Increasing frequency of acute kidney injury amongst children hospitalized with nephrotic syndrome

Risk factors and renal outcomes of AKI in children with secondary steroid-resistant nephrotic syndrome

BACKGROUND

Acute kidney injury (AKI) is increasingly prevalent in children with nephrotic syndrome (NS). It is associated with adverse outcomes in NS, especially steroid-resistant nephrotic syndrome (SRNS). The incidence, risk factors and outcomes of AKI in secondary SRNS remain undefined. The main objectives of this study were to determine the risk factors and prognosis of AKI in hospitalized children with secondary SRNS.

MATERIAL AND METHODS

This retrospective study was conducted from January 2014 to December 2019, involving 172 hospitalizations with secondary SRNS admitted to the First Affiliated Hospital of Sun Yat-sen University. AKI was defined and classified in accordance with the 2012 Kidney Disease Improving Global Outcomes (KDIGO) guidelines.

RESULTS

AKI was found in 67 (39.0%) of 172 hospitalizations with secondary SRNS. Average age of onset in our group is 4.4 (3.1, 6.7) years with AKI and 3.7 (1.8, 5.6) years without AKI. Urea nitrogen level is 5.9 (4.1, 10.0) mmol/L with AKI and 5.1 (3.7, 7.0) mmol/L. Uric acid level is 446.0 (340.0, 567.0) umol/L with AKI and 401.0 (303.0, 496.0) umol/L. 24-h urinary protein level is 4.14 (2.9, 6.5) g with AKI and 2.5 (1.3, 5.3) without AKI. Multivariate logistic regression revealed that infection (OR = 5.287; 95% confidence interval, 2.349 to 11.899; p < 0.001), age at onset (OR = 1.180; 95% confidence interval, 1.032 to 1.349; p = 0.015) and uric acid level (OR = 1.003; 95% confidence interval, 1.000 to 1.006; p = 0.031) were significantly associated with the development of AKI in children with secondary SRNS. Among 72 children with secondary SRNS, six went to end-stage kidney disease (ESKD). Children in the AKI group were more likely to progress to ESKD compared with children in the non-AKI group (p = 0.017) with a median follow-up of 48.5months.

CONCLUSION

AKI occurred in 39.0% of total hospitalizations associated with secondary SRNS. Risk factors including infection, age of onset, and uric acid level are associated with AKI in children with secondary SRNS. Furthermore, AKI was identified as a risk factor for the progression of secondary SRNS to ESKD.

Pediatric nephrologist-intensivist interaction in acute kidney injury

INTRODUCTION

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.

METHODS

Retrospective study, longitudinal evaluation of all children with AKI undergoing dialysis (2004 to 2016).

PARAMETERS STUDIED

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.

RESULTS

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.

CONCLUSION

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.

Clinical Profile and Outcomes of Nephrotic Syndrome With Acute Kidney Injury in Adults: A Prospective Cohort Study

BACKGROUND

Nephrotic syndrome (NS) is characterized by various clinicopathological conditions like proteinuria, hypoalbuminemia, and anasarca. Patients with NS are prone to experience associated problems like acute kidney injury (AKI). The present study aimed to investigate the clinical profile and outcomes of NS with AKI in adults.

MATERIALS AND METHODS

This prospective, observational study was conducted over a period of one year. Adult patients with NS diagnosed with AKI were enrolled in the study. Data were collected at baseline and patients were followed up for at least three months.

RESULTS

A total of 60 patients were enrolled. The majority of the patients (78.3%) were aged between 18 and 30 years. Anemia was observed among 96.7% of the patients. A significant improvement was observed in the mean levels of proteinuria (5.80 vs. 1.70 gm/dL; P < 0.001), total cholesterol (270.00 mg/dL vs. 160.00 mg/dL), serum creatinine (2.18 mg/dL vs. 1.68 mg/dL; P < 0.001), and serum albumin (1.86 gm/dL vs. 3.29 gm/dL; P < 0.001) at baseline to three months. Pre-renal AKI was diagnosed in 95% of patients. According to histological classification, 19 patients had minimal change disease, whereas focal segmental glomerulosclerosis was observed in 23 patients. It was observed that 96.7% of the patients did not necessitate the need for renal replacement therapy.

CONCLUSION

The present study successfully examined the clinical profile and outcomes of adults with NS and AKI. The findings provide valuable insights into the characteristics and prognosis of this patient population, contributing to a better understanding of NS with AKI in adults.

Incidence and risk factors of acute kidney injury among childhood nephrotic syndrome: a prospective cohort study

Acute kidney injury (AKI) is a known independent risk factor for morbidity/mortality but there is scarcity of robust data on it among childhood nephrotic syndrome (NS). We assessed the incidence of AKI among hospitalized children with NS as well as looked for any significant risk factors. Prospective observational study conducted across two tertiary pediatric hospitals in Eastern India from September 2020 to August 2021. Children aged 1-18 years admitted with NS and without any nephritic features or pre-existing chronic kidney disease (CKD) were included. In 200 admissions (n = 176; 63% female, median age 4 years [IQR: 3-7]), AKI occurred in 36 (18%; 95% CI 13 to 36%). Two children required kidney replacement therapy and one death was recorded. In 27/36 (75%), AKI resolved within 48 h, 4 had persistent AKI, 3 acute kidney disease, and two progressed to CKD. On multivariate regression analysis: fractional excretion of sodium ≤ 0.2% (OR 12.77; 95% CI 3.5-46.4), male gender (OR 6.38; 95% CI 2.76-14.74), underlying infection (OR 5.44; 95% CI 2.4-11.86), nephrotoxic drugs (OR 4.83; 95% CI 2.21-10.54), and albumin ≤ 1.4 g/dl (OR 4.35; 95% CI 1.55-12.8) were associated with AKI. A predictive equation using these five variables on admission had high AUC (0.86) in correctly identifying 17 children who subsequently developed AKI.   Conclusion: In a low resource setting, AKI is common among hospitalized children with NS. Larger multi-center prospective studies are needed to refine prediction equations and test its utility in preventing AKI development. What is Known: • Acute Kidney Injury is a known independent risk factor for increased morbidity and mortality. • There are few studies to assess the incidence of Acute kidney injury in hospitalised cases of childhood nephrotic syndrome.. What is New: • This is the largest prospective cohort of children suffering from nephrotic syndrome, in India, proposing a novel algorithm for predicting the risk of AKI among hospitalised cases of childhood nephrotic syndrome.

Racial and Ethnic Disparities in Acute Care Utilization Among Patients With Glomerular Disease

RATIONALE & OBJECTIVE

The effects of race, ethnicity, socioeconomic status (SES), and disease severity on acute care utilization in patients with glomerular disease are unknown.

STUDY DESIGN

Prospective cohort study.

SETTING & PARTICIPANTS

1,456 adults and 768 children with biopsy-proven glomerular disease enrolled in the Cure Glomerulonephropathy (CureGN) cohort.

EXPOSURE

Race and ethnicity as a participant-reported social factor.

OUTCOME

Acute care utilization defined as hospitalizations or emergency department visits.

ANALYTICAL APPROACH

Multivariable recurrent event proportional rate models were used to estimate associations between race and ethnicity and acute care utilization.

RESULTS

Black or Hispanic participants had lower SES and more severe glomerular disease than White or Asian participants. Acute care utilization rates were 45.6, 29.5, 25.8, and 19.2 per 100 person-years in Black, Hispanic, White, and Asian adults, respectively, and 55.8, 42.5, 40.8, and 13.0, respectively, for children. Compared with the White race (reference group), Black race was significantly associated with acute care utilization in adults (rate ratio [RR], 1.76 [95% CI, 1.37-2.27]), although this finding was attenuated after multivariable adjustment (RR, 1.31 [95% CI, 1.03-1.68]). Black race was not significantly associated with acute care utilization in children; Asian race was significantly associated with lower acute care utilization in children (RR, 0.32 [95% CI 0.14-0.70]); no significant associations between Hispanic ethnicity and acute care utilization were identified.

LIMITATIONS

We used proxies for SES and lacked direct information on income, household unemployment, or disability.

CONCLUSIONS

Significant differences in acute care utilization rates were observed across racial and ethnic groups in persons with prevalent glomerular disease, although many of these difference were explained by differences in SES and disease severity. Measures to combat socioeconomic disadvantage in Black patients and to more effectively prevent and treat glomerular disease are needed to reduce disparities in acute care utilization, improve patient wellbeing, and reduce health care costs.

Changes in Patterns of Infection Associated with Pediatric Idiopathic Nephrotic Syndrome: A Single-Center Experience in Japan

OBJECTIVE

We studied infection rates and risk factors for infection in current patients with idiopathic nephrotic syndrome (INS).

STUDY DESIGN

This retrospective cohort study included the clinical data for children with diagnosed INS in our center between January 2010 and December 2020. The infection rates and risk factors were analyzed.

RESULTS

We enrolled 187 patients, including 85 cases with steroid-dependent/frequently relapsing nephrotic syndrome and 45 with steroid-resistant nephrotic syndrome. Infection was observed a total of 84 times in 55 patients (95.5 per 1000 person-years). Pneumonia was the most common infection (21 cases, 23.9 per 1000 person-years), followed by febrile neutropenia (12 cases, 13.7 per 1000 person-years), whereas peritonitis and bacteremia were observed in only 3 and 2 cases, respectively. The multivariate analyses by logistic regression showed that rituximab treatment was significantly associated with infections in pediatric INS (P = .001). The infection rate during the B-cell-depleted state with immunosuppressants (318 per 1000 person-years) was greater than that with normal B-cell count with immunosuppressants (109 per 1000 person-years) or without immunosuppressants (76 per 1000 person-years).

CONCLUSION

Common infections, such as peritonitis and bacteremia, decreased, whereas infections associated with medication (eg, rituximab) increased. The rate of infection increases during B-cell depletion after treatments with rituximab and other immunosuppressants.

Risks and renal outcomes of severe acute kidney injury in children with steroid-resistant nephrotic syndrome

BACKGROUND

Risks and renal outcomes of severe acute kidney injury (AKI) in children with steroid-resistant nephrotic syndrome (SRNS), particularly those who require dialysis, have not been fully explored.

METHODS

This retrospective cohort study enrolled children who had been diagnosed with idiopathic nephrotic syndrome at the National Center for Child Health and Development between March 2002 and December 2018. Children with steroid-sensitive nephrotic syndrome or SRNS-related gene mutations were excluded.

RESULTS

Sixty-two children with SRNS (37 boys; median age, 3.6 years [interquartile range (IQR) 2.0-10.3]) were enrolled. Sixteen patients (25.8%) had severe AKI, including nine patients (14.5%) who received dialysis. The period from nephrotic syndrome (NS) onset to partial remission (median [IQR]) was not significantly influenced by dialysis status, but tended to be longer in the dialysis group (125 days [74-225] vs. 40 days [28-113]; p = 0.09); notably, no patient developed chronic kidney disease during the follow-up period. Infection and posterior reversible encephalopathy (PRES) were significantly associated with AKI. Patients with AKI tended to require dialysis in the presence of infection, undergo treatment with cyclosporine A, and have PRES. The period from onset of NS to AKI was significantly longer in the dialysis group (26 days [15.5-46.0] vs. 4 days [0.0-14.0]; p = 0.01).

CONCLUSION

Dialysis was commonly required among children with SRNS who exhibited severe AKI. The period from onset of NS to partial remission tended to be longer in patients receiving dialysis, whereas renal prognosis was satisfactory during subsequent follow-up.

Disease-Associated Systemic Complications in Childhood Nephrotic Syndrome: A Systematic Review

Introduction

Nephrotic syndrome (NS) is one of the most common childhood kidney diseases. During the active phase, the disease pathogenesis affects various biological functions linked to loss of proteins negatively, which can result in systemic complications. Complications of childhood NS are divided into two categories: disease-associated complications and drug-associated complications. However, complications in pediatric patients with NS, especially disease-associated complications are still limited. Although reported in the literature, information is not comprehensive and needs to be updated. This study aimed to systematically assess systemic complications in children with NS, especially disease-associated complications, to better understand how they impact outcomes.

Methods

We conducted a systematic search of several databases: BioMed Central Pediatrics, PubMed, Google Scholar, the National Library of Medicine, Cochrane Library, CINAHL/EBSCO, British Medical Journal, Science Direct, Scopus, and Elsevier’s ClinicalKey. We followed the PRISMA guidelines to plan, conduct, and report this review. We used the Joanna Briggs Institute’s critical appraisal tools for assuring the quality of the journal articles that were chosen.

Results

Eleven articles concerning complications in childhood NS were analyzed. Systemic disease-associated complications in covered were cardiovascular complications, infections, thyroid-hormone complication, kidney complications, and oral health complications.

Conclusion

NS is marked by heavy proteinuria, hypoalbuminemia, edema, and hyperlipidemia, which can result in systemic disease-associated complications. Cardiovascular complications, infections, thyroid-hormone complications, kidney complications, and oral health complications are the main systemic complications in childhood NS. It is essential that health-care providers prevent these complications for proper maintenance of patients’ health.

Acute kidney injury in idiopathic membranous nephropathy with nephrotic syndrome

BACKGROUND AND OBJECTIVES

The impact of acute kidney injury (AKI) on the progression of renal function in idiopathic membranous nephropathy (iMN) with nephrotic syndrome (NS) patients have not yet been reported, we sought to investigate the incidence, clinical features and prognosis of AKI in iMN with NS patients and determine clinical predictors for progression from AKI to advanced chronic kidney disease (CKD) stage.

METHODS

We analyzed clinical and pathological data of iMN with NS patients retrospectively collected from Jan 2012 to Dec 2018. The primary renal endpoint was defined as persistent eGFR <45ml/min per 1.73 m² more than 3 months. Comparisons of survival without primary renal endpoint were performed by Kaplan-Meier curves and log-rank test. Univariate and multivariate Cox proportional hazard models were constructed to determine independent variables associated with primary renal endpoint .

RESULTS

434 iMN with NS patients were enrolled. The incidence of AKI 1 stage, AKI 2 stage and AKI 3 stage was 23.1, 4.8 and 0.7% respectively. 66 (53.2%) patients with AKI had complete renal function recovery and 42 (33.9%) patients with AKI reached primary renal endpoint. Survival without primary renal endpoint was worse in AKI patients than No AKI patients (67.1 ± 5.3 and 43.7 ± 7.3% vs 99.5 ± 0.5 and 92.5 ± 4.2% at 2 and 4 years,p < 0.001). AKI was independently associated with primary renal endpoint, with an adjusted hazard ratio(HR) of 25.1 (95%CI 7.7-82.1, p < 0.001).

CONCLUSIONS

AKI was usually mild and overlooked in iMN patients with NS, but it had a strong association with poor clinical outcomes and was an independent risk factor for CKD progression.

Lower albumin level and longer disease duration are risk factors of acute kidney injury in hospitalized children with nephrotic syndrome

BACKGROUND

Children with nephrotic syndrome (NS) are at an increased risk of acute kidney injury (AKI) and the incidence of AKI in this population is reportedly increasing. This study aimed to investigate the incidence, clinical profiles, and risk factors of AKI in hospitalized children with NS through a nationwide study.

METHODS

This retrospective multicenter study included 14 pediatric nephrology centers in Korea. From 2013 to 2017, a total of 814 patients with idiopathic NS were cared for at participating centers. Among them, 363 patients were hospitalized for NS and investigated in this study.

RESULTS

A total of 363 children with NS were hospitalized 574 times. AKI occurred in 93 admissions (16.2%) of 89 patients: 30 (32.3%) stage 1; 24 (25.8%) stage 2; and 39 (41.9%) stage 3. Multivariate logistic regression analysis showed that longer disease duration, lower albumin level, and methylprednisolone pulse treatment were significantly associated with AKI development in hospitalized children with NS. AKI was associated with a longer hospital stay than non-AKI (median 10 vs. 7 days, P = 0.001). Among 93 admissions, 85 (91.4%) episodes recovered from AKI without complication, whereas 6 (6.5%) progressed to advanced chronic kidney disease (CKD).

CONCLUSIONS

AKI is not uncommon in hospitalized children with NS, and its incidence in this nationwide study was 16.2%. Risk factors for AKI in hospitalized children with NS include longer disease duration, lower albumin level, and methylprednisolone pulse therapy. Pediatric NS patients with these characteristics should be under more strict scrutiny for the occurrence of AKI. Graphical abstract.

Prospects of genetic testing for steroid-resistant nephrotic syndrome in Nigerian children: a narrative review of challenges and opportunities

The prevalence of childhood steroid-resistant nephrotic syndrome (SRNS) ranges from 35% to 92%. This steroid resistance among Nigerian children also reflects underlying renal histopathology, revealing a rare minimal-change disease and a varying burden of membranoproliferative glomerulonephritis and focal segmental glomerulosclerosis (FSGS). FSGS tends to progress to end-stage kidney disease, which requires dialysis and/or renal transplantation. While knowledge of the molecular basis of NS is evolving, recent data support the role of mutant genes that otherwise maintain the structural and functional composition of the glomerular filtration barrier to account for many monogenic forms of FSGS. With the advent of next-generation sequencing, >39 genes are currently associated with SRNS, and the number is likely to increase in the near future. Monogenic FSGS is primarily resistant to steroids, and this foreknowledge obviates the need for steroids, other immunosuppressive therapy, and renal biopsy. Therefore, a multidisciplinary collaboration among cell biologists, molecular physiologists, geneticists, and clinicians holds prospects of fine-tuning the management of SRNS caused by known mutant genes. This article describes the genetics of NS/SRNS in childhood and also gives a narrative review of the challenges and opportunities for molecular testing among children with SRNS in Nigeria. For these children to benefit from genetic diagnosis, Nigeria must aspire to have and develop the manpower and infrastructure required for medical genetics and genomic medicine, leveraging on her existing experiences in genomic medicine. Concerted efforts can be put in place to increase the number of enrollees in Nigeria’s National Health Insurance Scheme (NHIS). The scope of the NHIS can be expanded to cater for the expensive bill of genetic testing within or outside the structure of the National Renal Care Policy proposed by Nigerian nephrologists.

Association of infections and venous thromboembolism in hospitalized children with nephrotic syndrome

BACKGROUND

Nephrotic syndrome (NS) results in hypercoagulability and increased risk of infection. Furthermore, infection increases the risk of venous thromboembolism (VTE). Our objective was to determine the prevalence of infection, VTE, and the associated outcomes among a cohort of hospitalized children with NS.

METHODS

All children with NS admitted to 17 pediatric hospitals across North America from 2010 to 2012 were included. Prevalence of infection and VTE was determined. Wilcoxon rank-sum and logistic regression were performed.

RESULTS

Seven-hundred thirty hospitalizations occurred among 370 children with NS. One-hundred forty-eight children (40%) had ≥ 1 infection (211 episodes) and 11 (3%) had VTE. Those with VTE had infection more frequently (p = 0.046) and were younger at NS diagnosis (3.0 vs. 4.0 years; p = 0.008). The most common infectious pathogen identified was Streptococcus pneumoniae. The median hospital length of stay for those with infection [10 vs 5 days (p < 0.0001)] or VTE [22 vs 6 days (p < 0.0001)] was longer than those without either complication. Of those with infection, 13% had an intensive care unit (ICU) stay compared with 3.3% of those without infection. Median ICU stay was 4 days in those with VTE compared to 0 days in those without (p < 0.001). By logistic regression, only the number of ICU days was associated with VTE (OR 1.074, 95% CI 1.013-1.138).

CONCLUSIONS

Hospitalized children with NS have high rates of infection. Presence of VTE was associated with infection. Both were associated with longer hospitalizations and ICU stays.

Nephrotic Syndrome

Nephrotic syndrome is characterized by edema, proteinuria, hypoalbuminemia, and hyperlipidemia. Minimal change disease, the most common cause in childhood, generally responds to corticosteroids, although most patients experience disease relapses. Focal segmental glomerulosclerosis is usually resistant to corticosteroids and carries a significant risk of kidney failure, necessitating renal transplantation. Nephrotic syndrome may also be secondary to gene mutations and systemic diseases such as lupus. Clinical evaluation involves distinguishing primary and secondary causes and monitoring for disease complications, including blood clots and serious infections such as spontaneous bacterial peritonitis. Immunosuppressive medications are used to prevent relapses and treat corticosteroid-resistant disease.

Childhood nephrotic syndrome at the University of Abuja Teaching Hospital, Abuja, Nigeria: a preliminary report supports high steroid responsiveness

The response to steroid in childhood nephrotic syndrome (CNS) varies across geographical regions, depending on aetiology, genetics, and the underlying pathology. Recently, there is an increasing steroid responsiveness among Nigerian children with nephrotic syndrome (NS). This is the first report of CNS at the University of Abuja Teaching Hospital, Gwagwalada, Abuja, Nigeria, between 15th January 2016 and 30th June 2018. Prednisolone was administered to all the children with NS according to the regimen of the International Study of Kidney Disease in Children. There were 46 children aged 17 months to 18 years, including 37 males and 9 females. The peak age was 6-10 years with a mean age of 8.2 ± 4.4 years. Forty-one (89.1%) had idiopathic NS (INS). Secondary NS occurred in five (10.9%) children with hepatitis B infection, sickle cell anaemia, haemolytic-uraemic syndrome, and post-infectious glomerulonephritis (two cases). Plasmodium malariae was not seen. Overall, steroid-sensitive NS (SSNS) was seen in 34 (73.9%) and in 32 (78%) with INS. Five (16.7%) of the 30 with SSNS relapsed on follow-up. Twelve (26.1%) were resistant to steroid (steroid-resistant NS, SRNS). Renal biopsies in five SRNS revealed focal segmental glomerulosclerosis in three, minimal change lesion in one, and severe interstitial fibrosis/glomerulosclerosis in another one. Four (8.7%) children who had SRNS died. A child with SRNS is surviving on renal transplant from a living-unrelated donor. The study supports the notion that steroid responsiveness is increasing among ethnic black Nigerian children. Pre-treatment renal biopsy may be unwarranted.

Acute kidney injury in childhood-onset nephrotic syndrome: Incidence and risk factors in hospitalized patients

Background

Nephrotic syndrome (NS) is the most common glomerulopathy in children. Acute kidney injury (AKI) is a common complication of NS, caused by severe intravascular volume depletion, acute tubular necrosis, interstitial nephritis, or progression of NS. However, the incidence and risk factors of childhood-onset NS in Korea are unclear. Therefore, we studied the incidence, causes, and risk factors of AKI in hospitalized Korean patients with childhood-onset NS.

Methods

We conducted a retrospective review of patients with childhood-onset NS who were admitted to our center from January 2015 to July 2017. Patients with decreased renal function or hereditary/secondary NS, as well as those admitted for management of other conditions unrelated to NS, were excluded.

Results

During the study period, 65 patients with idiopathic, childhood-onset NS were hospitalized 90 times for management of NS or its complications. Of these 90 cases, 29 met the Kidney Disease Improving Global Outcomes criteria for AKI (32.2%). They developed AKI in association with infection (n = 12), NS aggravation (n = 11), dehydration (n = 3), and intravenous methylprednisolone administration (n = 3). Age ≥ 9 years at admission and combined use of cyclosporine and renin-angiotensin system inhibitors were risk factors for AKI.

Conclusion

AKI occurred in one-third of the total hospitalizations related to childhood-onset NS, owing to infection, aggravation of NS, dehydration, and possibly high-dose methylprednisolone treatment. Age at admission and use of nephrotoxic agents were associated with AKI. As the AKI incidence is high, AKI should be considered during management of high-risk patients.

Acute kidney injury complicating nephrotic syndrome of minimal change disease

Minimal change disease accounts for 70% to 90% of cases of nephrotic syndrome in children. It also causes nephrotic syndrome in adults, including patients older than age 60. Renal function is altered moderately in approximately 20% to 30% of patients because foot-process fusion impairs filtration of water and solutes. The glomerular filtration rate is reduced by approximately 20% to 30% and returns to baseline with remission of proteinuria. Over the past 50 years, a number of publications have reported cases of acute kidney injury occurring in approximately one-fifth to one-third of adult cases in the absence of prior or concomitant renal disease. Clinical attributes point to a male predominance, age >50, massive proteinuria, severe hypoalbuminemia, a background of hypertension and vascular lesions on kidney biopsy, along with ischemic tubular necrosis. Acute kidney injury may require dialysis for weeks or months until remission of proteinuria allows resolution of oliguria. In some cases, renal function does not recover. An effect of endothelin-1-induced vasoconstriction at the onset of proteinuria has been proposed to explain tubular cell ischemic necrosis. The main factors causing acute kidney injury in patients with minimal change disease are diuretic-induced hypovolemia and nephrotoxic agents. Acute kidney injury is uncommon in children in the absence of intercurrent complications. Infection, nephrotoxic medication, and steroid resistance represent the main risk factors. In all patients, the goal of supportive therapy is essentially to buy time until glucocorticoids obtain remission of proteinuria, which allows resolution of renal failure.

Acute kidney injury in children with nephrotic syndrome: a single-center study

Background

Children with nephrotic syndrome (NS) are at risk for the development of acute kidney injury (AKI) through a variety of mechanisms.The frequency of NS hospitalizations complicated by AKI has almost doubled in the last decade. Children with AKI have longer hospital length of stay and increased need for intensive care unit admission. The main objectives of this study were to determine the incidence, clinical characteristics, risk factors and short-term outcome of AKI in children hospitalized with NS.

Methods

In this retrospective study, 355 children ≤18 years of age with a clinical diagnosis of NS admitted in the Department of Nephrology, Gauhati Medical College and Hospital from January 2012 to December 2015 were reviewed.

Results

The incidence of AKI in children with NS was found to be 23.66%, 11.24%, 7.95% and 4.48% of children entered Pediatric Risk, Injury, Failure, Loss, End-Stage Renal Disease (pRIFLE) Stages R, I and F, respectively. Infection {odds ratio [OR] 2.53 [95% confidence interval (CI) 1.52–4.22]} and nephrotoxic medication exposure [OR 7.8 (95% CI 4.06–15.01)] were common factors associated with AKI. Children with steroid-dependent NS (SDNS) and steroid-resistant NS (SRNS) were more likely to develop AKI compared with children with steroid-sensitive NS (SSNS). The mean time to recovery for groups pRIFLE Stages R, I and F were 15 ± 2 , 22 ± 3 and 28 ± 5 days, respectively. Children with NS who were hypertensive, had higher urinary protein excretion and low serum albumin were more prone to develop AKI.

Conclusions

AKI is not uncommon in children with NS. Infection and exposure to nephrotoxic drugs are common factors associated with AKI. AKI is more frequent in SDNS and SRNS compared with SSNS. The mean time to recovery is prolonged with more severe AKI.

Acute Kidney Injury in Nephrotic Syndrome

Nephrotic syndrome (NS) is one of the commonest kidney diseases seen in childhood and is characterized by a relapsing remitting course. Various complications have been reported in children with NS, including infections, thromboembolism, hypovolemia, and acute kidney injury (AKI). There is often a modest decrease in renal function in patients with active proteinuria due to decreased glomerular permeability that improves when they go into remission. However, more pronounced AKI in NS is multifactorial in origin. It is most often secondary to hypovolemia, nephrotoxic medications, and infections, although other reasons may also be seen. Recent years have seen an increase in the incidence of AKI in NS. There is limited data on the correlation between AKI in pediatric NS and long-term outcomes. A better understanding of this increasingly common condition will help improve patient outcomes.

Acute kidney injury in idiopathic nephrotic syndrome of childhood is a major risk factor for the development of chronic kidney disease

Background: Acute kidney injury (AKI) is an important complication of idiopathic nephrotic syndrome (INS) and is associated with adverse outcomes, especially the development of chronic kidney disease (CKD). We aimed to determine the clinical profile of children with INS who developed AKI and its short-term outcome.

Material and methods: This prospective study was conducted from March 2014 to October 2015. A total of 119 children of INS (age: 2–18 years) fulfilling the pediatric RIFLE criteria for the diagnosis of AKI were enrolled and followed up for 3 months to determine the outcome. Factors predisposing to CKD were studied.

Results: The mean age at presentation was 8.8 ± 3.59 years and males were 74 (62.2%). At presentation, 61 (51.3%) children were in Risk category, 43 (36.1%) in Injury category, and 15 (12.6%) in Failure category. Most of them (41.2%) had steroid-resistant nephrotic syndrome (SRNS) and focal segmental glomerulosclerosis (FSGS) on histopathology (33.6%).

Infections were the major predisposing factor for AKI in 67 (56.3%) cases. Drug toxicity was the next common, found in 52 (43.7%) children. A total of 65 (54.6%) children recovered from AKI, while 54 (45.4%) did not. CKD developed in 49 (41.2%) non-recovered cases and 5 (4.2%) children succumbed to acute illness. SRNS, cyclosporine use, FSGS on histology, and drug toxicity were significant factors associated with the development of CKD.

Conclusion: AKI associated with INS is a reversible condition in most cases but it can progress to CKD, especially among those who have SRNS, FSGS, and drug toxicity.

AKI in Children Hospitalized with Nephrotic Syndrome

BACKGROUND AND OBJECTIVES

Children with nephrotic syndrome can develop life-threatening complications, including infection and thrombosis. While AKI is associated with adverse outcomes in hospitalized children, little is known about the epidemiology of AKI in children with nephrotic syndrome. The main objectives of this study were to determine the incidence, epidemiology, and hospital outcomes associated with AKI in a modern cohort of children hospitalized with nephrotic syndrome.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Records of children with nephrotic syndrome admitted to 17 pediatric nephrology centers across North America from 2010 to 2012 were reviewed. AKI was classified using the pediatric RIFLE definition.

RESULTS

AKI occurred in 58.6% of 336 children and 50.9% of 615 hospitalizations (27.3% in stage R, 17.2% in stage I, and 6.3% in stage F). After adjustment for race, sex, age at admission, and clinical diagnosis, infection (odds ratio, 2.24; 95% confidence interval, 1.37 to 3.65; P=0.001), nephrotoxic medication exposure (odds ratio, 1.35; 95% confidence interval, 1.11 to 1.64; P=0.002), days of nephrotoxic medication exposure (odds ratio, 1.10; 95% confidence interval, 1.05 to 1.15; P<0.001), and intensity of medication exposure (odds ratio, 1.34; 95% confidence interval, 1.09 to 1.65; P=0.01) remained significantly associated with AKI in children with nephrotic syndrome. Nephrotoxic medication exposure was common in this population, and each additional nephrotoxic medication received during a hospitalization was associated with 38% higher risk of AKI. AKI was associated with longer hospital stay after adjustment for race, sex, age at admission, clinical diagnosis, and infection (difference, 0.45 [log]days; 95% confidence interval, 0.36 to 0.53 [log]days; P<0.001).

CONCLUSIONS

AKI is common in children hospitalized with nephrotic syndrome and should be deemed the third major complication of nephrotic syndrome in children in addition to infection and venous thromboembolism. Risk factors for AKI include steroid-resistant nephrotic syndrome, infection, and nephrotoxic medication exposure. Children with AKI have longer hospital lengths of stay and increased need for intensive care unit admission.

The Genetics of Nephrotic Syndrome

Nephrotic syndrome (NS) is a common pediatric kidney disease and is defined as massive proteinuria, hypoalbuminemia, and edema. Dysfunction of the glomerular filtration barrier, which is made up of endothelial cells, glomerular basement membrane, and visceral epithelial cells known as podocytes, is evident in children with NS. While most children have steroid-responsive nephrotic syndrome (SSNS), approximately 20% have steroid-resistant nephrotic syndrome (SRNS) and are at risk for progressive kidney dysfunction. While the cause of SSNS is still not well understood, there has been an explosion of research into the genetic causes of SRNS in the past 15 years. More than 30 proteins regulating the function of the glomerular filtration barrier have been associated with SRNS including podocyte slit diaphragm proteins, podocyte actin cytoskeletal proteins, mitochondrial proteins, adhesion and glomerular basement membrane proteins, transcription factors, and others. A genetic cause of SRNS can be found in approximately 70% of infants presenting in the first 3 months of life and 50% of infants presenting between 4 and 12 months, with much lower likelihood for older patients. Identification of the underlying genetic etiology of SRNS is important in children because it allows for counseling of other family members who may be at risk, predicts risk of recurrent disease after kidney transplant, and predicts response to immunosuppressive therapy. Correlations between genetic mutation and clinical phenotype as well as genetic risk factors for SSNS and SRNS are reviewed in this article.

Healthcare burden of venous thromboembolism in childhood chronic renal diseases

BACKGROUND

Chronic renal diseases (CRD) are associated with approximately 5% of pediatric venous thromboembolism (VTE) cases, but the epidemiology of VTE in CRD is ill-defined.

METHODS

Children (<18 years) with CRD were identified from MarketScan® Research databases. The VTE status of subjects with CRD who qualified for this study was ascertained during the 6 months following the initial diagnosis of CRD. Demographics, healthcare utilization, mortality, and co-morbid conditions were assessed.

RESULTS

A total of 22,877 children with predefined CRD ICD-9-CM codes were identified between April 1, 2003 and June 30, 2012, among whom 0.55% had VTE. Our analysis revealed that in-hospital mortality was more likely in children with VTE than in those without VTE (11.9 vs. 0.9%, respectively; p < 0.0001). The usage of healthcare facilities, based on the number of inpatient admissions, length of stay, outpatient visits, and pharmaceutical claims, was also significantly higher in patients with VTE than in those without (p < 0.0001). Total mean healthcare expenditures for the 6-month follow-up period were 13-fold greater in the VTE group than in the group without VTE ($338,338 ± $544,045 vs. $25,171 ± $90,792; p < 0.0001). In a multivariate model, infection, hemodialysis, and trauma/surgery significantly increased the likelihood of VTE.

CONCLUSIONS

Venous thromboembolism is rare in children with CRD, but it is associated with higher mortality and healthcare utilization when present. Among the children with CRD enrolled in our study, the likelihood of VTE was increased among those with co-morbid, non-renal chronic conditions.

Long-Term Outcomes in Children with Steroid-Resistant Nephrotic Syndrome Treated with Calcineurin Inhibitors

BACKGROUND

Steroid-resistant nephrotic syndrome (SRNS) is an important cause of chronic kidney disease (CKD) in children that often progresses to end-stage renal disease (ESRD). Calcineurin inhibitors (CNIs) have been shown to be effective in inducing short-term remission in some patients with SRNS. However, there are little data examining their long-term impact on ESRD progression rates.

METHODS

We performed a retrospective chart review of all patients treated for SRNS with CNIs at our institution from 1995 to 2013. Data collected including demographics, initial response to medical therapy, number of relapses, progression to ESRD, and treatment complications.

RESULTS

A total of 16 patients met inclusion criteria with a mean follow-up of 6.6 years (range 0.6-17.6 years). Histopathological diagnoses were focal segmental glomerulosclerosis (8), mesangial proliferative glomerulonephritis (4), IgM nephropathy (3), and minimal change disease (1). Three patients (18.8%) were unresponsive to CNIs while the remaining 13 (81.2%) achieved remission with CNI therapy. Six patients (37.5%) progressed to ESRD during the study period, three of whom did so after initially responding to CNI therapy. Renal survival rates were 87, 71, and 57% at 2, 5, and 10 years, respectively. Non-Caucasian ethnicity was associated with progression to ESRD. Finally, a higher number of acute kidney injury (AKI) episodes were associated with a lower final estimated glomerular filtration rate.

DISCUSSION

Despite the majority of SRNS patients initially responding to CNI therapy, a significant percentage still progressed to ESRD despite achieving short-term remission. Recurrent episodes of AKI may be associated with progression of CKD in patients with SRNS.

Pathophysiology, Evaluation, and Management of Edema in Childhood Nephrotic Syndrome

Generalized edema is a major presenting clinical feature of children with nephrotic syndrome (NS) exemplified by such primary conditions as minimal change disease (MCD). In these children with classical NS and marked proteinuria and hypoalbuminemia, the ensuing tendency to hypovolemia triggers compensatory physiological mechanisms, which enhance renal sodium (Na(+)) and water retention; this is known as the "underfill hypothesis." Edema can also occur in secondary forms of NS and several other glomerulonephritides, in which the degree of proteinuria and hypoalbuminemia, are variable. In contrast to MCD, in these latter conditions, the predominant mechanism of edema formation is "primary" or "pathophysiological," Na(+) and water retention; this is known as the "overfill hypothesis." A major clinical challenge in children with these disorders is to distinguish the predominant mechanism of edema formation, identify other potential contributing factors, and prevent the deleterious effects of diuretic regimens in those with unsuspected reduced effective circulatory volume (i.e., underfill). This article reviews the Starling forces that become altered in NS so as to tip the balance of fluid movement in favor of edema formation. An understanding of these pathomechanisms then serves to formulate a more rational approach to prevention, evaluation, and management of such edema.

Nephrotic and nephritic syndrome in the newborn

Glomerular disorders in infancy can include nephrotic and nephritic syndromes. Congenital nephrotic syndrome (CNS) is most commonly caused by single gene mutations in kidney proteins, but may also be due to congenital infections or passive transfer of maternal antibodies that target kidney proteins. Prenatal findings of increased maternal serum α-fetoprotein and enlarged placenta suggest CNS. Neonatal nephritis is rare; its causes may overlap with those of CNS and include primary glomerulonephritis, systemic disease, infections, and transplacental transfer of maternal antibodies. These syndromes in the neonate can cause significant morbidity and mortality, making urgent diagnosis and treatment necessary.