Pediatric Nephrology Research Articles

Reliability of renal point-of-care ultrasound (POCUS) performed by pediatric postgraduates to diagnose hydronephrosis in infants.

Point-of-care ultrasound (POCUS) has gained prominence in a variety of medical specialties due to advances in ultrasound technology. POCUS has not been fully integrated into pediatric residency training programs despite its widespread use and proven benefits. At our institution, renal POCUS is performed by pediatric residents for the evaluation of hydronephrosis, which is the main pathology for which ultrasound is used in the clinical practice of pediatric nephrology. This study was conducted to evaluate the quality of renal POCUS performed by pediatric residents in infants. Four pediatric residents, comprising two first-year and two second-year residents at Konyang University Hospital, participated in the study conducted from May 2021 to May 2022. All participants had completed our Point-of-Care Ultrasound (POCUS) training program. The study focused on infants admitted to the pediatric inpatient unit, identified by attending physicians as requiring renal ultrasound. All infants underwent their initial kidney ultrasound examination. Temporal alignment between renal Point-of-Care Ultrasound (POCUS) performed by pediatric residents and conventional ultrasound (USG) conducted by radiologists was asynchronous. Pediatric residents conducted POCUS sessions during scheduled radiologist appointments throughout the day, occurring either before or after the radiologist's examination. There was no mutual awareness of each other's results. Inter-observer agreement between radiologists and pediatric residents was compared for the presence or absence of hydronephrosis and its grade, which are primary considerations in pediatric renal ultrasound. Our study found that 53 infants (68.8%) were diagnosed with hydronephrosis using point-of-care ultrasound (POCUS), compared to 48 infants (62.3%) diagnosed with conventional ultrasound (USG). Among the POCUS examinations conducted by pediatric residents, hydronephrosis of SFU grades 1, 2, 3, and 4 were observed in 56.6%, 35.8%, 7.5%, and 0%, respectively. Inter-observer reliability between POCUS and conventional USG showed good agreement, with Cohen's kappa coefficients exceeding 0.8 for sensitivity and 0.6 for grading. Renal POCUS performed well in diagnosing and grading hydronephrosis in infants when performed by pediatric residents who had completed a two-phase training program.

Are children with IgA nephropathy different from adult patients?

BackgroundPreviously, several studies have indicated that pediatric IgA nephropathy (IgAN) might be different from adult IgAN, and treatment strategies might be also different between pediatric IgAN and adult IgAN.MethodsWe analyzed two prospective cohorts established by pediatric and adult nephrologists, respectively. A comprehensive analysis was performed investigating the difference in clinical and pathological characteristics, treatment, and prognosis between children and adults with IgAN.ResultsA total of 1015 children and 1911 adults with IgAN were eligible for analysis. More frequent gross hematuria (88% vs. 20%, p < 0.0001) and higher proteinuria (1.8 vs. 1.3 g/d, p < 0.0001) were seen in children compared to adults. In comparison, the estimated glomerular filtration rate (eGFR) was lower in adults (80.4 vs. 163 ml/min/1.73 m2, p < 0.0001). Hypertension was more prevalent in adult patients. Pathologically, a higher proportion of M1 was revealed (62% vs. 39%, p < 0.0001) in children than in adults. S1 (62% vs. 28%, p < 0.0001) and T1–2 (34% vs. 8%, p < 0.0001) were more frequent in adults. Adjusted by proteinuria, eGFR, and hypertension, children were more likely to be treated with glucocorticoids than adults (87% vs. 45%, p < 0.0001). After propensity score matching, in IgAN with proteinuria > 1 g/d, children treated with steroids were 1.87 (95% CI 1.16–3.02, p = 0.01) times more likely to reach complete remission of proteinuria compared with adults treated with steroids.ConclusionsChildren present significantly differently from adults with IgAN in clinical and pathological manifestations and disease progression. Steroid response might be better in children.Graphical A higher resolution version of the Graphical abstract is available as Supplementary information

Effect of pre-emptive rituximab on EBV DNA levels and prevention of post-transplant lymphoproliferative disorder in pediatric kidney transplant recipients: A case series from the pediatric nephrology research consortium.

There are scant data on the effect of rituximab on EBV DNA levels and prevention of post-transplant lymphoproliferative disorder (PTLD) in pediatric kidney transplant recipients with EBV DNAemia. Kidney transplant recipients with EBV DNAemia treated with rituximab to prevent PTLD between 7/1999 and 7/2019 at five pediatric centers were included. Those with confirmed PTLD at the onset of rituximab were excluded. Primary outcomes included percentage change in EBV DNAemia and occurrence of PTLD post rituximab. Twenty-six pediatric kidney transplant recipients were included. Median age at transplant was 4 years (IQR 2.1-10.3). EBV DNA load monitoring by qPCR was performed at 1-3 month intervals. EBV DNAemia onset occurred at a median of 73 days post-transplant (IQR 52-307), followed by DNAemia peak at a median of 268 days (IQR 112-536). Rituximab was administered at a median of 9 days post peak (IQR 0-118). Rituximab regimens varied; median dose 375 mg/m2 (IQR 375-439) weekly for 1-4 doses per course. Following rituximab, EBV DNA load decreased to <10% of baseline at 120 days in 20/26 patients; however, only 30% achieved complete resolution at last follow-up (median 2094 days post-transplant [IQR 1538-3463]). Two (7%) developed PTLD at 915 and 1713 days post rituximab. All recipients had functioning grafts. One death occurred in a child with PTLD following remission due to unrelated reasons. In the largest pediatric kidney transplant recipient case series with EBV DNAemia given rituximab to prevent PTLD, rituximab achieved a short-term reduction in DNA load; however, recurrent DNAemia is common.

Neurogenic Bladder: A Rare Autonomic Sign in a Patient With Preserved Speech Variant (Zappella Variant) Rett Syndrome

Background: Rett syndrome is characterized by the loss of speech and purposeful hand movements, ambulation problems, and typical hand stereotypies. Preserved speech variant Rett syndrome (Zappella Variant) is a much less common form where speech is relatively preserved, from words to simple sentences. Lower urinary tract dysfunction and neurogenic bladder due to autonomic involvement have been only rarely reported in Rett syndrome. We aimed to emphasize neurogenic bladder due to autonomic dysfunction, which has very rarely been reported in the literature, in a patient with preserved speech variant Rett syndrome, a rare form of the Rett syndrome. Case presentation: A 7-year-old female patient who had been diagnosed with severe vesicoureteral reflux and neurogenic bladder when 11 months old due to the inability to urinate was suspected of suffering from Rett syndrome after intense eye contact and the stereotypic movement of hand wringing were observed. The patient could talk with phrases and walk and had purposeful hand movements. The presence of the c.961C&amp;gt;T (p.Arg321Trp) mutation in the C terminal region of the MECP2 gene was demonstrated with Sanger sequencing. The patient is currently 13 years old and is receiving special education and continues to be monitored for chronic renal disease at the pediatric nephrology department. Conclusion: The presence of hand stereotypies and intense eye pointing could indicate the Zappella variant Rett syndrome in a female patient who has developmental problems, can talk, has purposeful hand skills. Rett syndrome patients can also have lower urinary tract dysfunction although this is less common than cardiac, respiratory and gastrointestinal autonomic involvement. The development of intermittent urinary retention and vesicoureteral reflux may be associated with neurogenic bladder caused by autonomic involvement should be considered in these patients and one must be aware of the complications.

Introducing Exome Sequencing as Part of the Diagnostic Algorithm for Pediatric Nephrology Patients in Bulgaria: A Single-Center Experience

Introduction: In pediatric kidney patients, where clinical presentation is often not fully developed, and renal biopsy is too risky or inconclusive, it may be difficult to establish the underlying pathology. In cases such as these, genetic diagnosis may be used to guide treatment, prognosis, and counseling. Given the large number of genes involved in kidney disease, introducing next-generation sequencing with extended gene panels as part of the diagnostic algorithm presents a viable solution. Methods: A cohort of 87 consecutive independent cases (83 children and 4 terminated pregnancies) with renal disease was recruited. Exome sequencing with MiSeq or NovaSeq 6000 (Illumina) platforms and analysis of extended gene panels were used for genetic testing. Results: Depending on the presenting pathology, the cases were grouped as patients with glomerular disease, ciliopathies, congenital anomalies, renal electrolyte imbalances, and chronic/acute kidney disease. The overall diagnostic yield was approximately 42% (37 out of 87), with most disease-causing mutations found in COL4A3, COL4A4, COL4A5, and PKHD1 genes. A change or clarification of preliminary diagnosis or adjustment of initial treatment plan based on the results of the genetic testing was made for approximately one-third of the children with meaningful genetic findings (11 out of 37). Discussion: Our results prove the value of targeted exome sequencing as a non-invasive, versatile, and reliable diagnostic tool for pediatric renal disease patients. Providing genetic diagnosis will help for a better understanding of disease etiology and will give the basis for optimal clinical management and insightful genetic counseling.

Addressing the psychosocial aspects of transition to adult care in patients with cystinosis.

Cystinosis is a rare autosomal-recessive lysosomal storage disease that progressively affects multiple organs beginning with the kidneys. Patients require lifelong multidisciplinary care for the management of kidney disease and progressive extra-renal manifestations, and thus, they are especially fragile and vulnerable during transition from pediatric to adult care. Previous documents have provided guidance to help the medical transition of these highly burdened patients. Patients and their families often experience great psychological distress and face significant social challenges; for these reasons, they often need help from psychologists, social workers, and other psychosocial professionals. Due to the rarity of the disease, most psychosocial professionals have no expertise in this disorder and require advice. To this end, a steering committee (SC) composed of six experts, including pediatric nephrologists, psychologists, and social workers with experience in the care for patients with cystinosis, have identified and addressed seven key questions related to psychosocial challenges of the disease and the burden of treatment. Ten additional international experts (the extended faculty, EF) were invited to answer these questions. Since robust evidence is lacking, as in many rare diseases, conclusions were based on collective agreement between members of the SC and the EF, and the consolidated answers were summarized into expert opinion statements. The present document contains information on the concerns and psychosocial burden of patients with cystinosis and of their caregivers, and provides practical advice for timely and appropriate support to facilitate the transition to adult care.

COURSE PROGRAM “WKD in Ukraine: Advancing equitable access to pediatric nephrology care and optimal medication practice”

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Point-of-Care Ultrasound (POCUS) Training Curriculum for Pediatric Nephrology: PCRRT-ICONIC Group Recommendations.

Point of care ultrasound (POCUS) is commonly used in adult specialties, pediatric emergency medicine, and neonatal and pediatric critical care. Specifically, in the field of pediatric nephrology, POCUS plays a valuable role in the critical inpatient and outpatient settings. However, the lack of guidelines and a standardized curriculum for POCUS in pediatric nephrology has led to substantial discrepancies in both clinical practice and training. A multinational, multicenter survey regarding POCUS usefulness and training was sent to 225 pediatric nephrology residents, fellows, and physicians with expertise in pediatric nephrology. Based on the results, an ideal pediatric nephrology POCUS curriculum was formulated with a panel of experts from across the world. Eighteen experts were included, with each expert having greater than 10 years of experience in using POCUS in adult and pediatric nephrology. A Delphi method was utilized to further solidify guidelines regarding the content, curriculum, and vital skills of using POCUS in pediatric nephrology. A total of 134 pediatric nephrology trainees, specialists, and faculty responded to the survey (59.6% completion rate). A total of 87.4% of respondents believe that formal POCUS training is either highly desirable or should be mandatory in pediatric nephrology fellowship programs. Identified barriers to receiving training included lack of an organized curriculum, lack of POCUS experts and Pediatric intensivists, lack of ultrasound equipment, lack of financial support, and lack of dedicated time during training. An expert panel was convened and a Delphi survey was conducted to formulate guidelines to overcome the barriers to pediatric nephrology POCUS and standardize the training process. After collaborating with prominent pediatric nephrologists and global POCUS experts proposed a comprehensive POCUS training curriculum tailored specifically for pediatric nephrology trainees, with an appeal for all pediatric nephrology education programs to integrate POCUS instruction into their curricula.

Establishing age and gender-specific serum creatinine reference ranges for Thai pediatric population.

Accurate assessment of kidney function in children requires age and gender-specific reference ranges for serum creatinine. Traditional reference values, often derived from adult populations and different ethnic backgrounds, may not be suitable for children. This study aims to establish specific reference ranges for serum creatinine in the Thai pediatric population, addressing the gap in localized and age-appropriate diagnostic criteria. This retrospective study analyzed serum creatinine levels from Thai children aged newborn to 18 years, collected from the Laboratory Information System of the Queen Sirikit National Institute of Child Health from January 2017 to December 2021. The Bhattacharya method was employed to establish reference ranges, considering different age groups and genders. The study compared these newly established reference values with international studies, including those of Schlebusch H., Pottel H., and Chuang GT., to validate their relevance and accuracy. A total of 27,642 data entries (15,396 males and 12,246 females) were analyzed. The study established distinct reference ranges for serum creatinine, which varied significantly across different age groups and between genders. These ranges were found to gradually increase with age from 2 months to 18 years. The study also highlighted notable differences in reference values when compared with other ethnic populations. The study successfully establishes tailored reference ranges for serum creatinine in Thai children, providing a valuable tool for more accurate diagnosis and monitoring of kidney health in this demographic. This initiative marks a significant advancement in pediatric nephrology in Thailand and suggests a need for continuous refinement of these ranges and further research in this area.

Asymptomatic hematuria in children: Korean Society of Pediatric Nephrology recommendations for diagnosis and management.

Hematuria is a relatively common condition among school-aged children. Because international guidelines for asymptomatic hematuria in children are unavailable, developing practical guidelines for the diagnosis and management of asymptomatic hematuria based on scientific evidence while considering real-world practice settings, values, and patient and physician preferences is essential. The Korean Society of Pediatric Nephrology developed clinical guidelines to address key questions regarding the diagnosis and management of asymptomatic hematuria in children.

Achieving Consensus: Severity-Graded Definitions of Fontan-Associated Complications to Characterize Fontan Circulatory Failure

BackgroundFontan physiology leads to chronic changes in other organ systems that may affect long-term survival and the success of heart transplantation. Inadequate assessment and treatment of the extra-cardiac effects of Fontan may contribute to poor outcomes. Severity-graded/ordinal consensus definitions of Fontan complications are lacking, which limits understanding of how Fontan-specific morbidity affects patients’ outcomes. Methods and ResultsA panel of Fontan patient and physiology experts, including pediatric, adult congenital, heart failure, and critical-care cardiology as well as pediatric nephrology, hepatology and psychology, convened to develop definitions of Fontan complications. Definitions were created by using a severity-graded ordinal scale: grade 1, mild; grade 2, moderate; grade 3, severe; grade 4, disabling or life threatening. Following definition creation, a second panel of 21 experts in Fontan circulatory failure used a modified Delphi methodology to modify and vote on definitions until consensus (> 90% agreement without recommended further modification) was reached on final definitions. After 3 rounds of modifications and voting, consensus agreement was achieved on all Fontan-specific definitions. The defined complications and morbidities of Fontan include: anatomic Fontan pathway obstruction, cyanosis, systemic venous abnormalities resulting from venous insufficiency, atrial arrhythmia, ventricular arrhythmia, bradycardia, chronic pleural effusions, chronic ascites, protein-losing enteropathy, plastic bronchitis, hemoptysis and pulmonary hemorrhage, sleep apnea, Fontan-associated liver disease, portal and hepatic variceal disease, acute kidney injury affecting clinical treatment, polycythemia, thrombotic disease, recurrent or severe bacterial infection, skin atrophy, adrenal insufficiency, physical impact of previous stroke, mood/behavior disorder, and neurodevelopmental disorder. ConclusionConsensus and severity-graded definitions of Fontan-specific cardiac and extra-cardiac complications were achieved and are available for use in research. They will allow future robust analyses of Fontan patient outcomes.

Kidney adolescent and young adult clinic: A transition model in Africa.

Adolescents and Young Adults (AYAs) with chronic kidney disease (CKD) have challenges unique to this developmental period, with increased rates of high-risk behavior and non-adherence to therapy which may impact the progression of kidney disease and their requirement for kidney replacement therapy (KRT). Successful transition of AYA patients are particularly important in low- and middle-income countries (LMICs) where KRT is limited, rationed or not available. Kidney AYA transition clinics have the potential to improve clinical outcomes but there is a paucity of data on the clinical translational impact of these clinics in Africa. This review is a reflection of the 20-year growth and development of the first South African kidney AYA transition clinic. We describe a model of care for patients with CKD, irrespective of etiology, aged 10-25 years, transitioning from pediatric to adult nephrology services. This unique service was established in 2002 and re-designed in 2015. This multidisciplinary integrated transition model has improved patient outcomes, created peer support groups and formed a training platform for future pediatric and adult nephrologists. In addition, an Adolescent Centre of Excellence has been created to compliment the kidney AYA transition model of care. The development of this transition pathway challenges and solutions are explored in this article. This is the first kidney AYA transition clinic in Africa. The scope of this service has expanded over the last two decades. With limited resources in LMICs, such as KRT, the structured transition of AYAs with kidney disease is not only possible but essential. It is imperative to preserve residual kidney function, maximize the kidney allograft lifespan and improve adherence, to enable young individuals an opportunity to lead productive lives.

Pediatric nephrologist-intensivist interaction in acute kidney injury.

Acute Kidney Injury (AKI) in the Intensive Care Unit (ICU) have concepts of diagnosis and management have water balance as their main point of evaluation. In our ICU, from 2004 to 2012, the nephrologist's participation was on demand only; and as of 2013 their participation became continuous in meetings to case discussion. The aim of this study was to establish how an intense nephrologist/intensivist interaction influenced the frequency of dialysis indication, fluid balance and pRIFLE classification during these two observation periods. Retrospective study, longitudinal evaluation of all children with AKI undergoing dialysis (2004 to 2016). frequency of indication, duration and volume of infusion in the 24 hours preceding dialysis; diuresis and water balance every 8 hours. Non-parametric statistics, p ≤ 0.05. 53 patients (47 before and 6 after 2013). There were no significant differences in the number of hospitalizations or cardiac surgeries between the periods. After 2013, there was a significant decrease in the number of indications for dialysis/year (5.85 vs. 1.5; p = 0.000); infusion volume (p = 0.02), increase in the duration of dialysis (p = 0.002) and improvement in the discrimination of the pRIFLE diuresis component in the AKI development. Integration between the ICU and pediatric nephrology teams in the routine discussion of cases, critically approaching water balance, was decisive to improve the management of AKI in the ICU.

Antenatally detected urinary tract dilatation: a pediatric nephrologist's point of view

Antenatally diagnosed urinary tract dilatation (UTD), previously referred to as antenatal hydronephrosis, is the most commonly detected abnormality by prenatal ultrasonography. Several grading systems have been developed for the classification of antenatal UTD using prenatal and postnatal ultrasonography. UTD comprises a wide variety of congenital abnormalities of the kidney and urinary tract ranging from transient UTD to more significant abnormalities such as vesicoureteral reflux, ureteropelvic junction obstruction, ureterocele, ureterovesical junction obstruction, posterior urethral valves, and non-refluxing megaureter. Optimizing the evaluation of antenatally detected UTD is essential to recognize children with important disorders while avoiding excessive investigations. Conservative approach with close follow-up is increasingly accepted as an appropriate treatment option for patients with asymptomatic vesicoureteral reflux and ureteropelvic junction obstruction in recent years. However, predicting permanent kidney damage in an unselected group of children with antenatal UTD is still challenging. The management and follow-up of children with UTD should be individualized based on recommendations from a pediatric nephrologist, a pediatric urologist, or both. Future research directed at predicting long-term outcomes of children diagnosed with UTD from mild findings to severe disease is needed to refine management for those at higher risk of kidney disease progression.

Advances in metabolomics profiling of pediatric kidney diseases: A review.

Pediatric renal diseases encompass a diverse array of pathological conditions, often engendering enduring ramifications. Metabolomics, an emergent branch of omics sciences, endeavors to holistically delineate alterations in metabolite compositions through the amalgamation of sophisticated analytical chemistry techniques and robust statistical methodologies. Recent advancements in metabolomics research within the realm of pediatric nephrology have been substantial, offering promising avenues for the identification of robust biomarkers, the elaboration of novel therapeutic targets, and the intricate elucidation of molecular mechanisms. The present discourse aims to critically review the progress in metabolomics profiling pertinent to pediatric renal disorders over the previous 12 years.

Concurrent use of continuous kidney replacement therapy during extracorporeal membrane oxygenation: what pediatric nephrologists need to know-PCRRT-ICONIC practice points.

Extracorporeal membrane oxygenation (ECMO) provides temporary cardiorespiratory support for neonatal, pediatric, and adult patients when traditional management has failed. This lifesaving therapy has intrinsic risks, including the development of a robust inflammatory response, acute kidney injury (AKI), fluid overload (FO), and blood loss via consumption and coagulopathy. Continuous kidney replacement therapy (CKRT) has been proposed to reduce these side effects by mitigating the host inflammatory response and controlling FO, improving outcomes in patients requiring ECMO. The Pediatric Continuous Renal Replacement Therapy (PCRRT) Workgroup and the International Collaboration of Nephrologists and Intensivists for Critical Care Children (ICONIC) met to highlight current practice standards for ECMO use within the pediatric population. This review discusses ECMO modalities, the pathophysiology of inflammation during an ECMO run, its adverse effects, various anticoagulation strategies, and the technical aspects and outcomes of implementing CKRT during ECMO in neonatal and pediatric populations. Consensus practice points and guidelines are summarized. ECMO should be utilized in patients with severe acute respiratory failure despite the use of conventional treatment modalities. The Extracorporeal Life Support Organization (ELSO) offers guidelines for ECMO initiation and management while maintaining a clinical registry of over 195,000 patients to assess outcomes and complications. Monitoring and preventing fluid overload during ECMO and CKRT are imperative to reduce mortality risk. Clinical evidence, resources, and experience of the nephrologist and healthcare team should guide the selection of ECMO circuit.

Management of pediatric obesity as a pathway towards kidney transplantation.

Obesity is an increasing problem in pediatrics, leading to cardiovascular, metabolic and psychosocial complications. Additionally, for patients with chronic kidney disease (CKD), obesity can lead to CKD progression towards end-stage renal disease (ESRD) needing renal-replacement therapy (RRT). It is well-established that the optimal type of RRT for children with ESRD is kidney transplantation, as it provides significantly better life expectancy and quality of life. Unfortunately, pediatric patients with CKD/ESRD and obesity face barriers getting to kidney transplantation and often remain on dialysis for a long time, which negatively impacts their life expectancy and quality of life. One barrier to kidney transplant is that Body Mass Index (BMI) is still considered by most transplant centers as the main criterion for obesity assessment, although more recent evidence suggests that BMI is not the best measure of adiposity. Clearcut evidence is lacking that obesity has a long-term negative impact upon the graft. Another barrier to transplant can be bias on the part of referring providers that can deter or delay referral to an obesity treatment program. Our article describes the barriers that pediatric obese patients with CKD and ESRD face in their way towards kidney transplantation. In addition, our article encourages pediatric nephrologists to early refer their patients with CKD and ESRD who suffer from obesity to a specialized obesity treatment program and/or bariatric surgery. Our article also describes the treatment options for pediatric patients with CKD and ESRD who suffer from obesity in order to make them eligible for a kidney transplant.

Progress made toward equitable transplantation in children and young adults with kidney disease.

Racial disparities in pediatric kidney transplantation have been well described over the last two decades and include disparities in preemptive transplantation, waitlisting, time from activation to transplantation, living donation, and graft outcomes. Changes to the organ allocation system including the institution of Share 35 in 2005 and the Kidney Allocation System (KAS) of 2014 have resulted in resolution of some, but not all racial-ethnic disparities. Despite overall improvements in time from waitlist activation to transplant, disparities remain in preemptive transplantation, time to waitlisting, and living donor transplantation. Although improving under the KAS, racial disparities remain in graft survival as well. Racial disparity in kidney transplant access and graft survival is an international problem within pediatric nephrology. Although the racial group affected may differ, various minoritized pediatric groups across the world are affected by transplant disparities. Social determinants of health including financial access, language barriers, and the presence of a healthy living donor play a role in mediating these disparities. Further investigation is needed to better understand and intervene upon modifiable social, biological, and cultural factors driving the remaining disparity in transplant outcomes.

National study on the risks of COVID-19 infection for paediatric kidney transplant recipients: a retrospective, cross-sectional study

IntroductionDuring the COVID-19 pandemic, evidence emerged that immunosuppressed children were less affected by COVID-19 infections compared with immunosuppressed adults. The aim of our study was to investigate how COVID-19 infections...

Low Birth Weight is Associated with More Severe Course of Steroid-Sensitive Nephrotic Syndrome in Children, Multicentric Study.

Several previous studies have reported a more severe course of nephrotic syndrome in children with low birth weight. Cohort of 223 children with idiopathic nephrotic syndrome. We aimed to investigate the association between course of nephrotic syndrome and low birth weight. Data from seven paediatric nephrology centres were used. Children with low birth weight had 3.84 times higher odds for a more severe course of steroid-sensitive nephrotic syndrome (95% CI 1.20-17.22, P=0.041), and those with low birth weight and remission after 7 days had much higher odds for a more severe course of disease (OR 8.7). Low birth weight children had a longer time to remission (median 12 vs. 10 days, P=0.03). They had a higher need for steroid-sparing agents (OR for the same sex=3.26 [95% CI 1.17-11.62, P=0.039]), and the odds were even higher in females with low birth weight (OR 6.81). There was no evidence of an association either between low birth weight and focal segmental glomerulosclerosis or between low birth weight and steroid-resistant nephrotic syndrome. We conducted the first multicentric study confirming the worse outcomes of children with NS and LBW and we found additional risk factors. Low birth weight is associated with a more severe course of steroid-sensitive nephrotic syndrome, while being female and achieving remission after 7 days are additional risk factors.