Background: Immunocompromised (IC) pediatric patients are at increased risk of severe acute respiratory syndrome coronavirus 2 infection, but the viral kinetics and seroimmunologic response in pediatric IC patients are not fully understood. Methods: From April to June 2022, a prospective cohort study was conducted. IC pediatric patients hospitalized for coronavirus disease 2019 (COVID-19) were enrolled. Serial saliva swab and serum specimens were subjected to reverse transcription polymerase chain reaction assays with mutation sequencing, viral culture, anti-spike-protein, anti-nucleocapsid antibody assays, plaque reduction neutralization test (PRNT) and multiplex cytokine assays. Results: Eleven IC children were evaluated. Their COVID-19 symptoms resolved promptly (median, 2.5 days; interquartile range, 2.0–4.3). Saliva swab specimens contained lower viral loads than nasopharyngeal swabs (P = 0.008). All cases were BA.2 infection, and 45.5% tested negative within 14 days by saliva swab from symptom onset. Eight (72.7%) showed a time-dependent increase in BA.2 PRNT titers, followed by rapid waning. Multiplex cytokine assays revealed that monocyte/macrophage activation and Th 1 responses were comparable to those of non-IC adults. Activation of interleukin (IL)-1Ra and IL-6 was brief, and IL-17A was suppressed. Activated interferon (IFN)-γ and IL-18/IL-1F4 signals were observed. Conclusion IC pediatric patients rapidly recovered from COVID-19 with low viral loads.Antibody response was limited, but cytokine analysis suggested an enhanced IFN-γ- and IL-18-mediated immune response without excessive activation of inflammatory cascades. To validate our observation, immune cell-based functional studies need to be conducted among IC and non-IC children.

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.

Chronic rhinosinusitis with nasal polyps (CRSwNP) is a prevalent condition that significantly impacts quality of life and places a burden on healthcare systems. The advent of biologics targeting type 2 immune pathways offers new therapeutic options for severe and/or uncontrolled CRSwNP. Initially, biologic use was guided by the European Position Paper on Rhinosinusitis and Nasal Polyps (EPOS) 2020 and the European Forum for Research and Education in Allergy and Airway Diseases (EUFOREA) guidelines, despite limited data on clinical indications, response measures, and treatment duration. Since then, numerous studies and the EPOS/EUFOREA 2023 update have refined these guidelines. The update defines clinical indications for biologics based on type 2 inflammation markers by lowering the blood eosinophil threshold from 250 to 150 cells/μL. The response to biologics is now more simply categorized into three levels based on reductions in nasal polyp size, improvements in quality of life, and enhancement of smell. Treatment evaluation is recommended at 6 months with annual follow-up. Longer administration intervals, such as every four weeks, have also proven effective in well-controlled patients. Although specific guidelines for discontinuation or switching biologics remain lacking, clinical judgment is essential in determining when treatment should be stopped or adjusted. Additionally, regulatory updates support the use of biologics for CRSwNP, and novel agents such as tezepelumab (an anti-thymic stromal lymphopoietin monoclonal antibody) continue to show promise. Finally, in Korea, biologics for CRSwNP are not covered by national health insurance, leading to extended dosing intervals due to high costs. Despite this limitation, studies have shown that adjusted dosing can maintain subjective quality of life. Recent studies by Korean authors have also explored practical considerations such as dosing intervals and comparisons to surgery. Further research is needed to optimize treatment strategies, particularly regarding cost-effectiveness and prospective studies tailored to the Korean healthcare system.

Purpose: Hematopoietic stem cell transplantation (HSCT) has been an important method of treatment in the advance of pediatric acute lymphoblastic leukemia (ALL). The indications for HSCT are evolving and require updated establishment. In this study, we aimed to investigate the efficacy of HSCT on the treatment outcome of pediatric ALL, considering the indications for HSCT and subgroups. Materials and Methods: A retrospective analysis was conducted on ALL patients diagnosed and treated at a single center. Risk groups were categorized based on age at diagnosis, initial white blood cell count, disease lineage (B/T), and cytogenetic study results. Data on the patients’ disease status at HSCT and indications of HSCT were collected. Indications for HSCT were categorized as upfront HSCT at 1st complete remission, relapse, and refractory disease. Results: Among the 549 screened patients, a total of 418 patients were included in the study; B-cell ALL (n=379) and T-cell ALL (T-ALL) (n=39). HSCT was conducted on a total of 106 patients (25.4%), with a higher frequency as upfront HSCT in higher-risk groups and specific cytogenetics. The overall survival (OS) was significantly better when done upfront than in relapsed or refractory state in T-ALL patients (p=0.002). The KMT2A-rearranged ALL patients showed superior event-free survival (p=0.002) and OS (p=0.022) when HSCT was done as upfront treatment. Conclusion HSCT had a substantial positive effect in a specific subset of pediatric ALL. In particular, frontline HSCT for T-ALL and KMT2A-rearranged ALL offered a better prognosis than when HSCT was conducted in a relapsed or refractory setting.

Background: Immunocompromised (IC) pediatric patients are at increased risk of severe acute respiratory syndrome coronavirus 2 infection, but the viral kinetics and seroimmunologic response in pediatric IC patients are not fully understood. Methods: From April to June 2022, a prospective cohort study was conducted. IC pediatric patients hospitalized for coronavirus disease 2019 (COVID-19) were enrolled. Serial saliva swab and serum specimens were subjected to reverse transcription polymerase chain reaction assays with mutation sequencing, viral culture, anti-spike-protein, anti-nucleocapsid antibody assays, plaque reduction neutralization test (PRNT) and multiplex cytokine assays. Results: Eleven IC children were evaluated. Their COVID-19 symptoms resolved promptly (median, 2.5 days; interquartile range, 2.0–4.3). Saliva swab specimens contained lower viral loads than nasopharyngeal swabs (P = 0.008). All cases were BA.2 infection, and 45.5% tested negative within 14 days by saliva swab from symptom onset. Eight (72.7%) showed a time-dependent increase in BA.2 PRNT titers, followed by rapid waning. Multiplex cytokine assays revealed that monocyte/macrophage activation and Th 1 responses were comparable to those of non-IC adults. Activation of interleukin (IL)-1Ra and IL-6 was brief, and IL-17A was suppressed. Activated interferon (IFN)-γ and IL-18/IL-1F4 signals were observed. Conclusion IC pediatric patients rapidly recovered from COVID-19 with low viral loads.Antibody response was limited, but cytokine analysis suggested an enhanced IFN-γ- and IL-18-mediated immune response without excessive activation of inflammatory cascades. To validate our observation, immune cell-based functional studies need to be conducted among IC and non-IC children.

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.

Chronic rhinosinusitis with nasal polyps (CRSwNP) is a prevalent condition that significantly impacts quality of life and places a burden on healthcare systems. The advent of biologics targeting type 2 immune pathways offers new therapeutic options for severe and/or uncontrolled CRSwNP. Initially, biologic use was guided by the European Position Paper on Rhinosinusitis and Nasal Polyps (EPOS) 2020 and the European Forum for Research and Education in Allergy and Airway Diseases (EUFOREA) guidelines, despite limited data on clinical indications, response measures, and treatment duration. Since then, numerous studies and the EPOS/EUFOREA 2023 update have refined these guidelines. The update defines clinical indications for biologics based on type 2 inflammation markers by lowering the blood eosinophil threshold from 250 to 150 cells/μL. The response to biologics is now more simply categorized into three levels based on reductions in nasal polyp size, improvements in quality of life, and enhancement of smell. Treatment evaluation is recommended at 6 months with annual follow-up. Longer administration intervals, such as every four weeks, have also proven effective in well-controlled patients. Although specific guidelines for discontinuation or switching biologics remain lacking, clinical judgment is essential in determining when treatment should be stopped or adjusted. Additionally, regulatory updates support the use of biologics for CRSwNP, and novel agents such as tezepelumab (an anti-thymic stromal lymphopoietin monoclonal antibody) continue to show promise. Finally, in Korea, biologics for CRSwNP are not covered by national health insurance, leading to extended dosing intervals due to high costs. Despite this limitation, studies have shown that adjusted dosing can maintain subjective quality of life. Recent studies by Korean authors have also explored practical considerations such as dosing intervals and comparisons to surgery. Further research is needed to optimize treatment strategies, particularly regarding cost-effectiveness and prospective studies tailored to the Korean healthcare system.

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.

Chronic rhinosinusitis with nasal polyps (CRSwNP) is a prevalent condition that significantly impacts quality of life and places a burden on healthcare systems. The advent of biologics targeting type 2 immune pathways offers new therapeutic options for severe and/or uncontrolled CRSwNP. Initially, biologic use was guided by the European Position Paper on Rhinosinusitis and Nasal Polyps (EPOS) 2020 and the European Forum for Research and Education in Allergy and Airway Diseases (EUFOREA) guidelines, despite limited data on clinical indications, response measures, and treatment duration. Since then, numerous studies and the EPOS/EUFOREA 2023 update have refined these guidelines. The update defines clinical indications for biologics based on type 2 inflammation markers by lowering the blood eosinophil threshold from 250 to 150 cells/μL. The response to biologics is now more simply categorized into three levels based on reductions in nasal polyp size, improvements in quality of life, and enhancement of smell. Treatment evaluation is recommended at 6 months with annual follow-up. Longer administration intervals, such as every four weeks, have also proven effective in well-controlled patients. Although specific guidelines for discontinuation or switching biologics remain lacking, clinical judgment is essential in determining when treatment should be stopped or adjusted. Additionally, regulatory updates support the use of biologics for CRSwNP, and novel agents such as tezepelumab (an anti-thymic stromal lymphopoietin monoclonal antibody) continue to show promise. Finally, in Korea, biologics for CRSwNP are not covered by national health insurance, leading to extended dosing intervals due to high costs. Despite this limitation, studies have shown that adjusted dosing can maintain subjective quality of life. Recent studies by Korean authors have also explored practical considerations such as dosing intervals and comparisons to surgery. Further research is needed to optimize treatment strategies, particularly regarding cost-effectiveness and prospective studies tailored to the Korean healthcare system.

Background and Objectives: Outcomes of deferring percutaneous coronary intervention (PCI) without invasive physiologic assessment for intermediate coronary lesions is uncertain.We sought to compare long-term outcomes between medical treatment and PCI of intermediate lesions without invasive physiologic assessment. Methods: A total of 899 patients with intermediate coronary lesions between 50% and 70% diameter-stenosis were randomized to the conservative group (n=449) or the aggressive group (n=450). For intermediate lesions, PCI was performed in the aggressive group, but was deferred in the conservative group. The primary endpoint was major adverse cardiac events (MACE, a composite of all-cause death, myocardial infarction [MI], or ischemia-driven any revascularization) at 3 years. Results: The number of treated lesions per patient was 0.8±0.9 in the conservative group and 1.7±0.9 in the aggressive group (p=0.001). At 3 years, the conservative group had a significantly higher incidence of MACE than the aggressive group (13.8% vs. 9.3%; hazard ratio [HR], 1.49; 95% confidence interval [CI], 1.00–2.21; p=0.049), mainly driven by revascularization of target intermediate lesion (6.5% vs. 1.1%; HR, 5.69; 95% CI, 2.20–14.73;p<0.001). Between 1 and 3 years after the index procedure, compared to the aggressive group, the conservative group had significantly higher incidence of cardiac death or MI (3.2% vs.0.7%; HR, 4.34; 95% CI, 1.24–15.22; p=0.022) and ischemia-driven any revascularization. Conclusions For intermediate lesions, medical therapy alone, guided only by angiography, was associated with a higher risk of MACE at 3 years compared with performing PCI, mainly due to increased revascularization.