Background: Mycoplasma pneumoniae is a major cause of community-acquired pneumonia (CAP) in children, with a rising incidence of macrolide resistance. Early diagnosis is crucial for reducing the disease burden; however, current diagnostic tools have limitations.We evaluated the diagnostic accuracy of serological assays and their performance based on symptom onset in children with CAP. Methods: From September 2023 to September 2024, we prospectively enrolled children with CAP, classified as M. pneumoniae pneumonia (MPP) or non-MPP, from 16 hospitals in Korea. Serological testing included chemiluminescence immunoassay (CLIA) and ELISA for detecting IgM and IgG, along with particle agglutination (PA) for total antibody measurements. Serological responses were analyzed at different times after symptom onset (0–4, 5–9, and 10–21 days). Results: Among 472 children with CAP (362 MPP, 110 non-MPP), 138 (29.2%) underwent PA testing, and 334 (70.8%) underwent IgM testing. PA at a 1:640 cutoff showed 48.0% sensitivity and 100% specificity. CLIA and ELISA showed comparable sensitivities (69.1% vs. 69.2%) and specificities (76.9% vs. 66.7%) for IgM testing. Seropositivity increased significantly with time since symptom onset (P for trend < 0.001), reaching 97.9% for IgM, 62.5% for IgG, and 94.7% for PA at 10–21 days. Conclusions The time post-symptom onset significantly influenced the diagnostic utility of serological tests for pediatric MPP, which showed limited value during the early stage of illness. These findings emphasize the importance of symptom onset-based interpretation of serological test results and their utility in complementing PCR when optimizing MPP diagnosis in children.

The prevalence of dementia is 2- to 7-fold higher among patients with end-stage kidney disease (ESKD) than among the general population; however, its clinical implications in this population remain unclear. Therefore, this study aimed to determine whether comorbid dementia increases mortality among older patients with ESKD undergoing newly initiated hemodialysis. Methods: We analyzed data from the Korean Society of Geriatric Nephrology retrospective cohort, which included 2,736 older ESKD patients (≥70 years old) who started hemodialysis between 2010 and 2017. Kaplan-Meier survival and Cox regression analyses were used to examine all-cause mortality between the patients with and without dementia in this cohort. Results: Of the 2,406 included patients, 8.3% had dementia at the initiation of dialysis; these patients were older (79.6 ± 6.0 years) than patients without dementia (77.7 ± 5.5 years) and included more women (male:female, 89:111). Pre-ESKD diagnosis of dementia was associated with an increased risk of overall mortality (hazard ratio, 1.503; p < 0.001), and this association remained consistent after multivariate adjustment (hazard ratio, 1.268; p = 0.009). In subgroup analysis, prevalent dementia was associated with mortality following dialysis initiation in female patients, those aged <85 years, those with no history of cerebrovascular accidents or severe behavioral disorders, those not residing in nursing facilities, and those with no or short-term hospitalization. Conclusion: A pre-ESKD diagnosis of dementia is associated with mortality following dialysis initiation in older Korean population. In older patients with ESKD, cognitive assessment at dialysis initiation is necessary.

Sarcopenia upon admission to the intensive care unit (ICU) consistently correlates with adverse outcomes, including heightened mortality, in critically ill patients. This study aims to investigate the independent association of sarcopenia with both mortality and recovery from dialysis in critically ill patients with sepsis-induced acute kidney injury (SIAKI) undergoing continuous renal replacement therapy (CRRT). Methods: This retrospective study included 618 patients with SIAKI who underwent CRRT in our ICU. All patients had abdominal computed tomography (CT) scans within 3 days preceding ICU admission. The cross-sectional area of skeletal muscles at the third lumbar vertebra was quantified, and the skeletal muscle index (SMI), a normalized measure of skeletal muscle mass, was computed. Using Korean-specific SMI cutoffs, patients were categorized into sarcopenic and non-sarcopenic groups. Results: Among the 618 patients, 301 expired within 28 days of ICU admission. Multivariable Cox regression analysis revealed that sarcopenia independently predicted 28-day mortality. Among survivors, sarcopenia was independently associated with recovery from dialysis within 28 days after ICU admission. Kaplan-Meier analysis illustrated that sarcopenic patients had a higher mortality rate and a lower rate of recovery from dialysis within 28 days after ICU admission compared to non-sarcopenic patients. Conclusion: This study underscores the independent association of sarcopenia, assessed via CT-derived SMI, with both mortality and recovery from dialysis in critically ill patients with SIAKI undergoing CRRT. The inclusion of sarcopenia assessment could serve as a valuable tool for physicians in effectively stratifying the risk of adverse outcomes in these patients.

Background: Obesity is a major worldwide health problem and can be related to cellular senescence. Along with the rise in obesity, the comorbidity of renal ischemia-reperfusion (IR) injury is increasing. Whether obesity accelerates the severity of IR injury and whether senescence contributes to these conditions remain unclear. We studied the degree of injury and cellular senescence in the IR kidneys and perirenal adipose tissues of high-fat-diet–induced obese mice. Methods: C57BL/6 mice fed standard chow or a high-fat diet for 16 weeks were randomized to renal IR or sham group (n = 6–10 each). Renal IR was performed by unilateral clamping of the right renal pedicle for 30 minutes. Six weeks after surgery, renal function, perirenal fat/renal senescence, and histology were evaluated ex vivo. Results: Obese mice showed more renal tubular damage and fibrosis in IR injury than control mice, even though the degree of ischemic insult was comparable. Renal expression of senescence and its secretory phenotype was upregulated in either IR injury or with a high-fat diet and was further increased in the IR kidneys of obese mice. Fat senescence and the expression of tumor necrosis factor alpha were also increased, especially in the perirenal depot of the IR kidneys, with a high-fat diet. Conclusion A high-fat diet aggravates IR injury in murine kidneys, which is associated, at least in part, with perirenal fat senescence and inflammation. These observations support the exploration of therapeutic targets of the adipo-renal axis in injured obese kidneys.

Angioleiomyoma is benign smooth muscle tumor originating from the vascular wall. While they can occur in various anatomical locations, they are rarely reported in the vallecula region of the oropharynx. We present a case of a 58-year-old female patient with a five-year history of progressive dysphagia and throat discomfort. Laryngoscopy revealed a large, soft, mobile mass located on the right side of the vallecula. Radiological imaging further characterized the lesion as a well-circumscribed, heterogeneous mass. Surgical intervention in the form of Transoral Videolaryngoscopic Surgery (TOVS) was performed, leading to the successful removal of the mass. Histopathological analysis confirmed the diagnosis of angioleiomyoma.

Purpose: Renal tumors account for approximately 7% of all childhood cancers. These include Wilms tumor (WT), clear cell sarcoma of the kidney (CCSK), malignant rhabdoid tumor of the kidney (MRTK), renal cell carcinoma (RCC), congenital mesoblastic nephroma (CMN) and other rare tumors. We investigated the epidemiology of pediatric renal tumors in Korea. Materials and Methods: From January 2001 to December 2015, data of pediatric patients (0–18 years) newly-diagnosed with renal tumors at 26 hospitals were retrospectively analyzed. Results: Among 439 patients (male, 240), the most common tumor was WT (n=342, 77.9%), followed by RCC (n=36, 8.2%), CCSK (n=24, 5.5%), MRTK (n=16, 3.6%), CMN (n=12, 2.7%), and others (n=9, 2.1%). Median age at diagnosis was 27.1 months (range 0-225.5) and median follow-up duration was 88.5 months (range 0-211.6). Overall, 32 patients died, of whom 17, 11, 1, and 3 died of relapse, progressive disease, second malignant neoplasm, and treatment-related mortality. Five-year overall survival and event free survival were 97.2% and 84.8% in WT, 90.6% and 82.1% in RCC, 81.1% and 63.6% in CCSK, 60.3% and 56.2% in MRTK, and 100% and 91.7% in CMN, respectively (p < 0.001). Conclusion The pediatric renal tumor types in Korea are similar to those previously reported in other countries. WT accounted for a large proportion and survival was excellent. Non-Wilms renal tumors included a variety of tumors and showed inferior outcome, especially MRTK. Further efforts are necessary to optimize the treatment and analyze the genetic characteristics of pediatric renal tumors in Korea.

Background/Aims: Little is known about the clinical course of hepatitis B virus (HBV)-infected patients undergoing anti-tumor necrosis factor α (TNF-α) therapy for inflammatory bowel disease (IBD). We aimed to investigate the clinical course of HBV infection and IBD and to analyze liver dysfunction risks in patients undergoing anti-TNF-α therapy. Methods: This retrospective multinational study involved multiple centers in Korea, China, Tai-wan, and Japan. We enrolled IBD patients with chronic or resolved HBV infection, who received anti-TNF-α therapy. The patients’ medical records were reviewed, and data were collected using a web-based case report form. Results: Overall, 191 patients (77 ulcerative colitis and 114 Crohn’s disease) were included, 28.3% of whom received prophylactic antivirals. During a median follow-up duration of 32.4 months, 7.3% of patients experienced liver dysfunction due to HBV reactivation. Among patients with chronic HBV infection, the proportion experiencing liver dysfunction was significantly higher in the non-prophylaxis group (26% vs 8%, p=0.02). Liver dysfunction occurred in one patient with resolved HBV infection. Antiviral prophylaxis was independently associated with an 84% reduction in liver dysfunction risk in patients with chronic HBV infection (odds ratio, 0.16; 95% confidence interval, 0.04 to 0.66; p=0.01). The clinical course of IBD was not associated with liver dysfunction or the administration of antiviral prophylaxis. Conclusions Liver dysfunction due to HBV reactivation can occur in HBV-infected IBD patients treated with anti-TNF-α agents. Careful monitoring is needed in these patients, and antivirals should be administered, especially to those with chronic HBV infection.

Background: To evaluate prescription trends and clinical factors of the sodium-glucose cotransporter 2 inhibitors (SGLT2i) use according to the presence of atherosclerotic cardiovascular disease (ASCVD) or heart failure (HF) in Korean patients with type 2 diabetes mellitus (T2DM). Methods: Prescription patterns of SGLT2i use between 2015 and 2019 were determined using the Korean National Health Insurance Service database of claims. Results: Of all patients with T2DM (n=4,736,493), the annual prescription rate of SGLT2i increased every year in patients with ASCVD (from 2.2% to 10.7%) or HF (from 2.0% to 11.1%). After the first hospitalization for ASCVD (n=518,572), 13.7% (n=71,259) of patients initiated SGLT2i with a median of 10.6 months. After hospitalization for HF (n=372,853), 11.2% (n=41,717) of patients initiated SGLT2i after a median of 8.8 months. In multivariate regression for hospitalization, older age (per 10 years, odds ratio [OR], 0.57; 95% confidence interval [CI], 0.56 to 0.57), lower household income (OR, 0.93; 95% CI, 0.92 to 0.95), rural residents (OR, 0.95; 95% CI, 0.93 to 0.97), and dipeptidyl peptidase-4 inhibitor (DPP-4i) users (OR, 0.82; 95% CI, 0.81 to 0.84) were associated with lesser initiation of SGLT2i in ASCVD. Additionally, female gender (OR, 0.97; 95% CI, 0.95 to 0.99) was associated with lesser initiation of SGLT2i in HF. Conclusion The prescription rate of SGLT2i increased gradually up to 2019 but was suboptimal in patients with ASCVD or HF. After the first hospitalization for ASCVD or HF, older age, female gender, low household income, rural residents, and DPP-4i users were less likely to initiate SGLT2i.

Purpose: Preimplantation genetic testing for monogenic disorders (PGT-M) has been successfully used to prevent couples with monogenic disorders from passing them on to their child. Charcot–Marie–Tooth Disease (CMT) is a genetic disorder characterized by progressive extremity muscle degeneration and loss of sensory function. For the first time in Korea, we report our experience of applying single nucleotide polymorphism genotyping and karyomapping for PGT-M of CMT disease. Materials and Methods: Prior to clinical PGT-M, preclinical tests were performed using genotypes of affected families to identify informative single-nucleotide polymorphisms associated with mutant alleles. We performed five cycles of in vitro fertilization PGT-M in four couples with CMT1A, CMT2A, and CMT2S in CHA Fertility Center, Seoul Station. Results: From July 2020 through August 2021, five cycles of PGT-M with karyomapping in four cases with CMT1 and CMT2 were analyzed retrospectively. A total of 17 blastocysts were biopsied and 15 embryos were successfully diagnosed (88.2%).Ten out of 15 embryos were diagnosed as unaffected (66.7%). Five cycles of PGT-M resulted in four transfer cycles, in which four embryos were transferred. Three clinical pregnancies were achieved (75%) and the prenatal diagnosis by amniocentesis for all three women confirmed PGT-M of karyomapping. One woman delivered a healthy baby uneventfully and two pregnancies are currently ongoing. Conclusion This is the first report in Korea on the application of karyomapping in PGT-M for CMT patients. This study shows that karyomapping is an efficient, reliable and accurate diagnostic method for PGT-M in various types of CMT diseases.