1.Clonal Burden, Immunoglobulin Heavy Chain Variable Gene Somatic Hypermutations, and Immunoglobulin Gene Repertoire in Korean Patients with Chronic Lymphocytic Leukemia Assessed by Next-Generation Sequencing
Taegeun LEE ; Daehyun CHU ; Miyoung KIM ; Young-Uk CHO ; Sang-Hyun HWANG ; Jung-Hee LEE ; Dok Hyun YOON ; Hyungwoo CHO ; Seongsoo JANG
Annals of Laboratory Medicine 2026;46(2):136-145
Background:
We compared the immunoglobulin (IG) heavy chain (IGH) leader and FR1 primer sets to measure clone sizes and detect immunoglobulin heavy chain variable (IGHV) region somatic hypermutations (SHMs) in Korean patients with chronic lymphocytic leukemia (CLL). We also analyzed IGH and immunoglobulin kappa (IGK) to identify Korean-specific IGs in CLL.
Methods:
Next-generation sequencing (NGS)–based gene rearrangements and IGHV SHMs were assessed in 40 patients using IGH leader, IGH FR1, and IGK primers. Flow cytometry, karyotyping, interphase FISH, and NGS-based variant analyses were performed for 165 genes.
Results:
Clonal IGH and IGK rearrangements were detected in 100.0% and 97.5% of patients, respectively. Clonal size was generally smaller per NGS than per flow cytometry, particularly when using the IGH leader (median: 52.5%) versus the IGH FR1 primer set (73.2%). IGHV SHMs occurred in approximately 70% of patients; 10% showed primer set discrepancies. The incidence of IGHV SHMs was low in patients at high risk (i.e., with TP53 abnormalities; complex karyotypes; and ATM, NOTCH1, SF3B1, or BIRC3 variants). IGHV3 was the most common IGHV (58.3%), and IGHV4-34 was most frequently identified (14.6%). IGHV1 and IGHV1-69 usage differed significantly between Koreans and westerners. IGHJ4 was the most common IGHJ (56.3%). A single IGKV–IGKJ gene rearrangement was most frequently observed (18.9%), whereas intron-KDE was the most common rearrangement (30.6%).
Conclusions
NGS may underestimate CLL clonal size, particularly when using the IGH leader primer set. IGHV SHMs were inversely associated with negative prognostic factors.Our data suggest ethnic differences in CLL pathogenesis.
2.Pregnancy and Retinal Disorders: Pathophysiology, Clinical Features, and Management
Minsub LEE ; Hyeong Min KIM ; Hyungwoo LEE ; Hyewon CHUNG
Journal of Retina 2026;11(1):1-12
During pregnancy, various physiological and metabolic changes occur throughout the female body, including in the retina. In particular, women at high risk, such as those with gestational diabetes or pregnancy-induced hypertension, often present with ocular symptoms.The major retinal disorders associated with pregnancy include diabetic retinopathy, hypertensive retinopathy, central serous chorioretinopathy, and retinal vascular occlusions. In this review, we provide an in-depth overview of recent studies investigating the impact of pregnancy on the retina and highlight the importance of retinal screening in pregnant women.
3.Reproducibility of Optical Coherence Tomography Radiomics after Cataract Surgery: Effects of Media Opacity, Signal Strength, and Region of Interest Selection
Na Hee KIM ; Hyeong Min KIM ; Hyewon CHUNG ; Hyungwoo LEE
Korean Journal of Ophthalmology 2026;40(3):236-246
Purpose:
To determine how cataract-related image-quality improvement and region of interest (ROI) definition affect the reproducibility of optical coherence tomography (OCT) radiomics features.
Methods:
This retrospective study included 50 eyes from 46 patients who underwent cataract surgery. Preoperative and postoperative OCT images were acquired using a standardized protocol. Radiomics features (n = 93) were extracted from two ROI configurations: retina ROI (Rr; retina only) and full ROI (Rf; retina, choroid, vitreous). Preoperative versus postoperative differences were tested with the Wilcoxon signed-rank test and Cohen’s d; repeatability was assessed with the intraclass correlation coefficient (ICC). Agreement between ROIs was evaluated with Wilcoxon statistics, Spearman correlation, the concordance correlation coefficient (CCC) and Bland-Altman plots. The influence of signal strength was analyzed with paired t-tests and Spearman correlation.
Results:
Postoperative signal strength significantly improved from 28.24 ± 3.16 to 31.40 ± 3.06 dB (p < 0.001). Significant preoperative/ postoperative changes occurred in 49 / 93 features (52.7%) within Rr and in 81 / 93 (87.1%) within Rf. ICC showed good-to-excellent repeatability in 51.6% of Rr features and 87.1% of Rf features, yet 29.0% of Rr features still demonstrated poor reliability. Across ROI methods, 94.6% of feature pairs differed significantly between Rr and Rf, and no feature achieved CCC ≥0.85. Only two descriptors—first-order statistics 10th percentile and GLDM (gray level dependence matrix) gray level variance—showed no significant change with surgery and minimal dependence on signal strength.
Conclusions
Radiomics features in OCT respond variably to media opacity, signal-to-noise ratio, and ROI definition: most are susceptible to these factors, yet a small subset remains stable across them. Limiting analysis to an anatomically precise retina- bounded ROI and enrolling eyes with comparable cataract status and signal-strength scores may therefore improve reproducibility. Implementing these standardizations will help future OCT-radiomics studies identify the most reliable biomarkers for clinical use.
4.Association Between Hyperacute Blood Pressure Lowering and Outcomes in Patients With Endovascular Thrombectomy
Jae Wook JUNG ; Eun Lee KO ; JoonNyung HEO ; Hyungwoo LEE ; Byungjae KIM ; Young Dae KIM ; Haram JOO ; Byung Moon KIM ; Dong Joon KIM ; Hyo Suk NAM
Journal of Stroke 2026;28(1):136-149
Background:
and Purpose Although blood pressure (BP) elevation is common in acute ischemic stroke, and guidelines recommend reducing systolic BP to <185 mm Hg prior to reperfusion therapy, the safety and efficacy of active BP lowering in the hyperacute phase before endovascular thrombectomy (EVT) remain uncertain.
Methods:
We conducted a retrospective analysis of a prospective hospital-based registry that included consecutive patients with anterior circulation large-vessel occlusion who underwent EVT between 2016 and 2024. Patients were categorized into the active BP lowering in the emergency department (ED) group or the absence of BP lowering in the ED group based on whether they received intravenous antihypertensive treatment prior to EVT. The primary outcome was the distribution of the modified Rankin Scale (mRS) scores at 3 months. Propensity score matching and multivariable regression analyses were also performed.
Results:
Of the 492 included patients, 53 (10.8%) received active BP lowering in the ED. After propensity score matching, patients who underwent active BP lowering showed a worse distribution of 3-month mRS scores compared with those who did not receive BP lowering (adjusted odds ratio, 0.38; 95% confidence interval [CI], 0.18 to 0.80; p=0.013). The active BP lowering group exhibited greater infarct volume growth (adjusted β coefficient, 33.4; 95% CI, 18.2 to 48.7; p<0.001), whereas the incidence of symptomatic intracerebral hemorrhage did not differ between groups.
Conclusions
Active BP lowering in the ED before EVT was associated with worse functional outcomes and increased infarct growth without a corresponding reduction in the occurrence of symptomatic intracerebral hemorrhage. These findings highlight the need for caution in initiating antihypertensive therapy before reperfusion and support further investigations to define optimal pre-EVT BP management.
5.Different Long-Term Outcomes According to Thrombus Histology in Patients With Acute Ischemic Stroke
Hyungwoo LEE ; JoonNyung HEO ; Jae Wook JUNG ; Hyo Suk NAM ; Ji Hoe HEO ; Minyoul BAIK ; Joonsang YOO ; Jinkwon KIM ; Tae-Jin SONG ; Gyu Sik KIM ; Kwon-Duk SEO ; Tae Dong OK ; Jin Kyo CHOI ; Il KWON ; Young Dae KIM ;
Journal of Stroke 2026;28(2):263-272
Background:
and Purpose The relationship between thrombus histology and long-term stroke patient outcomes remains unexplored. We aimed to determine whether the histological characteristics of thrombi are associated with long-term outcomes in stroke patients and to identify the thrombus features linked to these outcomes.
Methods:
This retrospective multicenter cohort study included 512 patients with ischemic stroke who underwent endovascular thrombectomy between July 2017 and July 2023. Patients were followed up for long-term major adverse cardiovascular events occurrence. Thrombus histology was assessed using immunohistochemistry, including the proportion of fibrin, red blood cells, and platelets, as well as the distribution patterns categorized as layered, erythrocytic, diffuse platelet, and mixed.
Results:
During a median follow-up of 38.1 months, 164 patients experienced major adverse cardiovascular events, with an incidence rate of 3.02 per 100 person-years. Major adverse cardiovascular events occurrence was associated with the diffuse platelet pattern and proportion of platelets and red blood cells within the thrombus. After adjusting for confounders, the diffuse platelet pattern independently predicted major adverse cardiovascular events, including mortality and stroke recurrence. Subgroup analysis also demonstrated that the association between the diffuse platelet pattern and major adverse cardiovascular events was consistent across key clinical subgroups based on age (≥65 vs. <65 yr), atrial fibrillation, cancer status, and discharge medications.
Conclusions
Thrombus histology could provide predictive value for long-term prognosis. In particular, histological distribution patterns may be more important than simple composition in thrombus research, including in the prediction of prognosis.
6.Combined Oral Anticoagulant and Antiplatelet for Atrial Fibrillation and Cerebral Atherosclerosis: A Meta-Analysis
Hyungwoo LEE ; JoonNyung HEO ; Jae Wook JUNG ; Hyo Suk NAM ; Young Dae KIM
Journal of Stroke 2026;28(2):303-311
Background:
and Purpose Patients with ischemic stroke with both atrial fibrillation (AF) and large artery atherosclerosis (LAA) represent therapeutic challenges, and the optimal antithrombotic regimen remains uncertain. We conducted a meta-analysis comparing oral anticoagulant (OAC) monotherapy with OAC plus antiplatelet therapy in this population.
Methods:
PubMed and EMBASE were searched through June 30, 2025, for studies enrolling patients with ischemic stroke and evidence of both AF and LAA. Outcomes included recurrent ischemic stroke, major bleeding, all-cause mortality, and a composite outcome. Pooled odds ratios (ORs) with 95% confidence intervals (CIs) were calculated using the Peto method, with random-effects sensitivity analyses, stratified by short-term (<3 months) and long-term (≥1 year) follow-up.
Results:
Eight cohort studies were analyzed. In the short-term, combination therapy was associated with a reduced risk of recurrent ischemic stroke (OR, 0.37; 95% CI, 0.14–0.97; p=0.043), without a significant increase in major bleeding, although this association did not persist under random-effects sensitivity analysis (OR, 0.37; 95% CI, 0.13–1.07; p=0.067). Conversely, long-term combination therapy was associated with higher risks of major bleeding (OR, 1.25; 95% CI, 1.08–1.45; p=0.002), all-cause mortality (OR, 1.25; 95% CI, 1.01–1.54; p=0.039), and composite outcome (OR, 1.49; 95% CI, 1.27–1.74; p<0.001), without reducing recurrent ischemic stroke (OR, 1.12; 95% CI, 1.00–1.26; p=0.054).
Conclusions
While long-term OAC plus antiplatelet therapy increases bleeding risk without preventing recurrent stroke, short-term combination therapy may offer benefits in selected patients with concomitant LAA, though this early efficacy signal should be interpreted with caution.
7.Evidence‑based Korean guidelines for the clinical management of multiple myeloma: addressing 12 key clinical questions
Sung‑Hoon JUNG ; Youngil KOH ; Min Kyoung KIM ; Jin Seok KIM ; Joon Ho MOON ; Chang‑Ki MIN ; Dok Hyun YOON ; Sung‑Soo YOON ; Je‑Jung LEE ; Chae Moon HONG ; Ka‑Won KANG ; Jihyun KWON ; Kyoung Ha KIM ; Dae Sik KIM ; Sung Yong KIM ; Sung‑Hyun KIM ; Yu Ri KIM ; Young Rok DO ; Yeung‑Chul MUN ; Sung‑Soo PARK ; Young Hoon PARK ; Ho Jin SHIN ; Hyeon‑Seok EOM ; Sang Eun YOON ; Sang Mee HWANG ; Won Sik LEE ; Myung‑won LEE ; Jun Ho YI ; Ji Yun LEE ; Ji Hyun LEE ; Ho Sup LEE ; Sung‑Nam LIM ; Jihyang LIM ; Ho‑Young YHIM ; Yoon Hwan CHANG ; Jae‑Cheol JO ; Jinhyun CHO ; Hyungwoo CHO ; Yoon Seok CHOI ; Hee jeong CHO ; Ari AHN ; Jong Han CHOI ; Hyun Jung KIM ; Kihyun KIM
Blood Research 2025;60():9-
Multiple myeloma (MM), a hematological malignancy, is characterized by malignant plasma cell proliferation in the bone marrow. Recent treatment advances have significantly improved patient outcomes associated with MM.In this study, we aimed to develop comprehensive, evidence-based guidelines for the diagnosis, prognosis, and treat‑ ment of MM. We identified 12 key clinical questions essential for MM management, guiding the extensive literature review and meta-analysis of the study. Our guidelines provide evidence-based recommendations by integrating patient preferences with survey data. These recommendations include current and emerging diagnostic tools, thera‑ peutic agents, and treatment strategies. By prioritizing a patient-centered approach and rigorous data analysis, these guidelines were developed to enhance MM management, both in Korea and globally.
8.The Value of Magnetic Resonance Imaging-Driven Apparent Diffusion Coefficient to Predict Pathologic Response of Neoadjuvant Chemotherapy in Muscle-Invasive Bladder Cancer: A Single-Center Retrospective Study
Hyungwoo AHN ; Sung Il HWANG ; Hak Jong LEE ; Kyu Sang LEE ; Sung Kyu HONG ; Seok-Soo BYUN ; Sangchul LEE ; Jong Jin OH
Journal of Urologic Oncology 2025;23(2):198-206
Purpose:
This study aimed to evaluate the predictive value of apparent diffusion coefficient (ADC) values from magnetic resonance imaging (MRI) in assessing pathologic response to neoadjuvant chemotherapy (NAC) in patients with muscle-invasive bladder cancer (MIBC) and the optimal cutoff value of ADC for predicting NAC response.
Materials and Methods:
Among 582 patients who underwent radical cystectomy between December 2011 and December 2024, we included 146 patients who received preoperative NAC and pretreatment MRI. Pathologic response was determined based on the surgical pathology results: patients with pathologic stage >pT2 and/or presence of nodal involvement (N+) were classified as nonresponders, while those with ≤pT2 and no nodal involvement (N0) were classified as responders. MRI-derived ADC values were compared between the 2 groups. The receiver operating characteristic (ROC) curve was used to determine the optimal cutoff value for predicting NAC response. Multivariate logistic regression analysis using preoperative parameter was performed and Kaplan-Meier survival analysis were utilized to assess overall survival (OS) and cancer-specific survival (CSS) according to NAC response.
Results:
Among the 146 patients, 90 (61.6%) were classified as responders, 56 (38.4%) were nonresponders. The mean ADC value was significantly higher in responders (1,100.35±249.12 mm2/sec) than in nonresponders (763.95±118.97 mm2/sec, p<0.001). ROC analysis demonstrated an area under the curve of 0.69, with an optimal cutoff value of 845.0 mm2/sec. Multivariate logistic regression identified ADC value as an independent predictor of NAC response (odds ratio, 1.025; 95% confidence interval, 1.006–1.043; p=0.008). During median follow-up 30.3 months, Kaplan-Meier analysis revealed that responders had significantly better 5-year OS (80.8% vs. 45.9%) and 5-year CSS (92.6% vs. 54.5%), with log-rank test p<0.001.
Conclusion
MRI-derived ADC values are a reliable imaging biomarker for predicting pathologic response to NAC in MIBC. Further validation in large-scale prospective studies is required to confirm these findings.
9.Single-Center Real-World Experience with Primary Central Nervous System Lymphoma in the 21st Century
Hyungwoo CHO ; Jung Yong HONG ; Dae Ho LEE ; Shin KIM ; Kyoungmin LEE ; Eun Hee KANG ; Sunjong LEE ; Jung Sun PARK ; Jeong Hoon KIM ; Jin Sook RYU ; Jooryung HUH ; Cheolwon SUH
Korean Journal of Medicine 2024;99(1):37-49
Background/Aims:
In Korea, the incidence of primary diffuse large B-cell lymphoma of the central nervous system (PCNSL) is increasing and autologous stem cell transplantation (ASCT) has improved the survival of younger patients. We explored our real-world experience with PCNSL at Asan Medical Center (AMC).
Methods:
We used the AMC lymphoma registry to collect patient data prospectively. We analyzed 279 patients diagnosed from 2002 until August 2019.
Results:
The PCNSL incidence at AMC increased progressively and comprised 7.4-8.9% of new non-Hodgkin lymphoma patients annually during the most recent 4 years. The median age was 60 years (range, 17-85) and males comprised 55%. Patients under 65 years of age (n = 183) had no significant differences in characteristics compared to those aged 65 years or over, with the exception of less occipital lobe involvement and lower beta-2 microglobulin levels. Rituximab, methotrexate, procarbazine, and vincristine (R-MPV) combination induction had the best overall response, of 95%. The median overall survival was 3.8 years with 5- and 10-year survival rates of 41.5% and 30.2%, respectively. Survival was better in younger patients and those treated with ASCT. Thiotepa, busulfan, and cytoxan (TBC) conditioning chemotherapy had better survival than other combinations. The International Extranodal Lymphoma Study Group and Memorial Sloan Kettering Cancer Center prognostic score systems were valid in this cohort. Age and performance status were independent prognostic factors. Exclusive extra-central nervous system failure occurred in six patients (5.6%) among 107 failures.
Conclusions
The incidence of PCNSL is rising. R-MPV induction therapy followed by ASCT with TBC has improved the survival of young, fit PCNSL patients.
10.Single-Center Real-World Experience with Primary Central Nervous System Lymphoma in the 21st Century
Hyungwoo CHO ; Jung Yong HONG ; Dae Ho LEE ; Shin KIM ; Kyoungmin LEE ; Eun Hee KANG ; Sunjong LEE ; Jung Sun PARK ; Jeong Hoon KIM ; Jin Sook RYU ; Jooryung HUH ; Cheolwon SUH
Korean Journal of Medicine 2024;99(1):37-49
Background/Aims:
In Korea, the incidence of primary diffuse large B-cell lymphoma of the central nervous system (PCNSL) is increasing and autologous stem cell transplantation (ASCT) has improved the survival of younger patients. We explored our real-world experience with PCNSL at Asan Medical Center (AMC).
Methods:
We used the AMC lymphoma registry to collect patient data prospectively. We analyzed 279 patients diagnosed from 2002 until August 2019.
Results:
The PCNSL incidence at AMC increased progressively and comprised 7.4-8.9% of new non-Hodgkin lymphoma patients annually during the most recent 4 years. The median age was 60 years (range, 17-85) and males comprised 55%. Patients under 65 years of age (n = 183) had no significant differences in characteristics compared to those aged 65 years or over, with the exception of less occipital lobe involvement and lower beta-2 microglobulin levels. Rituximab, methotrexate, procarbazine, and vincristine (R-MPV) combination induction had the best overall response, of 95%. The median overall survival was 3.8 years with 5- and 10-year survival rates of 41.5% and 30.2%, respectively. Survival was better in younger patients and those treated with ASCT. Thiotepa, busulfan, and cytoxan (TBC) conditioning chemotherapy had better survival than other combinations. The International Extranodal Lymphoma Study Group and Memorial Sloan Kettering Cancer Center prognostic score systems were valid in this cohort. Age and performance status were independent prognostic factors. Exclusive extra-central nervous system failure occurred in six patients (5.6%) among 107 failures.
Conclusions
The incidence of PCNSL is rising. R-MPV induction therapy followed by ASCT with TBC has improved the survival of young, fit PCNSL patients.

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