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.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.
3.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.
4.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.
5.Colon cancer: the 2023 Korean clinical practice guidelines for diagnosis and treatment
Hyo Seon RYU ; Hyun Jung KIM ; Woong Bae JI ; Byung Chang KIM ; Ji Hun KIM ; Sung Kyung MOON ; Sung Il KANG ; Han Deok KWAK ; Eun Sun KIM ; Chang Hyun KIM ; Tae Hyung KIM ; Gyoung Tae NOH ; Byung-Soo PARK ; Hyeung-Min PARK ; Jeong Mo BAE ; Jung Hoon BAE ; Ni Eun SEO ; Chang Hoon SONG ; Mi Sun AHN ; Jae Seon EO ; Young Chul YOON ; Joon-Kee YOON ; Kyung Ha LEE ; Kyung Hee LEE ; Kil-Yong LEE ; Myung Su LEE ; Sung Hak LEE ; Jong Min LEE ; Ji Eun LEE ; Han Hee LEE ; Myong Hoon IHN ; Je-Ho JANG ; Sun Kyung JEON ; Kum Ju CHAE ; Jin-Ho CHOI ; Dae Hee PYO ; Gi Won HA ; Kyung Su HAN ; Young Ki HONG ; Chang Won HONG ; Jung-Myun KWAK ;
Annals of Coloproctology 2024;40(2):89-113
Colorectal cancer is the third most common cancer in Korea and the third leading cause of death from cancer. Treatment outcomes for colon cancer are steadily improving due to national health screening programs with advances in diagnostic methods, surgical techniques, and therapeutic agents.. The Korea Colon Cancer Multidisciplinary (KCCM) Committee intends to provide professionals who treat colon cancer with the most up-to-date, evidence-based practice guidelines to improve outcomes and help them make decisions that reflect their patients’ values and preferences. These guidelines have been established by consensus reached by the KCCM Guideline Committee based on a systematic literature review and evidence synthesis and by considering the national health insurance system in real clinical practice settings. Each recommendation is presented with a recommendation strength and level of evidence based on the consensus of the committee.
6.Factors affecting bone mineral density in children and adolescents with systemic lupus erythematosus
Su Jin PARK ; Soo Yeun SIM ; Dae Chul JEONG ; Byung-Kyu SUH ; Moon Bae AHN
Annals of Pediatric Endocrinology & Metabolism 2024;29(3):191-200
Purpose:
Patients with juvenile-onset systemic lupus erythematosus (JSLE) are at a high risk of entering adulthood with disease-related morbidities like reduced bone mass and osteoporosis. This study aimed to evaluate the clinical characteristics of JSLE and to analyze the factors associated with low bone mineral density (BMD) in these patients.
Methods:
Children and adolescents diagnosed with JSLE at a single institution in Korea were included. Demographic, clinical, and laboratory data as well as details about the use of glucocorticoids (GCs) and disease-modifying antirheumatic drugs were collected. The lumbar spine (LS) BMD z-score was measured using dual energy x-ray absorptiometry, and lateral thoracolumbar spine radiographs were collected.
Results:
A total of 29 patients with JSLE were included in this study. Of these patients, 7 had a BMD z-score of -2.0 or lower and were designated as the low BMD group. The differences in the clinical parameters and treatment variables between the low BMD and non-low BMD groups were compared. Higher cumulative GC dose, longer GC exposure, and higher cumulative hydroxychloroquine (HCQ) dose were all associated with low BMD; among them, the main factor was the duration of GC exposure. There was no significant correlation between BMD and clinical profile, disease activity, or bone-metabolism markers.
Conclusion
The duration of GC exposure, cumulative GC dose, and cumulative HCQ dose were risk factors for low BMD in patients with JSLE, with the main factor being the duration of GC exposure. Thus, patients with JSLE should be routinely monitored for low BMD and potential fracture risks, and GC-sparing treatment regimens should be considered.
7.Clinical Validation of the Unparalleled Sensitivity of the Novel Allele-Discriminating Priming System Technology–Based EGFR Mutation Assay in Patients with Operable Non–Small Cell Lung Cancer
Il-Hyun PARK ; Dae-Soon SON ; Yoon-La CHOI ; Ji-Hyeon CHOI ; Ji-Eun PARK ; Yeong Jeong JEON ; Minseob CHO ; Hong Kwan KIM ; Yong Soo CHOI ; Young Mog SHIM ; Jung Hee KANG ; Suzy PARK ; Jinseon LEE ; Sung-Hyun KIM ; Byung-Chul LEE ; Jhingook KIM
Cancer Research and Treatment 2024;56(1):81-91
Purpose:
Recently, we developed allele-discriminating priming system (ADPS) technology. This method increases the sensitivity of conventional quantitative polymerase chain reaction up to 100 folds, with limit of detection, 0.01%, with reinforced specificity. This prospective study aimed to develop and validate the accuracy of ADPS epidermal growth factor receptor (EGFR) Mutation Test Kit using clinical specimens.
Materials and Methods:
In total 189 formalin-fixed paraffin-embedded tumor tissues resected from patients with non–small cell lung cancer were used to perform a comparative evaluation of the ADPS EGFR Mutation Test Kit versus the cobas EGFR Mutation Test v2, which is the current gold standard. When the two methods had inconsistent results, next-generation sequencing–based CancerSCAN was utilized as a referee.
Results:
The overall agreement of the two methods was 97.4% (93.9%-99.1%); the positive percent agreement, 95.0% (88.7%-98.4%); and the negative percent agreement, 100.0% (95.9%-100.0%). EGFR mutations were detected at a frequency of 50.3% using the ADPS EGFR Mutation Test Kit and 52.9% using the cobas EGFR Mutation Test v2. There were 10 discrepant mutation calls between the two methods. CancerSCAN reproduced eight ADPS results. In two cases, mutant allele fraction was ultra-low at 0.02% and 0.06%, which are significantly below the limit of detection of the cobas assay and CancerSCAN. Based on the EGFR genotyping by ADPS, the treatment options could be switched in five patients.
Conclusion
The highly sensitive and specific ADPS EGFR Mutation Test Kit would be useful in detecting the patients who have lung cancer with EGFR mutation, and can benefit from the EGFR targeted therapy.
8.Prevalence and confounders of chronic endometritis diagnosed using CD138 in patients with recurrent implantation failure
Hye Jeong HUE ; Hyunji CHOI ; Hyun Kyoung LEE ; Jung Ryeol LEE ; Byung Chul JEE ; Chang Woo CHOO ; Seul Ki KIM
Clinical and Experimental Reproductive Medicine 2024;51(2):163-169
Objective:
This retrospective study aimed to investigate the prevalence of chronic endometritis, diagnosed using CD138 immunohistochemistry, among infertile women and to assess the association between chronic endometritis and recurrent implantation failure (RIF).
Methods:
In total, 266 patients who underwent hysteroscopy due to infertility between 2019 and 2020 were included in the analysis. Of these, 136 patients with RIF and 130 non-RIF patients were included in the study. CD138 immunohistochemistry test results, blood biomarkers (including natural killer cells, white blood cells, and the lymphocyte-to-neutrophil ratio), and data on pregnancy outcomes were obtained. If the CD138 test yielded a positive result, the patients received antibiotic treatment.
Results:
The overall proportion of CD138-positive patients was 32.7% (87/266). The CD138 positivity rate was not related to the number of cycles with implantation failure. In the RIF patient group, no significant associations were found between CD138 positivity and peripheral blood markers. The clinical pregnancy rates were similar between infertile women treated with antibiotics for chronic endometritis and those without chronic endometritis.
Conclusion
To improve the pregnancy rate in infertile patients, it may be helpful to combine CD138 testing with other laboratory tests and administer antibiotic treatment if the result is positive.
9.The Effect of Tegoprazan on the Treatment of Endoscopic Resection-Induced Artificial Ulcers: A Multicenter, Randomized, Active-Controlled Study
Byung-Wook KIM ; Jong Jae PARK ; Hee Seok MOON ; Wan Sik LEE ; Ki-Nam SHIM ; Gwang Ho BAIK ; Yun Jeong LIM ; Hang Lak LEE ; Young Hoon YOUN ; Jun Chul PARK ; In-Kyung SUNG ; Hyunsoo CHUNG ; Jeong Seop MOON ; Gwang Ha KIM ; Su Jin HONG ; Hyuk Soon CHOI
Gut and Liver 2024;18(2):257-264
Background/Aims:
Tegoprazan is a novel potassium-competitive acid blocker that has beneficial effects on acid-related disorders such as gastroesophageal reflux and peptic ulcer diseases.This study aimed to validate the effect of tegoprazan on endoscopic submucosal dissection (ESD)-induced artificial ulcers.
Methods:
Patients from 16 centers in Korea who underwent ESD for gastric neoplasia were enrolled. After ESD, pantoprazole was administered intravenously for 48 hours. The patients were randomly allocated to either the tegoprazan or esomeprazole group. Tegoprazan 50 mg or esomeprazole 40 mg were administered for 4 weeks, after which gastroscopic evaluation was performed. If the artificial ulcer had not healed, the same dose of tegoprazan or esomeprazole was administered for an additional 4 weeks, and a gastroscopic evaluation was performed.
Results:
One hundred sixty patients were enrolled in this study. The healing rates of artificial ulcers at 4 weeks were 30.3% (23/76) and 22.1% (15/68) in the tegoprazan and esomeprazole groups, respectively (p=0.006). At 8 weeks after ESD, the cumulative ulcer healing rates were 73.7% (56/76) and 77.9% (53/68) in the tegoprazan and esomeprazole groups, respectively (p=0.210). Delayed bleeding occurred in two patients in the tegoprazan group (2.6%) and in one patient in the esomeprazole group (1.5%). Other adverse events were negligible in both groups.
Conclusions
Tegoprazan showed similar effects on post-ESD artificial ulcer healing in comparison with esomeprazole.
10.A Causality Assessment Framework for COVID-19 Vaccines and Adverse Events at the COVID-19 Vaccine Safety Research Center
Seyoung KIM ; Jeong Ah KIM ; Hyesook PARK ; Sohee PARK ; Sanghoon OH ; Seung Eun JUNG ; Hyoung-Shik SHIN ; Jong Koo LEE ; Hee Chul HAN ; Jun Hee WOO ; Byung-Joo PARK ; Nam-Kyong CHOI ; Dong-Hyun KIM
Journal of Korean Medical Science 2024;39(26):e220-
During the coronavirus disease 2019 (COVID-19) pandemic, conclusively evaluating possible associations between COVID-19 vaccines and potential adverse events was of critical importance. The National Academy of Medicine of Korea established the COVID-19 Vaccine Safety Research Center (CoVaSC) with support from the Korea Disease Control and Prevention Agency to investigate the scientific relationship between COVID-19 vaccines and suspected adverse events. Although determining whether the COVID-19 vaccine was responsible for any suspected adverse event necessitated a systematic approach, traditional causal inference theories, such as Hill's criteria, encountered certain limitations and criticisms. To facilitate a systematic and evidence-based evaluation, the United States Institute of Medicine, at the request of the Centers for Disease Control and Prevention, offered a detailed causality assessment framework in 2012, which was updated in the recent report by the National Academies of Sciences, Engineering, and Medicine (NASEM) in 2024.This framework, based on a weight-of-evidence approach, allows the independent evaluation of both epidemiological and mechanistic evidence, culminating in a comprehensive conclusion about causality. Epidemiological evidence derived from population studies is categorized into four levels—high, moderate, limited, or insufficient—while mechanistic evidence, primarily from biological and clinical studies in animals and individuals, is classified as strong, intermediate, weak, or lacking. The committee then synthesizes these two types of evidence to draw a conclusion about the causal relationship, which can be described as “convincingly supports” (“evidence established” in the 2024 NASEM report), “favors acceptance,” “favors rejection,” or “inadequate to accept or reject.” The CoVaSC has established an independent committee to conduct causality assessments using the weightof-evidence framework, specifically for evaluating the causality of adverse events associated with COVID-19 vaccines. The aim of this study is to provide an overview of the weight-ofevidence framework and to detail the considerations involved in its practical application in the CoVaSC.

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