Anemia in children with chronic kidney disease

Chronic kidney disease (CKD) causes numerous changes that destabilize homeostasis, of which anemia is one of its important complications. Anemia significantly reduces the quality of life in children with CKD and plays a crucial role in the progression of cardiovascular disease such as left ventricular hypertrophy, a major cause of mortality in those with advanced CKD. The treatment of anemia is a pivotal factor in reducing morbidity and mortality rates in children with CKD, representing one of the methods for enhancing patients’ quality of life.

Tolvaptan: a possible preemptive treatment option in children with autosomal dominant polycystic kidney disease?

Tolvaptan is a highly selective vasopressin receptor 2 antagonist that regulates cyclic adenosine monophosphate levels to inhibit both epithelial cell proliferation and chloride ion excretion, two mechanisms known to induce cyst expansion in autosomal dominant polycystic kidney disease (ADPKD). Tolvaptan is currently the preferred treatment of rapidly progressive disease ADPKD in adult patients; however, since cyst formation in ADPKD begins early in life, (frequently in utero), and significant disease progression with cyst expansion occurs in the first decade, tolvaptan may be advantageous as a preemptive treatment in children with ADPKD. Tolvaptan has already been used to successfully treat refractory edema or hyponatremia in children; this literature review provides insight into the biochemical basis of its action to contextualize its use in the pediatric population.

Efficacy and safety of losartan in childhood immunoglobulin A nephropathy: a prospective multicenter study

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)

Effect of donor–recipient size mismatch on long-term graft survival in pediatric kidney transplantation: a multicenter cohort study

Donor–recipient size mismatching is commonly occurs in pediatric kidney transplantation (KT). However, its effect on graft survival remains unknown. This study aimed to determine the effect of donor–recipient size mismatch on the long-term survival rate of transplant kidneys in pediatric KT. Methods: A total of 241 pediatric patients who received KT were enrolled. The medical records of all patients were retrospectively reviewed, and the correlation between donor–recipient size mismatch and graft function and long-term graft outcome was analyzed according to donor–recipient size mismatch. Results: Recipients and donors’ mean body weight at the time of KT were 34.31 ± 16.85 and 56.53 ± 16.73 kg, respectively. The mean follow-up duration was 96.49 ± 52.98 months. A significant positive correlation was observed between donor–recipient body weight ratio (DRBWR) or donor–recipient body surface area ratio (DRBSR) and graft function until 1 year after KT. However, this correlation could not be confirmed at the last follow-up. The results of long-term survival analysis using Fine and Gray’s subdistribution hazard model showed no significant difference of the survival rate of the transplant kidney according to DRBWR or DRBSR. Conclusion: Donor–recipient size mismatch in pediatric KT is not an important factor in determining the long-term prognosis of transplant kidneys.

De Novo Crescentic Glomerulonephritis Following COVID-19 Infection:A Pediatric Case Report

As the global coronavirus disease 2019 (COVID-19) pandemic continues to sweep across the globe, reports of kidney involvement in adult patients infected with COVID-19 have been documented, and recently, cases in the pediatric population have also been reported.This report highlights the case of an 11-year-old boy who developed acute kidney injury presenting as gross hematuria, proteinuria, and hypertension immediately after a COVID-19 infection. A renal biopsy allowed us to diagnose the patient with post-COVID-19 infectionassociated de novo crescentic immune-mediated glomerulonephritis. Oral prednisolone and cyclophosphamide treatments were initiated after methylprednisolone pulse therapy administration. Currently, the patient is receiving medical treatment for five weeks, and his renal function is gradually recovering. Previous studies have suggested that, although quite rare, a variety of kidney complications can occur after COVID-19 infection or vaccination, and it is recommended to monitor renal function through evaluation. Herein, we report a pediatric case of post-COVID-19 infection-associated de novo crescentic immune-mediated glomerulonephritis consistent with rapidly progressive glomerulonephritis.

Clinical outcomes in pediatric patients with normal renal histopathology

There have been some cases where abnormal histopathologic findings could not be found in the kidney could even with proper specimen collection through percutaneous renal biopsy (PRB) in accordance with its indication. We analyzed the incidence and clinical outcomes of children who showed normal histopathological findings in their PRBs. Methods: The medical records of 552 pediatric subjects who underwent PRB between 2005 and 2016 were reviewed. Twenty-six subjects were excluded because allograft biopsy was performed in nine subjects, and the age at biopsy was greater than 18 years in 17 subjects. Finally, 526 subjects were enrolled in this study. Results: Of the 526 pediatric patients, 32 (6.1%) showed no histopathological abnormalities in their PRBs. The male-to-female ratio of the patients was 1.9:1, and the mean ages at the first visit and at biopsy were 10.6 ± 4.1 and 11.4 ± 3.8 years, respectively. In accordance with the biopsy indications, recurrent gross hematuria showed the highest incidence rate, but combined hematuria and proteinuria had the lowest incidence rate regarding normal renal histopathology among all the subjects. At a mean follow-up of 35.5 ± 23.6 months, urinary abnormalities had improved in more than 50% of the subjects with normal renal histopathology, and none of the patients showed progression to end-stage renal disease or required rebiopsy due to symptom worsening during the follow-up period. Conclusion: The clinical outcomes of children with normal PRB histopathologic findings are generally good. Further studies to evaluate their long-term outcomes are needed.

Kleefstra syndrome combined with vesicoureteral reflux and rectourethral fistula: a case report and literature review

Kleefstra syndrome is a rare genetic disease characterized by mental retardation, hypotonia, and a characteristic facial appearance. Furthermore, in some cases, Kleefstra syndrome is associated with various anorectal and genitourinary complications, including imperforated anus, vesicoureteral reflux, hydronephrosis, and chronic kidney disease. Herein, we present a case of Kleefstra syndrome with recurrent urinary tract infections associated with vesicoureteral reflux and rectourethral fistula, which was treated by a multidisciplinary approach.

Impact of COVID-19 on the clinical course of nephrotic syndrome in children: a single-center study

Purpose@#Children with nephrotic syndrome may experience disease relapse or aggravation triggered by various viral infections. Limited studies on the clinical implications of the coronavirus disease 2019 (COVID-19) pandemic in children with nephrotic syndrome have been published worldwide. Therefore, this study aimed to investigate the effects of COVID-19 on the clinical course of nephrotic syndrome in children. @*Methods@#The medical records of 59 patients with idiopathic nephrotic syndrome who visited our hospital between February and June 2022 were retrospectively analyzed. @*Results@#Twenty of the total 59 patients with nephrotic syndrome were diagnosed with COVID-19 during the study period. The mean age at the time of the diagnosis of nephrotic syndrome and COVID-19 in all 20 patients was 4.6±3.5 and 8.9±3.9 years, respectively. Three patients (15%) were diagnosed with nephrotic syndrome relapse during COVID-19 and the relapse rate was similar to them without COVID-19 (20.5%, 8/39 patients). At the time of the COVID-19 diagnosis, fever (85%) and cough (40%) were the most common symptoms. After the diagnosis of COVID-19, all patients showed improvement with symptomatic treatment, including antipyretic analgesics and cold medicine. None of the critical patients required hospitalization or oral antiviral medications. @*Conclusions@#Despite the use of immunosuppressants, the clinical manifestations of COVID-19 in children with nephrotic syndrome were not severe and are expected to be similar to that in the general population. The relapse rate of nephrotic syndrome in children with COVID-19 was also not different from them without COVID-19.

Intellectual Functioning of Pediatric Patients with Chronic Kidney Disease:Results from the KNOW-Ped CKD

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.

Characteristics of pediatric rhabdomyolysis and the associated risk factors for acute kidney injury: a retrospective multicenter study in Korea

Background@#The clinical features of pediatric rhabdomyolysis differ from those of the adults with rhabdomyolysis; however, multicenter studies are lacking. This study aimed to investigate the characteristics of pediatric rhabdomyolysis and reveal the risk factors for acute kidney injury (AKI) in such cases. @*Methods@#This retrospective study analyzed the medical records of children and adolescents diagnosed with rhabdomyolysis at 23 hospitals in South Korea between January 2007 and December 2016. @*Results@#Among 880 patients, those aged 3 to 5 years old composed the largest subgroup (19.4%), and all age subgroups were predominantly male. The incidence of AKI was 11.3%. Neurological disorders (53%) and infection (44%) were the most common underlying disorder and cause of rhabdomyolysis, respectively. The median age at diagnosis in the AKI subgroup was older than that in the non-AKI subgroup (12.2 years vs. 8.0 years). There were no significant differences in body mass index, myalgia, dark-colored urine, or the number of causal factors between the two AKI-status subgroups. The multivariate logistic regression model indicated that the following factors were independently associated with AKI: multiorgan failure, presence of an underlying disorder, strong positive urine occult blood, increased aspartate aminotransferase and uric acid levels, and reduced calcium levels. @*Conclusions@#Our study revealed characteristic clinical and laboratory features of rhabdomyolysis in a Korean pediatric population and highlighted the risk factors for AKI in these cases. Our findings will contribute to a greater understanding of pediatric rhabdomyolysis and may enable early intervention against rhabdomyolysis-induced AKI.

Intellectual Functioning of Pediatric Patients with Chronic Kidney Disease:Results from the KNOW-Ped CKD

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.

An Alport syndrome boy with Van Wyk-Grumbach syndrome induced by prolonged untreated congenital hypothyroidism

Alport syndrome (AS) is a rare genetic disorder that causes progressive nephritis and is more common among males. Studies have reported an association between thyroid antibodies and hypothyroidism in patients with AS, but the relevance of this relationship is under debate. Prolonged untreated hypothyroidism induces short stature, abnormal pubertal development, and various other symptoms. However, children with long-standing hypothyroidism rarely present with signs of precocious puberty, or Van Wyk-Grumbach syndrome (VWGS). We report the case of a boy, 8 years and 4 months old, who had VWGS caused by prolonged untreated congenital hypothyroidism and AS. The boy had repeated gross hematuria and proteinuria and was diagnosed with AS by renal biopsy and genetic testing. He had normal renal function but severe growth retardation and hypothyroidism. Obesity, bone age delay, hyperlipidemia, and abnormal increased testicle size were also present due to prolonged untreated hypothyroidism. His thyroid antibody titer elevation was unclear, although ultrasonography and thyroid scanning showed a decrease in thyroid volume. We diagnosed the patient with congenital hypothyroidism caused by thyroid dysgenesis. VWGS was diagnosed due to hypothyroidism, delayed bone age, and pseudoprecocious puberty. To the best of our knowledge, this is the first report of a prepubertal Korean boy with prolonged untreated congenital hypothyroidism complicated by VWGS in AS.

A Pediatric Case of AVPR2-related Nephrogenic Syndrome of Inappropriate Antidiuresis

Nephrogenic syndrome of inappropriate antidiuresis (NSIAD) is a rare X-linked genetic condition caused by a gain-of-function mutation of arginine vasopressin receptor 2 gene, AVPR2. We report the case of a male neonate diagnosed with NSIAD based on his DNA sequence of the AVPR2 gene and the clinical course. He demonstrated a complete correction of hyponatremia using oral urea. We suggest that (1) sequencing analysis of the AVPR2 gene ought to be done in newborns with prolonged euvolemic hyponatremia, hypo-osmolality, high urinary sodium and normal/low or undetectable AVP levels, and that (2) oral urea is a safe and effective treatment option in infants diagnosed with NSIAD until the patients are grown-up.

Clinical Characteristics and Long-Term Prognosis of Alport Syndrome: A Retrospective Single-Center Study

Purpose@#Alport syndrome (AS) is one of the most common inherited renal diseases caused due to mutations of genes encoding specific proteins of the type IV collagen family, and its major clinical manifestations include progressive renal failure, sensorineural deafness, and ocular abnormalities. We investigated the clinical characteristics and long-term prognosis of AS in Korean pediatric and adult populations. @*Methods@#We conducted a retrospective review of medical records of 33 children and adults who had been diagnosed or treated with AS from 1985 to 2019. @*Results@#The mean age of the 33 patients diagnosed with AS was 16.2±13.6 years, and the male-to-female ratio was 2:1. At the first visit, recurrent gross hematuria was the most common initial symptom. In 10 of 33 patients (30.3%), sensorineural hearing loss (SNHL) was diagnosed, but none had ophthalmic problems. Moreover, 11 of 33 patients (33.3%) had advanced to end-stage renal disease (ESRD), and a significant difference was observed in the age of the patients who progressed to ESRD based on the presence or absence of SNHL (P =0.035). @*Conclusion@#SNHL in AS can be an important prognostic factor for long-term deterioration of renal function. Further investigation is required to confirm the clinical course and the genetic characteristics of AS in Korea through prospective national cohort studies.

Infectious and Non-infectious Complications of Peritoneal Dialysis in Children

Despite the many advantages of peritoneal dialysis (PD) in children with endstage renal disease, there exist redoubtable complications of PD that should be overcome. To prevent and manage these complications, a multidisciplinary team should provide support highly tailored for each child and family, based on the standardized practice guidelines for the management of pediatric PD. In this review, we summarize the clinical manifestations and management of several complications of PD.

Monitoring BK virus infection in pediatric kidney transplant recipients / 소아과

No abstract available.

Susceptibility of the Index Urinary Tract Infection to Prophylactic Antibiotics Is a Predictive Factor of Breakthrough Urinary Tract Infection in Children with Primary Vesicoureteral Reflux Receiving Continuous Antibiotic Prophylaxis

BACKGROUND: Few studies have reported on breakthrough urinary tract infection (UTI) associated with the susceptibility of index UTI to prophylactic antibiotics in children with primary vesicoureteral reflux (VUR) receiving continuous antibiotic prophylaxis (CAP). We assessed the impact of the susceptibility of index UTI to prophylactic antibiotics in breakthrough UTIs in children with primary VUR receiving CAP. METHODS: We retrospectively reviewed the medical records of 81 children with primary VUR who were diagnosed after febrile or symptomatic UTI and subsequently received trimethoprim-sulfamethoxazole (TMP-SMX) as CAP between January 2010 and December 2013. We allocated children to a susceptible group or a resistant group based on the susceptibility of index UTI to TMP-SMX. We evaluated patient demographics and clinical outcomes after CAP according to the susceptibility of index UTI to TMP-SMX. Multivariate analysis was used to identify the predictive factors for breakthrough UTI. RESULTS: Of the 81 children, 42 were classified into the susceptible group and 39 into the resistant group. The proportion of breakthrough UTI was 31.0% (13/42) in the susceptible group and 53.8% (21/39) in the resistant group (P = 0.037). Progression of renal scarring was observed in 0% of children in the susceptible group and 15% in the resistant group (P = 0.053). Multivariate analysis showed that TMP-SMX resistance and initial renal scarring were significant predictors of breakthrough UTI. CONCLUSION: Susceptibility of index UTI to prophylactic antibiotics is a risk factor of breakthrough UTI and is associated with poor clinical outcomes in children with primary VUR receiving CAP.

Clinical Characteristics of Ureteral Duplication in Children

PURPOSE: Ureteral duplication is a relatively common congenital urinary tract abnormality that can be associated with various clinical problems such as vesicoureteral reflux (VUR), hydronephrosis, and ectopic ureters. The purpose of this study was to analyze the clinical characteristics of pediatric patients with recently diagnosed ureteral duplication and to identify any differences from those described in previous reports.METHODS: We retrospectively reviewed the clinical characteristics and course of pediatric patients who were diagnosed with ureteral duplication between January 2008 and June 2017.RESULTS: A total of 32 pediatric patients were diagnosed with ureteral duplication during the study period. The male to female ratio was 1:2.2. Twenty-seven patients (84.4%) were first diagnosed with ureteral duplication at less than 3 months of age, and 26 (81.3%) were first diagnosed by prenatal ultrasonography. Four of the 32 patients were diagnosed with bilateral ureteral duplication, for a total of 36 occurrences of ureteral duplication. In 17 occurrences of complete ureteral duplication (47.2%), other urinary tract anomalies were also found; namely, ureterocele (7), VUR (11), and ectopic ureter (5). However, none of the patients with incomplete ureteral duplication had ureterocele or VUR.CONCLUSION: With the advent of routine prenatal ultrasound, ureteral duplication is being diagnosed earlier than was previously possible, enabling timely treatment of the various accompanying urinary tract anomalies. Multicenter studies are needed to establish guidelines for standardized evaluation and treatment of ureteral duplication.

Renal involvement in children and adolescents with inflammatory bowel disease / 소아과

PURPOSE: The incidence of inflammatory bowel disease (IBD) is rapidly increasing, and several reports have described the renal complications of IBD. We sought to evaluate the clinical manifestations of renal complications in children with IBD in order to enable early detection and prompt treatment of the complications. METHODS: We retrospectively reviewed the medical records of 456 children and adolescents aged < 20 years who had been diagnosed with IBD since 2000. We analyzed patient age, sex, medication use, IBD disease activity, and clinical manifestations of renal symptoms. RESULTS: Our study comprising 456 children with IBD included 299 boys (65.6%) and 157 girls (34.4%). The study included 346 children with Crohn disease and 110 children with ulcerative colitis. The incidence of kidney-related symptoms was 14.7%, which was significantly higher than that in normal children. We observed 26 children (38.8%) with isolated hematuria, 30 children (44.8%) with isolated proteinuria, and 11 children (16.4%) with hematuria and concomitant proteinuria. A renal biopsy was performed in 7 children. Histopathological examination revealed immunoglobulin A nephropathy in 5 children (71.4%). All children presented with mild disease and well-controlled disease activity of IBD. CONCLUSION: Children with IBD are more likely to show kidney-related symptoms than healthy children and adolescents are. Therefore, regular screening of urine and evaluation of renal function in such children are necessary for early detection of renal complications.

Pediatric kidney transplantation is different from adult kidney transplantation / 소아과

Kidney transplantation (KT) is the gold standard for renal replacement therapy in pediatric patients with end-stage renal disease. Recently, it has been observed that the outcome of pediatric KT is nearly identical to that in adults owing to the development and application of a variety of immunosuppressants and newer surgical techniques. However, owing to several differences in characteristics between children and adults, pediatric KT requires that additional information be learned and is associated with added concerns. These differences include post-KT complications, donor-recipient size mismatch, problems related to growth, and nonadherence to therapy, among others. This review was aimed at elucidating the clinical characteristics of pediatric KT that differ from those observed in adults.