Complement component 3 glomerulonephritis (C3GN) is a rare kidney disease characterized by complement dysregulation that results in prominent complement component 3 (C3) deposition in the kidneys. The clinical course of C3GN varies from mild hematuria to progressive chronic kidney disease. In most patients, C3GN is driven by acquired factors, namely, autoantibodies that target C3 or C5 convertases. Genetic variations in complement-related genes are less frequent. We report the case of a 9-yearold Korean boy who presented with microscopic hematuria and a persistently low C3 level and had biopsy findings of C3GN, with the presence of a C3 gene mutation: a frameshift mutation associated with C3 deficiency. However, the patient did not exhibit any other symptoms of complement deficiency. Direct DNA sequencing of his family members revealed the same genetic mutation in his father and older brother. This case report is significant because there are very few such reports worldwide concerning gene mutations related to C3 deficiency to be discovered in patients with C3GN. Explaining C3GN pathogenesis is challenging; therefore, additional research is required in the future.

Purpose: Angiotensin-converting enzyme inhibitors and angiotensin II receptor blockers (ARBs) are frequently employed to counteract the detrimental effects of proteinuria on glomerular diseases. However, the effects of ARBs remain poorly examined in pediatric patients with immunoglobulin A (IgA) nephropathy. Herein, we evaluated the efficacy and safety of losartan, an ARB, in pediatric IgA nephropathy with proteinuria. Methods: This prospective, single-arm, multicenter study included children with IgA nephropathy exhibiting proteinuria. Changes in proteinuria, blood pressure, and kidney function were prospectively evaluated before and 4 and 24 weeks after losartan administration. The primary endpoint was the difference in proteinuria between baseline and 24 weeks. Results: In total, 29 patients were enrolled and received losartan treatment. The full analysis set included 28 patients who received losartan at least once and had pre- and post-urinary protein to creatinine ratio measurements (n=28). The per-protocol analysis group included 22 patients who completed all scheduled visits without any serious violations during the study period. In both groups, the mean log (urine protein to creatinine ratio) value decreased significantly at 6 months. After 24 weeks, the urinary protein to creatinine ratio decreased by more than 50% in approximately 40% of the patients. The glomerular filtration rate was not significantly altered during the observation period. Conclusions Losartan decreased proteinuria without decreasing kidney function in patients with IgA nephropathy over 24 weeks. Losartan could be safely employed to reduce proteinuria in this patient population. ClinicalTrials.gov trial registration (NCT0223277)

OBJECTIVES: We estimated the population prevalence of antibodies to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), including unreported infections, through a Korea Seroprevalence Study of Monitoring of SARS-CoV-2 Antibody Retention and Transmission (K-SEROSMART) in 258 communities throughout Korea. METHODS: In August 2022, a survey was conducted among 10,000 household members aged 5 years and older, in households selected through two stage probability random sampling. During face-to-face household interviews, participants self-reported their health status, COVID-19 diagnosis and vaccination history, and general characteristics. Subsequently, participants visited a community health center or medical clinic for blood sampling. Blood samples were analyzed for the presence of antibodies to spike proteins (anti-S) and antibodies to nucleocapsid proteins (anti-N) SARS-CoV-2 proteins using an electrochemiluminescence immunoassay. To estimate the population prevalence, the PROC SURVEYMEANS statistical procedure was employed, with weighting to reflect demographic data from July 2022. RESULTS: In total, 9,945 individuals from 5,041 households were surveyed across 258 communities, representing all basic local governments in Korea. The overall population-adjusted prevalence rates of anti-S and anti-N were 97.6% and 57.1%, respectively. Since the Korea Disease Control and Prevention Agency has reported a cumulative incidence of confirmed cases of 37.8% through July 31, 2022, the proportion of unreported infections among all COVID-19 infection was suggested to be 33.9%. CONCLUSIONS The K-SEROSMART represents the first nationwide, community-based seroepidemiologic survey of COVID-19, confirming that most individuals possess antibodies to SARS-CoV-2 and that a significant number of unreported cases existed. Furthermore, this study lays the foundation for a surveillance system to continuously monitor transmission at the community level and the response to COVID-19.

Background: Chronic kidney disease (CKD) has a negative impact on growth and development in children and is a risk factor for neurocognitive impairment; however, there is limited research on the cognitive function of children and adolescents with CKD. This study therefore aimed to investigate the mean intelligence and risk factors for low intelligence in children and adolescents with CKD. Methods: Eighty-one patients with CKD under 18 years old were included in the KoreaN cohort study for Outcomes in patients With Pediatric Chronic Kidney Disease (KNOW-Ped CKD). Participants completed either the Wechsler Intelligence Scale for Children (6–16 years), or Wechsler Adult Intelligence Scale (> 16 years). Results: The mean full-scale intelligence quotient (IQ) was 91 ± 19; 24.7% of participants scored a full-scale IQ below 80. Participants with a short stature (height Z scores < −1.88), failure to thrive (weight Z scores < −1.65), more severe CKD stage (≥ IIIb), longer duration of CKD (≥ 5 years), and those who were Medicare or Medicaid beneficiaries, had significantly lower mean full-scale IQs. Conclusion On linear regression analysis, the association between the full-scale IQ, and longer duration of CKD and growth failure, remained significant after controlling for demographic and clinical variables. It is therefore necessary to investigate cognitive impairment in pediatric patients with CKD who exhibit growth failure or for a longer postmorbid period. It is believed that early interventions, such as kidney transplantation, will have a positive effect on IQ in children with CKD, as the disease negatively affects IQ due to poor glomerular filtration rate over time.

Objective: To investigate long-term and serial functional outcomes in ischemic stroke patients without diabetes with post-stroke hyperglycemia. Methods: The Korean Stroke Cohort for Functioning and Rehabilitation (KOSCO) is a large, multi-center, prospective cohort study of stroke patients admitted to participating hospitals in nine areas of Korea. From KOSCO, ischemic stroke patients without diabetes were recruited and divided into two groups: patients without diabetes without (n=779) and with post-stroke hyperglycemia (n=223). Post-stroke hyperglycemia was defined as a glucose level >8 mmol/L. Functional assessments were performed 7 days and 3, 6, and 12 months after stroke onset. Results: There were no significant differences in baseline characteristics between the groups, except in the age of onset and smoking. Analysis of the linear correlation between the initial National Institutes of Health Stroke Scale (NIHSS) score and glucose level showed no significant difference. Among our functional assessments, NIHSS, Fugl-Meyer Assessment (affected side), Functional Ambulatory Category, modified Rankin Scale, and Korean Mini-Mental State Examination (K-MMSE) showed statistically significant improvements in each group. All functional improvements except K-MMSE were significantly higher in patients without post-stroke hyperglycemia at 7 days and 3, 6, and 12 months. Conclusion The glucose level of ischemic stroke patients without diabetes had no significant correlation with the initial NIHSS score. The long-term effects of stress hyperglycemia showed worse functional outcomes in ischemic stroke patients without diabetes with post-stroke hyperglycemia.

C1q nephropathy is a rare glomerulopathy that typically presents with nephrotic syndrome in children. Treatment with immunosuppressive agents renders patients vulnerable to infection and its complications. Gastroenteritis is common in children, and rotavirus is a leading cause. Extraintestinal manifestations of rotavirus have recently been reported; however, there is a paucity of cases exploring the involvement of a rotavirus on the respiratory system. Acute respiratory distress syndrome (ARDS) is a rapid onset respiratory failure characterized by noncardiogenic pulmonary edema and hypoxemia. Causes of ARDS include sepsis, pneumonia, pancreatitis, aspiration, and trauma. In this paper, we report a case of ARDS after rotavirus infection in a child with C1q nephropathy who had been treated with immunosuppressive agents.

Chronic kidney disease (CKD)-mineral and bone disorder (CKD-MBD) is a common complication of CKD, often accompanied by extra-skeletal calcification in adult patients. As increased vascular calcification is predicted to increase cardiovascular mortality and morbidity, the revised Kidney Disease: Improving Global Outcomes guidelines recommend avoiding calcium-containing phosphate chelators. However, extra-skeletal calcification is less commonly noticed in pediatric patients. Here, we report our experience of such a complication in pediatric patients receiving maintenance peritoneal dialysis. Extra-skeletal calcification was noticed at the corneas, pelvic cavity, and soft tissues of the lower leg in 4 out of 32 patients on maintenance peritoneal dialysis. These patients experienced the aggravation of extra-skeletal calcifications during peritoneal dialysis, and 2 of them underwent excisional operations. It is required to monitor extra-skeletal calcifications in children on kidney replacement therapy.

Asthma is a heterogeneous disease whose development is shaped by a variety of environmental and genetic factors. While several recent studies suggest that microbial dysbiosis in the gut may promote asthma, little is known about the relationship between the recently discovered lung microbiome and asthma. Innate lymphoid cells (ILCs) have also been shown recently to participate in asthma. To investigate the relationship between the lung microbiome, ILCs, and asthma, we recruited 23 healthy controls (HC), 42 patients with non-severe asthma, and 32 patients with severe asthma. Flow cytometry analysis showed severe asthma associated with fewer natural cytotoxicity receptor (NCR) + ILC3s in the lung.Similar changes in other ILC subsets, macrophages, and monocytes were not observed. The asthma patients did not differ from the HC in terms of the alpha and beta-diversity of the lung and gut microbiomes. However, lung function correlated positively with both NCR + ILC3 frequencies and microbial diversity in the lung. Sputum NCR + ILC3 frequencies correlated positively with lung microbiome diversity in the HC, but this relationship was inversed in severe asthma. Together, these data suggest that airway NCR + ILC3s may contribute to a healthy commensal diversity and normal lung function.

Alagille syndrome (AGS) is a rare autosomal dominant inherited disorder, with major clinical manifestations of bile duct paucity, cholestasis, cardiovascular anomaly, ophthalmic abnormalities, butterfly vertebrae, and dysmorphic facial appearance. It is caused by heterozygous mutations in JAG1 or NOTCH of the Notch signaling pathway presenting with variable phenotypic penetrance and involving multiple organ systems. The following case report describes a unique case of a 16-year-old female with AGS who presented with the primary complaint of renovascular hypertension. She had a medical history of ventricular septal defect and polycystic ovary syndrome. The patient had a dysmorphic facial appearance including frontal bossing, bulbous tip of the nose, a pointed chin with prognathism, and deeply set eyes with mild hypertelorism. Stenoocclusive changes of both renal arteries, celiac artery, lower part of the abdominal aorta, and left intracranial artery, along with absence of the left internal carotid artery were found on examination. Whole exome sequencing was performed and revealed a pathologic mutation of JAG1, leading to the diagnosis of AGS. Reverse phenotyping detected butterfly vertebrae and normal structure and function of the liver and gallbladder. While the representative symptom of AGS in most scenarios is a hepatic problem, in this case, the presenting clinical features were the vascular anomalies. Clinical manifestations of AGS are diverse, and this case demonstrates that renovascular hypertension might be in some cases a presenting symptom of AGS.