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.Continuous Positive Airway Pressure Therapy Alters Monocyte Activation and Immune Phenotype in Obstructive Sleep Apnea in Relation to Hypoxic Burden
Seung-No HONG ; Ara JO ; Jin-A PARK ; Hee-Suk LIM ; Kyoung Mi EUN ; Jivianne T LEE ; Jeffrey D SUH ; Dae Woo KIM
Clinical and Experimental Otorhinolaryngology 2026;19(2):177-184
Objectives:
. Obstructive sleep apnea (OSA) is associated with chronic intermittent hypoxia and systemic inflammation, both of which contribute to vascular and metabolic complications. Monocytes, as key immune cells of innate immunity, have been implicated in this inflammatory state. However, the effect of OSA treatment on monocyte function and inflammatory phenotype remains poorly understood.
Methods:
. In this prospective cohort study, OSA patients were evaluated before and after 3 months of continuous positive airway pressure (CPAP) therapy. Circulating monocytes were isolated, and inflammatory cytokine production (tumor necrosis factor [TNF]-α, interleukin [IL]-1β, and IL-6) was assessed at baseline and post-treatment, both at rest and after lipopolysaccharide (LPS) stimulation. Monocyte polarization (M1/M2-like marker expression) was measured by flow cytometry. Clinical severity parameters, including the apnea-hypopnea index (AHI) and oxygen desaturation index (ODI), were correlated with immune changes.
Results:
. Following CPAP treatment, LPS-induced inflammatory cytokine secretion and LPS responsiveness, defined as the increase in cytokine levels upon stimulation, both declined after CPAP in proportion to baseline ODI, but not AHI. Apart from TNF-α, baseline IL-1β and IL-6 levels were below the quantifiable range of the assay, which precluded reliable comparison after treatment. This effect may be explained by a parallel post-treatment shift in monocyte phenotype toward an anti-inflammatory M2-like (CD163+CD206+) profile, as demonstrated by our flow cytometry data, which was also significantly associated with baseline ODI.
Conclusion
. CPAP alleviates systemic inflammation in OSA by reducing hypoxic burden and reprogramming monocytes toward an anti-inflammatory phenotype. The magnitude of immune modulation was more closely linked to ODI than AHI, suggesting that oxygen desaturation burden serves as a meaningful adjunct to AHI in assessing monocyte-driven immune dysregulation in OSA.
3.Outcomes of Lung Transplantation for Bronchiolitis Obliterans after Hematopoietic Stem Cell Transplantation Compared with Those for Idiopathic Pulmonary Fibrosis
Bong Suk PARK ; Ha Eun KIM ; Young Ho YANG ; Dae Joon KIM ; Chang Young LEE ; Byung Jo PARK ; A La WOO ; Eun Young KIM ; Moo Suk PARK ; Song Yee KIM ; Jin Gu LEE
Yonsei Medical Journal 2026;67(1):27-33
Purpose:
Bronchiolitis obliterans syndrome (BOS) can develop as a manifestation of graft-versus-host disease following allogeneic hematopoietic stem cell transplantation (allo-HSCT), and may ultimately require lung transplantation (LT). However, reports on LT outcomes for BOS after allo-HSCT are limited. This study aimed to compare the outcomes of LT for BOS following allo-HSCT with those for idiopathic pulmonary fibrosis (IPF).
Materials and Methods:
A total of 487 patients underwent LT between January 2010 and August 2023. Among them, the baseline characteristics and outcomes of 35 patients with BOS following allo-HSCT and 216 patients with IPF were analyzed.
Results:
The BOS group was younger and had a lower body mass index (BMI) compared to the IPF group (33.7±11.9 years vs.59.7±7.3 years, p<0.001; 17.6±3.7 kg/m2 vs. 22.0±3.6 kg/m2 , p<0.001, respectively). The proportion of male patients was lower in the BOS group than in the IPF group (54.3% vs. 84.3%, p<0.001). Preoperative ventilator support was more common in the BOS group compared to the IPF group (62.9% vs. 32.4%, p=0.001). In Kaplan–Meier survival analysis, the 5-year survival rate was significantly higher in the BOS group than in the IPF group (71.0% vs. 44.9%, p=0.022). In the Cox proportional hazards model, age was the only factor significantly associated with survival [hazard ratio (95% confidence interval): 1.04 (1.02–1.07), p<0.001].
Conclusion
The survival rate of the BOS group was not inferior to that of the IPF group after adjusting for sex, age, and BMI. Therefore, LT should be actively considered as a treatment option for patients with BOS following allo-HSCT.
4.Characteristics and outcomes of portal vein thrombosis in patients with inflammatory bowel disease in Korea
Ki Jin KIM ; Su-Bin SONG ; Jung-Bin PARK ; June Hwa BAE ; Ji Eun BAEK ; Ga Hee KIM ; Min-Jun KIM ; Seung Wook HONG ; Sung Wook HWANG ; Dong-Hoon YANG ; Byong Duk YE ; Jeong-Sik BYEON ; Seung-Jae MYUNG ; Suk-Kyun YANG ; Chang Sik YU ; Yong-Sik YOON ; Jong-Lyul LEE ; Min Hyun KIM ; Ho-Su LEE ; Sang Hyoung PARK
The Korean Journal of Internal Medicine 2025;40(2):243-250
Background/Aims:
Portal vein thrombosis (PVT) frequently occurs in patients with inflammatory bowel disease (IBD), particularly when influenced by factors such as abdominal infections, IBD flare-ups, or surgical procedures. The implications of PVT range from immediate issues such as intestinal ischemia to long-term concerns including portal hypertension and its complications. However, there is a notable gap in comprehensive studies on PVT in IBD, especially with the increasing incidence of IBD in Asia. This research aimed to evaluate the clinical features and outcomes of PVT in patients with IBD at a leading hospital in South Korea.
Methods:
This retrospective analysis reviewed adult patients diagnosed with both IBD and PVT from 1989 to 2021 at a renowned South Korean medical center. The study focused on patient characteristics, specifics of PVT, administered treatments, and outcomes, all confirmed through enhanced CT scans.
Results:
A total of 78 patients met the study’s criteria. Notably, only 20.5% (16/78) were treated with oral anticoagulants; however, a vast majority (96.2%; 75/78) achieved complete radiographic resolution (CRR). When comparing patients receiving anticoagulants to those who did not, a significant preference for anticoagulant use was observed in cases where the main portal vein was affected, as opposed to just the left or right veins (p = 0.006). However, multivariable analysis indicated that neither anticoagulant use nor previous surgeries significantly impacted CRR.
Conclusions
Patients with IBD and PVT generally had favorable outcomes, regardless of anticoagulant use.
5.Medical disputes involving lower gastrointestinal endoscopies: cases from the Korean Medical Dispute Mediation and Arbitration Agency
Eun Hye OH ; Jeong Eun SHIN ; Jun Yong BAE ; Yoon Suk LEE ; Yehyun PARK ; Yong Hwan KWON ; Chang Nyol PAIK ; Jun Kyu LEE ; Tae Hee LEE
The Korean Journal of Internal Medicine 2025;40(3):404-426
Background/Aims:
As the number of lower gastrointestinal endoscopies and high-risk examinees increases, the incidence of adverse events associated with these endoscopies has also increased. Medical disputes and lawsuits related to adverse events are rapidly increasing.
Methods:
Medical disputes related to lower gastrointestinal endoscopy that had been filed in Korean Medical Dispute Mediation and Arbitration Agency (K-medi) from April 2012 to August 2020 were evaluated with the corresponding medical records and written appraisal. Facilities, patients, procedures, adverse events, and outcome-related variables related to medical disputes were analyzed.
Results:
As the number of lower gastrointestinal endoscopies in Korea increases each year, the number of medical disputes related to lower gastrointestinal endoscopy appraised by K-medi has also increased yearly during the same period. Among the 121 cases analyzed, 86 (71.1%) were conciliated and 35 (28.9%) were cosigned by prosecution. Perforations accounted for the largest proportion of cases (93 cases, 76.9%). Most patients (n = 119, 98.3%) underwent non-emergent procedures, and only 10 (8.3%) underwent them for therapeutic purposes. Approximately one-fifth of the patients (n = 25, 20.7%) died.
Conclusions
The number of medical disputes related to lower gastrointestinal endoscopy are increasing. To prevent this, it is important to review the data on existing cases and establish specific response guidelines.
6.Regenerative Capacity of Alveolar Type 2 Cells Is Proportionally Reduced Following Disease Progression in Idiopathic Pulmonary Fibrosis-Derived Organoid Cultures
Hyeon Kyu CHOI ; Gaeul BANG ; Ju Hye SHIN ; Mi Hwa SHIN ; Ala WOO ; Song Yee KIM ; Sang Hoon LEE ; Eun Young KIM ; Hyo Sup SHIM ; Young Joo SUH ; Ha Eun KIM ; Jin Gu LEE ; Jinwook CHOI ; Ju Hyeon LEE ; Chul Hoon KIM ; Moo Suk PARK
Tuberculosis and Respiratory Diseases 2025;88(1):130-137
Background:
Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive lung disease that culminates in respiratory failure and death due to irreversible scarring of the distal lung. While initially considered a chronic inflammatory disorder, the aberrant function of the alveolar epithelium is now acknowledged as playing a central role in the pathophysiology of IPF. This study aimed to investigate the regenerative capacity of alveolar type 2 (AT2) cells using IPF-derived alveolar organoids and to examine the effects of disease progression on this capacity.
Methods:
Lung tissues from three pneumothorax patients and six IPF patients (early and advanced stages) were obtained through video-assisted thoracoscopic surgery and lung transplantation. HTII-280+ cells were isolated from CD31-CD45-epithelial cell adhesion molecule (EpCAM)+ cells in the distal lungs of IPF and pneumothorax patients using fluorescence-activated cell sorting (FACS) and resuspended in 48-well plates to establish IPF-derived alveolar organoids. Immunostaining was used to verify the presence of AT2 cells.
Results:
FACS sorting yielded approximately 1% of AT2 cells in early IPF tissue, and the number decreased as the disease progressed, in contrast to 2.7% in pneumothorax. Additionally, the cultured organoids in the IPF groups were smaller and less numerous compared to those from pneumothorax patients. The colony forming efficiency decreased as the disease advanced. Immunostaining results showed that the IPF organoids expressed less surfactant protein C (SFTPC) compared to the pneumothorax group and contained keratin 5+ (KRT5+) cells.
Conclusion
This study confirmed that the regenerative capacity of AT2 cells in IPF decreases as the disease progresses, with IPF-derived AT2 cells inherently exhibiting functional abnormalities and altered differentiation plasticity.
7.Erratum: Correction of Text in the Article “The Long-term Outcomes and Risk Factors of Complications After Fontan Surgery: From the Korean Fontan Registry (KFR)”
Sang-Yun LEE ; Soo-Jin KIM ; Chang-Ha LEE ; Chun Soo PARK ; Eun Seok CHOI ; Hoon KO ; Hyo Soon AN ; I Seok KANG ; Ja Kyoung YOON ; Jae Suk BAEK ; Jae Young LEE ; Jinyoung SONG ; Joowon LEE ; June HUH ; Kyung-Jin AHN ; Se Yong JUNG ; Seul Gi CHA ; Yeo Hyang KIM ; Youngseok LEE ; Sanghoon CHO
Korean Circulation Journal 2025;55(3):256-257
8.Integration of Palliative Care in Neurosurgical Critical Care : Insights from a Single-Center Perspective
Nam Hee KIM ; Yejin KIM ; Se Yeon KIM ; Hyoung Suk HAN ; Hye Yoon PARK ; Eun Jin HA ; Shin Hye YOO
Journal of Korean Neurosurgical Society 2025;68(2):213-222
Objective:
: Palliative care is a specialized approach designed to enhance the quality of life for both patients and their families, offering patient-centered care through comprehensive assessment and care planning. However, the integration of palliative care within neurocritical care settings has been relatively understudied. This descriptive study aims to identify the characteristics, palliative care needs, and outcomes of patients referred to palliative care services during admission to the neurosurgical intensive care unit (NS-ICU).
Methods:
: A retrospective analysis of adults admitted to the NS-ICU at a referral hospital between December 2019 and December 2021 was conducted. The study focused on those referred to the inpatient palliative care team with diagnoses of non-traumatic brain hemorrhage, traumatic brain injury, or brain neoplasm. Excluded were patients who died before palliative care consultation or lacked sufficient information. The investigation assessed demographic and clinical characteristics at consultation, along with post-consultation hospital outcomes derived from medical records and interview notes.
Results:
: In this study involving 38 enrolled patients, the median age was 65, with 42.1% females. The most prevalent diagnosis was nontraumatic brain hemorrhage (47.4%). Reasons for palliative care consultation included psychosocial support (95%), goal-of-care discussions (68%), decision-making support (50%), and communication facilitation (39%). The median time from NS-ICU admission to consultation was 3.5 days (interquartile range, 1–8 days), and all interviews involved family members. Key decision topics encompassed mechanical ventilation (23.7%) and tracheostomy (21.1%). Patient preferences for life-sustaining treatment could be estimated in only 47.4% of cases, often resulting in treatment disagreement. Among the 38 patients, 26 (68.4%) died during admission. Before the consultation, full code status, partial code status, and comfort care alone were reported as 32%, 66%, and 2%, respectively; post-consultation, these figures shifted to 11%, 42%, and 47%, respectively.
Conclusion
: Palliative care was predominantly sought for psychosocial support and discussions concerning goals of care. Despite challenges in ascertaining patient treatment preferences, palliative care consultations proved invaluable in aiding family members and facilitating treatment decision-making. Our study suggests the potential integration of palliative care within neuro-critical care, contributing to a heightened utilization of comfort care at the end-of-life.
9.Integration of Palliative Care in Neurosurgical Critical Care : Insights from a Single-Center Perspective
Nam Hee KIM ; Yejin KIM ; Se Yeon KIM ; Hyoung Suk HAN ; Hye Yoon PARK ; Eun Jin HA ; Shin Hye YOO
Journal of Korean Neurosurgical Society 2025;68(2):213-222
Objective:
: Palliative care is a specialized approach designed to enhance the quality of life for both patients and their families, offering patient-centered care through comprehensive assessment and care planning. However, the integration of palliative care within neurocritical care settings has been relatively understudied. This descriptive study aims to identify the characteristics, palliative care needs, and outcomes of patients referred to palliative care services during admission to the neurosurgical intensive care unit (NS-ICU).
Methods:
: A retrospective analysis of adults admitted to the NS-ICU at a referral hospital between December 2019 and December 2021 was conducted. The study focused on those referred to the inpatient palliative care team with diagnoses of non-traumatic brain hemorrhage, traumatic brain injury, or brain neoplasm. Excluded were patients who died before palliative care consultation or lacked sufficient information. The investigation assessed demographic and clinical characteristics at consultation, along with post-consultation hospital outcomes derived from medical records and interview notes.
Results:
: In this study involving 38 enrolled patients, the median age was 65, with 42.1% females. The most prevalent diagnosis was nontraumatic brain hemorrhage (47.4%). Reasons for palliative care consultation included psychosocial support (95%), goal-of-care discussions (68%), decision-making support (50%), and communication facilitation (39%). The median time from NS-ICU admission to consultation was 3.5 days (interquartile range, 1–8 days), and all interviews involved family members. Key decision topics encompassed mechanical ventilation (23.7%) and tracheostomy (21.1%). Patient preferences for life-sustaining treatment could be estimated in only 47.4% of cases, often resulting in treatment disagreement. Among the 38 patients, 26 (68.4%) died during admission. Before the consultation, full code status, partial code status, and comfort care alone were reported as 32%, 66%, and 2%, respectively; post-consultation, these figures shifted to 11%, 42%, and 47%, respectively.
Conclusion
: Palliative care was predominantly sought for psychosocial support and discussions concerning goals of care. Despite challenges in ascertaining patient treatment preferences, palliative care consultations proved invaluable in aiding family members and facilitating treatment decision-making. Our study suggests the potential integration of palliative care within neuro-critical care, contributing to a heightened utilization of comfort care at the end-of-life.
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.

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