Jae Sung Ko

Background: Intestinal failure (IF) is a rare condition in which the intestine cannot maintain adequate nutrient absorption to support maintenance and/or growth. Data on pediatric home parenteral nutrition (HPN) in Korea are limited. We investigated the clinical characteristics of children with IF receiving HPN. Methods: A nationwide multicenter retrospective study was conducted across 10 tertiary hospitals in Korea from April 2023 to June 2024. Patients who were receiving HPN and had initiated parenteral nutrition (PN) in a hospital at ≤18 years of age were included. Clinical characteristics, including catheter‐related bloodstream infection (CRBSI), intestinal failure‐associated liver disease (IFALD), micronutrient status, and anthropometric Z ‐scores, were analyzed at enrollment and compared with values at HPN initiation. Results: A total of 51 patients (median age: 8.4 years) were enrolled. The most common etiologies were chronic intestinal pseudo‐obstruction (CIPO, 51%) and short bowel syndrome (39%). The median ages at initiation of PN and HPN were 0.8 and 2.5 years, respectively, and the median duration of PN at study enrollment was 7.7 years. Vitamin D deficiency was the most frequent micronutrient deficiency. From PN initiation to enrollment, 70.6% experienced at least one CRBSI episode (1.57/1000 catheter days), 17.6% had catheter thrombosis, and 41.2% had IFALD. Growth outcomes demonstrated persistent growth failure. A PN dependency ratio ≥75% was observed in 52.9% of patients at enrollment, indicating limited enteral autonomy. Conclusion: This first nationwide Korean cohort study of pediatric IF reveals CIPO as the leading cause. Despite long‐term HPN, patients exhibited high PN dependency and persistent growth failure.

Dong-Uk Kim, Jin Soo Moon, Yeoun Joo Lee, Yon Ho Choe, Hyeji Lim, Minsoo Shin, Soon Chul Kim, Hye Ran Yang, Eell Ryoo, Yoo Min Lee, Ji-Sook Park, Ki Soo Kang, Tae Hyeong Kim, Seak Hee Oh, Ben Kang, So Yoon Choi, Yoon Lee, Ju Young Chang, Jae Sung Ko, Jung Ok Shim. Gut and Liver 2026;20:814-23. https://doi.org/10.5009/gnl250605

Abnormal liver function tests (LFTs) are frequently performed in Emergency Departments (EDs); however, the systematic characterization of age-dependent clinical phenotypes and pathogen associations remains limited. Here we aimed to identify the distinct clinical presentations and pathogen-specific associations of pediatric and adult ED visits for abnormal LFTs. This retrospective cohort study analyzed 26,874 ED visits for abnormal LFTs in South Korea's National Emergency Department Information System (2019- 2023). Patients were stratified into pediatric (0-18 years) and adult (19-64 years) groups. We characterized the clinical presentations, concurrent diagnoses, temporal correlations with infectious pathogens, and metabolic comorbidity patterns. The ED visits included 3,152 pediatric (11.7%) and 23,722 adult patients (88.3%). Pediatric presentations demonstrated fever-predominant profiles (47.3%), respiratory symptoms (6.4%), and infectious disease diagnoses (39.8%) as well as temporal correlations with respiratory viruses (rhinovirus, r=0.30; adenovirus, r=0.28; P<0.001). Adult presentations revealed previously unreported population- level temporal associations with enteric pathogens, including astrovirus (r=0.35), sapovirus (r=0.32), enteropathogenic Escherichia coli (r=0.38), and enterotoxigenic Escherichia coli (r=0.36, all P<0.001) coupled with infectious gastroenteritis (20.9%) and upper gastrointestinal disorders, including gastritis (18.3%). Adults demonstrated clustering of the following metabolic comorbidities: dyslipidemia (7.9%), hypertension (7.8%), and diabetes (6.0%). During the coronavirus disease 2019 pandemic, pediatric visits remained stable, whereas adult visits increased following the implementation of social distancing measures (rate ratio, 0.82; P=0.004). The ED presentation of abnormal LFTs results demonstrated distinct age-dependent phenotypes with divergent temporal pathogen associations. Pediatric cases reflected acute respiratory viral infections, whereas adult presentations showed novel population-level enteric pathogen associations with upper gastrointestinal disorders and clusters of metabolic comorbidities. These findings provide evidence supporting age-stratified diagnostic approaches for EDs.

Alagille syndrome (ALGS) is a rare multisystem disorder most commonly resulting from pathogenic variants in JAG1 and, less frequently, NOTCH2. We evaluated long-term native liver survival (NLS) and overall survival (OS) in a Korean ALGS cohort and compared the genetic characteristics of this cohort with those of the Global ALagille Alliance (GALA) study cohort. We retrospectively reviewed 60 patients with clinically diagnosed ALGS at Seoul National University Hospital. Forty-three patients with genetically confirmed disease were analyzed. Eight patients (18.6%) underwent liver transplantation (median age: 3.9 years), revealing a lower rate than that in the comparator cohort. The estimated NLS percentages at 5, 10, and 18 years were 86.9%, 86.9%, and 76.6%, respectively, exceeding those in previous reports. The corresponding OS rates were 90.2%, 86.9%, and 86.9%, respectively. The following types of JAG1 variants were identified in 41 patients (95.3%): frameshift (34.1%), nonsense (26.8%), missense (24.4%), and splice-site (9.8%) variants and in-frame deletions (4.9%). Compared with the reference group, our cohort exhibited a greater frequency of non-protein-truncating variants (missense variants and in-frame deletions; p = 0.023) and no structural variants (p = 0.043). Two patients (4.7%) carried NOTCH2 nonsense variants. Mortality was significantly higher among patients with frameshift variants compared with patients with non-frameshift variants (4 of 5 deaths; p = 0.035). Conclusion: Compared with the GALA cohort, Korean patients with ALGS exhibited more favorable long-term NLS and a higher proportion of non-protein-truncating JAG1 variants, alongside the absence of structural variants. These findings suggest potential genetic influences and highlight the need for multicenter validation. What is Known: • The Global ALagille Alliance (GALA) study reports native liver survival (NLS) rates of 66.8%, 54.4%, and 40.3% at 5, 10, and 18 years, respectively, in patients with Alagille syndrome. • NLS rates are higher among Asians, with unclear genotype–phenotype correlations. What is New: • Compared to the GALA study cohort, the Korean cohort demonstrates superior NLS rates of 86.9%, 86.9%, and 76.6% at 5, 10, and 18 years and a higher frequency of non-truncating JAG1 variants, along with the absence of structural variants. • Protein-truncating variants are associated with higher initial gamma-glutamyl transferase levels, while frameshift variants are associated with reduced overall survival. Graphical Abstract

Background: Lifestyle modifications are fundamental in managing metabolic dysfunction-associated steatotic liver disease (MASLD). This study aimed to evaluate the effects of a 12-week lifestyle intervention on hepatic steatosis, liver function, and gut microbiota composition in pediatric MASLD patients, and to explore clinical and baseline microbial features associated with treatment response. Results: A total of 40 patients were recruited, and 31 were included after applying exclusion criteria. After 12 weeks, significant reductions were observed in body weight, waist circumference, liver enzymes, and triglycerides. MRI-measured hepatic steatosis decreased from 27.1% to 20.8% ( p < 0.05). Greater reductions in hepatic fat were associated with higher daily step counts and a higher proportion of dietary protein intake. Baseline gut microbial composition differed between clinical responder groups. Clostridium sensu stricto 1 was enriched in participants with significant weight loss, Faecalibacterium in those with ALT or GGT improvement, and Lachnospiraceae_ND3007_group in those with MRI-PDFF reduction, with baseline microbial profiles discriminating responders with AUC ≥ 0.75. Conclusions: A 12-week lifestyle intervention led to significant improvements in hepatic steatosis, metabolic parameters, and anthropometric measures in pediatric MASLD. Baseline gut microbial profiles differed between individuals with metabolic improvements, suggesting a potential association between pre-intervention microbiome composition and treatment response. Trial registration: The Clinical Research Information Service of the Korea Center for Disease Control and Prevention, Number: KCT0010340.

Ahn JE, et al. J Korean Med Sci. 2026 Apr;41(13):e108. https://doi.org/10.3346/jkms.2026.41.e108

Growth charts are important tools used to evaluate the growth status of children and estimate the nutritional and health status of the general population. In Korea, the national standardized growth charts were updated in 2017. However, the growth charts developed by the World Health Organization (WHO) are being adopted for children under 3 years of age despite a lack of evidence for their applicability to Koreans. Here we aimed to collect accurate physical measurement data, develop growth charts for infants and toddlers under 3 years of age based on breastfeeding, and evaluate the feasibility of adopting WHO growth standards as a reference in Korea. Beginning April 2020, 6 general and local hospitals were selected nationwide. Mothers and newborns without growth restriction-related factors were enrolled at birth, and they were followed up monthly until 12 months and every 3 months until 36 months. Data were collected on physical measurements; eating habits; childhood morbidity; perinatal factors; and socioeconomic, demographic, and environmental characteristics. All participating hospitals used the same standard equipment. The Korea Infant Physical Growth Examination Survey evaluated the suitability of the WHO growth charts and contributed to the next revision of the Korean growth charts. The results of this study provide a basis for developing health-related strategies for treating children in South Korea.

The aim of this study was to elucidate the genetic variants associated with progressive familial intrahepatic cholestasis (PFIC), a rare class of disorders driven by pathogenic monogenic variants in bile acid transporters. Furthermore, the long-term clinical outcomes of PFIC patients were evaluated. A retrospective cohort study was conducted at Seoul National University Hospital and included pediatric patients diagnosed with PFIC and confirmed by genetic testing between January 2000 and October 2024. Genetic testing, encompassing either single-gene testing or a neonatal cholestasis 34-gene panel, was performed for all patients. Six patients were identified, including five with PFIC2, classified as bile salt export pump deficiency, and one with PFIC3, classified as multidrug resistance protein 3 deficiency. The median age of symptom onset was 3 months. The genetic analyses revealed no widely known variants associated with PFIC. However, a novel frameshift variant (c.589dup, p.(Glu197GlyfsTer8)) was detected in the ABCB11 gene. Additionally, a missense variant (c.3812T>A, p.(Ile1271Asn)) was commonly identified in the same gene. All patients ultimately underwent liver transplantation; two patients who developed hepatocellular carcinoma (HCC) were diagnosed at a median age of 1.6 years. Notably, all patients survived without recurrence after transplantation, with a median follow-up duration of 12.0 years. This study is the first documented case of PFIC3 in a Korean child. Genotype is not associated with the risk of developing HCC. Given the early diagnosis of HCC observed in some patients, routine surveillance for HCC is strongly recommended in all patients with PFIC2.

Objective: Hepatopulmonary syndrome (HPS) is a rare complication of metabolic associated fatty liver disease (MAFLD) occurring subsequent to hypopituitarism, often developing after resection of hypothalamic or pituitary tumors. The aim of this study is to report an illustrative case of an HPS patient who was successfully treated with growth hormone replacement therapy, without liver transplantation which is conventionally regarded as the only treatment option. Additionally, we conducted a comprehensive review of published case reports of HPS in the pediatric population.Methods: We systematically searched literature databases to identify case reports and case series of HPS associated with hypopituitarism diagnosed in childhood. The search included MEDLINE/PubMed, Scopus, Embase, and Google Scholar from 1990 to 2023. The review process adhered to the PRISMA checklist for comprehensive reporting and methodological transparency.Results: An 18-year-old female, who had been followed up for MAFLD after craniopharyngioma resection, presented with cyanosis and progressive dyspnea. She was diagnosed with severe degree of HPS. The patient began treatment with recombinant human growth hormone, leading to a significant improvement in respiratory symptoms within 3 months, and normalization of lung shunt ratio after 6 months of therapy. In our systematic review, nine patients from nine studies across six countries were identified. The median age at diagnosis of hypopituitarism was 10.5 years (range 1–16 years), and HPS was diagnosed at a median interval of 7 years later (range 0–26 years). Half of the patients had not received growth hormone therapy after being diagnosed with hypopituitarism, which subsequently led to the diagnosis of HPS. Three patients underwent liver transplantation, but non-alcoholic steatohepatitis recurred in all cases. Six patients were successfully treated with growth hormone replacement therapy without undergoing liver transplantation.Conclusions: HPS can occur in pediatric patients with MAFLD who have undergone resection of the tumor in the hypothalamus or pituitary gland. Our findings suggest that growth hormone replacement therapy can be a possible alternative to liver transplantation for HPS patients. However, further investigations need to be performed to validate the efficacy of growth hormone treatment in different causes of HPS cases.