AimOur 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.MethodsThe 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.ResultsFour 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.ConclusionThese 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.

Context Acute kidney injury(AKI) and renal tubular damage(RTD), especially if complicated by acute tubular necrosis (ATN), could increase the risk of later chronic kidney disease. No prospective studies on AKI and RTD in children with type1diabetes mellitus(T1DM) onset are available. Objectives to evaluate the AKI and RTD prevalence, and their rate and timing of recovery in children with T1DM onset. Design prospective study. Settings and patients: 185children were followed up after 14days from T1DM onset. The patients who did not recover from AKI/RTD were followed-up 30 and 60days later. Main outcome measures AKI was defined according to the KDIGO criteria. RTD was defined by abnormal urinary beta-2-microglobulin and/or neutrophil gelatinase-associated lipocalin and/or tubular reabsorption of phosphate<85% and/or fractional excretion of Na(FENa)>2%. ATN was defined by RTD+AKI, prerenal-(P-)AKI by AKI+FENa<1% while acute tubular damage(ATD) by RTD without AKI. Results Prevalence of diabetic ketoacidosis(DKA) and AKI were 51.4% and 43.8% respectively. Prevalence of AKI in T1DM patients with and without DKA was 65.2% and 21.1%. 33.3% reached AKI stage2 and 66.7% of patients reached AKI stage1. RTD was evident in 136/185(73.5%) patients (32.4% showed ATN; 11.4% P-AKI; 29.7% ATD). All patients with DKA or AKI presented with RTD. The physiological and biochemical parameters of AKI and RTD were normal again in all patients. The former within 14days and the latter within 2months, respectively. Conclusions Most patients with T1DM onset may develop AKI and/or RTD, especially if presenting with DKA. Over time the physiological and biochemical parameters of AKI/RTD normalize in all patients.

Summary Background PNPLA3 I148M polymorphism has an effect on modulation of estimated glomerular filtration rate (eGFR) in nonobese nondiabetic adults and in children with histologically confirmed nonalcoholic fatty liver disease (NAFLD). Objectives The objective of the study is to explore the impact of PNPLA3 I148M polymorphism on eGFR in children with obesity with and without NAFLD. Methods We genotyped 591 patients with obesity for PNPLA3 I148M polymorphism. Anthropometrical, biochemical, and instrumental data were collected. NAFLD was defined by the presence of ultrasound‐detected liver steatosis and/or ALT levels greater than 40 IU/L. Results Patients with NAFLD showed significantly lower eGFR levels compared with subjects without NAFLD. Children with PNPLA3 MM genotype showed lower eGFR levels compared with those with either PNPLA3 IM or II genotypes both in the presence and absence of NAFLD. A general linear model for eGFR variance, including gender, duration of obesity, PNPLA3 genotypes, HOMA, BMI‐SDS, LDL‐C, and triglycerides as covariates, confirmed an inverse association between eGFR and PNPLA3 genotype only in the presence of NAFLD. Conclusions Children with obesity and PNPLA3 MM genotype show lower eGFR levels compared with other genotypes, with a major effect of this polymorphism in the presence of NAFLD.

Background/Aims: Mutations in the inwardly-rectifying K⁺-channel KCNJ10/Kir4.1 cause autosomal recessive EAST syndrome (epilepsy, ataxia, sensorineural deafness and tubulopathy). KCNJ10 is expressed in the distal convoluted tubule of the kidney, stria vascularis of the inner ear and brain glial cells. Patients diagnosed clinically with EAST syndrome were genotyped and mutations in KCNJ10 were studied functionally. Methods: Patient DNA was amplified and sequenced, and new mutations were identified. Mutant and wild-type KCNJ10 constructs were cloned and heterologously expressed in Xenopus oocytes. Whole-cell K⁺ currents were measured by 2-electrode voltage clamping and channel expression was analysed by Western blotting. Results: We identified 3 homozygous mutations in KCNJ10 (p.F75C, p.A167V and p.V91fs197X), with mutation p.A167V previously reported in a compound heterozygous state. Oocytes expressing wild-type human KCNJ10 showed inwardly rectified currents, which were significantly reduced in all of the mutants (p < 0.001). Specific inhibition of KCNJ10 currents by Ba²⁺ demonstrated a large residual function in p.A167V only, which was not compatible with causing disease. However, co-expression with KCNJ16 abolished function in these heteromeric channels almost completely. Conclusion: This study provides an explanation for the pathophysiology of the p.A167V KCNJ10 mutation, which had previously not been considered pathogenic on its own. These findings provide evidence for the functional cooperation of KCNJ10 and KCNJ16. Thus, in vitro ascertainment of KCNJ10 function may necessitate co-expression with KCNJ16.

In an evaluation of a large cohort of patients enrolled early with congenital solitary functioning kidney with a prenatal diagnosis, excluding those with neonatal onset of renal damage, the prevalence of renal damage was 3.9%. Among congenital anomalies of the kidney and urinary tract, congenital solitary functioning kidney represented the major risk factor.