Background: and Purpose Treatments for neuromyelitis optica spectrum disorder (NMOSD) such as eculizumab, ravulizumab, satralizumab, and inebilizumab have significantly advanced relapse prevention, but they remain expensive. Rituximab is an off-label yet popular alternative that offers a cost-effective solution, but its real-world efficacy needs better quantification for guiding the application of newer approved NMOSD treatments (ANTs). This study aimed to determine real-world rituximab failure rates to anticipate the demand for ANTs and aid in resource allocation. Methods: We conducted a nationwide retrospective study involving 605 aquaporin-4-antibody-positive NMOSD patients from 22 centers in South Korea that assessed the efficacy and safety of rituximab over a median follow-up of 47 months. Results: The 605 patients treated with rituximab included 525 (87%) who received continuous therapy throughout the follow-up period (median=47 months, interquartile range=15–87 months). During this period, 117 patients (19%) experienced at least 1 relapse. Notably, 68 of these patients (11% of the total cohort) experienced multiple relapses or at least 1 severe relapse.Additionally, 2% of the patients discontinued rituximab due to adverse events, which included severe infusion reactions, neutropenia, and infections. Conclusions This study has confirmed the efficacy of rituximab in treating NMOSD, as evidenced by an 87% continuation rate among patients over a 4-year follow-up period. Nevertheless, the occurrence of at least one relapse in 19% of the cohort, including 11% who experienced multiple or severe relapses, and a 2% discontinuation rate due to adverse events highlight the urgent need for alternative therapeutic options.

Background: and Purpose Treatments for neuromyelitis optica spectrum disorder (NMOSD) such as eculizumab, ravulizumab, satralizumab, and inebilizumab have significantly advanced relapse prevention, but they remain expensive. Rituximab is an off-label yet popular alternative that offers a cost-effective solution, but its real-world efficacy needs better quantification for guiding the application of newer approved NMOSD treatments (ANTs). This study aimed to determine real-world rituximab failure rates to anticipate the demand for ANTs and aid in resource allocation. Methods: We conducted a nationwide retrospective study involving 605 aquaporin-4-antibody-positive NMOSD patients from 22 centers in South Korea that assessed the efficacy and safety of rituximab over a median follow-up of 47 months. Results: The 605 patients treated with rituximab included 525 (87%) who received continuous therapy throughout the follow-up period (median=47 months, interquartile range=15–87 months). During this period, 117 patients (19%) experienced at least 1 relapse. Notably, 68 of these patients (11% of the total cohort) experienced multiple relapses or at least 1 severe relapse.Additionally, 2% of the patients discontinued rituximab due to adverse events, which included severe infusion reactions, neutropenia, and infections. Conclusions This study has confirmed the efficacy of rituximab in treating NMOSD, as evidenced by an 87% continuation rate among patients over a 4-year follow-up period. Nevertheless, the occurrence of at least one relapse in 19% of the cohort, including 11% who experienced multiple or severe relapses, and a 2% discontinuation rate due to adverse events highlight the urgent need for alternative therapeutic options.

Background: and Purpose Treatments for neuromyelitis optica spectrum disorder (NMOSD) such as eculizumab, ravulizumab, satralizumab, and inebilizumab have significantly advanced relapse prevention, but they remain expensive. Rituximab is an off-label yet popular alternative that offers a cost-effective solution, but its real-world efficacy needs better quantification for guiding the application of newer approved NMOSD treatments (ANTs). This study aimed to determine real-world rituximab failure rates to anticipate the demand for ANTs and aid in resource allocation. Methods: We conducted a nationwide retrospective study involving 605 aquaporin-4-antibody-positive NMOSD patients from 22 centers in South Korea that assessed the efficacy and safety of rituximab over a median follow-up of 47 months. Results: The 605 patients treated with rituximab included 525 (87%) who received continuous therapy throughout the follow-up period (median=47 months, interquartile range=15–87 months). During this period, 117 patients (19%) experienced at least 1 relapse. Notably, 68 of these patients (11% of the total cohort) experienced multiple relapses or at least 1 severe relapse.Additionally, 2% of the patients discontinued rituximab due to adverse events, which included severe infusion reactions, neutropenia, and infections. Conclusions This study has confirmed the efficacy of rituximab in treating NMOSD, as evidenced by an 87% continuation rate among patients over a 4-year follow-up period. Nevertheless, the occurrence of at least one relapse in 19% of the cohort, including 11% who experienced multiple or severe relapses, and a 2% discontinuation rate due to adverse events highlight the urgent need for alternative therapeutic options.

Many countries have published clinical practice guidelines for appropriate clinical decisions, optimal treatment, and improved clinical outcomes in patients with acute coronary syndrome. Developing guidelines that are specifically tailored to the Korean environment is crucial, considering the treatment system, available medications and medical devices, racial differences, and level of language communication. In 2017, the Korean Society of Myocardial Infarction established a guideline development committee. However, at that time, it was not feasible to develop guidelines, owing to the lack of knowledge and experience in guideline development and the absence of methodology experts. In 2022, the National EvidenceBased Healthcare Collaborating Agency collaborated with a relevant academic association to develop internationally reliable guidelines, with strict adherence to the methodology for evidence-based guideline development. The first Korean acute coronary syndrome guideline starts from the 9 key questions for pharmacotherapy.

Many countries have published clinical practice guidelines for appropriate clinical decisions, optimal treatment, and improved clinical outcomes in patients with acute coronary syndrome. Developing guidelines that are specifically tailored to the Korean environment is crucial, considering the treatment system, available medications and medical devices, racial differences, and level of language communication. In 2017, the Korean Society of Myocardial Infarction established a guideline development committee. However, at that time, it was not feasible to develop guidelines, owing to the lack of knowledge and experience in guideline development and the absence of methodology experts. In 2022, the National EvidenceBased Healthcare Collaborating Agency collaborated with a relevant academic association to develop internationally reliable guidelines, with strict adherence to the methodology for evidence-based guideline development. The first Korean acute coronary syndrome guideline starts from the 9 key questions for pharmacotherapy.

Many countries have published clinical practice guidelines for appropriate clinical decisions, optimal treatment, and improved clinical outcomes in patients with acute coronary syndrome. Developing guidelines that are specifically tailored to the Korean environment is crucial, considering the treatment system, available medications and medical devices, racial differences, and level of language communication. In 2017, the Korean Society of Myocardial Infarction established a guideline development committee. However, at that time, it was not feasible to develop guidelines, owing to the lack of knowledge and experience in guideline development and the absence of methodology experts. In 2022, the National EvidenceBased Healthcare Collaborating Agency collaborated with a relevant academic association to develop internationally reliable guidelines, with strict adherence to the methodology for evidence-based guideline development. The first Korean acute coronary syndrome guideline starts from the 9 key questions for pharmacotherapy.

Many countries have published clinical practice guidelines for appropriate clinical decisions, optimal treatment, and improved clinical outcomes in patients with acute coronary syndrome. Developing guidelines that are specifically tailored to the Korean environment is crucial, considering the treatment system, available medications and medical devices, racial differences, and level of language communication. In 2017, the Korean Society of Myocardial Infarction established a guideline development committee. However, at that time, it was not feasible to develop guidelines, owing to the lack of knowledge and experience in guideline development and the absence of methodology experts. In 2022, the National EvidenceBased Healthcare Collaborating Agency collaborated with a relevant academic association to develop internationally reliable guidelines, with strict adherence to the methodology for evidence-based guideline development. The first Korean acute coronary syndrome guideline starts from the 9 key questions for pharmacotherapy.

The aim of this study was to develop evidence-based recommendations for determining the surgical extent in patients with locally invasive differentiated thyroid cancer (DTC). Locally invasive DTC with gross extrathyroidal extension invading surrounding anatomical structures may lead to several functional deficits and poor oncological outcomes. At present, the optimal extent of surgery in locally invasive DTC remains a matter of debate, and there are no adequate guidelines. On October 8, 2021, four experts searched the PubMed, Embase, and Cochrane Library databases; the identified papers were reviewed by 39 experts in thyroid and head and neck surgery. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach was used to assess the quality of evidence, and to develop and report recommendations. The strength of a recommendation reflects the confidence of a guideline panel that the desirable effects of an intervention outweigh any undesirable effects, across all patients for whom the recommendation is applicable. After completing the draft guidelines, Delphi questionnaires were completed by members of the Korean Society of Head and Neck Surgery. Twenty-seven evidence-based recommendations were made for several factors, including the preoperative workup; surgical extent of thyroidectomy; surgery for cancer invading the strap muscles, recurrent laryngeal nerve, laryngeal framework, trachea, or esophagus; and surgery for patients with central and lateral cervical lymph node involvement. Evidence-based guidelines were devised to help clinicians make safer and more efficient clinical decisions for the optimal surgical treatment of patients with locally invasive DTC.

Background: and Purpose Fingolimod (FTY) inhibits lymphocyte egress from lymphoid organs to cause lymphopenia, but the clinical implications of FTY-induced lymphopenia are not fully understood. We aimed to determine the frequency and severity of lymphopenia during FTY treatment among Korean patients with multiple sclerosis (MS), and its association with infections. Methods: We retrospectively reviewed the medical records of patients with MS treated using FTY from 12 referral centers in South Korea between March 2013 and June 2021. Patients were classified according to their nadir absolute lymphocyte count (ALC) during treatment:grade 1, 800–999/μL; grade 2, 500–799/μL; grade 3, 200–499/μL; and grade 4, <200/μL. Results: FTY treatment was administered to 69 patients with a median duration of 18 months (range=1–169 months), with 11 patients being treated for ≥7 years. During FTY treatment, mean ALCs were reduced after the first month (653.0±268.9/μL, mean±standard deviation) (p<0.0001) and remained low during treatment lasting up to 84 months. During follow-up, 41 (59.4%) and 7 (10.1%) patients developed grade-3 and grade-4 lymphopenia, respectively.No significant difference was found in age at FTY initiation, sex, baseline ALC, body mass index, or prior disease-modifying treatment between patients with and without grade-4 lymphopenia. Infections were observed in 11 (15.9%) patients, and the frequencies of patients with and without grade-4 lymphopenia were similar. Conclusions FTY treatment induced grade-4 lymphopenia in 10% of South Korean patients with MS, but did not appear to be associated with an increased infection risk.

Background and Objectives: The clinical implications of the BRAF V600E mutation in papillary thyroid microcarcinoma (PTMC), defined as ≤1.0 cm of tumor size, remain controversial. We investigated the association between the BRAFV600E mutation and PTMC recurrence in a retrospective cohort of patients with thyroid cancer. Materials and Methods: This study included 2319 patients with PTMC (median age, 50 years [interquartile range (IQR), 41-57 years]) who underwent thyroid surgery from 2010 to 2019 at a single tertiary medical center. The median follow-up time was 75 months (IQR, 30-98 months). Tumor recurrence was confirmed by histological, cytological, radiographic, and biochemical criteria, combined with persistent and recurrent disease. Results: A total of 60.2% (1395/2319) patients with PTMC had the BRAF V600E mutation. The tumor recurrence rate was 2.1% (19/924) in BRAF mutation-negative patients and 2.9% (41/1395) in BRAF mutation-positive patients, with a hazard ratio (HR) of 1.05 (95% confidence interval [CI], 0.61-1.84) after adjusting for clinicopathological risk factors. Similar results were found in patients with high-risk PTMC (adjusted HR, 1.09; 95% CI, 0.56-2.11) who had lymph node metastasis (LNM), extrathyroidal extension (ETE), or distant metastasis (DM) at diagnosis and in patients with low-risk PTMC (adjusted HR, 1.00; 95% CI, 0.35-2.83) who had no LNM, ETE, or DM. Conclusion The finding that the BRAF V600E mutation was not associated with tumor recurrence in our cohort of Korean patients with PTMC, especially in patients with low-risk PTMC, suggests that its value in the prediction of disease progression is limited.