Background/Aims: This study investigated the clinical efficacy of low-dose mepolizumab (100 mg) in controlling severe eosinophilic asthma, aiming to induce eosinophilic granulomatosis with polyangiitis (EGPA) remission and reduce systemic steroid usage. Additionally, we constructed a basic frame for our longitudinal EGPA cohort by collecting serial blood samples before, during, and after mepolizumab treatment in EGPA patients. Methods: We conducted a 2-year prospective observational cohort study in patients with uncontrolled severe eosinophilic asthma and refractory EGPA who used systemic steroids (≥ 7.5 mg/day of prednisolone) or other immunosuppressant drugs for at least 6 months. All patients were treated with 100 mg of mepolizumab every 4 weeks for 1 year to control severe eosinophilic asthma and then were followed for an additional 1 year to monitor their disease course. We analyzed total systemic steroid use and EGPA remission/relapse during the study period. Results: Three EGPA patients were included in this study and completed 16 study visits over a 2-year period. After 1 year of treatment with mepolizumab (100 mg monthly), all 3 patients were able to reduce their maintenance dose of systemic steroids, with 2 patients completely discontinuing use. These 2 patients achieved EGPA remission during mepolizumab treatment, and their remission status remained stable for 1 year after they stopped receiving the medication. Conclusions Low-dose mepolizumab treatment demonstrated clinical efficacy in reducing the maintenance dose of systemic steroids required for severe refractory EGPA. While not all patients achieved EGPA remission with low-dose mepolizumab, some did, and their remission persisted even after treatment discontinuation.

Purpose: Autism spectrum disorder (ASD) exhibits heterogeneous developmental trajectories; however, longitudinal studies using the Korean Childhood Autism Rating Scale (K-CARS) are scarce. This study examined diagnostic changes and related developmental characteristics through repeated K-CARS assessments. Methods: We retrospectively reviewed the medical records of children who underwent repeated K-CARS assessments between May 2021 and December 2024 at Gyeongsang National University Hospital. Based on diagnostic status at the initial (T1) and follow-up (T2) evaluations, participants were classified as having persistent ASD (ASD at T1 and T2), emerging ASD (non-ASD at T1 but ASD at T2), or desisting ASD (ASD at T1 but non-ASD at T2). Developmental profiles were evaluated using the social quotient (SQ), visual-motor integration (VMI), and language quotients. Results: Forty-three children (32 boys; median age, 2.9 years at T1 and 4.3 years at T2) were included. Twenty-two met ASD criteria at T1, and 15 (68%) retained the diagnosis at T2. Across the cohort, 15 (35%) had persistent ASD, 21 (49%) had emerging ASD, and seven (16%) had desisting ASD. The desisting group showed higher baseline VMI and better outcomes at follow-up. The emerging group initially had higher SQ and VMI than the persistent group, but these differences disappeared over time. Higher baseline VMI was associated with desisting status and higher baseline SQ with emerging ASD (odds ratios, 3.14 and 2.59 per standard deviation increase, respectively; P=0.06 and P=0.07). Conclusion Early ASD diagnoses were generally stable yet variable, supporting repeated assessment. Baseline VMI and SQ may relate to later diagnostic changes.

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.

Purpose: Early differentiation between transient congenital hypothyroidism (TCH) and permanent congenital hypothyroidism (PCH) is crucial for optimizing the duration of treatment. This retrospective cohort study aimed to evaluate whether levothyroxine (LT4) dose requirements over time can predict TCH and guide earlier discontinuation of treatment. Methods: We retrospectively analyzed 105 infants with congenital hypothyroidism and normal thyroid glands confirmed by imaging at a single tertiary care center (Inha University Hospital) between January 2013 and December 2022. Patients were classified into TCH (n=70) or PCH (n=35) based on thyroid function after LT4 withdrawal at 3 years of age. LT4 dose/kg at 6, 12, and 24 months, along with clinical and biochemical parameters, were compared between the 2 groups. Receiver operating characteristic (ROC) curve analysis was used to assess the predictive performance of LT4 dose thresholds. Results: The LT4 dose was significantly lower in the TCH group at 6 (3.16±0.83 μg/kg vs. 3.75±0.99 μg/kg, P=0.005), 12 (2.51±0.82 μg/kg vs. 3.37±1.17 μg/kg, P<0.001), and 24 months (2.02±0.61 μg/kg vs. 3.09±1.19 μg/kg, P<0.001). ROC curve analysis showed an area under the curve (AUC) of 0.649, 0.746, and 0.794 at 6, 12, and 24 months, respectively. A logistic regression model incorporating LT4 dose, birth weight, and thyroid-stimulating hormone (TSH) levels improved prediction accuracy (AUC: 0.740, 0.782, 0.833 at 6, 12, and 24 months, respectively). Conclusion LT4 dose requirements at 6, 12, and 24 months serve as useful indicators for differentiating TCH from PCH. A combined predictive model incorporating LT4 dose, birth weight, and TSH levels may improve diagnostic accuracy, supporting earlier discontinuation of treatment.

Purpose: Early childhood dietary behaviors vary according to environmental and regional context, and evidence in rural preschool populations remains limited. Considering their persistence into adulthood and their association with health outcomes, understanding the dietary patterns among rural preschool children is important. This study examined the nutritional quotient scores and dietary behaviors according to the weight status among preschool-aged children in rural Korea. Methods: This cross-sectional study analyzed the secondary data from 233 preschool children aged 3–6 years, living in Changnyeong-gun, South Korea. The dietary behaviors were assessed using the Nutrition Quotient for Preschoolers (NQ-P), which comprises balance, moderation, and environmental domains. The anthropometric and body composition measurements were obtained using bioelectrical impedance analysis, and the weight status was defined using the age- and sex-specific body mass index percentiles. Results: The mean total NQ-P scores were comparable between non-obese children and obese children (56.0 and 56.3, respectively), with no significant differences observed in the total or domain-specific scores. The most common NQ-P grade was low among the non-obese children and medium-to-low among children with obesity, with no significant between-group differences in grade distribution. On the other hand, underweight and normal-weight children exhibited lower fruit and legume intake and were more likely to move around during meals. Conclusion The fruit and legume intake patterns and mealtime behaviors differed according to the weight status. These findings highlight the importance of nutrition and health promotion strategies tailored to the weight status and rural environment of preschool children.Nevertheless, further prospective studies will be needed to clarify the longitudinal relationships between regional factors, dietary behaviors, and growth patterns in early childhood.

Sparganosis is a rare parasitic infection caused by Spirometra species. Although it was relatively common in the past, it is now often overlooked. In this study, we review cases diagnosed through histopathological examination at a single institution in recent years to raise awareness of this neglected parasitic disease. Methods: We retrospectively analyzed cases of human sparganosis identified in the pathology archives of a single institution in South Korea between 2004 and 2025. A comprehensive review was conducted, including demographic data, clinical features, lesion locations, imaging findings, exposure history (such as dietary habits), and histopathologic findings. Results: A total of 15 patients were identified, including 10 females and 5 males, with a mean age of 65.1 years. Lesions were most commonly located in the lower extremities and breast. Imaging findings were largely nonspecific, with ultrasonography being the most frequently used modality. In most cases, clinical suspicion of sparganosis was absent, and excision was performed under the impression of a benign or malignant tumor. Histologically, variably degenerated parasitic structures were identified within granulomatous inflammation. However, preserved features such as calcospherules and tegumental structures facilitated definitive diagnosis. Conclusions: This study underscores the importance of recognizing the characteristic histopathological features of sparganosis, which can allow for accurate diagnosis even in the absence of clinical suspicion. Although rare, sparganosis remains a relevant diagnostic consideration in endemic regions, particularly in East Asia.

Background: Despite advancements in laboratory animal facility management, pinworm infections remain a persistent issue in immunodeficient mouse colonies. Rapid diagnosis and treatment are crucial to mitigating potential scientific and economic consequences. Effective control requires both the administration of anthelmintic agents and rigorous environmental decontamination. However, the safety and efficacy of these treatments in genetically modified mouse models remains uncertain.Case presentation Aspiculuris tetraptera infestation was identified in multiple immunodeficient mouse models housed in a laboratory facility. Diagnosis was confirmed through fecal flotation for egg detection and necropsy for adult worm examination in the large intestines. Mice received three subcutaneous ivermectin injections at two-week intervals, coupled with environmental decontamination using ivermectin spray for four consecutive weeks. Following treatment, all colonies tested negative for A. tetraptera without any mortality. Conclusions A combination of subcutaneous ivermectin injection and environmental spray application effectively eradicated A. tetraptera infestation in immunodeficient mouse colonies. The treatment protocol led to the complete elimination of eggs and adult worms, offering a practical strategy for managing pinworm infections in genetically modified mouse models. Limitations include the small sample size, and the lack of a comprehensive evaluation of physiological and metabolic safety in immunodeficient mice. Further validation will be required to confirm the broader applicability of this approach.