1.Considerations of Flow Cytometric Lymphocyte Subset Analysis in Korea Based on a Survey of Current Clinical Laboratory Practice
Mikyoung PARK ; Hyun-Woo CHOI ; Jihyang LIM ; Kyung-Hwa SHIN ; Eun-Jee OH ; Jaewoo SONG ; Kyeong-Hee KIM ; In Hwa JEONG ; Joo-Heon PARK ; Sang-Hyun HWANG ; Eun-Suk KANG
Annals of Laboratory Medicine 2026;46(2):220-225
Flow cytometric lymphocyte subset analysis (FCLSA) is essential for assessing immune status across various diseases and clinical settings. We surveyed current clinical laboratory practices related to FCLSA to establish a baseline reference for future standardization in Korea. Nine university hospitals actively performing FCLSA responded to the 22-question survey, which covered seven categories of laboratory practice. These hospitals used commercial reagent antibody kits from either Beckton Dickinson Biosciences (N = 4) or Beckman Coulter Diagnostics (N = 5). Most hospitals performed daily instrument setup and scheduled maintenance every 2–6 months. Two levels of commercial quality control materials were routinely used each day. Sample and reagent antibody volumes varied across hospitals, even when the same reagent kit was used. Acquired cell counts ranged from 5 × 10 3 to 5 × 10 4 cells, with two hospitals adjusting counts based on the cell type analyzed. Most laboratories reported percentages and general opinions; some additionally reported white blood cell and lymphocyte counts, along with lymphocyte percentages. This is the first comprehensive survey on the clinical laboratory practice of FCLSA in Korea.Standardization of FCLSA should be accelerated to ensure reliable and reproducible results.
2.Acute Heart Failure Across the Ejection Fraction Spectrum: Phenotypes, Management, and Outcomes From Nationwide KorHF III Registry
Huijin LEE ; Eung Ju KIM ; Seong Woo HAN ; Seong-Mi PARK ; Hyung-Seop KIM ; Myung-Chan CHO ; Hyo-Suk AHN ; Mi-Seung SHIN ; Seok-Jae HWANG ; Jin-Ok JEONG ; Dong Heon YANG ; Junho HYUN ; Jin Oh CHOI ; Hae-Young LEE ; Byung-Su YOO ; Seok-Min KANG ; Dong-Ju CHOI ; Hyun-Jai CHO ;
International Journal of Heart Failure 2026;8(1):43-55
Background and Objectives:
Clinical characteristics and outcomes in acute heart failure (AHF) vary by phenotype. We assessed phenotype-specific features, treatment patterns, and outcomes in a nationwide Korean cohort.
Methods:
The Korean Heart Failure III registry prospectively enrolled 7,351 AHF admissions at 47 hospitals. Among 6,777 patients with available left ventricular ejection fraction (EF), phenotypes were defined as heart failure with reduced EF (HFrEF, ≤40%), mildly reduced EF (HFmrEF,41–49%), or preserved EF (HFpEF, ≥50%). The primary endpoint was a 12-month composite of all-cause death or heart transplantation, evaluated from index admission and, among hospital survivors, from discharge. We used inverse probability weighting (multinomial generalized boosted models with stabilized, trimmed weights) and weighted Cox proportional-hazards models to estimate hazard ratios (HRs).
Results:
Phenotype distribution was 58.9% HFrEF, 13.6% HFmrEF, and 27.5% HFpEF. Crude 12-month composite rates from index admission were 13.4% (HFrEF), 12.7% (HFmrEF), and 16.8% (HFpEF). After weighting, from index admission, HFmrEF (HR, 0.892; 95% confidence interval [CI], 0.731–1.088) and HFpEF (HR, 1.101; 95% CI, 0.939–1.291) did not differ from HFrEF; from discharge, HFpEF had modestly higher risk (HR, 1.207; 95% CI, 1.008–1.445) whereas HFmrEF did not (HR, 1.039; 95% CI, 0.844–1.279). Hyponatremia and chronic kidney disease were consistent adverse markers, while angiotensin-converting enzyme inhibitor/ angiotensin II receptor blocker use at discharge was protective.
Conclusions
Across the EF spectrum, phenotypes showed distinct profiles and risk. Postdischarge risk was modestly higher in HFpEF, supporting phenotype-tailored care and systematic discharge optimization in Korean patients with AHF.
3.Outcomes of Deferring Percutaneous Coronary Intervention Without Physiologic Assessment for Intermediate Coronary Lesions
Jihoon KIM ; Seong-Hoon LIM ; Joo-Yong HAHN ; Jin-Ok JEONG ; Yong Hwan PARK ; Woo Jung CHUN ; Ju Hyeon OH ; Dae Kyoung CHO ; Yu Jeong CHOI ; Eul-Soon IM ; Kyung-Heon WON ; Sung Yun LEE ; Sang-Wook KIM ; Ki Hong CHOI ; Joo Myung LEE ; Taek Kyu PARK ; Jeong Hoon YANG ; Young Bin SONG ; Seung-Hyuk CHOI ; Hyeon-Cheol GWON
Korean Circulation Journal 2025;55(3):185-195
Background and Objectives:
Outcomes of deferring percutaneous coronary intervention (PCI) without invasive physiologic assessment for intermediate coronary lesions is uncertain.We sought to compare long-term outcomes between medical treatment and PCI of intermediate lesions without invasive physiologic assessment.
Methods:
A total of 899 patients with intermediate coronary lesions between 50% and 70% diameter-stenosis were randomized to the conservative group (n=449) or the aggressive group (n=450). For intermediate lesions, PCI was performed in the aggressive group, but was deferred in the conservative group. The primary endpoint was major adverse cardiac events (MACE, a composite of all-cause death, myocardial infarction [MI], or ischemia-driven any revascularization) at 3 years.
Results:
The number of treated lesions per patient was 0.8±0.9 in the conservative group and 1.7±0.9 in the aggressive group (p=0.001). At 3 years, the conservative group had a significantly higher incidence of MACE than the aggressive group (13.8% vs. 9.3%; hazard ratio [HR], 1.49; 95% confidence interval [CI], 1.00–2.21; p=0.049), mainly driven by revascularization of target intermediate lesion (6.5% vs. 1.1%; HR, 5.69; 95% CI, 2.20–14.73;p<0.001). Between 1 and 3 years after the index procedure, compared to the aggressive group, the conservative group had significantly higher incidence of cardiac death or MI (3.2% vs.0.7%; HR, 4.34; 95% CI, 1.24–15.22; p=0.022) and ischemia-driven any revascularization.
Conclusions
For intermediate lesions, medical therapy alone, guided only by angiography, was associated with a higher risk of MACE at 3 years compared with performing PCI, mainly due to increased revascularization.
4.Occupational disease monitoring by the Korea Occupational Disease Surveillance Center: a narrative review
Dong-Wook LEE ; Inah KIM ; Jungho HWANG ; Sunhaeng CHOI ; Tae-Won JANG ; Insung CHUNG ; Hwan-Cheol KIM ; Jaebum PARK ; Jungwon KIM ; Kyoung Sook JEONG ; Youngki KIM ; Eun-Soo LEE ; Yangwoo KIM ; Inchul JEONG ; Hyunjeong OH ; Hyeoncheol OH ; Jea Chul HA ; Jeehee MIN ; Chul Gab LEE ; Heon KIM ; Jaechul SONG
The Ewha Medical Journal 2025;48(1):e9-
This review examines the challenges associated with occupational disease surveillance in Korea, particularly emphasizing the limitations of current data sources such as the Industrial Accident Compensation Insurance (IACI) statistics and special health examinations. The IACI system undercounts cases due to its emphasis on severe diseases and restrictions on approvals. Special health examinations, although they cover a broad workforce, are constrained by their annual scheduling, which leads to missed acute illnesses and subclinical conditions. The paper also explores the history of occupational disease surveillance in Korea, highlighting the fragmented and disease-specific approach of earlier systems. The authors introduce the newly established Korea Occupational Disease Surveillance Center (KODSC), a comprehensive nationwide system designed to gather, analyze, and interpret data on occupational diseases through a network of regional centers. By incorporating hospital-based surveillance and focusing on acute poisonings and other sentinel events, the KODSC aims to overcome the limitations of previous systems and promote collaboration with various agencies. Although it is still in the early stages of implementation, the KODSC demonstrates potential for improving data accuracy and contributing valuable insights for public health policy.
5.Occupational disease monitoring by the Korea Occupational Disease Surveillance Center: a narrative review
Dong-Wook LEE ; Inah KIM ; Jungho HWANG ; Sunhaeng CHOI ; Tae-Won JANG ; Insung CHUNG ; Hwan-Cheol KIM ; Jaebum PARK ; Jungwon KIM ; Kyoung Sook JEONG ; Youngki KIM ; Eun-Soo LEE ; Yangwoo KIM ; Inchul JEONG ; Hyunjeong OH ; Hyeoncheol OH ; Jea Chul HA ; Jeehee MIN ; Chul Gab LEE ; Heon KIM ; Jaechul SONG
The Ewha Medical Journal 2025;48(1):e9-
This review examines the challenges associated with occupational disease surveillance in Korea, particularly emphasizing the limitations of current data sources such as the Industrial Accident Compensation Insurance (IACI) statistics and special health examinations. The IACI system undercounts cases due to its emphasis on severe diseases and restrictions on approvals. Special health examinations, although they cover a broad workforce, are constrained by their annual scheduling, which leads to missed acute illnesses and subclinical conditions. The paper also explores the history of occupational disease surveillance in Korea, highlighting the fragmented and disease-specific approach of earlier systems. The authors introduce the newly established Korea Occupational Disease Surveillance Center (KODSC), a comprehensive nationwide system designed to gather, analyze, and interpret data on occupational diseases through a network of regional centers. By incorporating hospital-based surveillance and focusing on acute poisonings and other sentinel events, the KODSC aims to overcome the limitations of previous systems and promote collaboration with various agencies. Although it is still in the early stages of implementation, the KODSC demonstrates potential for improving data accuracy and contributing valuable insights for public health policy.
6.Outcomes of Deferring Percutaneous Coronary Intervention Without Physiologic Assessment for Intermediate Coronary Lesions
Jihoon KIM ; Seong-Hoon LIM ; Joo-Yong HAHN ; Jin-Ok JEONG ; Yong Hwan PARK ; Woo Jung CHUN ; Ju Hyeon OH ; Dae Kyoung CHO ; Yu Jeong CHOI ; Eul-Soon IM ; Kyung-Heon WON ; Sung Yun LEE ; Sang-Wook KIM ; Ki Hong CHOI ; Joo Myung LEE ; Taek Kyu PARK ; Jeong Hoon YANG ; Young Bin SONG ; Seung-Hyuk CHOI ; Hyeon-Cheol GWON
Korean Circulation Journal 2025;55(3):185-195
Background and Objectives:
Outcomes of deferring percutaneous coronary intervention (PCI) without invasive physiologic assessment for intermediate coronary lesions is uncertain.We sought to compare long-term outcomes between medical treatment and PCI of intermediate lesions without invasive physiologic assessment.
Methods:
A total of 899 patients with intermediate coronary lesions between 50% and 70% diameter-stenosis were randomized to the conservative group (n=449) or the aggressive group (n=450). For intermediate lesions, PCI was performed in the aggressive group, but was deferred in the conservative group. The primary endpoint was major adverse cardiac events (MACE, a composite of all-cause death, myocardial infarction [MI], or ischemia-driven any revascularization) at 3 years.
Results:
The number of treated lesions per patient was 0.8±0.9 in the conservative group and 1.7±0.9 in the aggressive group (p=0.001). At 3 years, the conservative group had a significantly higher incidence of MACE than the aggressive group (13.8% vs. 9.3%; hazard ratio [HR], 1.49; 95% confidence interval [CI], 1.00–2.21; p=0.049), mainly driven by revascularization of target intermediate lesion (6.5% vs. 1.1%; HR, 5.69; 95% CI, 2.20–14.73;p<0.001). Between 1 and 3 years after the index procedure, compared to the aggressive group, the conservative group had significantly higher incidence of cardiac death or MI (3.2% vs.0.7%; HR, 4.34; 95% CI, 1.24–15.22; p=0.022) and ischemia-driven any revascularization.
Conclusions
For intermediate lesions, medical therapy alone, guided only by angiography, was associated with a higher risk of MACE at 3 years compared with performing PCI, mainly due to increased revascularization.
7.Outcomes of Deferring Percutaneous Coronary Intervention Without Physiologic Assessment for Intermediate Coronary Lesions
Jihoon KIM ; Seong-Hoon LIM ; Joo-Yong HAHN ; Jin-Ok JEONG ; Yong Hwan PARK ; Woo Jung CHUN ; Ju Hyeon OH ; Dae Kyoung CHO ; Yu Jeong CHOI ; Eul-Soon IM ; Kyung-Heon WON ; Sung Yun LEE ; Sang-Wook KIM ; Ki Hong CHOI ; Joo Myung LEE ; Taek Kyu PARK ; Jeong Hoon YANG ; Young Bin SONG ; Seung-Hyuk CHOI ; Hyeon-Cheol GWON
Korean Circulation Journal 2025;55(3):185-195
Background and Objectives:
Outcomes of deferring percutaneous coronary intervention (PCI) without invasive physiologic assessment for intermediate coronary lesions is uncertain.We sought to compare long-term outcomes between medical treatment and PCI of intermediate lesions without invasive physiologic assessment.
Methods:
A total of 899 patients with intermediate coronary lesions between 50% and 70% diameter-stenosis were randomized to the conservative group (n=449) or the aggressive group (n=450). For intermediate lesions, PCI was performed in the aggressive group, but was deferred in the conservative group. The primary endpoint was major adverse cardiac events (MACE, a composite of all-cause death, myocardial infarction [MI], or ischemia-driven any revascularization) at 3 years.
Results:
The number of treated lesions per patient was 0.8±0.9 in the conservative group and 1.7±0.9 in the aggressive group (p=0.001). At 3 years, the conservative group had a significantly higher incidence of MACE than the aggressive group (13.8% vs. 9.3%; hazard ratio [HR], 1.49; 95% confidence interval [CI], 1.00–2.21; p=0.049), mainly driven by revascularization of target intermediate lesion (6.5% vs. 1.1%; HR, 5.69; 95% CI, 2.20–14.73;p<0.001). Between 1 and 3 years after the index procedure, compared to the aggressive group, the conservative group had significantly higher incidence of cardiac death or MI (3.2% vs.0.7%; HR, 4.34; 95% CI, 1.24–15.22; p=0.022) and ischemia-driven any revascularization.
Conclusions
For intermediate lesions, medical therapy alone, guided only by angiography, was associated with a higher risk of MACE at 3 years compared with performing PCI, mainly due to increased revascularization.
8.Occupational disease monitoring by the Korea Occupational Disease Surveillance Center: a narrative review
Dong-Wook LEE ; Inah KIM ; Jungho HWANG ; Sunhaeng CHOI ; Tae-Won JANG ; Insung CHUNG ; Hwan-Cheol KIM ; Jaebum PARK ; Jungwon KIM ; Kyoung Sook JEONG ; Youngki KIM ; Eun-Soo LEE ; Yangwoo KIM ; Inchul JEONG ; Hyunjeong OH ; Hyeoncheol OH ; Jea Chul HA ; Jeehee MIN ; Chul Gab LEE ; Heon KIM ; Jaechul SONG
The Ewha Medical Journal 2025;48(1):e9-
This review examines the challenges associated with occupational disease surveillance in Korea, particularly emphasizing the limitations of current data sources such as the Industrial Accident Compensation Insurance (IACI) statistics and special health examinations. The IACI system undercounts cases due to its emphasis on severe diseases and restrictions on approvals. Special health examinations, although they cover a broad workforce, are constrained by their annual scheduling, which leads to missed acute illnesses and subclinical conditions. The paper also explores the history of occupational disease surveillance in Korea, highlighting the fragmented and disease-specific approach of earlier systems. The authors introduce the newly established Korea Occupational Disease Surveillance Center (KODSC), a comprehensive nationwide system designed to gather, analyze, and interpret data on occupational diseases through a network of regional centers. By incorporating hospital-based surveillance and focusing on acute poisonings and other sentinel events, the KODSC aims to overcome the limitations of previous systems and promote collaboration with various agencies. Although it is still in the early stages of implementation, the KODSC demonstrates potential for improving data accuracy and contributing valuable insights for public health policy.
9.Occupational disease monitoring by the Korea Occupational Disease Surveillance Center: a narrative review
Dong-Wook LEE ; Inah KIM ; Jungho HWANG ; Sunhaeng CHOI ; Tae-Won JANG ; Insung CHUNG ; Hwan-Cheol KIM ; Jaebum PARK ; Jungwon KIM ; Kyoung Sook JEONG ; Youngki KIM ; Eun-Soo LEE ; Yangwoo KIM ; Inchul JEONG ; Hyunjeong OH ; Hyeoncheol OH ; Jea Chul HA ; Jeehee MIN ; Chul Gab LEE ; Heon KIM ; Jaechul SONG
The Ewha Medical Journal 2025;48(1):e9-
This review examines the challenges associated with occupational disease surveillance in Korea, particularly emphasizing the limitations of current data sources such as the Industrial Accident Compensation Insurance (IACI) statistics and special health examinations. The IACI system undercounts cases due to its emphasis on severe diseases and restrictions on approvals. Special health examinations, although they cover a broad workforce, are constrained by their annual scheduling, which leads to missed acute illnesses and subclinical conditions. The paper also explores the history of occupational disease surveillance in Korea, highlighting the fragmented and disease-specific approach of earlier systems. The authors introduce the newly established Korea Occupational Disease Surveillance Center (KODSC), a comprehensive nationwide system designed to gather, analyze, and interpret data on occupational diseases through a network of regional centers. By incorporating hospital-based surveillance and focusing on acute poisonings and other sentinel events, the KODSC aims to overcome the limitations of previous systems and promote collaboration with various agencies. Although it is still in the early stages of implementation, the KODSC demonstrates potential for improving data accuracy and contributing valuable insights for public health policy.
10.Occupational disease monitoring by the Korea Occupational Disease Surveillance Center: a narrative review
Dong-Wook LEE ; Inah KIM ; Jungho HWANG ; Sunhaeng CHOI ; Tae-Won JANG ; Insung CHUNG ; Hwan-Cheol KIM ; Jaebum PARK ; Jungwon KIM ; Kyoung Sook JEONG ; Youngki KIM ; Eun-Soo LEE ; Yangwoo KIM ; Inchul JEONG ; Hyunjeong OH ; Hyeoncheol OH ; Jea Chul HA ; Jeehee MIN ; Chul Gab LEE ; Heon KIM ; Jaechul SONG
The Ewha Medical Journal 2025;48(1):e9-
This review examines the challenges associated with occupational disease surveillance in Korea, particularly emphasizing the limitations of current data sources such as the Industrial Accident Compensation Insurance (IACI) statistics and special health examinations. The IACI system undercounts cases due to its emphasis on severe diseases and restrictions on approvals. Special health examinations, although they cover a broad workforce, are constrained by their annual scheduling, which leads to missed acute illnesses and subclinical conditions. The paper also explores the history of occupational disease surveillance in Korea, highlighting the fragmented and disease-specific approach of earlier systems. The authors introduce the newly established Korea Occupational Disease Surveillance Center (KODSC), a comprehensive nationwide system designed to gather, analyze, and interpret data on occupational diseases through a network of regional centers. By incorporating hospital-based surveillance and focusing on acute poisonings and other sentinel events, the KODSC aims to overcome the limitations of previous systems and promote collaboration with various agencies. Although it is still in the early stages of implementation, the KODSC demonstrates potential for improving data accuracy and contributing valuable insights for public health policy.

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