Fluid management in children with volume depletion.

Volume depletion is a common condition and a frequent cause of hospitalization in children. Proper assessment of the patient includes a detailed history and a thorough physical examination. Biochemical tests may be useful in selected cases. Understanding the pathophysiology of fluid balance is necessary for appropriate management. A clinical dehydration scale assessing more physical findings may help to determine dehydration severity. Most dehydrated children can be treated orally; however, intravenous therapy may be indicated in patients with severe volume depletion, in those who have failed oral therapy, or in children with altered consciousness or significant metabolic abnormalities. Proper management consists of restoring circulatory volume and electrolyte balance. In this paper, we review clinical aspects, diagnosis, and management of children with volume depletion.

Proliferative glomerulonephritis with monoclonal IgG deposits in an adolescent successfully treated with daratumumab.

There is no specific treatment for proliferative glomerulonephritis with monoclonal IgG deposits (PGNMID), a disease that is very rare in the pediatric population. We report the case of a 15-year-old boy who presented with mildly reduced kidney function and nephrotic syndrome. Kidney biopsy revealed PGNMID with monoclonal deposits of IgG3 with kappa light chain restriction. Flow cytometry showed a significant CD38 plasma cell population in the peripheral blood in the absence of other signs of hematological malignancy. The patient was treated with a 6-month course of daratumumab, a monoclonal antibody targeting CD38. There was a significant reduction in proteinuria and normalization of kidney function. Based on positive experience with adults, daratumumab should also be studied in children with PGNMID.

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

BACKGROUND: Several previous studies have reported a more severe course of nephrotic syndrome in children with low birth weight. PATIENTS: Cohort of 223 children with idiopathic nephrotic syndrome. METHODS: We aimed to investigate the association between course of nephrotic syndrome and low birth weight. Data from seven paediatric nephrology centres were used. RESULTS: 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. DISCUSSION: We conducted the first multicentric study confirming the worse outcomes of children with NS and LBW and we found additional risk factors. CONCLUSIONS: 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.

Eculizumab use in patients with pneumococcal-associated hemolytic uremic syndrome and kidney outcomes.

BACKGROUND: Streptococcus pneumoniae-associated hemolytic uremic syndrome (P-HUS) is a rare and severe disease. Only a few reports have been published about eculizumab use in P-HUS. METHODS: We analyzed demographic, clinical, and laboratory data of patients with P-HUS from our center. RESULTS: The cohort consisted of 4 females and 3 males. All patients had pneumonia. Four were given eculizumab (days 1-3). The eculizumab group required a shorter duration of dialysis and mechanical ventilation (medians 20 vs. 28.5 and 30 vs 38.5 days, respectively) compared with the non-eculizumab group, but this was still much longer than normally reported; the thrombocytopenia resolution was similar in both groups (medians 10 vs. 8 days). Chronic kidney disease (CKD) was correlated with the duration of dialysis and mechanical ventilation duration at 1 year (r = 0.797, P = 0.032 and r = 0.765, P = 0.045) and last follow-up (r = 0.807, P = 0.028 and r = 0.814, P = 0.026, respectively); our scoring system showed even stronger correlations (r = 0.872, P = 0.011 and r = 0.901, P = 0.0057, respectively). The eculizumab group showed slightly better 1-year and last follow-up CKD stage (2.75 vs. 3, P = 0.879 and 2.5 vs. 3.67, P = 0.517). CONCLUSIONS: Despite the fact that the eculizumab group showed better outcomes, eculizumab does not seem to improve the course of P-HUS compared with previous reports. Kidney outcomes are strongly correlated with the duration of dialysis and mechanical ventilation duration. A higher resolution version of the Graphical abstract is available as Supplementary information.

Severe Acute Kidney Injury in Children as a Rare Complication of Paroxysmal Cold Hemoglobinuria.

Paroxysmal cold hemoglobinuria (PCH) is a rare condition in childhood characterized by complement-mediated premature destruction of red blood cells. PCH is associated with intravascular hemolysis causing hemoglobinuria, which may result in acute kidney injury of various severity. We aimed to retrospectively analyze clinical and laboratory features of children with PCH-associated acute kidney injury received at tertiary Pediatric Hematology and Nephrology Center, University Motol Hospital, Prague, Czech Republic during the period 2016 to 2022. We present here 3 children with PCH-associated acute kidney failure requiring renal replacement therapy. We highlight the association of PCH with kidney disease. Renal parameters and urine examination should be regularly tested in all children with PCH.

Genetic nephrotic syndrome associated with disturbed function of glomerular slit membrane and podocyte cytoskeleton in children.

BACKGROUND: Genetic nephrotic syndrome is caused by pathogenic variants in genes encoding proteins necessary for the stability and functionality of the glomerular filtration barrier. To date, more than 70 genes associated with steroid-resistant nephrotic syndrome have been identified. We review the clinical and molecular aspects of genetic nephrotic syndrome with a particular focus on genes associated with slit membrane and podocyte cytoskeleton defects. Sanger sequencing and next-generation sequencing are widely used in the identification of novel gene variants and help us gain a better understanding of the disease. Despite these findings, therapy is mainly supportive and focused on the reduction of proteinuria and management of chronic kidney disease with an unfavorable outcome for a significant proportion of cases. Positive therapeutic effects of immunosuppressive drugs have been reported in some patients; however, their long-time administration cannot be generally recommended. CONCLUSION: Personalized treatment based on understanding the distinct disease pathogenesis is needed. With this, it will be possible to avoid harmful immunosuppressive therapy and improve outcomes and quality of life for pediatric patients suffering from genetic nephrotic syndrome.

Abnormal kidney ultrasound and function in a five-year-old boy born prematurely with a birth weight of 370 grams.

It is known that prematurity and low birth weight are associated with chronic kidney disease and hypertension. A positive correlation between kidney volume and birth weight was also described. In our ongoing observational study in 5-year-old children, we perceived highly abnormal kidney ultrasound and functions of a male patient born weighing 370 grams. It was his first nephrology examination since discharge from the hospital. We believe that thorough follow up and timely diagnosis of developing renal insufficiency may help us to initiate proper treatment in high-risk children (Tab. 1, Fig. 1, Ref. 7). Text in PDF www.elis.sk Keywords: prematurity; extremely low birth weight; chronic kidney disease; renal ultrasound; renal function.

Practical recommendations for the management of children after kidney and liver transplantation.

The number of pediatric solid organ transplantations is growing. This therapy leads often to better quality of life but also brings some specific complications. Our review summarizes practical recommendations for long-time care of the children after kidney and liver transplantation. The knowledge of the issues related to transplantation is essential for the first contact physicians, whose cooperation with transplant centre contributes highly to adequate management of these children.

Diagnosis and management of hypernatraemia in children.

Hypernatraemia is most commonly caused by excessive loss of solute-free water or decreased fluid intake; less often, the aetiology is salt intoxication. Especially infants, young children and individuals with a lack of access to water are at risk of developing hypernatraemia. Diagnosis is based on detailed history, physical examination and basic laboratory tests. Correction of hypernatraemia must be slow to prevent cerebral oedema and irreversible brain damage. This article reviews the aetiology, differential diagnosis and management of conditions associated with paediatric hypernatraemia. Distinguishing states with water deficiency from states with salt excess is important for proper management of hypernatraemic patients.

Bartter and Gitelman syndromes.

Bartter and Gitelman syndromes belong to salt-losing tubulopathies. These rare diseases may be associated with severe electrolyte disorders. Early identification of tubulopathies is essential for appropriate management. Progress in molecular genetics enabled the identification of genes and pathophysiologic mechanisms associated with these diseases. Here, we review etiology and diagnostics of these disorders from the light of current knowledge. Additionally, we discuss contemporary therapeutic approaches.

Molecular basis and outcomes of atypical haemolytic uraemic syndrome in Czech children.

Atypical haemolytic uraemic syndrome is an ultra-rare, life-threatening disease. Causative variants in genes that encode complement factors can be identified in 40-70% of cases. We performed genetic analysis of 21 Czech children with atypical haemolytic uraemic syndrome. Genetic or acquired predisposition to the disease was identified in the majority of our patients: CFHR1 and CFHR3 deletions in 14/21 (67%; 13 of them were positive for anti-complement factor H antibodies), variants in complement genes or DGKE in 13/21 (62%). Multiple genetic findings were identified in eight patients (38%). The incidence of atypical haemolytic uraemic syndrome in the Czech paediatric population was estimated to be 0.092 (CI 0.053-0.131) cases per million inhabitants and 0.92 (CI 0.53-1.32) cases per 100,000 births for the entire reporting period. Ten patients were initially treated with plasma exchange and eight with eculizumab or with a combination of eculizumab and plasma exchange. At the last follow-up, 20 patients were alive and one patient had end-stage renal disease.Conclusion: The incidence of atypical haemolytic uraemic syndrome in the Czech paediatric population corresponds to the reported incidence in Europe. We detected the unusually high rate of CFHR1/CFHR3 deletions associated with anti-complement factor H antibodies in Czech paediatric patients. Treatment by eculizumab led to superior outcomes and prevention of the disease relapses compared with plasma exchange therapy. Our results may help to understand the polygenic nature of atypical haemolytic uraemic syndrome as a disease that results from a combination of various risk factors. What is Known: • Atypical haemolytic uraemic syndrome (aHUS) is considered a polygenic and multifactorial disease. Genetic predisposition to aHUS is identified in 40-70% of children. • Anti-complement factor H antibodies are usually found in 6-25% of affected children. What is New: • Potentially causative genetic or acquired factors were confirmed in the majority of patients. The prevailing finding was the unusually high rate of CFHR1/CFHR3 deletions associated with anti-complement factor H antibodies (62% of patients). • The incidence of aHUS in Czech children is 0.092 (CI 0.053-0.131) cases per million inhabitants and 0.92 (CI 0.53-1.32) cases per 100,000 births for the entire reporting period.

Influenza-associated thrombotic microangiopathies.

Thrombotic microangiopathy (TMA) refers to phenotypically similar disorders, including hemolytic uremic syndromes (HUS) and thrombotic thrombocytopenic purpura (TTP). This review explores the role of the influenza virus as trigger of HUS or TTP. We conducted a literature survey in PubMed and Google Scholar using HUS, TTP, TMA, and influenza as keywords, and extracted and analyzed reported epidemiological and clinical data. We identified 25 cases of influenza-associated TMA. Five additional cases were linked to influenza vaccination and analyzed separately. Influenza A was found in 83%, 10 out of 25 during the 2009 A(H1N1) pandemic. Two patients had bona fide TTP with ADAMTS13 activity <10%. Median age was 15 years (range 0.5-68 years), two thirds were male. Oligoanuria was documented in 81% and neurological involvement in 40% of patients. Serum C3 was reduced in 5 out of 14 patients (36%); Coombs test was negative in 7 out of 7 and elevated fibrin/fibrinogen degradation products were documented in 6 out of 8 patients. Pathogenic complement gene mutations were found in 7 out of 8 patients tested (C3, MCP, or MCP combined with CFB or clusterin). Twenty out of 24 patients recovered completely, but 3 died (12%). Ten of the surviving patients underwent plasma exchange (PLEX) therapy, 5 plasma infusions. Influenza-mediated HUS or TTP is rare. A sizable proportion of tested patients demonstrated mutations associated with alternative pathway of complement dysregulation that was uncovered by this infection. Further research is warranted targeting the roles of viral neuraminidase, enhanced virus-induced complement activation and/or ADAMTS13 antibodies, and rational treatment approaches.

Genetic diagnosis of steroid-resistant nephrotic syndrome in a longitudinal collection of Czech and Slovak patients: a high proportion of causative variants in NUP93.

BACKGROUND: Steroid-resistant nephrotic syndrome (SRNS) has a heterogeneous spectrum of monogenic causes that substantially differ among populations. The aim of this study was to analyse the genetic aetiology of SRNS in Czech and Slovak paediatric patients. METHODS: We analysed clinical data from 74 patients (38 boys) with congenital (15%), infant (14%), and childhood-onset (71%) SRNS collected from the Czech Republic and Slovakia from 2000 to 2017 (inclusive). The DNA samples were first analysed by Sanger sequencing (genes NPHS2, NPHS1, and WT1) and then by next generation sequencing (NGS) using a targeted panel of 48 genes previously associated with SRNS. Family segregation of the causative variants was confirmed by Sanger sequencing when possible. RESULTS: Genetic diagnosis was established in 28/74 patients (38%) based on findings of pathogenic or likely pathogenic causative variants in genotypes conforming to the expected mode of inheritance. Sanger sequencing diagnosed 26% of patients, whereas second-tier testing by a targeted NGS panel diagnosed a further 12%. Frequent causative genes were NPHS2 (15%), WT1 (9.5%), and surprisingly NUP93 with four (5.4%) unrelated cases. Additional causative genes included COQ2 (two patients), NPHS1, INF2, DGKE, and LMX1B (one patient each). CONCLUSIONS: Compared with outright use of NGS, our tiered genetic testing strategy was considerably more rapid and marginally less expensive. Apart from a high aetiological fraction of NPHS2 and WT1 genes, our study has identified an unexpectedly high frequency of a limited set of presumably ancestral causative mutations in NUP93. The results may aid in tailoring testing strategies in Central European populations.

Complement activation is associated with more severe course of diarrhea-associated hemolytic uremic syndrome, a preliminary study.

Diarrhea-associated hemolytic uremic syndrome is characterized by hemolytic anemia, thrombocytopenia, and acute kidney injury secondary to enteric infection, typically Shiga toxin-producing Escherichia coli. Shiga toxin 2 is able to activate alternative complement pathways; therefore, the aim of the study was to analyze C3 as a predictor of clinical courses in patients with diarrhea-associated hemolytic uremic syndrome. We hypothesized that the patients with increased complement activation at admission suffered from a more severe course. We retrospectively analyzed data of 33 pediatric patients between 1999 and 2015 in the Czech Republic. We tested the association of a C3 concentration with biochemical parameters and the clinical data reflecting the severity of the disease. We found significant correlation between the initial C3 and the duration of renal replacement therapy (r = - 0.62, p = 0.0001) and the initial glomerular filtration rate (r = 0.36, p = 0.026). Patients with C3 < 0.825 g/L needed renal replacement therapy and also had significantly more renal complications (p = 0.015).Conclusion: Based on our study, decreased C3 concentrations can be used as one of the risk factors that can help predict the need for acute dialysis and a more severe course of disease in children with diarrhea-associated hemolytic uremic syndrome. What is Known: • Shiga toxin modulates the function of complement regulatory proteins and thus contributes to complement activation in patients with diarrhea-associated hemolytic uremic syndrome. • Risk factors that can predict the need for acute renal replacement therapy and poor outcome in patients with diarrhea-associated hemolytic uremic syndrome are mainly the combination of oligoanuria, dehydration, leukocytosis, high hematocrit > 23%, and neurological involvement. What is New: • A lowered concentration of C3 at the time of initial presentation of diarrhea-associated hemolytic uremic syndrome was associated with more severe renal failure and the need for renal replacement therapy along with the development of more extra renal complications. • Decreased C3 at admission can predict complicated course of diarrhea-associated hemolytic uremic syndrome.

Urinary Neutrophil Gelatinase-Associated Lipocalin Does Not Distinguish Acute Rejection from Other Causes of Acute Kidney Injury in Pediatric Renal Transplant Recipients.

BACKGROUND: The aim of this prospective single center study was to investigate the ability of urinary neutrophil gelatinase-associated lipocalin (NGAL) to distinguish acute rejection from other causes of acute kidney injury (AKI) in children after renal transplantation. METHODS: Fifteen children fulfilled the inclusion criteria (acute kidney injury (AKI) with allograft biopsy, at least 21 days after renal transplantation, no sepsis) during 2013 - 2014 in our pediatric transplantation center. The mean age was 14.8  2.8, median time after renal transplantation was 0.4 years (range 0.1 - 3.8). Urinary NGAL was measured in spot urine by Chemiluminescent Microparticle Immunoassay technology. RESULTS: Four patients had biopsy proven acute rejection (rejection group), eleven children had AKI of other cause (non-rejection group). The median urinary NGAL concentration in the rejection group was not significantly different from NGAL in the non-rejection group (7.3 ng/mL, range 3.0 - 42.3 vs. 8.6 ng/mL, range 3.4 - 54.7, p = 0.48). There was a significant negative correlation between eGFR and urinary NGAL concentrations (r = -0.77, p < 0.001). CONCLUSIONS: Our small study suggests that in children after renal transplantation, urinary NGAL cannot be used as a specific marker for distinguishing acute rejection from other non-rejection causes of AKI. Urinary NGAL was mainly associated with graft function but not with the etiology of AKI.