1.Combination of Aβ40, Aβ42, and Tau Plasma Levels to Distinguish Amyloid-PET Positive Alzheimer Patients from Normal Controls
Seungyeop BAEK ; Jinny Claire LEE ; Byung Hyun BYUN ; Su Yeon PARK ; Jeong Ho HA ; Kyo Chul LEE ; Seung-Hoon YANG ; Jun-Seok LEE ; Seungpyo HONG ; Gyoonhee HAN ; Sang Moo LIM ; YoungSoo KIM ; Hye Yun KIM
Experimental Neurobiology 2025;34(1):1-8
Alzheimer disease (AD) diagnosis is confirmed using a medley of modalities, such as the detection of amyloid-β (Aβ) neuritic plaques and neurofibrillary tangles with positron electron tomography (PET) or the appraisal of irregularities in cognitive function with examinations. Although these methods have been efficient in confirming AD pathology, the rising demand for earlier intervention during pathogenesis has led researchers to explore the diagnostic potential of fluid biomarkers in cerebrospinal fluid (CSF) and plasma. Since CSF sample collection is invasive and limited in quantity, biomarker detection in plasma has become more attractive and modern advancements in technology has permitted more efficient and accurate analysis of plasma biomolecules. In this study, we found that a composite of standard factors, Aβ40 and total tau levels in plasma, divided by the variation factor, plasma Aβ42 level, provide better correlation with amyloid neuroimaging and neuropsychological test results than a level comparison between total tau and Aβ42 in plasma. We collected EDTA-treated blood plasma samples of 53 subjects, of randomly selected 27 AD patients and 26 normal cognition (NC) individuals, who received amyloid-PET scans for plaque quantification, and measured plasma levels of Aβ40, Aβ42, and total tau with digital enzyme-linked immunosorbent assay (ELISA) in a blinded manner. There was difficulty distinguishing AD patients from controls when analyzing biomarkers independently. However, significant differentiation was observed between the two groups when comparing individual ratios of total-tau×Aβ40/Aβ42. Our results indicate that collectively comparing fluctuations of these fluid biomarkers could aid in monitoring AD pathogenesis.
2.Recurrence Dynamics of Pathological N2 Non–Small Cell Lung Cancer Based on IASLC Residual Tumor Descriptor
In Ha KIM ; Geun Dong LEE ; Sehoon CHOI ; Hyeong Ryul KIM ; Yong-Hee KIM ; Dong Kwan KIM ; Seung-Il PARK ; Jae Kwang YUN
Cancer Research and Treatment 2025;57(1):105-115
Purpose:
This study investigated the recurrence patterns and timing in patients with pathologic N2 (pN2) non-small cell lung cancer (NSCLC) according to the residual tumor (R) descriptor proposed by the International Association for the Study of Lung Cancer (IASLC).
Materials and Methods:
From 2004 to 2021, patients with pN2 NSCLC who underwent anatomical resection were analyzed according to the IASLC R criteria using medical records from a single center. Survival analysis was performed using Cox proportional hazards models. Recurrence patterns between complete (R0) and uncertain resections (R[un]) were compared.
Results:
In total, 1,373 patients were enrolled in this study: 576 (42.0%) in R0, 286 (20.8%) in R(un), and 511 (37.2%) in R1/R2 according to the IASLC R criteria. The most common reason for R(un) classification was positivity for the highest lymph node (88.8%). In multivariable analysis, the hazard ratios for recurrence in R(un) and R1/R2 compared to R0 were 1.18 (95% confidence interval [CI], 0.96–1.46) and 1.58 (1.31–1.90), respectively. The hazard rate curves displayed similar patterns among groups, peaking at approximately 12 months after surgery. There was a significant difference in distant recurrence patterns between R0 and R(un). Further analysis after stratification with the IASLC N2 descriptor showed significant differences in distant recurrence patterns between R0 and R(un) in patients pN2a1 and pN2a2 disease, but not in those with pN2b disease.
Conclusion
The IASLC R criteria has prognostic relevance in patients with pN2 NSCLC. R(un) is a highly heterogeneous group, and the involvement of the highest mediastinal lymph node can affect distant recurrence patterns.
3.Anterior Segment Swept-Source Optical Coherence Tomography–based Assessment of Corneal Refractive Profiles in Stevens-Johnson Syndrome/Toxic Epidermal Necrolysis Patients: A Controlled Comparative Study
Dong Hee HA ; Seung Hyeun LEE ; Kyoung Woo KIM
Korean Journal of Ophthalmology 2025;39(2):103-113
Purpose:
To analyze anterior, posterior, and total corneal refractive profiles and thickness using anterior segment (AS) sweptsource optical coherence tomography (SS-OCT) in Stevens-Johnson syndrome (SJS) or toxic epidermal necrolysis (TEN) patients.
Methods:
This retrospective study compared 23 eyes from 14 patients with SJS/TEN with 23 eyes from 14 age- and sexmatched controls. AS SS-OCT measured corneal refractive profiles and pachymetry. Parameters included anterior, posterior, and total corneal power values, posterior to anterior curvature ratio, maximal corneal power, and thickness profiles. The SJS/TEN group was subdivided based on corneal opacity presence (subgroup A) or absence (subgroup B).
Results:
The SJS/TEN group showed significantly higher corneal astigmatism and maximal corneal power values for both anterior and posterior curvatures. Steep total corneal power and total corneal astigmatism were higher in the SJS/TEN group. The thinnest corneal thickness was lower, and its distance from the corneal vertex was greater in the SJS/TEN group. Subgroup analysis revealed that these differences were primarily attributed to the presence of corneal opacity. Additionally, automated keratometry of the anterior corneal surface showed significantly higher values, including steep, flat, and average keratometry and corneal astigmatism, in the SJS/TEN group.
Conclusions
AS SS-OCT shows significant alterations in both anterior and posterior corneal curvatures in patients with SJS/TEN. These findings emphasize the importance of considering posterior corneal curvature changes in pre-cataract surgery assessments and contact lens prescriptions for patients with SJS/TEN.
4.Ultrafast MRI for Pediatric Brain Assessment in Routine Clinical Practice
Hee Eun MOON ; Ji Young HA ; Jae Won CHOI ; Seung Hyun LEE ; Jae-Yeon HWANG ; Young Hun CHOI ; Jung-Eun CHEON ; Yeon Jin CHO
Korean Journal of Radiology 2025;26(1):75-87
Objective:
To assess the feasibility of ultrafast brain magnetic resonance imaging (MRI) in pediatric patients.
Materials and Methods:
We retrospectively reviewed 194 pediatric patients aged 0 to 19 years (median 10.2 years) who underwent both ultrafast and conventional brain MRI between May 2019 and August 2020. Ultrafast MRI sequences included T1 and T2-weighted images (T1WI and T2WI), fluid-attenuated inversion recovery (FLAIR), T2*-weighted image (T2*WI), and diffusion-weighted image (DWI). Qualitative image quality and lesion evaluations were conducted on 5-point Likert scales by two blinded radiologists, with quantitative assessment of lesion count and size on T1WI, T2WI, and FLAIR sequences for each protocol. Wilcoxon signed-rank tests and intraclass correlation coefficient (ICC) analyses were used for comparison.
Results:
The total scan times for equivalent image contrasts were 1 minute 44 seconds for ultrafast MRI and 15 minutes 30 seconds for conventional MRI. Overall, image quality was lower in ultrafast MRI than in conventional MRI, with mean quality scores ranging from 2.0 to 4.8 for ultrafast MRI and 4.8 to 5.0 for conventional MRI across sequences (P < 0.001 for T1WI, T2WI, FLAIR, and T2*WI for both readers; P = 0.018 [reader 1] and 0.031 [reader 2] for DWI). Lesion detection rates on ultrafast MRI relative to conventional MRI were as follows: T1WI, 97.1%; T2WI, 99.6%; FLAIR, 92.9%; T2*WI, 74.1%; and DWI, 100%. The ICC (95% confidence interval) for lesion size measurements between ultrafast and conventional MRI was as follows: T1WI, 0.998 (0.996–0.999); T2WI, 0.998 (0.997–0.999); and FLAIR, 0.99 (0.985–0.994).
Conclusion
Ultrafast MRI significantly reduces scan time and provides acceptable results, albeit with slightly lower image quality than conventional MRI, for evaluating intracranial abnormalities in pediatric patients.
5.Anterior Segment Swept-Source Optical Coherence Tomography–based Assessment of Corneal Refractive Profiles in Stevens-Johnson Syndrome/Toxic Epidermal Necrolysis Patients: A Controlled Comparative Study
Dong Hee HA ; Seung Hyeun LEE ; Kyoung Woo KIM
Korean Journal of Ophthalmology 2025;39(2):103-113
Purpose:
To analyze anterior, posterior, and total corneal refractive profiles and thickness using anterior segment (AS) sweptsource optical coherence tomography (SS-OCT) in Stevens-Johnson syndrome (SJS) or toxic epidermal necrolysis (TEN) patients.
Methods:
This retrospective study compared 23 eyes from 14 patients with SJS/TEN with 23 eyes from 14 age- and sexmatched controls. AS SS-OCT measured corneal refractive profiles and pachymetry. Parameters included anterior, posterior, and total corneal power values, posterior to anterior curvature ratio, maximal corneal power, and thickness profiles. The SJS/TEN group was subdivided based on corneal opacity presence (subgroup A) or absence (subgroup B).
Results:
The SJS/TEN group showed significantly higher corneal astigmatism and maximal corneal power values for both anterior and posterior curvatures. Steep total corneal power and total corneal astigmatism were higher in the SJS/TEN group. The thinnest corneal thickness was lower, and its distance from the corneal vertex was greater in the SJS/TEN group. Subgroup analysis revealed that these differences were primarily attributed to the presence of corneal opacity. Additionally, automated keratometry of the anterior corneal surface showed significantly higher values, including steep, flat, and average keratometry and corneal astigmatism, in the SJS/TEN group.
Conclusions
AS SS-OCT shows significant alterations in both anterior and posterior corneal curvatures in patients with SJS/TEN. These findings emphasize the importance of considering posterior corneal curvature changes in pre-cataract surgery assessments and contact lens prescriptions for patients with SJS/TEN.
6.Ultrafast MRI for Pediatric Brain Assessment in Routine Clinical Practice
Hee Eun MOON ; Ji Young HA ; Jae Won CHOI ; Seung Hyun LEE ; Jae-Yeon HWANG ; Young Hun CHOI ; Jung-Eun CHEON ; Yeon Jin CHO
Korean Journal of Radiology 2025;26(1):75-87
Objective:
To assess the feasibility of ultrafast brain magnetic resonance imaging (MRI) in pediatric patients.
Materials and Methods:
We retrospectively reviewed 194 pediatric patients aged 0 to 19 years (median 10.2 years) who underwent both ultrafast and conventional brain MRI between May 2019 and August 2020. Ultrafast MRI sequences included T1 and T2-weighted images (T1WI and T2WI), fluid-attenuated inversion recovery (FLAIR), T2*-weighted image (T2*WI), and diffusion-weighted image (DWI). Qualitative image quality and lesion evaluations were conducted on 5-point Likert scales by two blinded radiologists, with quantitative assessment of lesion count and size on T1WI, T2WI, and FLAIR sequences for each protocol. Wilcoxon signed-rank tests and intraclass correlation coefficient (ICC) analyses were used for comparison.
Results:
The total scan times for equivalent image contrasts were 1 minute 44 seconds for ultrafast MRI and 15 minutes 30 seconds for conventional MRI. Overall, image quality was lower in ultrafast MRI than in conventional MRI, with mean quality scores ranging from 2.0 to 4.8 for ultrafast MRI and 4.8 to 5.0 for conventional MRI across sequences (P < 0.001 for T1WI, T2WI, FLAIR, and T2*WI for both readers; P = 0.018 [reader 1] and 0.031 [reader 2] for DWI). Lesion detection rates on ultrafast MRI relative to conventional MRI were as follows: T1WI, 97.1%; T2WI, 99.6%; FLAIR, 92.9%; T2*WI, 74.1%; and DWI, 100%. The ICC (95% confidence interval) for lesion size measurements between ultrafast and conventional MRI was as follows: T1WI, 0.998 (0.996–0.999); T2WI, 0.998 (0.997–0.999); and FLAIR, 0.99 (0.985–0.994).
Conclusion
Ultrafast MRI significantly reduces scan time and provides acceptable results, albeit with slightly lower image quality than conventional MRI, for evaluating intracranial abnormalities in pediatric patients.
7.Anterior Segment Swept-Source Optical Coherence Tomography–based Assessment of Corneal Refractive Profiles in Stevens-Johnson Syndrome/Toxic Epidermal Necrolysis Patients: A Controlled Comparative Study
Dong Hee HA ; Seung Hyeun LEE ; Kyoung Woo KIM
Korean Journal of Ophthalmology 2025;39(2):103-113
Purpose:
To analyze anterior, posterior, and total corneal refractive profiles and thickness using anterior segment (AS) sweptsource optical coherence tomography (SS-OCT) in Stevens-Johnson syndrome (SJS) or toxic epidermal necrolysis (TEN) patients.
Methods:
This retrospective study compared 23 eyes from 14 patients with SJS/TEN with 23 eyes from 14 age- and sexmatched controls. AS SS-OCT measured corneal refractive profiles and pachymetry. Parameters included anterior, posterior, and total corneal power values, posterior to anterior curvature ratio, maximal corneal power, and thickness profiles. The SJS/TEN group was subdivided based on corneal opacity presence (subgroup A) or absence (subgroup B).
Results:
The SJS/TEN group showed significantly higher corneal astigmatism and maximal corneal power values for both anterior and posterior curvatures. Steep total corneal power and total corneal astigmatism were higher in the SJS/TEN group. The thinnest corneal thickness was lower, and its distance from the corneal vertex was greater in the SJS/TEN group. Subgroup analysis revealed that these differences were primarily attributed to the presence of corneal opacity. Additionally, automated keratometry of the anterior corneal surface showed significantly higher values, including steep, flat, and average keratometry and corneal astigmatism, in the SJS/TEN group.
Conclusions
AS SS-OCT shows significant alterations in both anterior and posterior corneal curvatures in patients with SJS/TEN. These findings emphasize the importance of considering posterior corneal curvature changes in pre-cataract surgery assessments and contact lens prescriptions for patients with SJS/TEN.
8.Ultrafast MRI for Pediatric Brain Assessment in Routine Clinical Practice
Hee Eun MOON ; Ji Young HA ; Jae Won CHOI ; Seung Hyun LEE ; Jae-Yeon HWANG ; Young Hun CHOI ; Jung-Eun CHEON ; Yeon Jin CHO
Korean Journal of Radiology 2025;26(1):75-87
Objective:
To assess the feasibility of ultrafast brain magnetic resonance imaging (MRI) in pediatric patients.
Materials and Methods:
We retrospectively reviewed 194 pediatric patients aged 0 to 19 years (median 10.2 years) who underwent both ultrafast and conventional brain MRI between May 2019 and August 2020. Ultrafast MRI sequences included T1 and T2-weighted images (T1WI and T2WI), fluid-attenuated inversion recovery (FLAIR), T2*-weighted image (T2*WI), and diffusion-weighted image (DWI). Qualitative image quality and lesion evaluations were conducted on 5-point Likert scales by two blinded radiologists, with quantitative assessment of lesion count and size on T1WI, T2WI, and FLAIR sequences for each protocol. Wilcoxon signed-rank tests and intraclass correlation coefficient (ICC) analyses were used for comparison.
Results:
The total scan times for equivalent image contrasts were 1 minute 44 seconds for ultrafast MRI and 15 minutes 30 seconds for conventional MRI. Overall, image quality was lower in ultrafast MRI than in conventional MRI, with mean quality scores ranging from 2.0 to 4.8 for ultrafast MRI and 4.8 to 5.0 for conventional MRI across sequences (P < 0.001 for T1WI, T2WI, FLAIR, and T2*WI for both readers; P = 0.018 [reader 1] and 0.031 [reader 2] for DWI). Lesion detection rates on ultrafast MRI relative to conventional MRI were as follows: T1WI, 97.1%; T2WI, 99.6%; FLAIR, 92.9%; T2*WI, 74.1%; and DWI, 100%. The ICC (95% confidence interval) for lesion size measurements between ultrafast and conventional MRI was as follows: T1WI, 0.998 (0.996–0.999); T2WI, 0.998 (0.997–0.999); and FLAIR, 0.99 (0.985–0.994).
Conclusion
Ultrafast MRI significantly reduces scan time and provides acceptable results, albeit with slightly lower image quality than conventional MRI, for evaluating intracranial abnormalities in pediatric patients.
9.Profiling of Anti-Signal-Recognition Particle Antibodies and Clinical Characteristics in South Korean Patients With Immune-Mediated Necrotizing Myopathy
Soo-Hyun KIM ; Yunjung CHOI ; Eun Kyoung OH ; Ichizo NISHINO ; Shigeaki SUZUKI ; Bum Chun SUH ; Ha Young SHIN ; Seung Woo KIM ; Byeol-A YOON ; Seong-il OH ; Yoo Hwan KIM ; Hyunjin KIM ; Young-Min LIM ; Seol-Hee BAEK ; Je-Young SHIN ; Hung Youl SEOK ; Seung-Ah LEE ; Young-Chul CHOI ; Hyung Jun PARK
Journal of Clinical Neurology 2025;21(1):31-39
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.
10.Evaluating Rituximab Failure Rates in Neuromyelitis Optica Spectrum Disorder: A Nationwide Real-World Study From South Korea
Su-Hyun KIM ; Ju-Hong MIN ; Sung-Min KIM ; Eun-Jae LEE ; Young-Min LIM ; Ha Young SHIN ; Young Nam KWON ; Eunhee SOHN ; Sooyoung KIM ; Min Su PARK ; Tai-Seung NAM ; Byeol-A YOON ; Jong Kuk KIM ; Kyong Jin SHIN ; Yoo Hwan KIM ; Jin Myoung SEOK ; Jeong Bin BONG ; Sohyeon KIM ; Hung Youl SEOK ; Sun-Young OH ; Ohyun KWON ; Sunyoung KIM ; Sukyoon LEE ; Nam-Hee KIM ; Eun Bin CHO ; Sa-Yoon KANG ; Seong-il OH ; Jong Seok BAE ; Suk-Won AHN ; Ki Hoon KIM ; You-Ri KANG ; Woohee JU ; Seung Ho CHOO ; Yeon Hak CHUNG ; Jae-Won HYUN ; Ho Jin KIM
Journal of Clinical Neurology 2025;21(2):131-136
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.

Result Analysis
Print
Save
E-mail