1.Characteristics and Prevalence of Sequelae after COVID-19: A Longitudinal Cohort Study
Se Ju LEE ; Yae Jee BAEK ; Su Hwan LEE ; Jung Ho KIM ; Jin Young AHN ; Jooyun KIM ; Ji Hoon JEON ; Hyeri SEOK ; Won Suk CHOI ; Dae Won PARK ; Yunsang CHOI ; Kyoung-Ho SONG ; Eu Suk KIM ; Hong Bin KIM ; Jae-Hoon KO ; Kyong Ran PECK ; Jae-Phil CHOI ; Jun Hyoung KIM ; Hee-Sung KIM ; Hye Won JEONG ; Jun Yong CHOI
Infection and Chemotherapy 2025;57(1):72-80
Background:
The World Health Organization has declared the end of the coronavirus disease 2019 (COVID-19) public health emergency. However, this did not indicate the end of COVID-19. Several months after the infection, numerous patients complain of respiratory or nonspecific symptoms; this condition is called long COVID. Even patients with mild COVID-19 can experience long COVID, thus the burden of long COVID remains considerable. Therefore, we conducted this study to comprehensively analyze the effects of long COVID using multi-faceted assessments.
Materials and Methods:
We conducted a prospective cohort study involving patients diagnosed with COVID-19 between February 2020 and September 2021 in six tertiary hospitals in Korea. Patients were followed up at 1, 3, 6, 12, 18, and 24 months after discharge. Long COVID was defined as the persistence of three or more COVID-19-related symptoms. The primary outcome of this study was the prevalence of long COVID after the period of COVID-19.
Results:
During the study period, 290 patients were enrolled. Among them, 54.5 and 34.6% experienced long COVID within 6 months and after more than 18 months, respectively. Several patients showed abnormal results when tested for post-traumatic stress disorder (17.4%) and anxiety (31.9%) after 18 months. In patients who underwent follow-up chest computed tomography 18 months after COVID-19, abnormal findings remained at 51.9%. Males (odds ratio [OR], 0.17; 95% confidence interval [CI], 0.05–0.53; P=0.004) and elderly (OR, 1.04; 95% CI, 1.00–1.09; P=0.04) showed a significant association with long COVID after 12–18 months in a multivariable logistic regression analysis.
Conclusion
Many patients still showed long COVID after 18 months post SARS-CoV-2 infection. When managing these patients, the assessment of multiple aspects is necessary.
2.Diagnosis of Pneumocystis jirovecii Pneumonia in Non-HIV Immunocompromised Patient in Korea: A Review and Algorithm Proposed by Expert Consensus Group
Raeseok LEE ; Kyungmin HUH ; Chang Kyung KANG ; Yong Chan KIM ; Jung Ho KIM ; Hyungjin KIM ; Jeong Su PARK ; Ji Young PARK ; Heungsup SUNG ; Jongtak JUNG ; Chung-Jong KIM ; Kyoung-Ho SONG
Infection and Chemotherapy 2025;57(1):45-62
Pneumocystis jirovecii pneumonia (PJP) is a life-threatening infection commonly observed in immunocompromised patients, necessitating prompt diagnosis and treatment. This review evaluates the diagnostic performance of various tests used for PJP diagnosis through a comprehensive literature review. Additionally, we propose a diagnostic algorithm tailored to non-human immunodeficiency virus immunocompromised patients, considering the specific characteristics of current medical resources in Korea.
3.Anti-inflammatory effects of rutin in lipopolysaccharide-stimulated canine macrophage cells
Hyunsoo JANG ; Su-Cheol HAN ; Jisu LEE ; Ha-Young SHIN ; Jeong Ho HWANG ; Jung-Heun HA
Nutrition Research and Practice 2025;19(1):143-153
BACKGROUND/OBJECTIVES:
Inflammatory responses are key pathological factors in various canine diseases, making the control of inflammatory responses vital for canine health.This study examined the anti-inflammatory effects of rutin on DH82 cells, a type of canine macrophage, against lipopolysaccharide (LPS)-induced inflammatory responses.MATERIALS/METHODS: The inflammatory in vitro experimental model was established by stimulating canine macrophage DH82 cells with LPS. To evaluate the inflammationpreventative effects of rutin, analyses were conducted using enzyme-linked immunosorbent assay, western blot, and real-time quantitative reverse transcription polymerase chain reaction.
RESULTS:
Rutin inhibited the LPS-induced increase in the protein and gene levels of proinflammatory cytokines (interleukin [IL]-1β, IL-6, tumor necrosis factor-α), while antiinflammatory cytokines (IL-10, transforming growth factor-β1) levels remained unchanged.Furthermore, rutin suppressed the LPS-induced activation of phosphorylated extracellular signal-regulated kinase, Jun N-terminal kinase, inhibitor of nuclear factor kappa B, and nuclear factor kappa B (NF-κB) in DH82 cells.
CONCLUSION
Rutin exerts anti-inflammatory effects by inhibiting the mitogen-activated protein kinase-NF-κB signaling pathway and reducing the production of pro-inflammatory cytokines in DH82 cells.
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.Prevalence of New Frailty at Hospital Discharge in Severe COVID-19 Survivors and Its Associated Factors
Jong Hwan JEONG ; Manbong HEO ; Sunghoon PARK ; Su Hwan LEE ; Onyu PARK ; Taehwa KIM ; Hye Ju YEO ; Jin Ho JANG ; Woo Hyun CHO ; Jung-Wan YOO ;
Tuberculosis and Respiratory Diseases 2025;88(2):361-368
Background:
The development of frailty at hospital discharge affects the clinical outcomes in severe coronavirus disease 2019 (COVID-19) survivors who had no frailty before hospitalization. We aimed to describe the prevalence of new frailty using the clinical frailty scale (CFS) and evaluate its associated factors in patients with severe COVID-19 without pre-existing frailty before hospitalization.
Methods:
We performed a secondary analysis of clinical data from a nationwide retrospective cohort collected from 22 hospitals between January 1, 2020 and August 31, 2021. The patients were at least 19 years old and survived until discharge after admission to the intensive care unit (ICU) because of severe COVID-19. Development of new frailty was defined as a CFS score ≥5 at hospital discharge.
Results:
Among 669 severe COVID-19 survivors without pre-existing frailty admitted to the ICU, the mean age was 65.2±12.8 years, 62.5% were male, and 50.2% received mechanical ventilation (MV). The mean CFS score at admission was 2.4±0.9, and new frailty developed in 27.8% (186/483). In multivariate analysis, older age, cardiovascular disease, CFS score of 3–4 before hospitalization, increased C-reactive protein level, longer duration of corticosteroid treatment, and use of MV and extracorporeal membrane oxygenation were identified as factors associated with new-onset frailty.
Conclusion
Our study suggests that new frailty is not uncommon and is associated with diverse factors in survivors of severe COVID-19 without pre-existing frailty.
6.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.
7.Factors Associated with Postoperative Recurrence in Stage I to IIIA Non–Small Cell Lung Cancer with Epidermal Growth Factor Receptor Mutation: Analysis of Korean National Population Data
Kyu Yean KIM ; Ho Cheol KIM ; Tae Jung KIM ; Hong Kwan KIM ; Mi Hyung MOON ; Kyongmin Sarah BECK ; Yang Gun SUH ; Chang Hoon SONG ; Jin Seok AHN ; Jeong Eun LEE ; Jae Hyun JEON ; Chi Young JUNG ; Jeong Su CHO ; Yoo Duk CHOI ; Seung Sik HWANG ; Chang Min CHOI ; Seung Hun JANG ; Jeong Uk LIM ;
Cancer Research and Treatment 2025;57(1):83-94
Purpose:
Recent development in perioperative treatment of resectable non–small cell lung cancer (NSCLC) have changed the landscape of early lung cancer management. The ADAURA trial has demonstrated the efficacy of adjuvant osimertinib treatment in resectable NSCLC patients; however, studies are required to show which subgroup of patients are at a high risk of relapse and require adjuvant epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor treatment. This study evaluated risk factors for postoperative relapse among patients who underwent complete resection.
Materials and Methods:
Data were obtained from the Korean Association for Lung Cancer Registry (KALC-R), a database created using a retrospective sampling survey by the Korean Central Cancer Registry (KCCR) and the Lung Cancer Registration Committee.
Results:
A total of 3,176 patients who underwent curative resection was evaluated. The mean observation time was approximately 35.4 months. Among stage I to IIIA NSCLC patients, the EGFR-mutant subgroup included 867 patients, and 75.2%, 11.2%, and 11.8% were classified as stage I, stage II, and stage III, respectively. Within the EGFR-mutant subgroup, 44 (5.1%) and 121 (14.0%) patients showed early and late recurrence, respectively. Multivariate analysis on association with postoperative relapse among the EGFR-mutant subgroup showed that age, pathologic N and TNM stages, pleural invasion status, and surgery type were independent significant factors.
Conclusion
Among the population that underwent complete resection for early NSCLC with EGFR mutation, patients with advanced stage, pleural invasion, or limited resection are more likely to show postoperative relapse.
8.Anti-inflammatory effects of rutin in lipopolysaccharide-stimulated canine macrophage cells
Hyunsoo JANG ; Su-Cheol HAN ; Jisu LEE ; Ha-Young SHIN ; Jeong Ho HWANG ; Jung-Heun HA
Nutrition Research and Practice 2025;19(1):143-153
BACKGROUND/OBJECTIVES:
Inflammatory responses are key pathological factors in various canine diseases, making the control of inflammatory responses vital for canine health.This study examined the anti-inflammatory effects of rutin on DH82 cells, a type of canine macrophage, against lipopolysaccharide (LPS)-induced inflammatory responses.MATERIALS/METHODS: The inflammatory in vitro experimental model was established by stimulating canine macrophage DH82 cells with LPS. To evaluate the inflammationpreventative effects of rutin, analyses were conducted using enzyme-linked immunosorbent assay, western blot, and real-time quantitative reverse transcription polymerase chain reaction.
RESULTS:
Rutin inhibited the LPS-induced increase in the protein and gene levels of proinflammatory cytokines (interleukin [IL]-1β, IL-6, tumor necrosis factor-α), while antiinflammatory cytokines (IL-10, transforming growth factor-β1) levels remained unchanged.Furthermore, rutin suppressed the LPS-induced activation of phosphorylated extracellular signal-regulated kinase, Jun N-terminal kinase, inhibitor of nuclear factor kappa B, and nuclear factor kappa B (NF-κB) in DH82 cells.
CONCLUSION
Rutin exerts anti-inflammatory effects by inhibiting the mitogen-activated protein kinase-NF-κB signaling pathway and reducing the production of pro-inflammatory cytokines in DH82 cells.
9.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.
10.Prevalence of New Frailty at Hospital Discharge in Severe COVID-19 Survivors and Its Associated Factors
Jong Hwan JEONG ; Manbong HEO ; Sunghoon PARK ; Su Hwan LEE ; Onyu PARK ; Taehwa KIM ; Hye Ju YEO ; Jin Ho JANG ; Woo Hyun CHO ; Jung-Wan YOO ;
Tuberculosis and Respiratory Diseases 2025;88(2):361-368
Background:
The development of frailty at hospital discharge affects the clinical outcomes in severe coronavirus disease 2019 (COVID-19) survivors who had no frailty before hospitalization. We aimed to describe the prevalence of new frailty using the clinical frailty scale (CFS) and evaluate its associated factors in patients with severe COVID-19 without pre-existing frailty before hospitalization.
Methods:
We performed a secondary analysis of clinical data from a nationwide retrospective cohort collected from 22 hospitals between January 1, 2020 and August 31, 2021. The patients were at least 19 years old and survived until discharge after admission to the intensive care unit (ICU) because of severe COVID-19. Development of new frailty was defined as a CFS score ≥5 at hospital discharge.
Results:
Among 669 severe COVID-19 survivors without pre-existing frailty admitted to the ICU, the mean age was 65.2±12.8 years, 62.5% were male, and 50.2% received mechanical ventilation (MV). The mean CFS score at admission was 2.4±0.9, and new frailty developed in 27.8% (186/483). In multivariate analysis, older age, cardiovascular disease, CFS score of 3–4 before hospitalization, increased C-reactive protein level, longer duration of corticosteroid treatment, and use of MV and extracorporeal membrane oxygenation were identified as factors associated with new-onset frailty.
Conclusion
Our study suggests that new frailty is not uncommon and is associated with diverse factors in survivors of severe COVID-19 without pre-existing frailty.

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