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 Anti-agrin antibodies (agrin Abs) have recently been identified in patients with myasthenia gravis (MG), sometimes in conjunction with antibodies (Abs) to the acetylcholine receptor (AChR), muscle-specific tyrosine kinase (MuSK), or low-density lipoprotein receptor-related protein 4. This study aimed to develop an in-house cell-based assay (CBA) for detecting agrin Abs, and to test its application to serum samples collected from individuals diagnosed with MG. Methods: Agrin complementary DNA as cloned into a pCMV6-AC-GFP vector, which was subsequently transfected into human embryonic kidney 293T (HEK293T) cells. Transfected HEK293T cells were incubated with patient serum and antihuman immunoglobulin G Ab conjugated with a red fluorescent dye. Agrin Ab levels were measured using the CBA in 389 serum samples: 340 from patients with MG, 36 from patients with other neuromuscular diseases, and 13 from healthy controls. The presence of agrin Ab was determined based on the fluorescence intensity and colocalization using fluorescence microscopy. Results: The expression levels of agrin mRNA and protein in transfected HEK293T cells were confirmed using the reverse-transcription polymerase chain reaction and Western blotting, respectively. Agrin expression in cells was further confirmed by immunocytochemistry.Two (0.6%) of the 340 patients with MG tested positive for agrin Ab: 1 of 191 AChR-positive patients and 1 of 54 MuSK-positive patients. Conclusions We have developed and validated a novel CBA for detecting agrin Abs. This CBA was successfully applied to detect agrin Abs in serum samples obtained from individuals with MG.

Purpose: Since 1995, the Korean Gastric Cancer Association (KGCA) has been periodically conducting nationwide surveys on patients with surgically treated gastric cancer. This study details the results of the survey conducted in 2023. Materials and Methods: The survey was conducted from March to December 2024 using a standardized case report form. Data were collected on 86 items, including patient demographics, tumor characteristics, surgical procedures, and surgical outcomes. The results of the 2023 survey were compared with those of previous surveys. Results: Data from 12,751 cases were collected from 66 institutions. The mean patient age was 64.6 years, and the proportion of patients aged ≥71 years increased from 9.1% in 1995 to 31.7% in 2023. The proportion of upper-third tumors slightly decreased to 16.8% compared to 20.9% in 2019. Early gastric cancer accounted for 63.1% of cases in 2023.Regarding operative procedures, a totally laparoscopic approach was most frequently applied (63.2%) in 2023, while robotic gastrectomy steadily increased to 9.5% from 2.1% in 2014.The most common anastomotic method was the Billroth II procedure (48.8%) after distal gastrectomy and double-tract reconstruction (51.9%) after proximal gastrectomy in 2023.However, the proportion of esophago-gastrostomy with anti-reflux procedures increased to 30.9%. The rates of post-operative mortality and overall complications were 1.0% and 15.3%, respectively. Conclusions The results of the 2023 nationwide survey demonstrate the current status of gastric cancer treatment in Korea. This information will provide a basis for future gastric cancer research.

Background: Hearing level reference values based on the results of recent audiometry have not been established for the general population of South Korea. This study aimed to evaluate the mean hearing levels of each age group and to measure the annual progression of hearing loss. Methods: We used the database of the eighth and ninth Korea National Health and Nutrition Examination Survey from 2020 to 2022, and included participants with normal tympanic membranes and without occupational noise exposure. Mean hearing levels were calculated by averaging hearing levels at 0.5 kHz, 1 kHz, 2 kHz, and 4 kHz. Hearing loss was defined as a hearing level exceeding 25 dB in the better ear, and severity of hearing loss was classified as moderate, moderately severe, severe, and profound, following the World Health Organization classification. Results: Hearing levels and the proportions of patients with hearing loss increased with age. Hearing levels were 9.11 ± 6.28 dB, 13.33 ± 7.85 dB, 19.90 ± 10.30 dB, and 31.95 ± 13.37 dB in those in their 40s, 50s, 60s, and 70s, respectively, and the proportions of patients with hearing loss were 1.81%, 7.51%, 25.32%, and 63.94%, respectively. The annual increase in hearing level was 0.71 dB, and increases were greater at higher frequencies. Hearing loss was also worse in men. Conclusion The present study provides reference values for normal hearing levels by age group, and indirectly reveals the progression of age-related hearing loss. Based on the results, physicians will be able to provide appropriate advice regarding hearing levels and the need for monitoring in the elderly.

Korea has undergone rapid transformation, achieving significant advancements in both economic development and social security. Notably, the country achieved universal health coverage within a remarkably short period, representing a significant institutional milestone in healthcare. However, the healthcare system faces substantial challenges due to limited resources, a reliance on private healthcare providers, and a rapidly aging population which threatens its sustainability. Various efforts have been made to strengthen Korea’s primary care environment. This study aims to examine the multifaceted healthcare landscape surrounding primary care in Korea, analyze associated systems to identify institutional limitations, and propose strategies to enhance primary care in the future. Additionally, it seeks to raise awareness of the current state of primary care in Korea and serves as an example for other countries striving to improve their primary care systems. Furthermore, this review provides a comprehensive overview of key data sources relevant to primary care research in Korea, such as the National Health Insurance Service claims data and the Korea Health Panel Survey. It also outlines practical research methodologies—from epidemiological studies to policy analyses—serving as a valuable reference for both domestic and international scholars seeking to enhance primary care systems.

Background: s/Aims: Microwave ablation (MWA) is an emerging ablative therapy that surpasses previous methods by achieving higher temperatures and creating larger ablation zones within shorter periods. This study compared the therapeutic outcomes of MWA with those of liver resection in real-world clinical practice. Methods: A total of 178 patients with 259 nodules who underwent MWA or liver resection between January 2015 and July 2023 were enrolled. Local tumor progression (LTP)-free survival, overall progression (OP)-free survival, and overall survival (OS) were assessed based on the treatment modality for the index nodule. Results: Of the 178 patients, 134 with 214 nodules underwent MWA, and 44 with 45 nodules underwent liver resection. The median follow-up period was 2.0±1.5 years. The annual incidence of LTP was 3.7% for MWA and 1.4% for liver resection. Treatment modality did not significantly affect LTP-free survival (hazard ratio, 0.61; 95% confidence interval, 0.14-2.69; P=0.511). For nodules larger than 3 cm, LTP-free survival was not affected by the treatment modality. Similarly, OP-free survival and OS were not influenced by treatment modality. Conclusions MWA and liver resection demonstrated comparable treatment outcomes in terms of local tumor control, overall recurrence, and survival. MWA may be an alternative treatment option for select patients; however, further studies are necessary to generalize these findings.

Background: Epidermal growth factor receptor (EGFR) gene mutation testing is crucial for the administration of tyrosine kinase inhibitors to treat non–small cell lung cancer. In addition to traditional tissue-based tests, liquid biopsies using plasma are increasingly utilized, particularly for detecting T790M mutations. This study compared tissue- and plasma-based EGFR testing methods. Methods: A total of 248 patients were tested for EGFR mutations using tissue and plasma samples from 2018 to 2023 at Pusan National University Yangsan Hospital. Tissue tests were performed using PANAmutyper, and plasma tests were performed using the Cobas EGFR Mutation Test v2. Results: All 248 patients underwent tissue-based EGFR testing, and 245 (98.8%) showed positive results. Of the 408 plasma tests, 237 (58.1%) were positive. For the T790M mutation, tissue biopsies were performed 87 times in 69 patients, and 30 positive cases (38.6%) were detected. Plasma testing for the T790M mutation was conducted 333 times in 207 patients, yielding 62 positive results (18.6%). Of these, 57 (27.5%) were confirmed to have the mutation via plasma testing. Combined tissue and plasma tests for the T790M mutation were positive in nine patients (13.4%), while 17 (25.4%) were positive in tissue only and 12 (17.9%) in plasma only. This mutation was not detected in 28 patients (43.3%). Conclusions Although the tissue- and plasma-based tests showed a sensitivity of 37.3% and 32.8%, respectively, combined testing increased the detection rate to 56.7%. Thus, neither test demonstrated superiority, rather, they were complementary.

This study aimed to investigate the dental utilization status, satisfaction with dental treatment, and the need for improvement among pediatric patients with rare diseases in Korea. A survey was conducted from June 2023 to May 2024 among caregivers of patients with rare diseases who visited the pediatric dentistry departments of eight dental institutions. The questionnaire for this study was divided into two sections: 126 caregivers participated in the dental utilization survey, while 91 caregivers completed the survey on satisfaction with dental treatment. Many caregivers believed that the patient’s poor oral health could impact overall health and reported positive functional and psychological changes following dental treatment. However, dental care for these patients presents challenges due to insufficient oral care information, specialized dentists, specialized dental facilities, and insurance coverage. Caregivers identified the need for an increase in specialized dental facilities as the highest priority (42.9%), with many emphasizing the necessity for expanded insurance coverage (38.9%). Notably, caregivers of patients who had undergone dental caries treatment advocated for broader insurance coverage (p = 0.0141), particularly for prosthetic (p = 0.0330) and restorative treatments (p = 0.0129). Furthermore, caregivers of patients with congenital disorders reported a significant economic burden associated with orthodontic treatment (p = 0.0405). Additionally, caregivers emphasized the need for an increase in specialized dentists (33.3%) and improved collaboration with pediatricians (25.4%). This study underscores the critical necessity for tailored policies and comprehensive support systems that reflect the current needs of the dental care system for pediatric patients with rare diseases.