Lithium poisoning and renal replacement therapy: pathophysiology and current clinical recommendations

Lithium intoxication is still an undefined and underestimated disease, especially those cases requiring extracorporeal treatment. Lithium is a monovalent cation with small molecular mass of 7 Da that has been regularly and successfully used since 1950 in the treatment of mania and bipolar disorders. However, its careless assumption can lead to a wide spectrum of cardiovascular, central nervous system and kidney diseases in case of acute, acute on chronic and chronic intoxications. In fact, lithium serum range is strict between 0.6 and 1.3 mmol/L, with a mild lithium toxicity observed at the steady-state of 1.5-2.5 mEq/L, moderate toxicity when lithium reaches 2.5-3.5 mEq/L, and severe intoxication with observed serum levels > 3.5 mEq/L. Its favorable biochemical profile allows the complete filtration and partial reabsorption in the kidney due to the similarity to sodium and also the complete removal by renal replacement therapy, that should be considered in specific poisoning conditions. In this narrative and updated review we discussed a clinical case of lithium intoxication, the different pattern of diseases attributable to excessive lithium load and the current indications for extracorporeal treatment.

Multi-population genome-wide association study implicates immune and non-immune factors in pediatric steroid-sensitive nephrotic syndrome

Pediatric steroid-sensitive nephrotic syndrome (pSSNS) is the most common childhood glomerular disease. Previous genome-wide association studies (GWAS) identified a risk locus in the HLA Class II region and three additional independent risk loci. But the genetic architecture of pSSNS, and its genetically driven pathobiology, is largely unknown. Here, we conduct a multi-population GWAS meta-analysis in 38,463 participants (2440 cases). We then conduct conditional analyses and population specific GWAS. We discover twelve significant associations-eight from the multi-population meta-analysis (four novel), two from the multi-population conditional analysis (one novel), and two additional novel loci from the European meta-analysis. Fine-mapping implicates specific amino acid haplotypes in HLA-DQA1 and HLA-DQB1 driving the HLA Class II risk locus. Non-HLA loci colocalize with eQTLs of monocytes and numerous T-cell subsets in independent datasets. Colocalization with kidney eQTLs is lacking but overlap with kidney cell open chromatin suggests an uncharacterized disease mechanism in kidney cells. A polygenic risk score (PRS) associates with earlier disease onset. Altogether, these discoveries expand our knowledge of pSSNS genetic architecture across populations and provide cell-specific insights into its molecular drivers. Evaluating these associations in additional cohorts will refine our understanding of population specificity, heterogeneity, and clinical and molecular associations.

Uromodulin and Vesico-Ureteral Reflux: A Genetic Study

Vesicoureteral reflux (VUR) is associated with urinary tract infections (UTI) and renal scars. The kidney damage is correlated with the grade of reflux and the number of UTI, but other factors may also play a role. Uromodulin (UMOD) is a protein produced by kidney tubular cells, forming a matrix in the lumen. We evaluated whether the common variant rs4293393 in the UMOD gene was associated with febrile UTI (FUTI) and/or scars in a group of children with VUR. A total of 31 patients with primary VUR were enrolled. Renal scars were detected in 16 children; no scar was detected in 15 children. Genotype rs4293393 TC (TC) was present in 8 patients, 7 (88%) had scars; genotype rs4293393 TT (TT) was found in 23 patients, and 9 (39%) had scars. Among children with scars, those with TC compared with those with TT were younger (mean age 77 vs. 101 months), their reflux grade was comparable (3.7 vs. 3.9), and the number of FUTI was lower (2.9 vs. 3.7 per patient). Children with VUR carrying UMOD genotype rs4293393 TC seem more prone to developing renal scars, independent of FUTI.

Childhood Idiopathic Nephrotic Syndrome: Does the Initial Steroid Treatment Modify the Outcome? A Multicentre, Prospective Cohort Study

Background: A great majority of children with idiopathic nephrotic syndrome will relapse after successful treatment of the initial episode. The possibility that different steroid dosing regimens at onset, adjusted for risk factors, can reduce the rate of relapse represents an interesting option to investigate. Objectives: To evaluate the effect of the initial steroid regimen, adjusted for time to remission (TTR), on the frequency of relapses and steroid dependence, and to verify the influence of prognostic factors on disease course. Methods: A multicentre, prospective, cohort study. Children with nephrotic syndrome, with TTR ≤ 10 days (Group A), were given a 20-week prednisone regimen (2,828 mg/m2) and those with a TTR >10 days, a 22-week regimen (3,668 mg/m2) (Group B). Previously published retrospective data from the same centers were also evaluated. Main outcomes were: relapse rate, number of frequent relapsers + steroid dependent children and total prednisone dose after induction. Results: 143 children were enrolled. Rate of relapsed subjects (77 vs. 79%) and frequent relapsers + steroid dependent subjects (40 vs. 53%) did not differ between Groups A and B, or between the retrospective and prospective cohorts. The cumulative prednisone dose taken after the induction treatment was similar in both groups and in the retrospective and prospective cohorts. TTR was not associated with relapse risk. Age at onset and total serum protein were significantly lower in relapsing patients. At ROC analysis, the best cut-off was 5.3 years for age at onset and 4.2 g/dL for total serum protein. According to these cut-offs, older children with higher total serum protein had a higher relapse free survival rate (58%) than younger children with lower total serum protein (17%). Conclusions: TTR was not found to be a prognostic factor of relapse; because of this, different steroid regimens, adjusted for TTR, did not modify the relapse rate in any relevant measure. Conversely, younger age and low total serum protein were independent predictors of relapse risk, however this outcome was not modified by higher prednisone regimens. Clinical Trial Registration:https://www.ClinicalTrials.gov/, identifier: NCT01386957 (www.nefrokid.it).

Updated Italian recommendations for the diagnosis, treatment and follow-up of the first febrile urinary tract infection in young children

AIM

Our aim was to update the recommendations for the diagnosis, treatment and follow-up of the first febrile urinary tract infection in young children, which were endorsed in 2012 by the Italian Society of Pediatric Nephrology.

METHODS

The Italian recommendations were revised on the basis of a review of the literature published from 2012 to October 2018. We also carried out an ad hoc evaluation of the risk factors to identify children with high-grade vesicoureteral reflux or renal scarring, which were published in the previous recommendations. When evidence was not available, the working group held extensive discussions, during various meetings and through email exchanges.

RESULTS

Four major modifications have been introduced. The method for collecting urine for culture and its interpretation has been re-evaluated. We have reformulated the algorithm that guides clinical decisions to proceed with voiding cystourethrography. The suggested antibiotics have been revised, and we have recommended further restrictions of the use of antibiotic prophylaxis.

CONCLUSION

These updated recommendations have now been endorsed by the Italian Society of Pediatric Nephrology and the Italian Society for Pediatric Infectivology. They can also be used to compare other recommendations that are available, as a worldwide consensus in this area is still lacking.

First urinary tract infections in children: the role of the risk factors proposed by the Italian recommendations

AIM

In 2009, the Italian society for paediatric nephrology suggested the need for cystography, following a first febrile urinary tract infection (UTI), only in children at high risk for dilating vesicoureteral reflux or in the event of a second infection. The aim of this study was to evaluate the adequacy of the risk factors proposed by the Italian guidelines.

METHODS

Children aged 2-36 months, managed by 10 Italian hospitals between 2009 and 2013, with a first febrile UTI were retrospectively evaluated.

RESULTS

Four hundred and fourteen children were included: 51% female, mean age eight months. Escherichia coli was responsible of 84% UTIs. 269 children (65%) presented at least one risk factor, thus were further investigated: 44% had a reflux. The presence of a pathogen other than E. coli significantly predicted high-grade reflux, both in the univariate (Odd Ratio 2.52, 95% Confidence Interval 1.32-4.81, p < 0.005) and multivariate analysis (OR 2.74, 95% CI: 1.39-5.41, p: 0.003). 26/145 children (18%) with no risk factors experienced a second UTI, which prompted the execution of cystography, showing a dilating reflux in 11.

CONCLUSION

Among the risk factors proposed by the Italian guidelines, only the presence of a pathogen other than E. coli significantly predicted reflux. Cystography can be postponed in children with no risk factors.

[Survey on the Prevalence of Rare Kidney Diseases in Sicily]

Renal Diseases represent almost 6% of all Rare Diseases but are often misdiagnosed. In a survey made in Sicily in 2016, based on cases reported from all public hospitals according to a list of rare kidney diseases, we were able to collect 337 cases (199 males and 138 females). The highest prevalence was detected in children: 13.9 cases in 100.000 children; the mean age was 10, and the median 5 years, at the time of the diagnosis. Comparing our data with those available in the Sicilian Register of Rare Diseases we found that only 141 cases (54%) were present in the register. Promoting regional registries of rare kidney diseases in Italy may be useful for epidemiologic studies.

Acute renal insufficiency and pancreatitis in a child with atypical Henoch-Schönlein purpura: efficacy of a single dose of cyclophosphamide

A 9-year-old boy with petechiae on the legs and abdominal pain was unsuccessfully treated with steroids. He was admitted to our hospital for the onset of fever, ecchymosis, and arthralgia. Skin lesions suggested vasculitis, but they were not typical of Henoch–Schönlein purpura. He showed ecchymosis of the scrotal bursa, diffusion of petechiae to the trunk and arms, vomiting, severe abdominal pain, oliguria with hyponatremia, hypoalbuminemia, low C3 levels, high levels of creatinine, blood urea nitrogen, and tubular enzymes, proteinuria, and glycosuria. The urinary sediment showed macrohaematuria, and hyaline and cellular casts. Ultrasound showed polyserositis. He was treated with intravenous furosemide, albumin, and methylprednisolone. He underwent colonoscopy and gastroscopy because of development of acute pancreatitis and severe anaemia. Typical lesions of Henoch–Schönlein purpura were observed in the small intestine and colon mucosa. He received three high doses of methylprednisolone, followed by intravenous cyclophosphamide. A dramatic and persistent response was observed after these doses. A single high dose of cyclophosphamide is appropriate in Henoch–Schönlein purpura with acute renal failure and severe pancreatitis that are non-responsive to high-dose steroids.

Fourier Transform Infrared Analysis of Urinary Calculi and Metabolic Studies in a Group of Sicilian Children

INTRODUCTION

Prevalence of urinary calculi in children has been increasing in the past years. We performed an analysis of the chemical composition of stones formers of the pediatric population in our geographical area over the years 2005 to 2013.

MATERIALS AND METHODS

Fourier transform infrared spectroscopy was employed for the determination of the calculus composition of a group of Sicilian children, and metabolic studies were performed to formulate the correct diagnosis and establish therapy.

RESULTS

The prevalence of stone formation was much higher for boys than for girls, with a sex ratio of 1.9:1. The single most frequent component was found to be calcium oxalate monohydrate, and calcium oxalates (pure or mixed calculi) were the overall most frequent components. Calcium phosphates ranked 2nd for frequency, most often in mixed calculi, while urates ranked 3rd. The metabolic disorder most often associated with pure calcium oxalate monohydrate calculi was hypocitraturia, while hyperoxaluria was predominantly associated with calcium oxalate dihydrate calculi.

CONCLUSIONS

Mixed calculi had the highest prevalence in our pediatric population. Our data showed that Fourier transform infrared spectroscopy was a useful tool for the determination of the calculi composition.

The Italian Society for Pediatric Nephrology (SINePe) consensus document on the management of nephrotic syndrome in children: Part I - Diagnosis and treatment of the first episode and the first relapse

This consensus document is aimed at providing an updated, multidisciplinary overview on the diagnosis and treatment of pediatric nephrotic syndrome (NS) at first presentation. It is the first consensus document of its kind to be produced by all the pediatric nephrology centres in Italy, in line with what is already present in other countries such as France, Germany and the USA. It is based on the current knowledge surrounding the symptomatic and steroid treatment of NS, with a view to providing the basis for a separate consensus document on the treatment of relapses. NS is one of the most common pediatric glomerular diseases, with an incidence of around 2-7 cases per 100000 children per year. Corticosteroids are the mainstay of treatment, but the optimal therapeutic regimen for managing childhood idiopathic NS is still under debate. In Italy, shared treatment guidelines were lacking and, consequently, the choice of steroid regimen was based on the clinical expertise of each individual unit. On the basis of the 2015 Cochrane systematic review, KDIGO Guidelines and more recent data from the literature, this working group, with the contribution of all the pediatric nephrology centres in Italy and on the behalf of the Italian Society of Pediatric Nephrology, has produced a shared steroid protocol that will be useful for National Health System hospitals and pediatricians. Investigations at initial presentation and the principal causes of NS to be screened are suggested. In the early phase of the disease, symptomatic treatment is also important as many severe complications can occur which are either directly related to the pathophysiology of the underlying NS or to the steroid treatment itself. To date, very few studies have been published on the prophylaxis and treatment of these early complications, while recommendations are either lacking or conflicting. This consensus provides indications for the prevention, early recognition and treatment of these complications (management of edema and hypovolemia, therapy and prophylaxis of infections and thromboembolic events). Finally, recommendations about the clinical definition of steroid resistance and its initial diagnostic management, as well as indications for renal biopsy are provided.

Mutational Spectrum of CYP24A1 Gene in a Cohort of Italian Patients with Idiopathic Infantile Hypercalcemia

BACKGROUND/AIMS

Loss-of-function mutations in the CYP24A1 gene, which encodes the vitamin D-24 hydroxylase, have been recognized as a cause of elevated 1,25-dihydroxyvitamin D concentrations, hypercalcemia, hypercalciuria, nephrocalcinosis and nephrolithiasis in infants and adults. As only a case report describing 2 adult patients has been reported in Italian population, we report here the mutation analysis of CYP24A1 gene in an Italian cohort of 12 pediatric and adult patients with idiopathic infantile hypercalcemia (IIH).

METHODS

We performed mutational screening of CYP24A1 gene in a cohort of 12 Italian patients: 8 children with nephrocalcinosis, hypercalcemia and PTH levels <10 pg/ml and 4 adult patients with nephrolithiasis, mild hypercalcemia and PTH levels <10 pg/ml from 11 unrelated Italian families. Clinical and biochemical data were collected. Genomic DNA was extracted from peripheral blood leucocytes using standard methods, and whole coding sequence of CYP24A1 gene was analysed in all patients and family members by polymerase chain reaction and direct sequencing. The potential pathogenicity of the newly identified missense mutations was evaluated by 3 different in silico approaches (Sorting Intolerant from Tolerant, Polyphen and Mutation Taster) and by comparative analysis in 14 different species using ClustalW software.

RESULTS

CYP24A1 bi-allelic mutations were found in 8 individuals from 7 Italian families (7/11; 64%). Overall, 6 different CYP24A1 mutations, including one small deletion (p.Glu143del), 4 missense mutations (p.Leu148Pro; p.Arg396Trp; p.Pro503Leu; p.Glu383Gln) and one nonsense mutation (p.Tyr220*) were identified. Two out of 6 mutations (p.Tyr220* and p.Pro503Leu) were not previously described. Moreover, a new CYP24A1 variant was identified by genetic screening of asymptomatic controls.

CONCLUSION

To the best of our knowledge, this is the first report of a CYP24A1 molecular analysis performed in an Italian cohort of adult and pediatric Italian patients. This study (1) confirms that CYP24A1 plays a causal role in some but not all cases of IIH (64%); (2) expands the spectrum of known CYP24A1 pathogenic mutations; (3) describes 2 hotspots detected in 50% of all Italian cases; and (4) emphasizes the importance of recognition and genetic diagnosis of CYP24A1 defects in infantile as well as adult hypercalcemia.

Eculizumab is a safe and effective treatment in pediatric patients with atypical hemolytic uremic syndrome

Atypical hemolytic uremic syndrome (aHUS) is caused by alternative complement pathway dysregulation, leading to systemic thrombotic microangiopathy (TMA) and severe end-organ damage. Based on 2 prospective studies in mostly adults and retrospective data in children, eculizumab, a terminal complement inhibitor, is approved for aHUS treatment. Here we prospectively evaluated efficacy and safety of weight-based dosing of eculizumab in eligible pediatric patients with aHUS in an open-label phase II study. The primary end point was complete TMA response by 26 weeks. Twenty-two patients (aged 5 months-17 years) were treated; 16 were newly diagnosed, 12 had no prior plasma exchange/infusion during current TMA symptomatology, 11 received baseline dialysis and 2 had prior renal transplants. By week 26, 14 achieved a complete TMA response, 18 achieved hematologic normalization, and 16 had 25% or better improvement in serum creatinine. Plasma exchange/infusion was discontinued in all, and 9 of the 11 patients who required dialysis at baseline discontinued, whereas none initiated new dialysis. Eculizumab was well tolerated; no deaths or meningococcal infections occurred. Bone marrow failure, wrist fracture, and acute respiratory failure were reported as unrelated severe adverse events. Thus, our findings establish the efficacy and safety of eculizumab for pediatric patients with aHUS and are consistent with proposed immediate eculizumab initiation following diagnosis in children.

[Atypical Hemolytic Uremic Syndrome: experience of a pediatric center]

In the last two years we admitted in our Hospital 38 children with acute renal failure (ARF). Six of them were affected by hemolytic uremic syndrome (HUS) atypical. The aHUS is diagnosed in the presence of thrombotic microangiopathy (MAT), renal insufficiency (GFR 5%). The clinical presentation of our children has been varied and so also its evolution. Patients observed were all male, aged 2 to 12 years, and no one had a family history of kidney disease. In four patients we documented alterations of complement factors (MCP deficiency and factor H and presence of anti factor H). Repeated blood transfusions were required in 4 patients and in 3 patients the platelet count was slightly reduced. In 5 patients we did plasmapheresis and in 3 patients dialysis (hemodialysis and peritoneal dialysis). In three patients in whom the diagnosis was not clear, renal biopsy was performed to confirm the diagnosis. Eculizumab was administered in 3 patients resistant to plasma exchange. We obtain a rapid response on MAT with normalization of platelet count. The effect on renal function was variable (complete remission in a patient, partial improvement in another, and unresponsiveness in the last). The last had on Kidney biopsy signs of severe impairment and we documented the presence of antibodies to eculizumab. HUS is a rare condition, but probably much more common than reported. In children with ARF and microangiopathic anemia is necessary evaluated complement factors as early to obtain an improved clinical response to treatment with eculizumab.

[Nephrocalcinosis in children]

Nephrocalcinosis (NC) is a renal disease characterized by deposition of calcium salts into the renal medulla. There are several causes, organic, iatrogenic, hereditary and sometimes related to extrarenal diseases. We studied 34 children affected by NC, 21 M and 13 F (average age at diagnosis 7.8 months), with the aim of analyzing the associated diseases, clinical manifestations, metabolic abnormalities, growth and renal function at onset and after follow-up. At onset 70% of patients were asymptomatic and diagnosis was occasional. Renal function was normal in 33 patients. The most frequent clinical symptoms were failure to thrive (9%), abdominal pain (6%), proteinuria/hematuria (7%). The associated diseases were: tubulopathies (8 pcs - tubular acidosis, Dent, Bartter and Lowe Syndromes), medullary sponge kidney, policalicosis (3 pcs ), Short bowel Syndrome (3 pcs), hyperparathyroidism, hypothyroidism (2 pcs), thalassemia (1pc), tyrosinemia (1 pc.). We recognized two forms of hypervitaminosis D. In a pc NC would be correlated with prematurity, another one with lipid necrosis. Among the metabolic abnormalities, observed in 25% of pcs, hyperoxaluria is the most frequent (47%), hypercalciuria (20%), hypercalcemia (15%). In some cases we found endocrine non pathogenic alterations: hypovitaminosis D (2 pcs) and hypoparathyroidism (6 pcs). During follow-up the growth was normal in 87% of cases and glomerular function was stable in 90% of pcs; IRC developed in 3 cases. From our analysis, it appears that the treatment of the underlying condition of NC is associated with catch-up growth and stabilization of renal function in most patients, but not with the reduction of the degree of the NC.

[Cardiovascular Disease In Children With Ckd]

Cardiovascular disease (CVD) is the most important risk factor for morbidity and mortality in patients with chronic kidney disease (CKD). Aim of this study was to evaluate cardiac and vascular geometry in children with CKD stages 2, 3 and 4.Twenty-seven patients (18 males and 9 females) mean age 10.9 +/- 5.4 years with CKD and 30 children (control group) were enrolled with comparable age and sex. Weight, height, systolic and diastolic blood pressure were evaluated. We also analyzed biochemical assessments and proteinuria. We performed echocardiography with Philips iE33 and pulse wave velocity (PWV) with Vicorder PWS system. We documented significantly higher level of left ventricular mass index (LVMI) (30.3 +/- 7.6 g/m2.7) and PWV (4.7 +/- 1.6 m/sec) in CKD patients. Left ventricular hypertrophy (LVH) was present in 12 % and concentric remodelling in 36% of our patients. PWV values were significantly correlated with interventricular septal thickness (p<0.01) and with LVMI (p<0.05). In this study we documented the alterations of cardiac and vascular geometry since the early stages of CKD. PWV and echocardiographic measurements must be considered to assess cardiovascular risk in children with CKD stages 2-4.

Acute respiratory distress syndrome associated with tumor lysis syndrome in a child with acute lymphoblastic leukemia

Tumor lysis syndrome is a serious and dangerous complication usually associated with antiblastic treatment in some malignancies characterized by high cell turn-over. Mild or severe electrolyte abnormalities including high serum levels of uric acid, potassium, phosphorus, creatinine, bun and reduction of calcium can be responsible for multi-organ failure, involving mostly kidneys, heart and central nervous system. Renal damage can be followed by acute renal failure, weight gain, progressive liver impairment, overproduction of cytokines, and subsequent maintenance of multi-organ damage. Life-threatening acute respiratory failure associated with tumor lysis syndrome is rare. We describe a child with T-cell acute lymphoblastic leukemia, who developed an unusually dramatic tumor lysis syndrome, after administration of the first low doses of steroid, that was rapidly associated with severe acute respiratory distress syndrome. Subsequent clinical course and treatment modalities that resulted in the gradual and full recovery of the child are also described.

Adiponectin, resistin and leptin in paediatric chronic renal failure: correlation with auxological and endocrine profiles

INTRODUCTION

Chronic renal failure (CRF) compromises nutrition, growth, puberty, glycometabolic homeostasis, and adipokine secretion (i.e. adiponectin, resistin, and leptin). Adipokines play a role in the clinical outcome, but data in paediatric patients is scant.

AIM

To evaluate the link between kidney function, adiponectin, resistin, leptin, hormonal status, nutritional state and late outcome of CRF children.

MATERIALS AND METHODS

We studied leptin, adiponectin and resistin levels in 31 CRF patients (19 males, 12 females, aged 12.1 ± 4.47 years) managed conservatively, and 30 healthy age- and gender-matched controls. Clinical, auxological, biochemical, hormonal data, glucose and insulin levels were correlated with adipokine levels.

RESULTS

Six percent of patients had glycaemia T0' > 126 mg/dl, 23 % glycaemia T60' > 126, and 23 % glycaemia T120' ≥ 140. Glycated haemoglobin (HbA1c) measured during follow-up was in the normal range in all patients (4-5.6 %). Insulinaemia was significantly higher in CRF patients than controls. Homeostatic model of assessment-insulin resistance (HOMA-IR) levels were more elevated in patients (32 % had HOMA-IR > 2.5) than controls. Leptin levels were significantly higher in CRF patients than controls and differed significantly between males and females. Leptin correlated significantly with creatinine, body mass index (BMI), BA, pubertal stage, insulin-like growth factor 1, and HOMA-IR in females. Adiponectin levels were significantly higher in patients than controls, higher in patients with BMI < 85th centile and significantly inversely correlated to BMI, BA, haemoglobin, ferritin, proteins, albumin, and creatininuria. Resistin levels showed a direct correlation with C-reactive protein and an inverse correlation with haemoglobin.

CONCLUSION

Normal resistin levels are an expression of both adequate nutritional state and controlled inflammatory state. Adiponectin could protect against chronic inflammation, atherosclerosis, and cardiovascular diseases. Preventing obesity and ensuring a correct nutritional state are primary goals for physicians following children with CRF. Adipokines could be a useful marker in the follow-up.

Focus on prevention, diagnosis and treatment of hypertension in children and adolescents

The European Society of Hypertension has recently published its recommendations on prevention, diagnosis and treatment of high blood pressure in children and adolescents. Taking this contribution as a starting point the Study Group of Hypertension of the Italian Society of Pediatrics together with the Italian Society of Hypertension has conducted a reappraisal of the most recent literature on this subject. The present review does not claim to be an exhaustive description of hypertension in the pediatric population but intends to provide Pediatricians with practical and updated indications in order to guide them in this often unappreciated problem.

This document pays particular attention to the primary hypertension which represents a growing problem in children and adolescents. Subjects at elevated risk of hypertension are those overweight, with low birth weight and presenting a family history of hypertension. However, also children who do not present these risk factors may have elevated blood pressure levels. In pediatric age diagnosis of hypertension or high normal blood pressure is made with repeated office blood pressure measurements that show values exceeding the reference values. Blood pressure should be monitored at least once a year with adequate methods and instrumentation and the observed values have to be interpreted according to the most updated nomograms that are adjusted for children’s gender, age and height. Currently other available methods such as ambulatory blood pressure monitoring and home blood pressure measurement are not yet adequately validated for use as diagnostic instruments. To diagnose primary hypertension it is necessary to exclude secondary forms. The probability of facing a secondary form of hypertension is inversely proportional to the child’s age and directly proportional to blood pressure levels. Medical history, clinical data and blood tests may guide the differential diagnosis of primary versus secondary forms. The prevention of high blood pressure is based on correct lifestyle and nutrition, starting from childhood age. The treatment of primary hypertension in children is almost exclusively dietary/behavioral and includes: a) reduction of overweight whenever present b) reduction of dietary sodium intake c) increase in physical activity. Pharmacological therapy will be needed rarely and only in specific cases.

Puberty is associated with increased deterioration of renal function in patients with CKD: data from the ItalKid Project

OBJECTIVE

To analyse the timing of end stage renal disease in children with chronic kidney disease (CKD).

DESIGN

A population-based cohort study.

SETTING

A nationwide registry (ItalKid Project) collecting information on all patients with CKD aged <20 years.

PATIENTS

935 children with CKD secondary to renal hypodysplasia with or without urologic malformation. In a subgroup of patients (n=40) detailed pubertal staging was analysed in relation to CKD progression.

MAIN OUTCOME MEASURES

Kidney survival (KS) was estimated using renal replacement therapy (RRT) as the end-point. Puberty was staged by identifying the pubertal growth spurt.

RESULTS

A non-linear decline in the probability of KS was observed, with a steep decrease during puberty: the probability of RRT was estimated to be 9.4% and 51.8% during the first and second decades of life, respectively. A break-point in the KS curve was identified at 11.6 and 10.9 years of age in male and female patients, respectively.

CONCLUSIONS

The present analysis suggests that puberty is associated with increased deterioration of renal function in CKD. The mechanism(s) underlying this unique and specific (to children) pattern of progression have not yet been identified, but it may be that sex hormones play a role in this puberty-related progression of CKD.

Prevalence and predictors of the sub-target Hb level in children on dialysis

BACKGROUND

Anaemia is a common and potentially treatable co-morbidity of end-stage renal disease. We aimed to determine the prevalence of the sub-target haemoglobin (Hb) level among European children on dialysis and to identify factors associated with a low Hb level.

METHODS

From the European Society for Paediatric Nephrology (ESPN)/European Renal Association-European Dialysis Transplant Association (ERA-EDTA) registry, data were available on 2351 children between 1 month and 18 years of age, totalling 5546 measurements from 19 countries.

RESULTS

The mean Hb level was 10.8 g/dL (5th-95th percentiles, 7.4-13.9). Among those above 2 years of age, the mean Hb level was 10.9 g/dL (11.4% below 8.5 g/dL), while it was 10.3 g/dL among those below 2 years (11.2% below 8.0 g/dL). A total of 91.2% of the patients were on an erythropoiesis-stimulating agent (ESA). Hb levels increased with age and were higher in peritoneal dialysis compared with haemodialysis patients. Patients with congenital anomalies of the kidney and urinary tract showed the highest Hb levels, and those with cystic kidney diseases or metabolic disorders the lowest ones. Ferritin levels between 25 and 50 ng/mL were associated with the highest Hb levels. We found a weak inverse association between parathyroid hormone (PTH) and Hb. Whereas standardized blood pressure (BP) was not elevated in patients with above-target Hb, elevated systolic BP z-score was noted in those with sub-target Hb levels.

CONCLUSIONS

Sub-target Hb levels remain common in children on dialysis, in spite of virtually all children being treated with ESA; although we cannot exclude under-dosing. Optimal ferritin levels seemed to be slightly lower in children (25-50 ng/mL) than those in adults. Other risk factors for sub-target Hb are dialysis modality and a high PTH level.

[Vesicoureteral reflux in children]

Vesicoureteral reflux is a common disease in children and is usually associated with urinary tract infections and renal scars. Renal damage associated with vesicoureteral reflux occurs secondary to renal maldevelopment during fetal life or renal infections in children and may produce hypertension, diseases in pregnancy and chronic renal failure. Bladder dysfunction may be responsible for persistent reflux and renal scars. In order to prevent renal damage, early diagnosis and prompt medical treatment or surgical correction are advised in a selected group of children. In the past all children with urinary tract infections were investigated with voiding uretrocystogram and received long-term antibiotic prophylaxis or surgery. In recent years several trials have provided information that suggest it is better to reduce the number of diagnostic and surgical procedures in children affected by vesicoureteral reflux.

Peritoneal dialysis in infants: the experience of the Italian Registry of Paediatric Chronic Dialysis

BACKGROUND

Although chronic peritoneal dialysis (CPD) is considered the replacement therapy of choice for infants with end-stage renal failure, many questions persist about treatment risks and outcomes.

METHODS

We present data on 84 infants who started CPD at <1 year of age; these patients represent 12% of the total population of the Italian Registry of Paediatric Chronic Dialysis. We analysed patient records from all children consecutively treated with CPD between 1995 and 2007 in Italy. Growth data analysis was performed only in infants with complete auxological parameters at 0, 6 and 12 months of follow-up.

RESULTS

Median age at the start of CPD was 6.9 months, weight was 6.1 kg and length 63.6 cm. In one-half of the study population diagnosis leading to renal failure was congenital nephrouropathy. Twenty-eight per cent of the children had at least one pre-existing comorbidity. The mean height standard deviation score was -1.65 at the start of CPD, -1.82 after 12 months and -1.53 after 24 months. Catch-up growth was documented in 50% of patients during dialysis. A positive correlation was observed between longitudinal growth and both exchange volume (R(2) = 0.36) and dialysis session length (R(2) = 0.35), while a negative association was found with the number of peritonitis cases (P = 0.003). Peritonitis incidence was 1:20.7 episode:CPD-months (1:28.3 in the older children from the same registry) and was significantly higher in children with oligoanuria (1:15.5 episode:CPD-months) compared to infants with residual renal function (1:37.4 episode:CPD-months). Catheter survival rate was 70% at 12 months and 51% at 24 months. Catheter-related complications were similar in infants and older children (1:20.5 versus 1:19.8 episode:CPD-months), while clinical complications were more frequent in children under 1 year of age (1:18.3 versus 1:25.2 episode:CPD-months; P < 0.05). During the follow-up period, 33 patients were transplanted (39.3%), 18 were shifted to haemodialysis (21.4%) and 8 died (9.5%). The mortality rate was 4-fold greater than in older children (2.3%).

CONCLUSIONS

Our data confirm that infants on CPD represent a high-risk group; however, our experience demonstrated that growth was acceptable and a large portion was successfully transplanted. Increased efforts should be aimed at optimizing dialysis efficiency and preventing peritonitis. The higher mortality rate in infants was largely caused by comorbidities.

No clear evidence of ACEi efficacy on the progression of chronic kidney disease in children with hypodysplastic nephropathy--report from the ItalKid Project database

BACKGROUND

Chronic kidney diseases (CKD) tend to progress to end-stage renal failure (ESRF). As it has been demonstrated that angiotensin-converting enzyme inhibitors (ACEi) have a renoprotective effect in adults with proteinuric disease and may be effective in reducing hyperfiltration and proteinuria, they are also frequently used as anti-progression agents in paediatric patients with CKD despite the lack of data confirming their role in the nephropathies peculiar to children. The aim of this study was to investigate whether patients with hypodysplastic CKD (the most common cause of ESRF in children) treated with ACEi show a significantly slower decline in creatinine clearance (Ccr).

METHODS

The analysis was based on the information available in the database of the ItalKid Project, a nationwide, population-based registry of chronic renal insufficiency (CRI) in children in Italy. Of the 822 patients with CRI due to hypodysplasia, we selected those who had been continuously treated with ACEi; the control patients were identified from the same diagnostic group and matched for gender, age and baseline Ccr.

RESULTS

Progression was analysed as the slope of Ccr in a total of 164 patients: 41 cases and 123 matched controls. There were no significant between-group differences in blood pressure, duration of follow-up or pre-study slope of Ccr (-0.31+/-2.26 vs -0.33+/-3.58 ml/min/1.73 m2/year; P=NS). After an average of 4.9+/-2.3 years, the mean slope of Ccr was 40% lower in the ACEi-treated cases in comparison to controls (-1.08+/-2.08 vs -1.80+/-4.42 ml/min/1.73 m2/year), however, this difference was not statistically significant (P=0.31).

CONCLUSIONS

We conclude that ACEi treatment does not significantly modify the naturally progressive course of hypodysplastic nephropathy in children and further studies are necessary before such treatment is routinely proposed for anti-progression purposes in children with CKD.

Prescription of drugs blocking the renin-angiotensin system in Italian children

Little is known about the prescription pattern of antihypertensive drugs for children with impaired kidney function. We have therefore documented the use of antihypertensive drugs in this patient group by evaluating the Italian pediatric population-based registry of patients with chronic kidney disease on conservative treatment (ItalKid) from 1995 to 2003. In 1995, prescriptions written for antihypertensive drugs for use by children were approximately equally divided among drugs blocking the renin-angiotensin system and calcium channel blockers (38 vs. 43% of all prescriptions), followed by beta-blockers and diuretics (15 and 4%, respectively). During subsequent years the proportion of prescriptions for drugs blocking the renin-angiotensin system increased (2003: 61%; p<0.001) and that of calcium channel blockers decreased (2003: 18%, p<0.001). In 1995, blockers of the renin-angiotensin system were prescribed, either as monotherapy or in combination, in 53% of the patients, but the relative frequency of the patients prescribed these drugs increased up to 83% in 2003 (p<0.0005). In conclusion, physicians caring for Italian children with impaired kidney function are increasingly prescribing drugs blocking the renin-angiotensin system.

Molecular characterisation and clonal analysis of group A streptococci causing pharyngitis among paediatric patients in Palermo, Italy

Group A streptococci (n = 123), isolated consecutively from paediatric patients with pharyngitis from Palermo, Italy, were analysed. The emm and sof genes were sequenced, the presence of the speA and speC genes was investigated, and the macrolide resistance phenotypes and genotypes were determined. A limited number of emm/sof genotypes was found, and the most prevalent types were different from those found in a previous study from Rome. Macrolide resistance was found in the most prevalent clones, suggesting that the spread of mobile antibiotic resistance genes among the fittest clones in the community was the main mechanism influencing macrolide resistance rates in different emm types.

[Severe renal failure in a child]

A four-year-old male child was admitted with severe renal failure, apparently recent in onset and he was treated with peritoneal dialysis (PD). A renal biopsy showed interstitial cellular infiltration with crystals within the tubules and sclerotic glomeruli. Type I hyperoxaluria was diagnosed and the child received a liver and kidney transplant after 10 months of dialysis. Two years later, he has normal renal function, and blood and urine oxalate levels are within normal ranges.

A multicenter experience on patient and technique survival in children on chronic dialysis

In this study we compared patient and technique survival of 163 new hemodialysis (HD) patients (age 11.4+/-3.1 years) and 295 peritoneal dialysis patients (7.7+/-4.8 years. P< 0.001), treated in 23 dialysis centers participating in the Italian Registry of Pediatric Chronic Peritoneal Dialysis (CPD) during the years 1989-2000. Three HD (1.8%) and 17 CPD (5.8%) patients died; the overall average death rate was 9.8/1,000 patient-years in HD and 29.8/1,000 patient-years in CPD patients. No statistically significant difference in patient survival between CPD and HD was found, while the survival of 102 CPD children younger than 5 years at the start of dialysis was lower ( P=0.0001) than that of 193 CPD and 160 HD patients aged 5-15 years. We registered 12 modality failures among HD (7.4%) patients and 44 among CPD (14.9%) patients. The main causes were vascular access failure and patient choice in HD, and infection in CPD patients. Technique survival was lower ( P=0.007) in CPD than in HD patients; a statistically significant difference ( P=0.01) was also observed between both the 0- to 5- and the 5- to 15-year-old CPD patients and the HD patients aged 5-15 years. Logistic regression analysis confirmed age at initiation of dialysis to be a predictor of patient death ( P=0.0001) in the whole patient population, and of technique failure in HD ( P=0.006) but not in CPD patients ( P=0.16).

Risk factors for poor renal prognosis in children with hemolytic uremic syndrome

Many factors have been proposed as predictors of poor renal prognosis in children with hemolytic uremic syndrome (HUS), but their role is still controversial. Our aim was to detect the most reliable early predictors of poor renal prognosis to promptly identify children at major risk of bad outcome who could eventually benefit from early specific treatments, such as plasmapheresis. Prognostic factors identifiable at onset of HUS were evaluated by survival analysis and a proportional hazard model. These included age at onset, prodromal diarrhea (D), leukocyte count, central nervous system (CNS) involvement, and evidence of Shiga toxin-producing Escherichia coli (STEC) infection. Three hundred and eighty-seven HUS cases were reported; 276 were investigated for STEC infection and 189 (68%) proved positive. Age at onset, leukocyte count, and CNS involvement were not associated with the time to recovery. Absence of prodromal D and lack of evidence of STEC infection were independently associated with a poor renal prognosis; only 34% of patients D(-)STEC(- )recovered normal renal function compared with 65%-76% of D(+)STEC(+), D(+)STEC(-) and D(-)STEC(+ )patients. In conclusion, absence of both D and evidence of STEC infection are needed to identify patients with HUS and worst prognosis, while D(-) but STEC(+) patients have a significantly better prognosis.

Calcium, phosphate, and PTH levels in the hemodialysis population: a multicenter study

BACKGROUND

Hyperphosphatemia is one of the main factors in the pathogenesis of secondary hyperparathyroidism. In addition, in dialysis patients elevated levels of phosphate and calcium times phosphate (Ca x P) ion product are associated with extraskeletal calcifications, as well as an increased risk of death. Cardiovascular calcifications may possibly be related to the high cardiovascular mortality seen in dialysis patients. In the USA the prevalence of hyperphosphatemia among dialysis patients is very high, over 60% of patients having serum P levels > 5.5 mg/dl, but no data are available for the Italian population, which follows different diet and dialysis schedules.

METHODS

We looked at a random sample of 638 patients enrolled in 29 outpatient dialysis units in Southern Italy (Campania and Sicily). Data were centrally analyzed after extraction from a computerized database. In each patient the average of two or more values obtained in the six-month observation period (from Jan. 99 to June 99) was calculated. Mean age was 61.2 years (95% CI 59.9-62.5) years, dialytic age 72.2 months (95% CI 67.4-77.0).

RESULTS

Mean +/- SD (95% CI) levels of phosphate were 5.74 +/- 1.57 (5.62-5.86) mg/dl; total calcium 9.06 +/- 0.98 (8.98-9.14) mg/dl; Ca x P 51.4 +/- 14.4 (50.3-52.5) mg2/dl2; alkaline phosphatase was 167 +/- 119 (157-177) IU/L; intact parathyroid hormone (PTH) levels, available in a subset of 239 patients, were 318 +/- 413 (265-370) pg/ml. Among these patients 51.6% had serum P > 5.5 mg/dl, 36% > 6 mg/dl; Ca x P levels were > 55 mg2/dl2 in 35.5% of the population, 24% > 60 mg2/dl2; iPTH levels were < 100 pg/ml in 43%; 25.4% had hyperparathyroidism (defined as iPTH > 400 pg/ml), and only 19.5% of patients had PTH in the desired interval of 100 to 250 pg/ml.

CONCLUSIONS

Compared to data reported from the USA, mean levels of phosphate, Ca x P, and PTH seem better controlled in this Italian hemodialysis population. However, in a significant number of patients these parameters were still outside the normal range. Both over-suppression of PTH levels and hyperparathyroidism are present, although surprisingly the former was more frequent. Treatment of hyperphosphatemia should be more aggressive in hemodialysis patients; PTH levels are difficult to maintain in the desired range of 100-250 pg/ml.

A multicenter survey on automated peritoneal dialysis prescription in children

Automated peritoneal dialysis (APD) is considered the first-choice chronic peritoneal dialysis modality for pediatric patients. Nighttime APD courses reduce the impact of PD treatment on a patient's and family's way of life, and the wide range of prescription options permit the dialysis schedule to be tailored to the needs of children of varying age and body size. We registered data concerning the dialytic regimens adopted in 12 pediatric dialysis centers for the treatment of 110 children on APD. Of the 110 children, 64 (aged 7.6 +/- 5.1 years) were on nightly intermittent peritoneal dialysis (NIPD); 29 (aged 9.2 +/- 4.3 years) were on tidal peritoneal dialysis (TPD); and 17 (aged 8.2 +/- 4.9 years) were on continuous cycling peritoneal dialysis (CCPD). The main prescription parameters for the various regimens (mean +/- standard deviation) were these: NIPD--exchanges: 13.0 +/- 5.8; duration: 10.0 +/- 1.1 hours; dwell volume: 36.5 +/- 6.2 mL/kg body weight (BW); glucose concentration: 1.69% +/- 0.41%. TPD--exchanges: 23.3 +/- 8.1; duration: 10.0 +/- 1.0 hours; dwell volume: 36.1 +/- 5.9 mL/kg BW; glucose concentration: 1.63% +/- 0.37%. CCPD--exchanges: 13.0 +/- 4.7; duration: 10.1 +/- 1.3 hours; dwell volume: 37.7 +/- 5.2 mL/kg BW; glucose concentration: 1.65% +/- 0.28%. Tidal volume was 52.2% +/- 9.0% of initial fill volume. Daytime dwell volume was 54.8% +/- 17.3% of night volume in CCPD patients, and 56.6% +/- 13.3% in 9 patients on continuous TPD. Because the patient population in this report varied in age, body size, and metabolic needs, the resulting range in prescription parameters was quite wide. Nevertheless, the duration of nightly PD sessions averaged 10 hours, fill volume averaged 36 mL per kilogram body weight, and daytime volume averaged 50% of nighttime fill volume.

Lipoprotein(a) levels in relation to albumin concentration in childhood nephrotic syndrome

BACKGROUND

Lipoprotein(a) [Lp(a)] is a lipoprotein consisting of a low-density lipoprotein (LDL) particle linked to a polymorphic glycoprotein, apoprotein(a) [apo(a)]. Prior studies have reported high Lp(a) levels in the nephrotic syndrome, but it is still controversial whether this is due to the degree of hypoalbuminemia or proteinuria.

METHODS

To investigate a model of nephrotic syndrome in the absence of renal failure, we studied a group of 84 children in different clinical stages of the disease for a period of five years. We evaluated the direct relationships between lipoproteins, including Lp(a), and/or plasma albumin and proteinuria.

RESULTS

Lp(a) levels were significantly higher in the subjects with the active disease compared with patients in remission, and were also significantly different when subjects were ranked by albumin quartiles. Multiple regression analysis revealed that Lp(a) levels were inversely correlated with apo(a) isoform size and plasma albumin levels but not with the proteinuria/creatinine clearance ratio. Among subjects in complete remission, Lp(a) levels were different in patients with albumin levels below or above the fifth percentile. After the improvement of the clinical stage of the disease, the Delta% variation of albumin levels was related to the Delta% of apoB and LDL cholesterol (LDL-C), but not with the Delta% variation of Lp(a), whereas the Delta% variation of LDL-C was, in turn, related to the Delta% of Lp(a) levels.

CONCLUSIONS

These results suggest that in the childhood nephrotic syndrome, the increased Lp(a) levels are mainly related to hypoalbuminemia, probably through a mechanism involving apoB overproduction, which leads to an increased number of LDL particles to be converted into Lp(a).

Frequency of renal diseases and clinical indications for renal biopsy in children (report of the Italian National Registry of Renal Biopsies in Children). Group of Renal Immunopathology of the Italian Society of Pediatric Nephrology and Group of Renal Immunopathology of the Italian Society of Nephrology

BACKGROUND

Children's renal biopsy data were gathered for 3 consecutive years (1992-1994) by the Group of Renal Immunopathology of the Italian Society of Pediatric Nephrology, which opened a paediatric section of the Italian Registry of Renal Biopsies.

MATERIALS

The Registry recorded the histological diagnosis and the clinical data at renal biopsy of 432 children < or = 15 years old (mean age 8.96 +/- 3.7 years).

RESULTS

The most common glomerulonephritis (GN) at renal biopsy was idiopathic IgAGN (18.8%) and the most frequent secondary GN was Henoch-Schönlein purpura (HSP) nephritis (11.6%). Minimal-change disease (MCD) accounted for 11.6%, focal and segmental sclerosis (FSG) 8.5%, mesangial proliferative GN (MPGN) 9.5%, membranoproliferative GN 5.5%, and thin-membrane disease 5%. Lupus nephritis was diagnosed in 5% and Alport's GN in 3.9% of the cases. The annual incidence of primary GN in Italian children was 11.1 cases per million children population (p.m.c.p.), IgAN accounting for 3.1 cases, MCD 2.3, and HSP nephritis 1.9 cases p.m.c.p. respectively. Italian children underwent renal biopsy because of isolated microscopic haematuria in 19.3% of the cases, non-nephrotic proteinuria with or without microscopic haematuria in 31.2%, and nephrotic-range proteinuria in 34.2%, less frequently (15.3%) because of acute or chronic renal failure. Children with persistent isolated microscopic haematuria had most frequently IgAN (34.9%) or thin-membrane disease (25.3%), while those with non-nephrotic proteinuria had IgAN (30.4%) and HSP nephritis (23%). In cases with nephrotic proteinuria renal biopsy showed MCD in 34.5% of the cases, FSG in 16.9%, and MPGN in 12.2%. When renal biopsy was performed in chronic renal failure, chronic interstitial renal disease was detected in 62.5% of the cases.

CONCLUSIONS

This National Registry provides data on the indications for performing renal biopsy in Italian children and on the frequency and annual incidence of histological lesions detected. IgAN, primary or related to HSP, was the most common nephritis in Italian children undergoing renal biopsy.

The phenotype of SLE associated with complete deficiency of complement isotype C4A

Complete deficiency of the complement C4A isotype is a known genetic risk factor for systemic lupus erythematosus (SLE). The disease phenotype of C4A-deficient patients has never been defined. Among 200 patients with SLE from five centers, 18 (9%) with C4A deficiency were identified. These individuals were compared to those who were C4A replete with regard to a series of clinical and serologic features. The only significant differences between the two groups were in the presence of renal disease (C4A deficient, 11%; C4A replete, 46%; P < 0.006) and a decrease in the serum concentrations of C3 (C4A deficient, 11%; C4A replete, 35%; P < 0.04). There was also a trend for the C4A-deficient individuals to have milder disease. In light of the tendency for C4A-deficient individuals to have lower serum concentrations of C4, it is important that such patients not be subjected to overly aggressive efforts to "normalize" their C4 levels.

Combined homozygous factor H and heterozygous C2 deficiency in an Italian family

Three of four children in a family have homozygous (less than 1% of normal) deficiency of factor H of the complement system and both parents, who are first cousins, are heterozygous for the same defect. The father and two of the H-deficient siblings also have a partial C2 deficiency. One of the children with combined deficiencies is affected by systemic lupus erythematosus with nephritis. No increased susceptibility to infections has been observed in the family. H deficiency is inherited in an autosomal codominant manner and is independently transmitted from C2 deficiency and HLA haplotypes. In the homozygous state it is associated with very low serum concentrations of B and C3, barely demonstrable as activated molecules. C5 is greatly reduced (less than 5%). Also, properdin and C6-9 are decreased. The findings in this family demonstrate that the occurrence of systemic lupus erythematosus in one of the children affected by a combined deficiency of factor H and C2 raises the question whether this pathology is related to the complete factor H or to the heterozygous C2 deficiency. Complete H deficiency is not necessarily accompanied by overt illness.

Light-chain nephropathy in patient with renal carcinoma

Paraneoplastic syndromes are often associated with renal parenchymal tumours. This report describes a case of renal-cell carcinoma with kappa-chain nephropathy. The patient, a 60-year-old man, had renal tubular dysfunction, shown by low serum concentrations of urate and phosphate. Kappa-chains were found in both serum and urine, but no lambda-chains were found. Investigations showed a clear-cell carcinoma, and the patient underwent a radical nephrectomy. Two years after operation serum phosphate and urate concentrations had returned to normal, and kappa-chains were undetectable in serum or urine. The absence of lambda-chains indicates that the light-chain proteinuria was due to overproduction of the M component, and the disappearance of kappa-chains after the operation suggests a causal relation between the renal tumour and the overproduction of the M component.