1.Mutation and Functional Characteristics of MYH9 Responsible for Giant Platelet Syndromes in Korean Patients
Jin Soo HWANG ; Hee Jo BAEK ; Soo Min PARK ; Bo Ram KIM ; Hoon KOOK
Clinical Pediatric Hematology-Oncology 2026;33(1):1-12
Background:
Autosomal dominant giant platelet syndrome (GPS) is characterized by thrombocytopenia, giant platelets, and Döhle-like inclusion bodies in leukocytes.Previous studies suggest relatively preserved platelet structure and function, implicating impaired megakaryocyte fragmentation. This study aimed to identify myosin heavy chain 9 (MYH9) mutations in Korean patients with GPS and to define the associated clinical, molecular and functional characteristics.
Methods:
After detailed personal and family history taking, peripheral blood smears were reviewed for platelet size, count, and leukocyte inclusions. MYH9 mutations were analyzed in peripheral blood mononuclear cells by direct sequencing of selected exons or complementary DNA (cDNA). Computer-assisted structural modeling was performed to evaluate the functional consequences of identified mutations.
Results:
Twenty-two affected individuals from six unrelated families were diagnosed with hereditary macrothrombocytopenia consistent with GPS. The median platelet count was 59,000/L, and the mean platelet volume was markedly increased (17.8 fL). Platelets ranged from approximately half to 1.5 times the size of red blood cells.Döhle-like inclusions were observed in 25-33% of leukocytes in four families. Extrahematologic manifestations included hearing impairment (family with Ile1816Val) and renal involvement, ranging from mild proteinuria to chronic renal failure requiring renal transplantation (family with Lys373Asn). Five families harbored MYH9 mutations—Arg1933Ter, Trp33Cys (novel), Lys373Asn, Ile1816Val, and Arg1165Cys—located in exons 40, 1, 10, 37, and 26, respectively; mutations segregated with affected status.Biochemical analysis revealed decreased MYH9 in soluble fractions with increased insoluble pellets; Trp33Cys and Lys373Asn produced aberrant approximately 140 kDa bands in addition to the normal 224 kDa band. Modeling localized Trp33Cys to the proximal myosin head region implicated in actin interaction.
Conclusion
Five GPS-associated MYH9 mutations were identified, including a novel Trp33Cys variant. Altered MYH9 solubility and disturbed protein–protein interactions may contribute to disease pathogenesis.
2.The Clinical Utility of the Cognitive Impairment Screening Test (CIST)
Hyeseon HAN ; Soyeon LIM ; Suah KIM ; Byung Hwa LEE ; Hee Jin KIM ; Juhee CHIN
Dementia and Neurocognitive Disorders 2026;25(1):42-53
Background:
and Purpose: The Cognitive Impairment Screening Test (CIST) was developed for use at the Community Dementia Reassurance Center in South Korea. This study evaluated convergent and discriminant validity of CIST, as well as its clinical utility in identifying cognitive impairment and differentiating amyloid deposition.
Methods:
We enrolled 252 participants from a hospital memory clinic (47 cognitively unimpaired [CU], 116 amnestic mild cognitive impairment, and 89 dementia). Participants completed CIST, K-MMSE-2, the Seoul Neuropsychological Screening Battery, 2nd edition (SNSB-II), and underwent amyloid positron emission tomography. To evaluate the convergent and discriminant validity of CIST, we conducted correlation analyses with SNSBII. Receiver operating characteristic analyses were used to evaluate the ability to discriminate cognitive impairment and to distinguish amyloid positivity. Areas under the curve (AUCs) for CIST and K-MMSE-2 were compared using DeLong’s test.
Results:
The total score of CIST correlated significantly with all SNSB-II subtests, and the domain scores of CIST showed stronger associations with corresponding SNSB-II subtests than with unrelated ones. Both CIST and K-MMSE-2 effectively distinguished cognitively impaired individuals from CU, with CIST demonstrating superior discrimination (AUC=0.926 vs.0.887, p=0.042). In the non-demented group, both CIST and K-MMSE-2 showed acceptable discrimination for amyloid positivity (AUC≈0.73), with high specificity but low sensitivity;however, there were no significant differences between the two tests.
Conclusions
The CIST demonstrated strong validity and discriminatory ability for detecting cognitive impairment. It also showed acceptable discrimination for amyloid positivity in non-demented participants, supporting its utility as a screening tool in both clinical and community settings.
3.A Protocol of Korean JOint RegistrY for ALZheimer’s Treatment and Diagnostics (JOY-ALZ)
Geon Ha KIM ; Jung-Min PYUN ; Danbee KANG ; Sung Hoon KANG ; Seong-Ho KOH ; Jae Seung KIM ; So Young MOON ; Won-Jin MOON ; Young Ho PARK ; YongSoo SHIM ; Dong Won YANG ; Young Chul YOUN ; Young Hee JUNG ; Hanna CHO ; Hojin CHOI ; Jae-Sung LIM ; Kee Hyung PARK ; Seong Hye CHOI
Dementia and Neurocognitive Disorders 2026;25(1):25-41
Background:
and Purpose: To assess the long-term effectiveness, safety, and economic viability of recently approved Alzheimer’s disease (AD) therapies, as well as to evaluate the real-world application of novel diagnostics among AD patients with diverse comorbidities, comprehensive real-world data (RWD) analysis is essential. The Korean JOint RegistrY for ALZheimer’s Treatment and Diagnostics (JOY-ALZ) endeavors to create a registry of RWD derived from clinical practice on new diagnostic methods and therapeutic agents for AD introduced in Korea since 2021.
Methods:
Participants must fulfill all the following: 1) be at least 19 years old; 2) be actively receiving, scheduled to initiate, or undergoing evaluation for any AD disease-modifying treatment; 3) have completed amyloid positron emission tomography or cerebrospinal fluid AD immunoassay (a positive result is not essential for participation); 4) have a clinical classification of cognitively unimpaired, mild cognitive impairment, or probable AD dementia. Data generated during routine care is segmented into a minimum dataset, extended dataset, and research-only dataset requiring extra consent. Assessments encompass clinical, cognitive, functional, neurobehavioral, neuroimaging, and biomarker evaluations, in addition to systematic monitoring of new AD treatments and their safety.Data are collected and monitored at baseline, at semiannual intervals during the initial 2 years, and then annually up to 2034. To date, 46 medical centers will participate in JOY-ALZ.
Conclusions
JOY-ALZ is expected to promote understanding of the long-term clinical outcomes, safety, and cost-effectiveness of recently introduced diagnostics and treatments for AD, thereby supporting the progress of precision medicine in AD care and diagnosis.
4.New Users of Sodium-Glucose Cotransporter 2 Inhibitors Are at Low Risk of Prostate Cancer: A Nationwide Cohort Study
Yun Kyung CHO ; Sehee KIM ; Myung Jin KIM ; Woo Je LEE ; Ye-Jee KIM ; Chang Hee JUNG
Diabetes & Metabolism Journal 2026;50(1):90-100
Background:
Preclinical studies have reported anticancer properties of sodium-glucose cotransporter 2 inhibitors (SGLT2is). We aimed to elucidate the association between the use of SGLT2is and the risk of prostate cancer among male patients with type 2 diabetes mellitus (T2DM).
Methods:
An active-comparator, new-user cohort design using a nationwide database between September 2014 and June 2020 was conducted on 45,601 new SGLT2i users and 205,395 new users of other glucose-lowering medications (oGLMs). In the following 1:1 propensity score matched (PSM) analysis, 35,371 SGLT2i users matched with an equivalent number of oGLM users were assessed. The hazard ratios (HRs) and 95% confidence intervals (CIs) for prostate cancer were calculated.
Results:
Among the cohort, prostate cancer was diagnosed in 210 out of 45,601 SGLT2i users, corresponding to a cumulative incidence of 1.0%, in contrast to 1,880 cases among 205,395 users of oGLMs, with a cumulative incidence of 1.5%. The use of SGLT2is was significantly correlated with a reduced risk of prostate cancer based on a multivariable-adjusted HR of 0.83 (95% CI, 0.71 to 0.98). PSM analysis affirmed 18% reduction in prostate cancer risk associated with SGLT2i use (HR, 0.82; 95% CI, 0.67 to 0.99). Subgroup analyses revealed that body mass index (BMI) significantly influenced the effect of SGLT2i on prostate cancer risk, with a more pronounced reduction in the subgroup with a BMI <25 kg/m2 (P=0.037).
Conclusion
The use of SGLT2is in Korean male patients with T2DM is associated with a lower risk of prostate cancer.
5.Establishing Epidemiological Cutoff Values for Helicobacter pylori Strains in Korea: A Model-Based Analysis of Antibiotic Resistance Patterns
Jin Hee NOH ; Jung Mogg KIM ; Hwoon-Yong JUNG ; Ji Yong AHN ; Sun Mi LEE ; Seong Woo JEON ; Yong Hwan KWON ; Jeong Hoon LEE ; Kee Don CHOI ; Eun Jeong GONG
Gut and Liver 2026;20(1):47-58
Background/Aims:
The absence of standardized clinical minimum inhibitory concentration (MIC) breakpoints for Helicobacter pylori infection has resulted in inconsistent resistance definitions, even within the same research group in Korea. Therefore, establishing epidemiological cutoff values (ECOFFs) is essential for standardization.
Methods:
The MIC distributions for antibiotics commonly used against H. pylori infection in South Korea were analyzed from 2015 to 2023. A total of 5,925 primary H. pylori isolates were collected from five data sources, and MIC values were determined using the serial 2-fold agar dilution method. The ECOFFinder program was used to establish ECOFFs for six antibiotics.
Results:
The tentative ECOFFs for amoxicillin and clarithromycin were 0.125 μg/mL. The ECOFFs for levofloxacin, metronidazole, and tetracycline were 0.5, 8.0, and 0.25 μg/mL, respec-tively. The ECOFF for rifabutin could not be determined due to insufficient data. On the basis of these ECOFFs, the resistance rate was 17.9% for amoxicillin, 31.9% for clarithromycin, 40.9% for levofloxacin, 24.7% for metronidazole, and 11.5% for tetracycline.
Conclusions
This comprehensive analysis defined regional antibiotic resistance patterns and established Korea-specific ECOFFs, providing a foundation for determining clinical breakpoints and optimizing H. pylori eradication strategies.
6.Early Onset, High Comorbidity Burden, and Regional Disparities of CADASIL:A Nationwide Cohort Study in South Korea
Ju-Yeun LEE ; Minwoo LEE ; Jae-Sung LIM ; Mi Sun OH ; Kyung-Ho YU ; Young Eun KIM ; Hyeo-Il MA ; Yun Jin KIM ; Jong Ho PARK ; Young Hee JUNG
Journal of Clinical Neurology 2026;22(2):172-182
Background:
and Purpose To compare the epidemiological and clinical features of the rare patients with cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) with age- and sex-matched controls in a nationwide cohort from South Korea.
Methods:
This observational cohort study analyzed newly diagnosed CADASIL patients aged at least 20 years and matched controls using data from the National Health Information Database for 2004–2022. The cumulative incidence of CADASIL was assessed by age and sex, and compared between regions. Neurologic and systemic diseases were compared between the CADASIL and control groups.
Results:
The study analyzed 816 CADASIL patients and 816 age- and sex-matched controls aged 56.8±15.2 years (mean±standard deviation), among whom 48.3% were male. The cumulative incidence of CADASIL was 1.86 per 100,000 people (95% confidence interval [CI]=1.85– 1.87 per 100,000), and peaked at 60–69 years of age. In terms of regional distribution, the incidence was highest for Jeju, at 39.67 per 100,000 (95% CI 37.84–41.49 per 100,000). Neurologic diseases were more frequent in CADASIL patients, including Alzheimer’s disease (33.1% vs.20.0%), vascular dementia (84.9% vs. 5.0%), epilepsy (34.6% vs. 15.9%), stroke (70.7% vs. 27.6%), parkinsonism (18.9% vs. 11.0%), and depression (60.8% vs. 44.9%). Systemic diseases such as diabetes mellitus (78.9% vs. 68.9%) were also more common in CADASIL patients, while cancer (27.9% vs. 38.7%) and myocardial infarction (10.0% vs. 13.6%) were less common than in controls. The onset ages of all diseases were lower in CADASIL patients.
Conclusions
This study has provided a precise nationwide estimate of the CADASIL incidence and its regional distribution in South Korea. CADASIL patients showed higher incidence rates and earlier onsets of diverse clinical manifestations.
7.Twig-Like Middle Cerebral Artery : Acquired Lesion Rather than Congenital Anomaly
Yung Ki PARK ; Byul-Hee YOON ; Eui-Hyun HWANG ; Jae Hoon KIM ; Hee In KANG ; Yu Deok WON ; Jin Whan CHEONG
Journal of Korean Neurosurgical Society 2026;69(1):51-60
Objective:
: A twig-like middle cerebral artery (T-MCA) is a rare condition characterized by steno-occlusion of the M1 segment of the middle cerebral artery (MCA) with nearby collateral arterial networks. Despite unclear pathophysiology, it is often classified as a congenital anomaly caused by failure of fusion of the plexiform MCA arterial plexus. We aimed to improve understanding of the pathophysiology of T-MCAs by analyzing incidental T-MCA findings and their natural history.
Methods:
: A retrospective chart review was performed between January 2011 and December 2023 at three medical centers treating both ischemic and hemorrhagic strokes. Patients with suspected MCA lesions were selected through radiology reports from computed tomography, magnetic resonance angiography, and digital subtraction imaging.
Results:
: We identified 51 T-MCA cases from a radiology report search spanning 13 years across three medical centers. The study included 9875 patients with ischemic stroke and 2097 with hemorrhagic stroke. Of the 51 T-MCA cases, incidental findings accounted for 25 (49.0%), ischemic stroke for 18 (35.3%), and hemorrhagic strokes accounted for eight cases (15.7%). T-MCA related ischemic and hemorrhagic strokes accounted for 0.18–0.38% of all strokes. The RNF213.R4810K mutation was identified in seven of 15 patients (46.7%) tested. We found three cases of a de-novo T-MCA that progressed from a normal MCA architecture.
Conclusion
: T-MCAs may represent an acquired secondary anomaly rather than a congenital lesion, followed by steno-occlusion of the focal MCA with new arterial network formation. Both Moyamoya angiopathy and chronic atherosclerosis likely contributed to disease progression. Formation of a microaneurysm, dilatation of the lenticulostriate artery, and hemodynamic stress can lead to stroke.
8.Associations of Changes in Metabolic Syndrome Status and Risk Factor Count With Incident Cardiovascular Events Among Cancer Survivors
Jaeyong LEE ; Hyeok-Hee LEE ; Eun-Jin KIM ; Hyeon Chang KIM ; Hokyou LEE
Journal of Lipid and Atherosclerosis 2026;15(1):98-110
Objective:
This study investigated the associations of changes in metabolic syndrome status and the number of metabolic syndrome risk factors after cancer diagnosis with the incidence of cardiovascular disease (CVD) events among cancer survivors.
Methods:
Using nationwide health screening data, we identified 344,681 individuals diagnosed with cancer at age ≥19 years from 2012 to 2017, who survived for at least 3 years without CVD events. Participants were classified according to their metabolic syndrome status and risk factor count both before and after cancer diagnosis. A CVD event was defined as a composite of myocardial infarction, stroke, or cardiovascular death.
Results:
During a median follow-up period of 5.0 years after surviving cancer for 3 years, 7,529 CVD events occurred. The cumulative incidence of CVD was highest among participants with persistent metabolic syndrome. Compared to participants consistently free of metabolic syndrome, the multivariable-adjusted hazard ratios (HRs) for CVD were 1.21 (95% confidence interval [CI], 1.13–1.30) for newly developed metabolic syndrome, 1.19 (95% CI, 1.10–1.27) for recovered metabolic syndrome, and 1.37 (95% CI, 1.30–1.45) for persistent metabolic syndrome. Participants who recovered from metabolic syndrome exhibited a lower risk compared to those with persistent metabolic syndrome (HR, 0.86; 95% CI, 0.80–0.93).Each +1 increase in risk factor count after cancer diagnosis was associated with increased CVD risk (HR, 1.09; 95% CI, 1.07–1.11).
Conclusion
Changes in metabolic syndrome status and metabolic syndrome risk factor count after cancer diagnosis were significantly associated with CVD risk among cancer survivors.
9.Establishing a rabbit sham model of cervical esophageal surgery for circumferential esophageal transplantation
Ji Hyun KIM ; Yu Jin KIM ; Hee Yeon JEON ; Young Shin JOO ; Jae Hee CHUNG
Clinical Transplantation and Research 2026;40(1):96-103
Background:
This study was performed to establish a rabbit model for esophageal surgery in the treatment of cervical esophageal diseases. The necessary steps for postoperative treatment and esophageal examination were detailed.
Methods:
This study aimed to confirm the feasibility of the surgical procedure in rabbits and develop a postoperative management protocol. Six New Zealand White rabbits underwent esophagectomy and end-to-end anastomosis of the cervical esophagus under general anesthesia. Postoperatively, the rabbits were fed a specially formulated therapeutic liquid diet for 3 to 7 days. Recovery was monitored for 8 weeks, after which the rabbits were euthanized. Esophagography and endoscopy were conducted during the first postoperative week to assess healing.
Results:
Of the six rabbits that underwent surgery, two died from nonsurgical complications within 7 days after the operation. Of the remaining rabbits, two were diagnosed with esophageal stricture via esophagography and underwent endoscopy after the first postoperative week. The final two rabbits completed the 8-week postoperative period without complications.
Conclusions
Esophageal surgery and postoperative treatment in rabbits require careful attention. We anticipate that this study will provide valuable and practical information for researchers conducting esophageal studies using rabbits.
10.Exosomes from Human Embryonic Stem Cell-Derived Mesenchymal Stem Cells Protect Lung Epithelium and Attenuate Fibrosis
Sangryul CHA ; Jooyeon LEE ; Jimin JANG ; Yeongcheol KIM ; Dahee HAN ; Seok-Ho HONG ; Seung-Jin KIM ; Dae-Hee LEE ; Chung Hyeun MA ; Han Pil LEE ; Se-Ran YANG
International Journal of Stem Cells 2026;19(1):66-82
Idiopathic pulmonary fibrosis (IPF) is characterized by maladaptive epithelial–mesenchymal crosstalk and progressive extracellular matrix accumulation, whereas currently available antifibrotic agents merely decelerate functional decline.This study investigated whether exosomes derived from human mesenchymal stem cells derived from embryonic stem cells (ESC-MSCs) restore epithelial stress responses and attenuate fibrotic remodeling. Human IPF lung transcriptomes were integrated with a bleomycin-induced murine model analyzed by RNA sequencing and protein signaling, together with cigarette smoke extract-induced injury in A549 epithelial cells. ESC-MSCs-derived exosomes exhibited typical morphology and size distribution, enrichment of tetraspanins, and absence of endoplasmic reticulum contamination, consistent with high-purity preparations. Across human IPF and bleomycin-injured lungs, transcriptomic profiling revealed prominent enrichment of extracellular matrix and cytoskeletal gene programs, whereas mitogen-activated protein kinase (MAPK) and Smad families displayed only modest alterations at the mRNA level. In vivo administration of exosomes during the fibrotic remodeling phase, via either intravenous or intratracheal delivery, resulted in improved body weight, reduced lung weight-to-body weight ratios, and decreased collagen deposition and Ashcroft scores. These structural and functional improvements were accompanied by suppression of profibrotic and mesenchymal markers and selective attenuation of activator protein-1 (AP-1) activity. In epithelial injury models, ESC-MSCs-derived exosomes enhanced cell viability, restored redox homeostasis, and constrained stress-induced mesenchymal gene expression and MAPK phosphorylation in both co-treatment and post-treatment settings. Collectively, these data support an epithelial-centered mechanism in which ESC-MSCs-derived exosomes re-establish oxidative balance and selectively restrict AP-1-driven stress signaling, thereby secondarily limiting extracellular matrix accumulation and fibrotic remodeling.

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