1.Regions of Homozygosity Identified with a Chromosomal Microarray in a Korean Population:Distribution, Frequency, and Clinical Interpretation
Jaeryuk KIM ; Sunghee MIN ; Chang Ahn SEOL ; Eul-Ju SEO
Annals of Laboratory Medicine 2026;46(1):83-93
Background:
Single nucleotide polymorphism-based chromosomal microarray analysis (CMA) can detect regions of homozygosity (ROHs), which may be associated with medical conditions; however, limited ROH data, especially in East Asians, complicates clinical interpretations. We characterized ROH distributions and frequencies in a Korean population using CMA, highlighting clinically relevant findings, including suspected uniparental disomy (UPD), using standardized criteria.
Methods:
We analyzed ROHs in 1,731 individuals who underwent postnatal CMA at a Ko-rean medical center. ROHs ≥ 3 Mb long were detected using the CytoScan Dx platform and Chromosome Analysis Suite Dx. Suspected UPD and consanguinity were assessed per the American College of Medical Genetics and Genomics technical standards.
Results:
We identified 3,962 ROHs, with 76.7% of patients carrying at least one. Common “hotspot” regions included 3p21.31p21.1 (20.3%), 11p11.2 (18.2%), 1q21.1q21.3(17.7%), and 1p33p32.3 (12.0%). Almost all ROHs observed in > 1% of patients had a median size of < 5 Mb. ROH frequencies correlated negatively with chromosomal recombina-tion rates and positively with gene densities. Additionally, 1.2% (N = 21) of patients exhib-ited ROH patterns suggestive of UPD or consanguinity (13 suspected UPDs on imprinted chromosomes, 6 on non-imprinted chromosomes, and 2 consanguinities); 8 of 13 patients with suspected UPD were diagnosed as having imprinting disorders, with no pathogenic copy number variations detected.
Conclusions
Our population-specific ROH data for Koreans improve clinical interpretations by minimizing the risk of overinterpreting benign variants and highlight the value of standardized criteria for reliably detecting UPD and consanguinity and integrating ROH analysis into routine CMA interpretations.
2.Defect Size-Based Comparative Analysis of Treatment Modalities for Esophagojejunal Anastomotic Leakage Following Gastrectomy
Ba Ool SEONG ; Ji Yong AHN ; Juno YOO ; Chang Seok KO ; Sa-Hong MIN ; Chung Sik GONG ; Beom Su KIM ; Moon-Won YOO ; Jeong Hwan YOOK ; Hee Jin CHOI ; In-Seob LEE
Journal of Gastric Cancer 2026;26(2):295-306
Purpose:
Esophagojejunal anastomotic leakage (EJAL) represents a severe postoperative complication following total or proximal gastrectomy. Treatment strategies include conservative management, endoscopic interventions, and surgery; however, comparative data remain limited. This study aimed to compare clinical outcomes of different strategies to identify the optimal approach based on anastomotic defect size.
Materials and Methods:
This retrospective study reviewed 100 patients diagnosed with EJAL between January 2015 and October 2024. Patients were categorized into four groups:conservative management, endoscopic vacuum-assisted closure (E-VAC), other endoscopic treatments, and surgery. The primary outcomes were leakage duration and length of hospital stay after EJAL diagnosis, whereas the secondary outcome was time to C-reactive protein normalization. Subgroup analyses were performed according to defect size.
Results:
Among the 100 patients, 76 were male and 24 were female, with a mean age of 65.7 years. Conservative treatment was the most common modality (53%), followed by other endoscopic treatments (19%), E-VAC (14%), and surgery (14%). In patients with a defect size <1 cm, conservative treatment was associated with significantly shorter leakage duration (P=0.035) and earlier resumption of diet (P=0.029) compared with endoscopic treatment.Among those with defects ≥2 cm, E-VAC demonstrated the most favorable median outcomes across all variables; however, statistical significance was not achieved because of the small sample size.
Conclusions
Conservative treatment appears to be the most effective treatment strategy for EJAL with anastomotic defects <1 cm. For larger defects (≥2 cm), E-VAC may offer clinical benefit, although further studies are needed to confirm its efficacy. These findings highlight the importance of individualized treatment selection based on defect size.
3.Burning Mouth Syndrome 2026: From “Diagnosis of Exclusion” to a Structured Diagnostic Algorithm (Narrative Review)
Chang-Kyu OH ; Hye-Min JU ; Sung-Hee JEONG ; Yong-Woo AHN ; Hye-Mi JEON ; Soo-Min OK
Journal of Oral Medicine and Pain 2026;51(1):20-28
Burning mouth syndrome remains a frequent source of diagnostic delay, repeated consultations, and fragmented care because it has long been treated as a “diagnosis of exclusion.” Recent updates in orofacial pain classification and research diagnostic frameworks support a practical shift: from an exclusionary label toward a structured diagnostic algorithm and staged, phenotype-guided management. This narrative, algorithm-focused clinical review aims to summarize clinically actionable evidence and to propose a “minimum sufficient workup” that prioritizes safety, efficiency, and patient-centered communication.We first outline pragmatic diagnostic criteria and key symptom patterns, then integrate current concepts of mixed mechanisms—peripheral neuropathic features, centralociplastic amplification, and psychosocial modulators—that account for symptom fluctuation and discordance between symptom severity and objective findings. The core of this review is a one-page stepwise algorithm: (1) confirm chronicity and absence of visible mucosal disease, (2) screen for red flags requiring urgent evaluation, (3) address common local contributors (e.g., candidiasis, irritants, contact allergy, xerostomia), (4) perform a targeted systemic/medication/deficiency panel, and (5) phenotype patients to guide staged treatment choices and follow-up. Finally, we provide a practical management framework emphasizing education, trigger control, and individualized combinations of topical, systemic, and behavioral interventions with predefined reassessment intervals. Future priorities include phenotype-stratified randomized trials and implementation outcomes that quantify reductions in diagnostic delay, misdiagnosis, and unnecessary testing.
4.Comparative analysis of hematological changes in patients with rheumatoid arthritis treated with different Janus kinase inhibitors: a real-world study
Soo Min AHN ; Ji Seon OH ; Yong-Gil KIM ; Chang-Keun LEE ; Bin YOO ; Seokchan HONG
Journal of Rheumatic Diseases 2026;33(2):86-94
Objective:
Janus kinase (JAK) inhibitors are widely used to treat rheumatoid arthritis (RA); however, comparative analyses regarding their adverse events remain limited. This study aimed to compare the effects of different JAK inhibitors (tofacitinib, baricitinib, and upadacitinib) on hematological parameters in patients with RA in a real-world setting.
Methods:
This retrospective analysis included 552 patients with RA treated with JAK inhibitors between August 2015 and February 2024. Hematological parameters, including absolute neutrophil count (ANC) and platelet count, were assessed at baseline and after 6 months of treatment. Statistical analysis was performed to evaluate changes over time, and logistic regression analysis identified factors associated with hematologic alterations.
Results:
The 552 patients were divided into three groups: tofacitinib (n=264), baricitinib (n=143), and upadacitinib (n=145). No significant differences in baseline hematological parameters were observed across the groups. After 6 months, ANC decreased in all groups without significant differences among them (p=0.465). Patients receiving baricitinib had significantly higher platelet counts than those receiving tofacitinib (Pillai’s trace value of 0.063, p<0.001) or upadacitinib (Pillai’s trace value of 0.029, p<0.001).Multivariate analysis revealed that baricitinib was significantly associated with increased platelet counts (odds ratio, 2.009; 95% confidence interval, 1.212~3.331; p=0.007).
Conclusion
Although all three JAK inhibitors reduced ANC, baricitinib was associated with a substantial increase in platelet counts. These findings highlight the differences in adverse effect profiles among JAK inhibitors, emphasizing the importance of tailored monitoring in RA management.
5.Coronary CT Angiography-Derived Fractional Flow Reserve in Asia and the United States: 2025 Status Update
Woo Jin AHN ; Maros FERENCIK ; Ming-Yen NG ; Liang ZHONG ; Mona BHATIA ; Akira KURATA ; Pannipa SUWANNASOM ; Yung-Liang WAN ; Trang Ngoc NGUYEN ; Suyon CHANG ; Sung Mok KIM ; Hwan Seok YONG ; Cherry KIM
Korean Journal of Radiology 2026;27(1):27-33
Coronary CT-derived fractional flow reserve (CT-FFR) is a noninvasive alternative to invasive FFR for assessing the hemodynamic significance of coronary artery stenosis. CT-FFR uses routinely acquired coronary CT angiography (CCTA) with artificial intelligence and computational fluid dynamics to estimate pressure gradients, thereby supporting clinical decisionmaking without procedural risk. Adoption and implementation vary widely across regions. In Asia, South Korea exclusively uses HeartMedi+, which enables rapid analysis, streamlined workflow integration, and high user satisfaction. Japan relies primarily on FFR CT, which has national reimbursement and significantly influences treatment strategies, reducing unnecessary invasive procedures. Hong Kong, Singapore, Taiwan, Thailand, and Vietnam remain in early or exploratory phases due to cost, reimbursement, and infrastructure barriers. In the United States, CT-FFR is guideline-endorsed and reimbursed, where HeartFlow is the most widely used, supported by robust clinical validation and outcome data. Despite regional variability, CTFFR offers a noninvasive solution that enhances patient management, reduces unnecessary invasive testing, and is poised for broader clinical integration as technology and validation advance.
6.Improving prediction of ypT0–1N0 response in rectal cancer: the added value of gross tumor type to magnetic resonance tumor regression grade after chemoradiotherapy in a retrospective cohort study
Kyong-Min KANG ; Mi-Jeong CHOI ; Hong-min AHN ; Heung-Kwon OH ; Duck-Woo KIM ; Jungheum CHO ; Won CHANG ; Young Hoon KIM ; Kyoung Ho LEE ; Yu Kyung JUN ; Yonghoon CHOI ; Sung-Bum KANG
Annals of Surgical Treatment and Research 2026;110(4):237-245
Purpose:
While MRI-based tumor regression grade (mrTRG) has shown promise in evaluating pathologic response to concurrent chemoradiotherapy (CCRT) in rectal cancer, its ability to predict pathologic complete response remains limited.This study aimed to enhance mrTRG’s diagnostic performance in predicting ypT0–1N0 status, a key factor in considering non-radical management after CCRT for locally advanced rectal cancer (LARC).
Methods:
This retrospective study included 430 patients with LARC who underwent radical resection following CCRT at a single referral hospital between April 2018 and September 2024. Multivariable logistic regression was used to identify predictive factors associated with achieving ypT0–1N0 status. The diagnostic performances of mrTRG1–2 alone and in combination with other factors were assessed by comparing sensitivity, specificity, positive-predictive value (PPV), negative-predictive value, and area under the curve (AUC).
Results:
Ninety-three patients (21.6%) achieved ypT0–1N0. In the multivariable analysis, fungating type, cT1–2, and mrTRG1–2 were independent predictors for ypT0–1N0. Integrating mrTRG with gross tumor type yielded the highest AUC of 0.689 among the combined models. For predicting ypT0–1N0, the combination of mrTRG and gross tumor type improved PPV (79.2% vs. 41.5% for mrTRG alone) while also demonstrating enhanced sensitivity compared with ycT0–1N0, the conventional MRI-based predictor (40.9% vs. 22.6%).
Conclusion
This study demonstrated that combining mrTRG and gross tumor type improved the PPV of mrTRG in predicting ypT0–1N0 after CCRT in LARC. Further studies are warranted to validate the role of gross tumor type in refining predictive systems for selecting candidates for non-radical treatment.
7.Survival Rates of Patients with Gastric Cancer According to Age and Sex: A Large-Scale Study Using Data from 14,739 Patients
Yonghoon CHOI ; Nayoung KIM ; Ji Hyun KIM ; Hyeong Ho JO ; Hyeon Jeong OH ; Hye Seung LEE ; Yu Kyung JUN ; Hyuk YOON ; Cheol Min SHIN ; Young Soo PARK ; Dong Ho LEE ; So Hyun KANG ; Young Suk PARK ; Sang-Hoon AHN ; Yun-Suhk SUH ; Do Joong PARK ; Hyung Ho KIM ; Ji-Won KIM ; Jin Won KIM ; Keun-Wook LEE ; Won CHANG ; Yoon Jin LEE ; Kyoung Ho LEE ; Young Hoon KIM
Cancer Research and Treatment 2026;58(1):252-263
Purpose:
The male predominance in the incidence of gastric cancer (GC) is established; however, sex differences in the prognosis of GC remain controversial. As such, this study analyzed the prognosis of patients with GC based on age and sex.
Materials and Methods:
Data from 14,739 patients diagnosed with GC at Seoul National University Bundang Hospital between 2003 and 2023 were analyzed. Baseline characteristics, histological types of GC, overall and GC-specific survival rates (age and stage stratification), and associated risk factors were analyzed.
Results:
Females were significantly younger (p < 0.001) and exhibited more gastric body cancers (p < 0.001) and tumors with diffuse-type or poorly differentiated histology (p < 0.001) than males. Females exhibited an advantage over males in terms of overall survival (p=0.004), but not in GC-specific survival. However, age stratification revealed significant sex differences, that females < 50 years of age exhibited survival disadvantages (p < 0.001); however, this trend was reversed with age, and females > 60 years exhibited survival advantages (p < 0.001) for both overall and GC-specific survival. This may be explained by the lower ratio of diffuse-type GC as females age. Furthermore, in the analysis according to stage, females with stage IV disease exhibited significant survival disadvantages, with significantly younger age and a higher proportion of diffuse-type GC which exhibits aggressive features, resulting in poorer survival than in males.
Conclusion
Age and stage stratification revealed significant differences in survival between the sexes, which can be helpful for public health strategies.
9.Association between cardiovascular health measured by Life’s Essential 8 and depressive symptoms
Jeong Hyun AHN ; Hyejin KIM ; Hyeon Chang KIM ; Hokyou LEE ; Younga Heather LEE ; Donald M. LLOYD-JONES ; Sun Jae JUNG
Epidemiology and Health 2026;48(1):e2026013-
OBJECTIVES:
Poor cardiovascular health (CVH) and the high prevalence of depressive symptoms represent significant public health concerns, underscoring the importance of examining their association. This study aimed to investigate the association between CVH, as defined by the American Heart Association’s 2022 Life’s Essential 8 (LE8) framework, and depressive symptoms.
METHODS:
This study used data from the 2014, 2016, 2018, and 2020 Korea National Health and Nutrition Examination Survey. Overall CVH, measured using LE8, was categorized into 3 groups: low score (0–<50), moderate score (50–<80), and high score (80–100). LE8 comprises 2 subdomains: health behaviors and health factors. Depressive symptoms were defined as a total score ≥10 on the Patient Health Questionnaire-9. Multiple logistic regression analyses were performed, adjusting for sex, age, socioeconomic status, and current drinking status.
RESULTS:
Among 17,294 adults, 257 male and 681 female reported significant depressive symptoms. Compared with individuals in the low LE8 category (reference), the odds ratio (OR) for depressive symptoms was 0.29 (95% confidence interval [CI], 0.21 to 0.40) for those in the high LE8 category. The OR for depressive symptoms was 0.39 (95% CI, 0.29 to 0.53) for individuals with a high health behavior score compared with those with a low health behavior score. In contrast, the health factor score was not significantly associated with depressive symptoms.
CONCLUSIONS
These findings suggest that overall CVH, particularly the health behavior subdomain, was associated with lower odds of depressive symptoms. Prospective longitudinal studies are warranted to validate these findings and clarify the directionality of the observed associations.
10.Protective Effect of Brain Derived Neurotrophic Factor-Overexpressing Wharton’s Jelly-Derived Mesenchymal Stromal Cells in Severe Intraventricular Hemorrhage in Newborn Rats
So Yeon JUNG ; Misun YANG ; Young Eun KIM ; Dong Kyung SUNG ; Se In SUNG ; Chang-Woo LEE ; Yun Sil CHANG ; So Yoon AHN
International Journal of Stem Cells 2026;19(1):54-65
The brain-derived neurotrophic factor (BDNF) plays a crucial role in neuroprotection, and we have previously demonstrated BDNF-mediated neuroprotective effects in mesenchymal stromal cells (MSCs). The present study aimed to investigate whether BDNF-overexpressing MSCs enhance the therapeutic efficacy of naïve MSCs in a preclinical model of severe neonatal intraventricular hemorrhage (IVH). We exposed primary rat neuronal cells to 40 U of thrombin overnight in vitro. Subsequently, the neuronal cells were co-cultured with either naïve MSCs or BDNF-overexpressing MSCs (1×105 cells in 1 mL media) for 24 hours. Next, 300 μL of maternal blood was injected into bilateral ventricles on postnatal day (P)4 to induce severe IVH in newborn Sprague-Dawley male rats. At P6, either naïve MSCs or BDNF-overexpressing MSCs (1×105 cells in 10 μL saline) were transplanted intraventricularly. Behavioral function tests, including passive avoidance, followed by endpoint analyses of brain tissue and cerebrospinal fluid were performed at P35. BDNF-overexpressing MSCs enhanced the effects of naïve MSCs against cell death, cytotoxicity, and oxidative stress in vitro. Notably, naïve and BDNF-overexpressing MSCs did not attenuate post-hemorrhagic ventricular dilatation, neuronal cell death, or gliosis. However, BDNF-overexpressing MSCs attenuated microglial activation.Furthermore, inflammatory cytokine (interleukin [IL]-1α, IL-1β, IL-6, and tumor necrosis factor-α) levels and memory function assessed using a passive avoidance test significantly improved in the BDNF-overexpressing MSC transplanted group compared with the naïve MSC transplanted group. Our data suggest that BDNF-overexpressing MSCs may offer superior protective effects to naïve MSCs in a neonatal IVH model.

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