1.Two cases of common variable immunodeficiency in adults
Chang-Gyu JUNG ; Ji-Ho LEE ; Jae-Hyuk JANG ; Yoo Seob SHIN ; Hae-Sim PARK
Allergy, Asthma & Respiratory Disease 2026;14(1):38-43
Common variable immunodeficiency (CVID) is a heterogeneous primary immunodeficiency characterized by reduced levels of immunoglobulin (Ig)G, with or without IgA and/or IgM deficiency, and hypogammaglobulinemia. Clinical manifestations are diverse, ranging from recurrent infections to autoimmune and allergic diseases. While CVID has been rarely reported in the Korean population, particularly in adults, we report 2 adult cases of CVID comorbid with asthma and Behcet’s disease. The first case of a 53-year-old with severe allergic asthma and chronic rhinosinusitis experienced recurrent respiratory infections, stomatitis, and cystitis requiring frequent antibiotic treatment. Laboratory findings indicated a T2-high asthma phenotype, with elevated serum total IgE specific IgE to dog hair and fractional exhaled nitric oxide. Immunological evaluation revealed decreased serum IgG (including IgG1 and IgG2), along with hypogammaglobulinemia. She had been treated with regular anti-IgE antibody therapy and intravenous immunoglobulin replacement therapy (IVIGRT). The second case of a 38-year-old with Behçet’s disease and uveitis had bronchial asthma and rhinitis that were exacerbated by recurrent infections despite standard asthma therapy. Laboratory findings revealed a T2-low phenotype and a marked reduction in serum IgG (including IgG1, IgG2, and IgG4), and hypogammaglobulinemia, consistent with CVID.IVIGRT effectively reduced asthma exacerbations and infection episodes in both cases. These cases highlight the clinical heterogeneity of CVID and its potential overlap with allergic and autoimmune diseases. Immunological evaluation of underlying immunodeficiency should be considered in adult patients with asthma who present with frequent exacerbations and recurrent infections. Early diagnosis and IVIGRT can prevent complications and improve outcomes.
2.Clinical Outcomes of Endoscopic Radiofrequency Stretta Therapy for Gastroesophageal Reflux Disease Treatment: A Retrospective Analysis From2 Tertiary Centers in Korea
Hyun LIM ; Yuri KIM ; Jin Hee NOH ; Jung In LEE ; Eun Jeong GONG ; Boram CHA ; Chan Hyuk PARK ; Da Hyun JUNG ; Ju Yup LEE ; Sun Hyung KANG ; In Kyung YOO ; Joo Young CHO ; Do Hoon KIM ;
Journal of Neurogastroenterology and Motility 2026;32(2):290-297
Background/Aims:
Endoscopic anti-reflux therapy is a therapeutic option for gastroesophageal reflux disease (GERD), providing durable effects. However, clinical data from Korea remain limited. This study evaluates the clinical outcomes of endoscopic radiofrequency Stretta therapy in Korean patients.
Methods:
A retrospective analysis was conducted on 71 patients with GERD who underwent Stretta therapy at 2 tertiary hospitals in Korea between November 2015 and July 2021. Clinical outcomes, including patient satisfaction, medication cessation or reduction, and complications, were evaluated. Pre- and post-procedural esophageal manometry and 24-hour pH monitoring test results were also analyzed.
Results:
Patient satisfaction rates at 1, 6, and 12 months post-procedure were 54.7% (35/64), 70.0% (28/40), and 75.0% (21/28), respectively. Medication cessation or reduction was achieved in 31.2% (20/64) at 1 month, 70.0% (28/40) at 6 months, and 67.9% (19/28) at 12 months. Esophageal manometry (n = 21) showed no significant changes in mean lower esophageal sphincter pressure (18.7 mmHg [2.5-52.9] vs 17.4 mmHg [0.0-43.0], P = 0.702) or mean integrated relaxation pressure (8.2 mmHg [0.0-28.0] vs 10.1 mmHg [0.0-31.0], P = 0.840). The 24-hour pH monitoring (n = 18) demonstrated a nonsignificant decrease in acid exposure time (pH < 4) from 2.3% (0.0-8.4) to 1.6% (0.0-7.3) (P = 0.182). Similarly, the DeMeester score decreased non-significantly from 8.4 (0.8-27.7) to 6.6 (0.8-21.8) (P = 0.352). No procedure-related complications occurred.
Conclusion
Endoscopic radiofrequency Stretta therapy appears to be a safe treatment option for GERD and may provide favorable patient satisfaction and medication reduction.
3.How to Identify Type 2 Chronic Rhinosinusitis in East Asian Patients
Shin Hyuk YOO ; Ki-Il LEE ; Gwanghui RYU ; Jun-Sang BAE ; Ji-Hun MO
Journal of Rhinology 2026;33(1):21-28
Chronic rhinosinusitis (CRS) is increasingly recognized as a heterogeneous disease with distinct inflammatory endotypes, among which eosinophilic CRS (ECRS)—a category that substantially overlaps with, but is not equivalent to, Type 2 CRS—is associated with severe symptoms, frequent recurrence, and comorbid asthma. Accurate identification of Type 2 CRS has become clinically essential with the emergence of biologic therapies that target Type 2 inflammatory pathways. However, most diagnostic criteria, including those proposed by European Position Paper on Rhinosinusitis and Nasal Polyps 2020 (EPOS 2020), were developed from Western populations, in which ECRS with nasal polyps predominates. This review critically examines the applicability of these criteria in Asian populations, in which non-eosinophilic and mixed inflammatory endotypes remain prevalent. Evidence from Korean and Japanese cohorts indicates that the EPOS 2020 Type 2 criteria have poor specificity in Asian patients with CRS with nasal polyps, classifying nearly all such patients as Type 2 because of differences in baseline biomarker distributions. We discuss histological thresholds for defining ECRS and highlight that Asian studies support higher tissue eosinophil cut-offs, approximately 70 eosinophils per high-power field (HPF) or around 10% of total inflammatory cells, compared with the 10 eosinophils per HPF recommended by Western guidelines. This review also evaluates outpatient- friendly scoring systems, such as Japanese Epidemiological Survey of Refractory Eosinophilic Chronic Rhinosinusitis (JESREC) and newly proposed Korean diagnostic criteria, as well as emerging machine-learning approaches for noninvasive prediction of ECRS. We conclude that clinicians in Asia should adopt regionally validated criteria that integrate histological, serological, and clinical parameters to accurately identify Type 2 CRS, optimize selection of biologic candidates, and improve prognostic counseling in this population.
4.Successful Treatment of Gastrointestinal Polyposis-Related Iron Deficiency Anemia and Hypoalbuminemia with Sirolimus in Bannayan–Riley–Ruvalcaba Syndrome
Sumin YOO ; Ho Jung CHOI ; In Hyuk YOO
Clinical Pediatric Hematology-Oncology 2026;33(1):51-56
Refractory iron deficiency anemia (IDA) in children should be investigated beyond dietary deficiency, particularly when accompanied by growth faltering or hypoalbuminemia. PTEN hamartoma tumor syndrome, which includes the Bannayan–Riley– Ruvalcaba syndrome (BRRS) spectrum, may cause diffuse gastrointestinal polyposis, resulting in chronic occult blood and protein loss. We report the case of a girl born in 2015 who presented at the age of two years with severe IDA (hemoglobin 5.0 g/dL, mean corpuscular volume 53.6 fL). Oral iron therapy was initiated, followed by intermittent intravenous iron infusions at progressively shorter intervals; however, the anemia recurred. Stool occult blood and fecal calprotectin test results were consistently negative during this period. Endoscopy and capsule endoscopy revealed diffuse gastrointestinal polyposis, including numerous small bowel polyps with ulcerative features. Genetic analysis revealed a heterozygous pathogenic variant in PTEN, NM_000314.8:c.389G>A (p.Arg130Gln). Despite endoscopic polypectomy and oral nutritional supplementation, IDA, hypoalbuminemia (albumin, 2.5-3.2 g/dL), and growth faltering persisted. Extraintestinal findings included macrocephaly, lipomatous masses, a subcutaneous hamartoma, and brain magnetic resonance imaging findings consistent with BRRS. Sirolimus therapy was initiated in September 2025, targeting a trough level of 6-10 ng/mL. By 6 months, hemoglobin stabilized at 12.9 g/dL, albumin normalized to 4.4 g/dL, weight increased by 5.1 kg, body mass index improved from below the 3rd percentile to the 10th percentile, and intravenous iron was no longer required. This case suggests that sirolimus may be beneficial in the treatment of diffuse PTEN-related gastrointestinal polyposis when endoscopic management is insufficient.
5.Coffee and the Risk of Hepatocellular Carcinoma: A Systematic Review and Meta-Analysis of Mendelian Randomization Studies
Hyun Bin CHOI ; Hyuk KIM ; Jeong-Ju YOO ; Sang Gyune KIM ; Young-Seok KIM
Gut and Liver 2026;20(1):153-157
This systematic review and meta-analysis examined the potential causal link between coffee consumption and hepatocellular carcinoma (HCC) risk via Mendelian randomization (MR) studies.Five eligible MR studies that involved the use of analytical approaches such as inverse variance weighted (IVW), MR-Egger, and weighted median methods were included. While previous observational studies suggested a protective role of coffee, the MR-based analyses in this study did not demonstrate a statistically significant association across all methods. IVW analysis yielded an odds ratio of 0.92 (95% confidence interval, 0.58 to 1.47), indicating no significant effect. Moderate to substantial heterogeneity was observed, but no publication bias was detected. These findings suggest that the previously reported inverse association may have been overestimated due to methodological limitations in observational research. Our results emphasize the importance of using genetically informed methods to infer causality, and the results indicate that coffee consumption may not causally reduce the risk of HCC.
6.Implant-assisted removable partial denture restoration in a patient with mandibular single tooth: a case report
Yoo-Cheung CHOI ; Ji-Won BANG ; Sung-Yong KIM ; Hee-Won JANG ; Yong-Sang LEE ; Keun-Woo LEE ; Joo-Hyuk BANG
The Journal of Korean Academy of Prosthodontics 2026;64(1):104-112
With a solitary remaining tooth in the mandible, restoration with a conventional removable partial denture is often associated with insufficient retention, support, and stability, as well as excessive stress concentration on the remaining tooth, leading to an unfavorable prognosis. Recently, treatment plans involving the placement of a small number of strategically positioned implants to fabricate removable partial dentures have been adopted to overcome these limitations.The use of implant surveyed crowns is considered to offer superior long-term outcomes compared with implant attachments. This report describes the restoration of a partially edentulous mandible with a single remaining tooth using an implant-assisted removable partial denture assisted by a surveyed fixed partial denture following bilateral posterior implant placement, achieving favorable clinical results.
7.Development of Korean Standardized Heart Failure Registry: Experience From Integration of KorAHF and KorHF III
Eui-Soon KIM ; Huijin LEE ; Jong-Chan YOUN ; Byung-Su YOO ; Hae-Young LEE ; Ju-Hee LEE ; Dong-Hyuk CHO ; Mi-Hyang JUNG ; Hye Sun LEE ; Hyun-Jai CHO
International Journal of Heart Failure 2026;8(1):1-11
Heart failure (HF) prevalence and associated socio-economic costs have risen rapidly in Korea, creating urgent demand for a national, standardized prospective registry to support quality monitoring, outcome comparison, and real-world evidence. Standardized data definitions are essential for valid comparisons across studies and healthcare settings. We created a unified national HF cohort by integrating the two largest Korean registries, KorAHF (2011–2014;n=5,625) and KorHF III (2018–2023; n=7,351), yielding 12,976 hospitalized HF patients. Because heterogeneous variable definitions impeded direct comparisons, we implemented a harmonization pipeline across demographic, clinical, imaging, biomarker, therapeutic, and outcome domains, aligned with international standards and reinforced by systematic data quality checks.A multidisciplinary panel then conducted a structured decision process to produce the Korean HF Standard Dataset, a tiered and interoperable variable set spanning six domains: demographics, presentation at admission, in-hospital events and comorbidities, discharge status, outpatient follow-up, and readmission events. This integrated platform and standardized variables enable precise identification of HF patient phenotypes and prognostic factors, establishing an evidence-based foundation for disease management. This supports an analysis of temporal changes in treatment patterns and outcomes, generates data to inform future clinical practice guidelines, and provides a practical basis for planning large, continuous, prospective HF registries. Furthermore, it also facilitates pragmatic, registry-based randomized clinical trials and unmet-needs assessments that can guide national health policy. Establishing a foundation for future linkage with national health databases, this platform will allow for enhanced accuracy, comparability, and representativeness, powering quality improvement initiatives and population-level monitoring of Korea’s growing HF burden.
8.Korean Thyroid Association Guidelines on the Management of Differentiated Thyroid Cancers; Part II. Follow-up Surveillance after Initial Treatment 2026
Eun Kyung LEE ; Seung Heon KANG ; Bon Seok KOO ; Mijin KIM ; Min Joo KIM ; Bo Hyun KIM ; Ji Won KIM ; Dong Gyu NA ; Sohyun PARK ; Ji-In BANG ; Kyorim BACK ; Youngduk SEO ; Young-Ik SON ; Young Shin SONG ; Dong Yeob SHIN ; Jong-Hyuk AHN ; Hwa Young AHN ; So Won OH ; Ho-Ryun WON ; Won Sang YOO ; Min Kyoung LEE ; Sang-Woo LEE ; Jeongmin LEE ; Ji Ye LEE ; Dong-Jun LIM ; Ki-Wook CHUNG ; Ari CHONG ; Jin Hyang JUNG ; Sun Wook CHO ; Yoon Young CHO ; Chae Moon HONG ; Young Joo PARK ;
International Journal of Thyroidology 2026;19(1):1-40
In patients with differentiated thyroid cancer (DTC), initial recurrence risk stratification based on clinical, histopathological, and perioperative data remains the key determinant for guiding management strategies during the first 1-2 years post-treatment. However, the adoption of ongoing risk stratification (ORS), which dynamically reassesses risk by integrating longitudinal clinical data and treatment response, enables more precise long-term prognostic assessment and facilitates highly individualized management. Building upon recent guidelines, the 2026 KTA guideline has been further refined by incorporating robust evidence from large-scale national cohorts and comprehensive systematic reviews. These updated recommendations outline contemporary concepts of ORS, risk-adapted TSH suppression targets, optimized surveillance modalities for recurrence detection, and disease-specific long-term follow-up strategies. Reflecting the paradigm shift toward de-escalated treatment, this revision integrates evolved perspectives on TSH suppression intensity, the clinical interpretation of thyroglobulin levels, and tailored follow-up intervals. These evidence-based recommendations aim to minimize unnecessary treatment and excessive surveillance in the large proportion of patients with excellent prognosis after initial therapy, while ensuring that each patient receives appropriately tailored and effective long-term management.
9.The Prevalence of BRAF Mutation in Papillary Thyroid Carcinoma Decreases Significantly with Increasing Tumor Size
Da Eun LEEM ; Hyunju PARK ; Ji Hyun YOO ; Bo Ram KIM ; Young Lyun OH ; Tae Hyuk KIM ; Sun Wook KIM ; Jae Hoon CHUNG
International Journal of Thyroidology 2026;19(1):95-103
Background and Objectives:
Studies investigating the correlation between papillary thyroid carcinoma (PTC) tumor size and the prevalence of the B-type Raf kinase (BRAF) mutation have yielded conflicting results. Therefore, we evaluated the prevalence of BRAF mutation according to tumor size in a large cohort of PTC patients to clarify this association.
Materials and Methods:
We retrospectively analyzed 6,438 patients with surgically diagnosed classic PTC between January 2009 and December 2017 at Samsung Medical Center, Seoul, Republic of Korea.During the study period, BRAF mutation testing was attempted on all fine-needle aspiration specimens, except for a small number of inadequate specimens. All other histologic subtypes were excluded. The prevalence of BRAF mutation was assessed based on tumor size, and further analyzed by age group and sex according to tumor size.
Results:
The overall prevalence of BRAF mutation was 79.2%. When PTCs ≤1 cm were excluded, the prevalence was 77.2%. The prevalence significantly decreased with increasing tumor size (p for trend <0.001). It was significantly higher in men than in women (p=0.013), but did not differ by age. The inverse correlation between tumor size and prevalence was prominent in patients aged 20-49 years but was less distinct in those aged 50 years and older.
Conclusion
In this large cohort of patients with PTC, the prevalence of BRAF mutation significantly decreased with increasing tumor size. These findings suggest that BRAF mutation is enriched in smaller surgically treated classic PTCs and may provide a hypothesis-generating clue regarding its role in early PTC development, although selection bias cannot be excluded.
10.Clinical Characteristics of Pediatric Chronic Rhinosinusitis: A Nationwide Retrospective Multicenter Study
Donghyeok KIM ; Gwanghui RYU ; Sang Duk HONG ; Shin Hyuk YOO ; Sue Jean MUN ; Eun Jung LEE ; Sung-Jae HEO ; Jin Hyeok JEONG ; Dae Woo KIM ; Hyung-Ju CHO ; Min-Seok RHA ; Yong Min KIM ; Ki-Il LEE ; Ji-Hun MO ;
Journal of Rhinology 2025;32(1):28-35
Background and Objectives:
Pediatric chronic rhinosinusitis (CRS) significantly affects children’s quality of life and learning abilities. This study aimed to evaluate the postoperative outcomes in pediatric patients who underwent functional endoscopic sinus surgery (FESS) for CRS.
Methods:
A retrospective review was conducted on pediatric patients who underwent FESS for CRS at 11 university hospitals. The inclusion criteria were patients under 20 years old with bilateral disease who were operated on between January 2005 and December 2021. The data collected included demographics, clinical history, blood tests, preoperative computed tomography, and preoperative and postoperative symptom control. The Kruskal-Wallis and Fisher exact tests were used to compare the quantitative and qualitative data, respectively.
Results:
In total, 213 patients were enrolled. The mean age was 13.4±3.0 years, and 145 (68.1%) were male. One hundred sixty-four patients (77.0%) had nasal polyps and 33 patients (15.5%) underwent revision FESS. The preoperative symptoms, in order of prevalence, included nasal obstruction (87.8%), rhinorrhea (71.8%), a sense of postnasal drip (58.2%), hyposmia (44.6%), cough (24.4%), and facial fullness (18.3%). These symptoms were significantly alleviated for up to 3 years after surgery (p<0.001). At the time of the last follow-up, 121 patients (56.8%) were controlled, 80 (37.6%) were partly controlled, and 12 (5.6%) were uncontrolled. Patients in the uncontrolled group had higher Lund-Mackay scores, longer follow-up durations, and more instances of revision surgery compared to those in the controlled and partly controlled groups. When age was categorized into three groups, those aged 16 years or older tended to have lower Lund-Mackay scores and better control.
Conclusion
FESS significantly improves both the postoperative symptoms and the long-term quality of life in pediatric CRS patients. Better symptom control is associated with older age and a lower disease burden.

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