1.Diagnostic Accuracy of Serological Tests for Mycoplasma pneumoniae Infections in Children with Pneumonia, Based on Symptom Onset
Gahee KIM ; Ki Wook YUN ; Dayun KANG ; Taek Jin LEE ; Byung Wook EUN ; Hyunju LEE ; Yae-Jean KIM ; Doo Ri KIM ; Areum SHIN ; Hyun Mi KANG ; Ye Ji KIM ; Byung Ok KWAK ; Younghee LEE ; Ye Kyung KIM ; Young June CHOE ; Woosuck SUH ; Kyo Jin JO ; Kyung-Ran KIM ; Eun Young CHO ; Kyung Min KIM ; Joon Kee LEE ; Su Eun PARK
Annals of Laboratory Medicine 2026;46(2):162-170
Background:
Mycoplasma pneumoniae is a major cause of community-acquired pneumonia (CAP) in children, with a rising incidence of macrolide resistance. Early diagnosis is crucial for reducing the disease burden; however, current diagnostic tools have limitations.We evaluated the diagnostic accuracy of serological assays and their performance based on symptom onset in children with CAP.
Methods:
From September 2023 to September 2024, we prospectively enrolled children with CAP, classified as M. pneumoniae pneumonia (MPP) or non-MPP, from 16 hospitals in Korea. Serological testing included chemiluminescence immunoassay (CLIA) and ELISA for detecting IgM and IgG, along with particle agglutination (PA) for total antibody measurements. Serological responses were analyzed at different times after symptom onset (0–4, 5–9, and 10–21 days).
Results:
Among 472 children with CAP (362 MPP, 110 non-MPP), 138 (29.2%) underwent PA testing, and 334 (70.8%) underwent IgM testing. PA at a 1:640 cutoff showed 48.0% sensitivity and 100% specificity. CLIA and ELISA showed comparable sensitivities (69.1% vs. 69.2%) and specificities (76.9% vs. 66.7%) for IgM testing. Seropositivity increased significantly with time since symptom onset (P for trend < 0.001), reaching 97.9% for IgM, 62.5% for IgG, and 94.7% for PA at 10–21 days.
Conclusions
The time post-symptom onset significantly influenced the diagnostic utility of serological tests for pediatric MPP, which showed limited value during the early stage of illness. These findings emphasize the importance of symptom onset-based interpretation of serological test results and their utility in complementing PCR when optimizing MPP diagnosis in children.
2.2025 Focused Update of the Seoul Consensus on Gastroesophageal Reflux Disease: Evidence-based Recommendations on Acid Suppressive Therapy
Cheal Wung HUH ; Jin Won CHANG ; Nak-Hoon SON ; Da Hyun JUNG ; Hye-Kyung JUNG ; Seung Joo KANG ; Seung Young KIM ; Miyoung CHOI ; Da Mi JEONG ; Hyun Jin KIM ; Moo In PARK ; In-Kyung SUNG ; Young Hoon YOUN ; Kwang Jae LEE ;
Journal of Neurogastroenterology and Motility 2026;32(1):7-18
Gastroesophageal reflux disease (GERD) is a chronic and relapsing gastrointestinal disorder characterized by the reflux of gastric contents into the esophagus, leading to troublesome symptoms and/or complications. Since the publication of the 2020 Seoul Consensus on GERD, significant new evidence has emerged, particularly regarding acid-suppressive therapies and diagnostic approaches. This 2025 focused update aims to refine GERD management strategies by incorporating the latest evidence on acid suppressive therapies and regional considerations in Asian populations. This study builds on the 2020 Seoul Consensus by integrating systematic reviews, meta-analyses, and expert consensuses to offer updated recommendations for the definition and medical treatment of GERD. These guidelines incorporate recent advances in acid-suppressive therapies, particularly potassium-competitive acid blockers, and adopt updated diagnostic frameworks in accordance with the Lyon Consensus 2.0. Key clinical questions were identified and structured using the following format: Population, Intervention, Comparator, Outcome. The resulting recommendations address the initial treatment, long-term maintenance strategies, and role of personalized therapy based on disease severity, such as the grade of reflux esophagitis. Six key statements are presented: updated definition and classification of GERD (Statement 1); initial and long-term treatment strategies tailored to GERD phenotypes, such as non-erosive reflux disease, mild erosive esophagitis, and severe erosive esophagitis (Statements 2-5); and dose optimization strategies for long-term safety (Statement 6). These guidelines aim to support gastroenterologists and general healthcare providers in making individualized evidence-based decisions for GERD management.
3.Impact of Thyroid CT on Detecting Macroscopic Nodal Metastasis in Patients With Papillary Thyroid Microcarcinoma
Young Hun JEON ; Ji Ye LEE ; Taehyuk HAM ; Kyu Sung CHOI ; Inpyeong HWANG ; Roh-Eul YOO ; Koung Mi KANG ; Ji-hoon KIM
Korean Journal of Radiology 2026;27(5):484-494
Objective:
To evaluate the impact of adding CT to ultrasound (US) for nodal assessment in patients with papillary thyroid microcarcinoma (PTMC), particularly in those with US-node-negative disease.
Materials and Methods:
This single-center retrospective study included consecutive patients with PTMC (≤1 cm on US) who underwent both US and CT for PTMC staging between August 2016 and January 2020, and subsequently underwent surgery including neck dissection. The number of patients with clinical N1 and pathological N1 disease was assessed. The diagnostic performance of US, CT, and combined US + CT (positive if either was positive) for macroscopic lymph node metastasis (LNM) (i.e., metastatic tumor foci >2 mm) was evaluated. Cases with discordant nodal staging between US and CT were identified.The diagnostic utility of CT was also assessed in a subgroup of patients with node-negative findings on US.
Results:
Among 982 patients (mean age ± standard deviation, 47.3 ± 11.5 years; 774 female), pathological analysis confirmed cervical LNM in 377 patients, including macroscopic, microscopic, and size-unknown LNM in 187, 175, and 15 patients, respectively. The addition of CT to US improved sensitivity for detecting macroscopic LNM compared to US alone (68.4% [128/187] vs. 26.7% [50/187]; P < 0.001), while maintaining high specificity despite a significant decrease (90.9% [709/780] vs. 97.2% [758/780]; P < 0.001). Discordant nodal staging between US and CT regarding macroscopic LNM was observed in 149 cases (15.2% [149/982]), with 131 patients (87.9% [131/149]) being upstaged by CT. In patients with node-negative US findings, CT detected US-undetected macroscopic LNM in 78 patients (8.7% [78/895]) and exhibited a sensitivity of 56.9% (78/137) and specificity of 93.5% (709/758) for macroscopic LNM.
Conclusion
The integration of CT with US improved sensitivity for detecting macroscopic LNM in patients with PTMC, identifying those who would otherwise be inappropriately considered candidates for active surveillance based solely on US findings. This may assist in refining patient management.
4.Bioavailability of lutein following short-term consumption of raw vegetables and juice
Seung-Hui CHOI ; Kyoung Yun KIM ; Ha-Rin MOON ; Ha-Yun JEONG ; Min-Jung KANG ; Soomin LEE ; Eunju PARK ; Young-Shick HONG ; Jung-Mi YUN
Nutrition Research and Practice 2026;20(2):253-271
BACKGROUND/OBJECTIVES:
Lutein, a dietary carotenoid, plays a crucial role in protecting eye health as an anti-inflammatory agent and antioxidant. Green leafy vegetables constitute a major source of lutein; however, comparative studies on different consumption methods are limited. Therefore, this study aimed to evaluate the bioavailability of lutein from lutein-rich foods, namely, raw vegetables and raw vegetable juice.
SUBJECTS/METHODS:
In this study, 18 adults were recruited. They were randomly divided into three groups: commercial lutein supplement (LUT, 20 mg), raw vegetable (RV), and raw vegetable juice (RVJ) groups. Blood was collected at 0-, 4-, 6-, 8-, 12-, 24-, and 30-h intervals after the consumption of each test meal. Participants’ serum lutein levels were analyzed using high-performance liquid chromatography (HPLC). Considering lutein’s wellestablished anti-inflammatory properties, changes in inflammatory status were assessed by measuring serum high-sensitivity C-reactive protein (hs-CRP) levels. Furthermore, urinary metabolomic profiling was conducted using 1 H nuclear magnetic resonance spectroscopy to evaluate metabolic alterations.
RESULTS:
After consuming each lutein-rich food, participants’ blood lutein levels were analyzed, and the serum concentration peaked at 12 h (0.37 ± 0.13 μg/mL), 24 h (0.61 ± 0.18 μg/mL), and 30 h (0.42 ± 0.16 μg/mL) after RV, LUT, and RVJ consumption, respectively.Additionally, hs-CRP levels decreased following lutein-rich food consumption. Twelve hours after consumption, hs-CRP levels decreased to 0.81 and 0.83 mg/L in the RV and RVJ groups, respectively. Twenty-four hours after consumption, they further decreased to 0.68 and 0.74 mg/L in the LUT and RVJ groups, respectively. Thirty hours after consumption, a reduction to 0.61 mg/L was observed in the RVJ group. Furthermore, after consuming each luteinrich food, N-acetyl glycoprotein levels decreased at 24 h, reflecting metabolic alterations potentially associated with lutein metabolism.
CONCLUSION
These findings suggest that the short-term consumption of lutein-rich foods, regardless of their type or source, potentially yields health benefits.
5.Improving prediction of ypT0–1N0 response in rectal cancer: the added value of gross tumor type to magnetic resonance tumor regression grade after chemoradiotherapy in a retrospective cohort study
Kyong-Min KANG ; Mi-Jeong CHOI ; Hong-min AHN ; Heung-Kwon OH ; Duck-Woo KIM ; Jungheum CHO ; Won CHANG ; Young Hoon KIM ; Kyoung Ho LEE ; Yu Kyung JUN ; Yonghoon CHOI ; Sung-Bum KANG
Annals of Surgical Treatment and Research 2026;110(4):237-245
Purpose:
While MRI-based tumor regression grade (mrTRG) has shown promise in evaluating pathologic response to concurrent chemoradiotherapy (CCRT) in rectal cancer, its ability to predict pathologic complete response remains limited.This study aimed to enhance mrTRG’s diagnostic performance in predicting ypT0–1N0 status, a key factor in considering non-radical management after CCRT for locally advanced rectal cancer (LARC).
Methods:
This retrospective study included 430 patients with LARC who underwent radical resection following CCRT at a single referral hospital between April 2018 and September 2024. Multivariable logistic regression was used to identify predictive factors associated with achieving ypT0–1N0 status. The diagnostic performances of mrTRG1–2 alone and in combination with other factors were assessed by comparing sensitivity, specificity, positive-predictive value (PPV), negative-predictive value, and area under the curve (AUC).
Results:
Ninety-three patients (21.6%) achieved ypT0–1N0. In the multivariable analysis, fungating type, cT1–2, and mrTRG1–2 were independent predictors for ypT0–1N0. Integrating mrTRG with gross tumor type yielded the highest AUC of 0.689 among the combined models. For predicting ypT0–1N0, the combination of mrTRG and gross tumor type improved PPV (79.2% vs. 41.5% for mrTRG alone) while also demonstrating enhanced sensitivity compared with ycT0–1N0, the conventional MRI-based predictor (40.9% vs. 22.6%).
Conclusion
This study demonstrated that combining mrTRG and gross tumor type improved the PPV of mrTRG in predicting ypT0–1N0 after CCRT in LARC. Further studies are warranted to validate the role of gross tumor type in refining predictive systems for selecting candidates for non-radical treatment.
6.FDFT1 Acts as a Negative Regulator of Autophagy by Modulating AMPK–ULK1 Signaling in Hepatocellular Carcinoma Cells
Thi Ha NGUYEN ; Yongook LEE ; Minh Tuan NGUYEN ; Seoung Gyu CHOI ; Phuong Ngan NGUYEN ; Boram KIM ; Eun Ji KIM ; Gyeoung Jin KANG ; Mi Kyung PARK ; Sung Hoon LEE ; Sang Geon KIM ; Chang Hoon LEE
Biomolecules & Therapeutics 2026;34(3):632-640
Autophagy is a conserved catabolic process that degrades proteins and damaged organelles to maintain cellular homeostasis, and its role in cancer depends on stage and context. Farnesyl-diphosphate farnesyltransferase 1 (FDFT1) is an essential enzyme in the sterol branch of the mevalonate pathway, but its functions in hepatocellular carcinoma (HCC) and in the regulation of autophagy remain poorly understood. In this study, we show that FDFT1 acts as a negative regulator of autophagy in HCC cells. Loss of FDFT1 led to increased autophagosome formation and fusion with lysosomes, whereas its overexpression suppressed both basal and induced autophagy. These changes were associated with AMPK–ULK1 signaling, suggesting that FDFT1 influences a central pathway controlling autophagy. Our findings connect cholesterol metabolism with autophagy regulation and tumor growth, highlighting FDFT1 as a potential prognostic marker and therapeutic target in liver cancer.
7.Optimal use and cycling strategies of Janus kinase inhibitors in ulcerative colitis: current evidence and clinical implications from the KASID Guidelines Task Force Team
Seung Min HONG ; Dong Hyun KIM ; June Hwa BAE ; Seung Yong SHIN ; Eun Mi SONG ; Ji Eun KIM ; Young Joo YANG ; Jiyoung YOON ; Sang-Bum KANG ; Eun Soo KIM ; Seong-Eun KIM ; Seong-Jung KIM ; Jun LEE ; Soo-Young NA ; Soo Jung PARK ; Sang Hyoung PARK ; Miyoung CHOI ; Myung Ha KIM ; Won MOON ; Sung-Ae JUNG ;
Intestinal Research 2026;24(1):27-37
Janus kinase (JAK) inhibitors are an important treatment option for ulcerative colitis, providing rapid onset of action, oral administration, and efficacy even after biologic failure. The 3 approved agents—tofacitinib, filgotinib, and upadacitinib—differ in JAK isoform selectivity, leading to clinically meaningful differences in efficacy and safety. Evidence from network meta-analyses, clinical trials, and real-world studies consistently shows that upadacitinib provides the highest efficacy for induction and maintenance of remission, whereas filgotinib demonstrates the most favorable safety profile. The strong efficacy of upadacitinib and tofacitinib is particularly relevant in patients with severe disease, including acute severe ulcerative colitis, and upadacitinib maintains high efficacy regardless of prior advanced therapy exposure. JAK inhibitors also benefit extraintestinal manifestations. Although risks such as herpes zoster, serious infection, thromboembolism, and major cardiovascular events differ among agents, long-term data suggest generally acceptable safety when used appropriately. Intraclass JAK-to-JAK cycling is feasible, with about half of patients achieving steroid-free clinical remission in retrospective cohorts. Based on mechanistic, clinical, and real-world evidence, filgotinib may be a first-line option for patients with lower disease activity or when safety is a priority, whereas upadacitinib or tofacitinib may be preferred in higher disease activity. Strategically selecting agents may improve durability and outcomes.
8.Trends and Sociodemographic Characteristics of Nontuberculous Mycobacterial Infections in South Korea: A Nationwide NHIS-Based Study (2010−2022)
Jeong Mi SEO ; Sungchan KANG ; Taeyoon LIM ; So-mi SHIN ; Jake WHANG ; Jinsoo KO ; Gyeong In LEE
Tuberculosis and Respiratory Diseases 2026;89(2):306-320
Background:
In South Korea, nontuberculous mycobacteria (NTM) is not a notifiable disease, while the absence of a national surveillance system hampers accurate assessment of its incidence. Therefore, this study utilized National Health Insurance Service (NHIS) claims data to investigate nationwide trends in NTM occurrence over the past decade.
Methods:
We used NHIS claims (2010−2022) to assemble a cohort with International Classification of Diseases, 10th Revision A31 (A31.0, A31.1, A31.8, A31.9). For incidence, cases diagnosed in 2010−2011 were excluded. Incidence was estimated under three definitions: ≥2 outpatient visits or ≥1 inpatient admission with A31 during the study period; same as A, but with ≤180 days between visits; meeting B plus ≥1 antibiotic prescription within 180 days (treatment initiation). Age-standardized prevalence and incidence were calculated using the 2010 Korean population.
Results:
A total of 178,287 newly diagnosed NTM cases were identified from 2012 to 2022 (mean age 51.4 years; 66.8 % female). The age-standardized prevalence increased from 15.5 to 69.8 per 100,000 in 2010 to 2022. Incidence peaked in 2017 (38.9/100,000), then declined to 26.9 in 2022. Age-specific incidence of NTM infection showed distinct sex-related patterns. Among men, incidence was consistently concentrated in older adults, particularly those ≥80 years, throughout 2012−2022. In contrast, women experienced a marked epidemiologic shift beginning in 2017, with incidence in their 20s and 30s surpassing older age groups. Medical Aid beneficiaries consistently showed higher incidence rates. By region, Daejeon and Chungnam showed the greatest increase in incidence rates in 2022, compared to 2012.
Conclusion
NTM infection is increasing in Korea, with distinct epidemiologic patterns by sex, age, and socioeconomic status. The rising burden, especially among young women and the socioeconomically disadvantaged, warrants targeted public health strategies.
9.Systemic Gaps in Heart Failure Care and the Need for Specialized Management: A Nationwide Survey of Korean Cardiologists
SungA BAE ; Soo-Yong LEE ; So-Ree KIM ; Minjae YOON ; Kang Un CHOI ; Junho HYUN ; Kyung-Hee KIM ; Suk Min SEO ; Byung-Su YOO ; Seong-Mi PARK ;
International Journal of Heart Failure 2026;8(1):95-100
10.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.

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