSD patients. Conclusions This study has revealed that NMOSD experts in Korea principally follow the available treatment guidelines. However, the differences in specific clinical practices applied to uncertain cases that have been revealed will need to be investigated further in order to formulate suitable recommendations.

Purpose: The introduction of immune checkpoint inhibitors represents a major advance in the treatment of lung cancer, allowing sustained recovery in a significant proportion of patients. Nivolumab is a monoclonal anti–programmed death cell protein 1 antibody licensed for the treatment of locally advanced or metastatic non-small cell lung cancer (NSCLC) after prior chemotherapy. In this study, we describe the demographic and clinical outcomes of patients with advanced NSCLC treated with nivolumab in the Korean expanded access program. Materials and Methods: Previously treated patients with advanced non-squamous and squamous NSCLC patients received nivolumab at 3 mg/kg every 2 weeks up to 36 months. Efficacy data including investigator-assessed tumor response, progression data, survival, and safety data were collected. Results: Two hundred ninety-nine patients were treated across 36 Korean centers. The objective response rate and disease control rate were 18% and 49%, respectively; the median progression-free survival was 2.1 months (95% confidence interval [CI], 1.87 to 3.45), and the overall survival (OS) was 13.2 months (95% CI, 10.6 to 18.9). Patients with smoking history and patients who experienced immune-related adverse events showed a prolonged OS. Cox regression analysis identified smoking history, presence of immune-related adverse events as positive factors associated with OS, while liver metastasis was a negative factor associated with OS. The safety profile was generally comparable to previously reported data. Conclusion This real-world analysis supports the use of nivolumab for pretreated NSCLC patients, including those with an older age.

Background: Although neuromyelitis optica spectrum disorder (NMOSD) is known to be a rare disease, its prevalence and incidence have not yet been studied in Korea. We performed a population-based study to examine the prevalence and incidence of NMOSD in Korea using data from the Korean National Health Insurance (NHI) claims database. Methods: Data from 2013 to 2017 were obtained, with a washout period set as 2013 and 2014. The prevalence and incidence of NMOSD in 2016 and 2017 were calculated using population census data. Subjects were divided into 5 groups at 15-year intervals, depending on the age at which the diagnostic code was entered. The relative risk (RR) for each age group was compared with the oldest (≥ 60 years) age group. Results: The overall prevalence was estimated to be 3.36 and 3.56 per 100,000 individuals, with an incidence of 0.41 and 0.65 per 100,000 individuals-year in 2016 and 2017, respectively. The mean age was 43.08 (standard deviation, 14.56) years, and the ratio of male to females was 1:4.7. The incidence was higher in female individuals aged between 30 and 59 years (RR, 2.8–3.05; P < 0.05). Conclusion Nationwide prevalence of NMOSD in Korea was 3.36 and 3.56/100,000 and its incidence was 0.41 and 0.65/100,000-year in 2016 and 2017 respectively.

BACKGROUND AND OBJECTIVES: Microvascular damage due to distal embolization during percutaneous coronary intervention (PCI) is an important cause of periprocedural myocardial infarction. We assessed the lipid-core plaque using near-infrared spectroscopy (NIRS) and microvascular dysfunction invasively with the index of microcirculatory resistance (IMR) and evaluated their relationship. METHODS: This study is pilot retrospective observational study. We analyzed 39 patients who performed NIRS before and after PCI, while fractional flow reserve, thermo-dilution coronary flow reserve (CFR) and IMR were measured after PCI. The maximum value of lipid core burden index (LCBI) for any of the 4-mm segments at the culprit lesion (culprit LCBI(4mm)) was calculated at the culprit lesion. We divided the patients into 2 groups using a cutoff of culprit LCBI(4mm) ≥500. RESULTS: Mean pre-PCI LCBI was 333±196 and mean post-PCI IMR was 20±14 U. Post-PCI IMR was higher (15.6±7.3 vs. 42.6±17.6 U, p<0.001) and post-PCI CFR was lower (3.7±2.2 vs. 2.1±1.0, p=0.029) in the high LCBI group. Pre-PCI LCBI was positively correlated with post-PCI IMR (ρ=0.358, p=0.025) and negatively correlated with post-PCI CFR (ρ=−0.494, p=0.001). The incidence of microvascular dysfunction (IMR ≥25 U) was higher in the high LCBI group (9.4% vs. 85.7%, p<0.001). However, there were no significant differences in the incidences of creatine Kinase-MB (9.4% vs. 14.3%, p=0.563) and troponin-I elevation (12.5% vs. 14.3%, p=1.000). CONCLUSIONS A large lipid-core plaque at the ‘culprit’ lesion is observed higher incidence of post-PCI microvascular dysfunction after PCI. Prospective study with adequate subject numbers will be needed.

BACKGROUND AND OBJECTIVES: Microvascular damage due to distal embolization during percutaneous coronary intervention (PCI) is an important cause of periprocedural myocardial infarction. We assessed the lipid-core plaque using near-infrared spectroscopy (NIRS) and microvascular dysfunction invasively with the index of microcirculatory resistance (IMR) and evaluated their relationship. METHODS: This study is pilot retrospective observational study. We analyzed 39 patients who performed NIRS before and after PCI, while fractional flow reserve, thermo-dilution coronary flow reserve (CFR) and IMR were measured after PCI. The maximum value of lipid core burden index (LCBI) for any of the 4-mm segments at the culprit lesion (culprit LCBI(4mm)) was calculated at the culprit lesion. We divided the patients into 2 groups using a cutoff of culprit LCBI(4mm) ≥500. RESULTS: Mean pre-PCI LCBI was 333±196 and mean post-PCI IMR was 20±14 U. Post-PCI IMR was higher (15.6±7.3 vs. 42.6±17.6 U, p<0.001) and post-PCI CFR was lower (3.7±2.2 vs. 2.1±1.0, p=0.029) in the high LCBI group. Pre-PCI LCBI was positively correlated with post-PCI IMR (ρ=0.358, p=0.025) and negatively correlated with post-PCI CFR (ρ=−0.494, p=0.001). The incidence of microvascular dysfunction (IMR ≥25 U) was higher in the high LCBI group (9.4% vs. 85.7%, p<0.001). However, there were no significant differences in the incidences of creatine Kinase-MB (9.4% vs. 14.3%, p=0.563) and troponin-I elevation (12.5% vs. 14.3%, p=1.000). CONCLUSIONS: A large lipid-core plaque at the ‘culprit’ lesion is observed higher incidence of post-PCI microvascular dysfunction after PCI. Prospective study with adequate subject numbers will be needed.
Coronary Artery Disease ; Creatine ; Humans ; Incidence ; Microvessels ; Myocardial Infarction ; Observational Study ; Percutaneous Coronary Intervention ; Prospective Studies ; Retrospective Studies ; Spectroscopy, Near-Infrared ; Troponin I

PURPOSE: To investigate patterns of recurrence and oncologic outcomes after recurrence between preoperative and postoperative chemoradiotherapy (CRT). METHODS: Records of patients with stage II or III locally advanced rectal cancer seen between January 2000 and December 2010 were analyzed. The outcomes for patients undergoing preoperative CRT followed by radical resection (n = 466) were compared with outcomes of patients matched for sex, age, and stage who had surgery and then postoperative CRT (n = 466). Recurrence rates and sites, treatment of recurrence, and oncologic outcomes after recurrence were investigated. The rate of sphincter preservation and permanent stoma formation were also evaluated. RESULTS: Recurrence occurred in 124 and 140 patients in the pre- and postoperative CRT groups, respectively. The local and systemic recurrence rates were 3.6% and 20.8%, respectively, in the preoperative CRT group and 3.0% and 25.3%, respectively, in the postoperative CRT group (P = 0.245). Time to recurrence was longer in the postoperative CRT group (19 months vs. 24.2 months, P = 0.029). The overall rates of sphincter preservation (sphincter preservation operation and postoperative permanent stoma formation) did not significantly different between the two groups (P = 0.381). The 5-year overall survival rate after recurrence did not differ between the two groups (25.6% vs. 18.6%, P = 0.051). CONCLUSION: Preoperative and postoperative CRT are both safe and suitable treatment methods for rectal cancer, so the choice can be tailored to the patient's situation.
Case-Control Studies* ; Chemoradiotherapy* ; Colorectal Surgery ; Humans ; Rectal Neoplasms* ; Recurrence ; Survival Rate ; Treatment Outcome

BACKGROUND AND PURPOSE: Eosinophilic granulomatosis with polyangiitis (EGPA) is a rare systemic small-vessel vasculitis accompanied by asthma, eosinophilia, and eosinophilic inflammation of various tissues including the peripheral nerves. This study investigated the clinical course and long-term outcomes of peripheral neuropathy in patients with EGPA. METHODS: Seventy-one patients with physician-diagnosed EGPA were identified at Samsung Medical Center between January 1995 and April 2014. Sixty-one of these patients were followed-up for more than 1 year and received corticosteroid therapy with or without intravenous cyclophosphamide pulse therapy for 6 to 18 months. Medical records of the 61 patients including demographic data, clinical features, laboratory and pathological findings, treatments, and outcomes were reviewed. RESULTS: Peripheral neuropathy as a manifestation of EGPA was present in 46 (75%) of the 61 patients. The mean follow-up duration of the patients with neuropathy was 6.4 years (range 1.2–18.8 years). The scores on the neurological functional disability scale before and after the combination treatment with corticosteroid and cyclophosphamide were 2.43±0.86 and 0.54±0.95 (mean±SD; p<0.001), respectively. The peripheral neuropathy relapsed in one patient. CONCLUSIONS: The long-term clinical outcome of peripheral neuropathy in patients with EGPA receiving initial corticosteroid and cyclophosphamide combination therapy was favorable with a very low relapse rate.
Asthma ; Cyclophosphamide ; Eosinophilia ; Eosinophils* ; Follow-Up Studies ; Granulomatosis with Polyangiitis* ; Humans ; Inflammation ; Medical Records ; Peripheral Nerves ; Peripheral Nervous System Diseases* ; Prognosis ; Recurrence ; Vasculitis

BACKGROUND AND OBJECTIVES: This trial evaluated the safety and efficacy of the Genoss drug-eluting coronary stent. METHODS: This study was a prospective, multicenter, randomized trial with a 1:1 ratio of Genoss drug-eluting stent (DES)™ and Promus Element™. Inclusion criteria were the presence of stable angina, unstable angina, or silent ischemia. Angiographic inclusion criteria were de novo coronary stenotic lesion with diameter stenosis >50%, reference vessel diameter of 2.5–4.0 mm, and lesion length ≤40 mm. The primary endpoint was in-stent late lumen loss at 9-month quantitative coronary angiography follow-up. Secondary endpoints were in-segment late lumen loss, binary restenosis rate, death, myocardial infarction (MI), target lesion revascularization (TLR), target vessel revascularization (TVR), and stent thrombosis during 9 months of follow-up. RESULTS: We enrolled 38 patients for the Genoss DES™ group and 39 patients for the Promus Element™ group. In-stent late lumen loss at 9 months was not significantly different between the 2 groups (0.11±0.25 vs. 0.16±0.43 mm, p=0.567). There was no MI or stent thrombosis in either group. The rates of death (2.6% vs. 0%, p=0.494), TLR (2.6% vs. 2.6%, p=1.000), and TVR (7.9% vs. 2.6%, p=0.358) at 9 months were not significantly different. CONCLUSION: This first-in-patient study of the Genoss DES™ stent showed excellent angiographic outcomes for in-stent late lumen loss and major adverse cardiac events over a 9-month follow-up.
Angina, Stable ; Angina, Unstable ; Constriction, Pathologic ; Coronary Angiography ; Coronary Artery Disease ; Drug-Eluting Stents ; Follow-Up Studies ; Humans ; Ischemia ; Mortality ; Myocardial Infarction ; Polymers* ; Prospective Studies ; Sirolimus ; Stents* ; Thrombosis