Background: and Purpose This study evaluated the diagnostic utility of an anti-signal-recognition particle 54 (anti-SRP54) antibody-based enzyme-linked immunosorbent assay (ELISA) as well as the clinical, serological, and pathological characteristics of patients with SRP immune-mediated necrotizing myopathy (IMNM). Methods: We evaluated 87 patients with idiopathic inflammatory myopathy and 107 healthy participants between January 2002 and December 2023. The sensitivity and specificity of the ELISA for anti-SRP54 antibodies were assessed, and the clinical profiles of patients with antiSRP54 antibodies were determined. Results: The ELISA for anti-SRP54 antibodies had a sensitivity and specificity of 88% and 99%, respectively, along with a test–retest reliability of 0.92 (p<0.001). The 32 patients diagnosed with anti-SRP IMNM using a line-blot immunoassay included 28 (88%) who tested positive for anti-SRP54 antibodies using the ELISA, comprising 12 (43%) males and 16 (57%) females whose median ages at symptom onset and diagnosis were 43.0 years and 43.5 years, respectively. Symptoms included proximal muscle weakness in all 28 (100%) patients, neck weakness in 9 (32%), myalgia in 15 (54%), dysphagia in 5 (18%), dyspnea in 4 (14%), dysarthria in 2 (7%), interstitial lung disease in 2 (7%), and myocarditis in 2 (7%). The median serum creatine kinase (CK) level was 7,261 U/L (interquartile range: 5,086–10,007 U/L), and the median anti-SRP54 antibody level was 2.0 U/mL (interquartile range: 1.0–5.6 U/mL). The serum CK level was significantly higher in patients with coexisting anti-Ro-52 antibodies. Conclusions This study has confirmed the reliability of the ELISA for anti-SRP54 antibodies and provided insights into the clinical, serological, and pathological characteristics of South Korean patients with anti-SRP IMNM.

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.

Background: Intraoperative hemoglobin (Hb) monitoring is critical for ensuring patient safety during bimaxillary orthognathic surgery. Intraoperative Hb monitoring performed using portable devices with arterial blood samples is invasive, is time-consuming, and lacks the ability to provide real-time information. This retrospective study investigated the correlation between continuous and real-time total Hb (SpHb) using a Masimo Radical 7 device and Hb levels derived by portable devices during bimaxillary orthognathic surgery. Methods: Patients who underwent elective bimaxillary orthognathic surgery were enrolled. The correlation between SpHb and laboratory Hb (Lab-Hb) was evaluated immediately after the induction of anesthesia (T1) and at surgical closure (T2) and compared with postoperative Hb. Results: Eighty-eight patients were included. The correlation coefficients between SpHb and Lab-Hb were 0.795 and 0.859 at T1 and T2, respectively. The correlation coefficient between Lab-Hb at T2 and postoperative Hb was 0.918. A Bland-Altman analysis of the Lab-Hb at T2 and postoperative Hb showed a mean bias of 0.49. Conclusion In conclusion, here we demonstrated acceptable accuracy of the SpHb measured by the Masimo Radical 7 device during bimaxillary orthognathic surgery. However, SpHb is valuable as an adjunct value to Lab-Hb and a substitute for Hb monitoring due to its wide limits of agreement. These findings suggest that SpHb can help guide the timing of invasive blood sampling for Hb measurements, which may facilitate earlier intervention and treatment.

Purpose: This study evaluated the postoperative quality of life (QoL) after various types of gastrectomy for gastric cancer. Materials and Methods: A multicenter prospective observational study was conducted in Korea using the Korean Quality of Life in Stomach Cancer Patients Study (KOQUSS)-40, a new QoL assessment tool focusing on postgastrectomy syndrome. Overall, 496 patients with gastric cancer were enrolled, and QoL was assessed at 5 time points: preoperatively and at 1, 3, 6, and 12 months after surgery. Results: Distal gastrectomy (DG) and pylorus-preserving gastrectomy (PPG) showed significantly better outcomes than total gastrectomy (TG) and proximal gastrectomy (PG) with regard to total score, indigestion, and dysphagia. DG, PPG, and TG also showed significantly better outcomes than PG in terms of dumping syndrome and worry about cancer. Postoperative QoL did not differ significantly according to anastomosis type in DG, except for Billroth I anastomosis, which achieved better bowel habit change scores than the others. No domains differed significantly when comparing double tract reconstruction and esophagogastrostomy after PG. The total QoL score correlated significantly with postoperative body weight loss (more than 10%) and extent of resection (P<0.05 for both).Reflux as assessed by KOQUSS-40 did not correlate significantly with reflux observed on gastroscopy 1 year postoperatively (P=0.064). Conclusions Our prospective observation using KOQUSS-40 revealed that DG and PPG lead to better QoL than TG and PG. Further study is needed to compare postoperative QoL according to anastomosis type in DG and PG.

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 and Objectives: In chronic heart failure (HF), natriuretic peptide (NP) levels are higher in atrial fibrillation (AF) compared to sinus rhythm (SR). However, due to the loss of atrial contraction, AF patients are prone to hemodynamic decompensation at earlier stages.Since NP levels reflect disease severity, acutely decompensated AF patients may exhibit lower NP levels compared to SR patients, who retain greater hemodynamic reserve. Methods: We analyzed 5,048 patients with acute HF from the Korea Acute Heart Failure registry with available NP data. NP levels and echocardiographic parameters were compared between AF and SR patients. The association of NP levels with in-hospital and one-year mortality was also assessed according to cardiac rhythm. Results: Brain natriuretic peptide (BNP) and N-terminal pro-B-type natriuretic peptide (NT-proBNP) were measured in 2,027 and 3,021 patients, respectively. NP levels were lower in AF than in SR (median BNP, 740 vs. 1,044 pg/mL; median NT-proBNP, 4,420 vs. 5,198 pg/mL), particularly in HF with reduced or mildly reduced ejection fraction. A similar trend was observed regardless of HF onset or etiology. AF patients had smaller left ventricular (LV) end-diastolic diameter and larger left atrial size compared to SR patients. Higher NP tertiles were associated with increased in-hospital and one-year mortality in both groups. Conclusions In acute HF, NP levels are lower in AF than in SR. AF patients also exhibited smaller LV chamber sizes. Nevertheless, NP levels remain strong predictors of outcomes in both AF and SR patients.

Purpose: Adjuvant chemotherapy (AC) is recommended for muscle-invasive or lymph node-positive upper urinary tract urothelial carcinoma (UTUC) after radical nephroureterectomy (RNU). However, disease recurrences are frequently observed in pT1 disease, and AC may increase the risk of overtreatment in pT2 UTUC patients. This study aimed to validate a risk-adapted scoring model for selecting UTUC patients with ≤pT2 disease who would benefit from AC. Materials and Methods: We retrospectively analyzed 443 ≤pT2 UTUC patients who underwent RNU. A risk-adapted scoring model was applied, categorizing patients into low- or high-risk groups. Recurrence-free survival (RFS) and cancer-specific survival (CSS) were analyzed according to risk group. Results: Overall, 355 patients (80.1%) and 88 patients (19.9%) were categorized into the low- and high-risk groups, respectively, with the latter having higher pathological stages, concurrent carcinoma in situ, and synchronous bladder tumors. Disease recurrence occurred in 45 patients (10.2%), among whom 19 (5.4%) and 26 (29.5%) belonged to the low- and high-risk groups, respectively (p<0.001). High-risk patients had significantly shorter RFS (64.3% vs. 93.6% at 60 months; hazard ratio [HR] 13.66; p<0.001) and worse CSS (80.7% vs. 91.5% at 60 months; HR 4.25; p=0.002). Multivariate analysis confirmed that pT2 stage and the high-risk group were independent predictors of recurrence and cancer-specific death (p<0.001). Decision curve analysis for RFS showed larger net benefits with our model than with the T stage model. Conclusions The risk-adapted scoring model effectively predicts recurrence and identifies optimal candidates for AC post RNU in non-metastatic UTUC.

Background/Aims: Despite of the coronavirus disease 2019 (COVID-19) pandemic, there is little data regarding its impact on colorectal cancer (CRC)-related clinical practice. This study aimed to assess the changes in its impact during the COVID-19 pandemic. Methods: This was a retrospective national population-based study using the Health Insurance Review and Assessment database from January 2019 to December 2021. The number of patients in 2020 and 2021 was compared with those in 2019 for the diagnostic and therapeutic colonoscopy, CRC-related operation, and any treatment for CRC. Results: The annual number of patients undergoing diagnostic colonoscopies decreased by 6.9% in 2020 but increased 8.1% in 2021, compared to those in 2019; number of patients undergoing therapeutic colonoscopies increased by 6.0% and 37.7% in 2020 and 2021, respectively; number of patients operated for CRC decreased by 4.2% in 2020 and increased by 2.3% in 2021. The number of patients treated for CRC decreased by 2.8% in 2020 and increased by 4.4% in 2021. Diagnostic and therapeutic colonoscopies and any CRC-related treatment decreased by 43.8%, 37.5%, and 11.3% in March 2020, during the first surge of COVID-19, but increased by 26.0%, 58.1%, and 9.5% in June 2021, respectively. CRC-related operations decreased by 24.1% in April 2020 and increased by 12.6% in August 2021. Conclusions Negative impact of the COVID-19 pandemic on clinical practices related to CRC completely recovered within second year. It could be considered for the development of an optimal strategy on CRC management in response to the pandemic-driven crisis.