Antibiotic Prophylaxis in Infants with Grade III, IV, or V Vesicoureteral Reflux.

BACKGROUND: The efficacy of continuous antibiotic prophylaxis in preventing urinary tract infection (UTI) in infants with grade III, IV, or V vesicoureteral reflux is controversial. METHODS: In this investigator-initiated, randomized, open-label trial performed in 39 European centers, we randomly assigned infants 1 to 5 months of age with grade III, IV, or V vesicoureteral reflux and no previous UTIs to receive continuous antibiotic prophylaxis (prophylaxis group) or no treatment (untreated group) for 24 months. The primary outcome was the occurrence of the first UTI during the trial period. Secondary outcomes included new kidney scarring and the estimated glomerular filtration rate (GFR) at 24 months. RESULTS: A total of 292 participants underwent randomization (146 per group). Approximately 75% of the participants were male; the median age was 3 months, and 235 participants (80.5%) had grade IV or V vesicoureteral reflux. In the intention-to-treat analysis, a first UTI occurred in 31 participants (21.2%) in the prophylaxis group and in 52 participants (35.6%) in the untreated group (hazard ratio, 0.55; 95% confidence interval [CI], 0.35 to 0.86; P = 0.008); the number needed to treat for 2 years to prevent one UTI was 7 children (95% CI, 4 to 29). Among untreated participants, 64.4% had no UTI during the trial. The incidence of new kidney scars and the estimated GFR at 24 months did not differ substantially between the two groups. Pseudomonas species, other non-Escherichia coli organisms, and antibiotic resistance were more common in UTI isolates obtained from participants in the prophylaxis group than in isolates obtained from those in the untreated group. Serious adverse events were similar in the two groups. CONCLUSIONS: In infants with grade III, IV, or V vesicoureteral reflux and no previous UTIs, continuous antibiotic prophylaxis provided a small but significant benefit in preventing a first UTI despite an increased occurrence of non-E. coli organisms and antibiotic resistance. (Funded by the Italian Ministry of Health and others; PREDICT ClinicalTrials.gov number, NCT02021006; EudraCT number, 2013-000309-21.).

Factors influencing circuit lifetime in paediatric continuous kidney replacement therapies - results from the EurAKId registry.

BACKGROUND: Continuous kidney replacement therapy (CKRT) has recently become the preferred kidney replacement modality for children with acute kidney injury (AKI). We hypothesise that CKRT technical parameters and treatment settings in addition to the clinical characteristics of patients may influence the circuit lifetime in children. METHODS: The study involved children included in the EurAKId registry (NCT02960867), who underwent CKRT treatment. We analysed patient characteristics and CKRT parameters. The primary end point was mean circuit lifetime (MCL). Secondary end points were number of elective circuit changes and occurrence of dialysis-related complications. RESULTS: The analysis was composed of 247 children who underwent 37,562 h of CKRT (median 78, IQR 37-165 h per patient). A total of 1357 circuits were utilised (3, IQR 2-6 per patient). MCL was longer in regional citrate anticoagulation (RCA), compared to heparin (HA) and no anticoagulation (NA) (42, IQR 32-58 h; 24, IQR 14-34 h; 18, IQR 12-24 h, respectively, p < 0.001). RCA was associated with longer MCL regardless of the patient's age or dialyser surface. In multivariate analysis, MCL correlated with dialyser surface area (beta = 0.14, p = 0.016), left internal jugular vein vascular access site (beta = -0.37, p = 0.027), and the use of HA (beta = -0.14, p = 0.038) or NA (beta = -0.37, p < 0.001) vs. RCA. RCA was associated with the highest ratio of elective circuit changes and the lowest incidence of complications. CONCLUSION: Anticoagulation modality, dialyser surface, and vascular access site influence MCL. RCA should be considered when choosing first-line anticoagulation for CKRT in children. Further efforts should focus on developing guidelines and clinical practice recommendations for paediatric CKRT.

Urine soluble TLR4 levels may contribute to predict urinary tract infection in children: the UTILISE Study.

BACKGROUND: One of the most common bacterial infections in childhood is urinary tract infection (UTI). Toll-like receptors (TLRs) contribute to immune response against UTI recognizing specific pathogenic agents. Our aim was to determine whether soluble TLR4 (sTLR4), soluble TLR5 (sTLR5) and interleukin 8 (IL-8) can be used as biomarkers to diagnose UTI. We also aimed to reveal the relationship between urine Heat Shock Protein 70 (uHSP70) and those biomarkers investigated in this study. METHODS: A total of 802 children from 37 centers participated in the study. The participants (n = 282) who did not meet the inclusion criteria were excluded from the study. The remaining 520 children, including 191 patients with UTI, 178 patients with non-UTI infections, 50 children with contaminated urine samples, 26 participants with asymptomatic bacteriuria and 75 healthy controls were included in the study. Urine and serum levels of sTLR4, sTLR5 and IL-8 were measured at presentation in all patients and after antibiotic treatment in patients with UTI. RESULTS: Urine sTLR4 was higher in the UTI group than in the other groups. UTI may be predicted using 1.28 ng/mL as cut-off for urine sTLR4 with 68% sensitivity and 65% specificity (AUC = 0.682). In the UTI group, urine sTLR4 levels were significantly higher in pyelonephritis than in cystitis (p < 0.0001). Post-treatment urine sTLR4 levels in the UTI group were significantly lower than pre-treatment values (p < 0.0001). CONCLUSIONS: Urine sTLR4 may be used as a useful biomarker in predicting UTI and subsequent pyelonephritis in children with UTI. A higher resolution version of the Graphical abstract is available as Supplementary information.

Acute kidney injury in children hospitalised for febrile urinary tract infection.

AIM: To determine (i) prevalence and the risk factors for acute kidney injury (AKI) in children hospitalised for febrile urinary tract infection (fUTI) and (ii) role of AKI as indicator of an underlying VUR. AKI, in fact, is favoured by a reduced nephron mass, often associated to VUR. METHODS: This retrospective Italian multicentre study enrolled children aged 18 years or younger (median age = 0.5 years) discharged with a primary diagnosis of fUTI. AKI was defined using Kidney Disease/Improving Global Outcomes serum creatinine criteria. RESULTS: Of 849 children hospitalised for fUTI (44.2% females, median age 0.5 years; IQR = 1.8), 124 (14.6%) developed AKI. AKI prevalence rose to 30% in the presence of underlying congenital anomalies of the kidney and urinary tract (CAKUT). The strongest AKI predictors were presence of CAKUT (OR = 7.5; 95%CI: 3.8-15.2; p = 9.4e-09) and neutrophils levels (OR = 1.13; 95%CI: 1.08-1.2; p = 6.8e-07). At multiple logistic regression analysis, AKI during fUTI episode was a significant indicator of VUR (OR = 3.4; 95%CI: 1.7-6.9; p = 0.001) despite correction for the diagnostic covariates usually used to assess the risk of VUR after the first fUTI episode. Moreover, AKI showed the best positive likelihood ratio, positive predictive value, negative predictive value and specificity for VUR. CONCLUSION: AKI occurs in 14.6% of children hospitalised for fUTI and is a significant indicator of VUR.

A multicenter retrospective study of calcineurin inhibitors in nephrotic syndrome secondary to podocyte gene variants.

While 44-83% of children with steroid-resistant nephrotic syndrome (SRNS) without a proven genetic cause respond to treatment with a calcineurin inhibitor (CNI), current guidelines recommend against the use of immunosuppression in monogenic SRNS. This is despite existing evidence suggesting that remission with CNI treatment is possible and can improve prognosis in some cases of monogenic SRNS. Herein, our retrospective study assessed response frequency, predictors of response and kidney function outcomes among children with monogenic SRNS treated with a CNI for at least three months. Data from 203 cases (age 0-18 years) were collected from 37 pediatric nephrology centers. Variant pathogenicity was reviewed by a geneticist, and 122 patients with a pathogenic and 19 with a possible pathogenic genotype were included in the analysis. After six months of treatment and at last visit, 27.6% and 22.5% of all patients respectively, demonstrated partial or full response. Achievement of at least partial response at six months of treatment conferred a significant reduction in kidney failure risk at last follow-up compared to no response (hazard ratio [95% confidence interval] 0.25, [0.10-0.62]). Moreover, risk of kidney failure was significantly lower when only those with a follow-up longer than two years were considered (hazard ratio 0.35, [0.14-0.91]). Higher serum albumin level at CNI initiation was the only factor related to increased likelihood of significant remission at six months (odds ratio [95% confidence interval] 1.16, [1.08-1.24]). Thus, our findings justify a treatment trial with a CNI also in children with monogenic SRNS.

Vesico-ureteric reflux in children and young people undergoing kidney transplantation.

Vesico-ureteric reflux (VUR) into transplanted kidneys in children and young people is a common occurrence, found in 19 to 60% of those who had an anti-reflux procedure and up to 79% in the absence of such a procedure. While VUR is unlikely to be of concern without evidence of symptomatic urinary tract infections, less certainty exists regarding outcomes when the VUR is associated with urinary tract infection (UTI) and transplant pyelonephritis. Issues explored will include additional risk factors that might predispose to UTI, any effect of pyelonephritis on acute and long-term kidney allograft function and practical strategies that may reduce the prevalence of infection.

Epidemiology, severity, and risk of SARS-CoV-2-related relapse in children and young adults affected by idiopathic nephrotic syndrome: a retrospective observational cohort study.

BACKGROUND: Children with underlying kidney diseases display a mild course of SARS-CoV-2 infection, but they only accounted for a minority of cases until the spread of the Omicron variant. Nonetheless, idiopathic nephrotic syndrome (INS) has been advocated as a predictor of worse outcome. METHODS: We investigated the spread, severity, and risk of relapse related to SARS-CoV-2 infection among children with INS. The incidence and characteristics of SARS-CoV-2 infections, immunosuppression, and vaccination status were retrospectively collected from the beginning of the pandemic to May 31, 2022. RESULTS: We enrolled 176 patients (73 females, median age 10.22 years); 28 had a steroid-resistant disease, and 108 (61.4%) were on immunosuppressive therapy. Sixty-one (34.7%) patients reported a SARS-CoV-2 infection, with incidence peaking between December 2021 and January 2022. No hospitalization or deaths were reported, and symptoms were absent or mild. The rate of SARS-CoV-2 infection was similar in children with and without immunosuppression (33.8% vs 35.2%; p = 0.85). None of the 38 immunosuppressed patients discontinued the therapy, but they had a longer time to negativization (13.31 vs. 10.04 days; p = 0.03). Proteinuria was detected in 7 patients, but only one had a relapse requiring steroid therapy, with prompt remission and a mild course. CONCLUSIONS: After the spread of the Omicron variant, the rate of SARS-CoV-2 infection in children with INS was much higher than previously reported. In this large cohort, symptoms were mild, even in immunosuppressed patients and those with proteinuria. During the infection, transient proteinuria was common with a low rate of relapses. A higher resolution version of the Graphical abstract is available as Supplementary information.

Low dialysate sodium in children and young adults on maintenance hemodialysis: a prospective, randomized, crossover study.

BACKGROUND: The optimal dialysate sodium concentration (dNa) in children on hemodialysis (HD) is unknown. The aim of this study was to compare the effect on interdialytic weight gain (IDWG) and blood pressure (BP) of a low (135 mmol/l) and standard dNa (138 mmol/l) in children and young adults on maintenance HD. METHODS: This prospective single-blind randomized crossover study consisted of a randomized sequence of two phases: "standard dNa" of 138 mmol/L and "low dNa" of 135 mmol/L. Each phase lasted 4 weeks. Inclusion criteria were age < 25 years, hypertension, pre-HD serum Na (sNa) ≥ 130 mmol/L, and occurrence of symptoms in less than 25% of sessions. Primary outcomes were pre-HD systolic and diastolic BP and IDWG. RESULTS: Fifteen patients were recruited, mean age 17.8 ± 4.4 years. Pre-HD SBP and DBP were not different between the two treatments. Mean IDWG was significantly lower with low dNa than with standard dNa: 2.12 ± 1.39% vs. 2.77 ± 1.53%, respectively (p = 0.008). The first-hour refill index (a volume index based on blood-volume monitoring) was significantly lower with dNa 135 mmol/L (p = 0.018). The mean Na gradient (dNa-sNa) was - 2.53 ± 2.4 mmol/L with dNa 135 mmol/L and 0.17 ± 2.8 mmol/L with dNa 138 mmol/L (p = 0.0001). The incidence of symptomatic sessions was similar (1.0% vs. 1.0%). CONCLUSIONS: In a selected population of hypertensive pediatric and young adult HD patients, a dNa of 135 mmol/L was associated with a significant reduction of IDWG compared with a dNa of 138 mmol/L. Furthermore, long-term studies are needed to investigate the effect of lowering dNa on BP. A higher resolution version of the Graphical abstract is available as Supplementary information.

Relapse rate in children with nephrotic syndrome during the SARS-CoV-2 pandemic.

BACKGROUND: Viral upper respiratory tract infections trigger nephrotic syndrome relapses. Few data exist on the impact of the SARS-CoV-2 pandemic on the risk of relapse in children with idiopathic nephrotic syndrome (INS). METHODS: In a Belgian and Italian cohort of children with INS, we performed a retrospective analysis on the number and duration of relapses observed in 3 different periods in 2020: first COVID period, February 15-May 31; second COVID period, June 1-September 14; third COVID period, September 15-December 31. Relapse rates were compared to those of the previous 5 years (PRECOVID period). For the years 2019 and 2020, all causes and INS relapse-related hospitalizations were recorded. Hospitalizations and deaths due to SARS-CoV-2 infection were also recorded. In the Belgian cohort, SARS-CoV-2 serologies were performed. RESULTS: A total of 218 patients were enrolled, and 29 (13.3%) were diagnosed with new-onset INS during the COVID period. Relapse rates per 1000 person-days were as follows: 3.2 in the PRECOVID period, 2.7 in the first COVID period, 3.3 in the second COVID period, and 3.0 in the third COVID period. The incidence rate ratio for the total COVID period was 0.9 (95%CI 0.76 to 1.06; P = 0.21) as compared to the PRECOVID period. During 2020, both the proportion of patients hospitalized for recurrence (14.2% vs. 7.6% in 2019; P = 0.03) and the rate of hospitalization for recurrence (IRR 1.97 (95%CI 1.35 to 2.88); P = 0.013) were higher compared to 2019. In December 2020, anti-SARS-CoV-2 antibodies were detected in 31% of the Belgian cohort. Patients with positive and negative SARS-CoV-2 serology did not differ significantly in relapse rate (2.4 versus 4.2 per 1000 person-days). The number of new INS cases remained similar between 2020, 2019, and 2018. CONCLUSION: The first year of the SARS-CoV-2 pandemic did not significantly affect the relapse rate in children with INS. No serious infections were reported in this population of immunosuppressed patients. A higher resolution version of the Graphical abstract is available as Supplementary information.

Urinary HSP70 improves diagnostic accuracy for urinary tract infection in children: UTILISE study.

BACKGROUND: The accuracy of conventional urinalysis in diagnosing urinary tract infection (UTI) in children is limited, leading to unnecessary antibiotic exposure in a large fraction of patients. Urinary heat shock protein 70 (uHSP70) is a novel marker of acute urinary tract inflammation. We explored the added value of uHSP70 in discriminating UTI from other infections and conditions confused with UTI. METHODS: A total of 802 children from 37 pediatric centers in seven countries participated in the study. Patients diagnosed with UTI (n = 191), non-UTI infections (n = 178), contaminated urine samples (n = 50), asymptomatic bacteriuria (n = 26), and healthy controls (n = 75) were enrolled. Urine and serum levels of HSP70 were measured at presentation in all patients and after resolution of the infection in patients with confirmed UTI. RESULTS: Urinary (u)HSP70 was selectively elevated in children with UTI as compared to all other conditions (p < 0.0001). uHSP70 predicted UTI with 89% sensitivity and 82% specificity (AUC = 0.934). Among the 265 patients with suspected UTI, the uHSP70 > 48 ng/mL criterion identified the 172 children with subsequently confirmed UTI with 90% sensitivity and 82% specificity (AUC = 0.862), exceeding the individual diagnostic accuracy of leukocyturia, nitrite, and leukocyte esterase positivity. uHSP70 had completely normalized by the end of antibiotic therapy in the UTI patients. Serum HSP70 was not predictive. CONCLUSIONS: Urine HSP70 is a novel non-invasive marker of UTI that improves the diagnostic accuracy of conventional urinalysis. We estimate that rapid urine HSP70 screening could spare empiric antibiotic administration in up to 80% of children with suspected UTI. A higher resolution version of the Graphical abstract is available as Supplementary information.

Conflicting views of physicians and surgeons concerning pediatric urinary tract infection: a comparative review.

BACKGROUND: A first febrile urinary tract infection (UTI) is a common condition in children, and pathways of management have evolved over time. OBJECTIVE: To determine the extent to which pediatricians and surgeons differ in their investigation and management of a first febrile UTI, and to evaluate the justifications for any divergence of approach. MATERIALS AND METHODS: A literature search was conducted for papers addressing investigation and/or management following a first febrile UTI in children published between 2011 and 2021. Searches were conducted on Medline, Embase, and the Cochrane Controlled Trials Register. To be eligible for inclusion, a paper was required to provide recommendations on one or more of the following: ultrasound (US) and voiding cystourethrogram (VCUG), the need for continuous antibiotic prophylaxis and surgery when vesicoureteral reflux (VUR) was detected. The authorship required at least one pediatrician or surgeon. Authorship was categorized as medical, surgical, or combined. RESULTS: Pediatricians advocated less imaging and intervention and were more inclined to adopt a "watchful-waiting" approach, confident that any significant abnormality, grades IV-V VUR in particular, should be detected following a second febrile UTI. In contrast, surgeons were more likely to recommend imaging to detect VUR (p<0.00001), and antibiotic prophylaxis (p<0.001) and/or surgical correction (p=0.004) if it was detected, concerned that any delay in diagnosis and treatment could place the child at risk of kidney damage. Papers with combined authorship displayed intermediate results. CONCLUSION: There are two distinct directions in the literature regarding the investigation of an uncomplicated first febrile UTI in a child. In general, when presented with a first febrile UTI in a child, physicians recommend fewer investigations and less treatment, in contrast to surgeons who advocate extensive investigation and aggressive intervention in the event that imaging detects an abnormality. This has the potential to confuse the carers of affected children.

Renal outcome and plasma methylmalonic acid levels after isolated or combined liver or kidney transplantation in patients with methylmalonic acidemia: A multicenter analysis.

BACKGROUND: Methylmalonic acidemia (MMAemia) is characterized by accumulation of methylmalonic acid (MMA) in all body tissues. To minimize disease-related complications, isolated kidney (KTx), liver (LTx) or combined liver-kidney transplantation (LKTx) have been suggested. However, the impact of these different transplant strategies on outcome are unclear. METHODS: In this multicenter retrospective observational study, we compared plasma MMA levels and estimated glomerular filtration rate (eGFR) data of 83 patients. Sixty-eight patients (82%) had a mut0-type MMAemia, one patient had a mut--type MMAemia, and seven (7.3%) had an inherited defect in cobalamin metabolism (cblA- or cblB-type MMAemia). Median observation period was 3.7 years (0-15.1 years). RESULTS: Twenty-six (31%) patients underwent KTx, 24 (29%) LTx and 33 (40%) LKTx. Posttransplant, mean plasma MMA concentration significantly decreased in all three cohorts; but at month 12, plasma MMA in KTx (1372 ± 1101 µmol/L) was 7.8-fold higher than in LTx (176 ± 103 µmol/L; P < 0.001) and 6.4-fold higher than in LKTx (215 ± 110 µmol/L; P < 0.001). Comparable data were observed at month 24. At time of transplantation, mean eGFR in KTx was 18.1 ± 24.3 mL/min/1.73 m2, in LTx 99.8 ± 29.9 mL/min/1.73 m2, and in LKTx 31.5 ± 21.2 mL/min/1.73 m2. At month 12 posttransplant, mean eGFR in KTx (62.3 ± 30.3 mL/min/1.73 m2) was 33.4% lower than in LTx (93.5 ± 18.3 mL/min/1.73 m2; P = 0.0053) and 25.4% lower than in LKTx (83.5 ± 26.9 mL/min/1.73 m2; P = 0.0403). CONCLUSIONS: In patients with isolated MMAemia, LTx and LKTx lead to markedly lower plasma MMA levels during the first 2 years posttransplant than KTx and are associated with a better preservation of kidney function. LTx should therefore be part of the transplant strategy in MMAemia.

Heterozygous COL4A3/COL4A4 mutations: the hidden part of the iceberg?

BACKGROUND: Single mutations in COL4A3/COL4A4 genes have been described in patients with autosomal dominant Alport syndrome and thin basement membrane nephropathy, without a shared definition of these patients within the medical community. We aimed to better categorize this clinical entity by examining clinical manifestations, family history, pathological features and genetics. METHODS: We retrospectively analyzed patients with causative heterozygous COL4A3/COL4A4 mutations referred to us between 1990 and 2019. Index cases were defined as children who were the first to be diagnosed in their families. RESULTS: The study included 24 index cases and 29 affected relatives, belonging to 25 families with a heterozygous mutation in the COL4A3/COL4A4 genes. During the follow-up, nine patients developed proteinuria [median age 15.7 years (range 5.6-33)], six at clinical diagnosis and four with progression toward chronic kidney disease (CKD) (three required kidney replacement therapy at 25, 45 and 53 years and one had CKD Stage 2 at 46 years). Extrarenal involvement was observed in 24.5% of patients. Hematuria was transmitted in consecutive generations, while CKD was reported in nonconsecutive generations of 11 families [median age 53 years (range 16-80)]. Seventeen patients (32%) underwent kidney biopsy: findings were consistent with Alport syndrome in 12 cases and with thin basement membrane nephropathy in 5 cases. CONCLUSIONS: Despite the benign course for these patients described in the literature, a significant percentage is at risk for disease progression. Consequently, we suggest that the assessment of these patients must take into account family history, genetic analysis and pathologic findings. After comparison with the literature, our data suggest that a different definition for Alport syndrome must be considered.

Acute paediatric kidney replacement therapies in Europe: demographic results from the EurAKId Registry.

BACKGROUND: Acute kidney injury (AKI), particularly that requiring dialysis, is a severe complication in hospitalized children that is associated with high morbidity and mortality. A prospective European AKI registry (EurAKId registry, NCT02960867) was created to describe the epidemiology and outcomes of paediatric patients treated with acute dialysis. METHODS: Children were recruited who were between 0 and 18 years of age and were treated both in and outside the paediatric intensive care unit (PICU) with peritoneal dialysis (PD), haemodialysis (HD) or continuous kidney replacement therapy (CKRT) for AKI or metabolic derangement, fluid overload (FO), sepsis or respiratory distress. Five age groups and 12 categories of primary diseases were defined. RESULTS: Data on 340 patients were analysed, of whom 86% received dialysis for AKI and 14% for reasons other than AKI. Boys accounted for 60% of the patients. Illness severity was greater in children with cardiac and haematologic diseases than those with kidney diseases. Most patients received dialysis in the PICU (84%). The most frequently used dialysis modality was CKRT (64%), followed by PD (14%) and HD (14%). The overall survival rate was 65%. Survival was significantly lower in children with three comorbidities than in children with no comorbidities (41% and 83%; P < 0.001). CONCLUSIONS: The EurAKId registry is the first prospective registry considering paediatric acute kidney replacement therapies (KRTs) in both critical and non-critical care settings, focusing on the three dialysis modalities in Europe. The clinical indications for KRT have expanded; our population was characterized by critically ill patients, primarily boys, who frequently received dialysis in the PICU with CKRT.

Definition, diagnosis and clinical management of non-obstructive kidney dysplasia: a consensus statement by the ERKNet Working Group on Kidney Malformations.

Kidney dysplasia is one of the most frequent causes of chronic kidney failure in children. While dysplasia is a histological diagnosis, the term 'kidney dysplasia' is frequently used in daily clinical life without histopathological confirmation. Clinical parameters of kidney dysplasia have not been clearly defined, leading to imprecise communication amongst healthcare professionals and patients. This lack of consensus hampers precise disease understanding and the development of specific therapies. Based on a structured literature search, we here suggest a common basis for clinical, imaging, genetic, pathological and basic science aspects of non-obstructive kidney dysplasia associated with functional kidney impairment. We propose to accept hallmark sonographic findings as surrogate parameters defining a clinical diagnosis of dysplastic kidneys. We suggest differentiated clinical follow-up plans for children with kidney dysplasia and summarize established monogenic causes for non-obstructive kidney dysplasia. Finally, we point out and discuss research gaps in the field.

Incidence and outcome of SARS-CoV-2 infection in a pediatric kidney transplant recipient cohort from a single center in Northern Italy.

BACKGROUND: Concern about SARS-CoV-2 infection has increased over the possible effects on immunocompromised patients. Among them, recipients of solid organ transplantation deserve special attention. Data from the adult population suggest they may be at high risk for developing severe COVID-19, but little data are available for pediatric solid organ transplantation recipients. METHODS: From March 2020 to April 2021, KT recipients aged <21 years, routinely managed at our center, who underwent RT-PCR testing with nasopharyngeal swabs to detect SARS-CoV-2 infection, were studied. Tests were performed according to clinical and/or epidemiological criteria. RESULTS: One hundred one transplanted patients were managed at our center during the observation period. Among this population, 57 patients were tested for SARS-CoV-2 infection with a RT-PCR test and were subsequently enrolled. A total of 111 swabs were performed. Twelve out of the 57 patients tested (21.1%) had a positive RT-PCR test result. Among the positive patients, eight were symptomatic (66.7%). Median duration of symptoms and RT-PCR positivity was two days (IQR 1-2.25) and 17 days (IQR 11-27.25), respectively. No patients required specific treatment or IS therapy reduction; no one was admitted to hospital. CONCLUSIONS: Our data show that pediatric renal transplant recipients are at low risk of clinically relevant COVID-19, as is the healthy age-related population. On the contrary, our results differed substantially from those seen in adult SOT recipient populations that have a high incidence and an even earlier and higher mortality rate.

COVID-19 and idiopathic nephrotic syndrome in children: systematic review of the literature and recommendations from a highly affected area.

BACKGROUND: Coronavirus Disease 2019 has spread from China as a global pandemic, Italy being one of the earliest affected countries. The infection displays a more complicated and often fatal course in adults with a history of kidney disease, while it does not seem to affect children in the same way. Pediatric patients with idiopathic nephrotic syndrome (INS), with or without chronic immunosuppressive therapy, are at greater risk of infections which may also trigger relapses. OBJECTIVES: We performed a systematic review of the literature to identify all articles on SARS-CoV-2 infections in children with INS in order to describe the severity of all SARS-CoV-2 infections reported in children with INS, to evaluate the risk of new onset and relapses associated with SARS-CoV-2 infection, and to draw recommendations on their management and vaccination. The search was conducted on the following databases: MEDLINE (via Pubmed), Google Scholar, and Web of Science. The search methodology used with the selected free text terms or MesH was ("nephrotic syndrome" OR "idiopathic nephrotic syndrome") and ("covid 19" OR "severe acute respiratory syndrome coronavirus 2" OR "2019-nCoV" OR "SARS-CoV-2"). RESULTS: The literature search provided 36 records. After screening for their relevance to the topic, 11 studies were selected. Two additional publications were identified through the reference list of all included articles and 13 articles were included in the review. A total of 43 cases of children with INS and SARS-CoV-2 infection have been reported; the course of the disease was mild for most patients with low need of respiratory support and no death in high income countries. In 5 patients, the infection was complicated by relapse, which anyway showed a good response to steroids. Two children had a new onset of INS during a SARS-CoV-2 infection. CONCLUSIONS: Children with INS, with or without immunosuppression, are not at higher risk of severe SARS-CoV-2 infection. Relapse is a possible complication, but steroid treatment is safe and effective. After summarizing the evidence, we have suggested recommendations for the management of children with INS during the pandemic and the vaccination campaign.

Management of the congenital solitary kidney: consensus recommendations of the Italian Society of Pediatric Nephrology.

BACKGROUND: In recent years, several studies have been published on the prognosis of children with congenital solitary kidney (CSK), with controversial results, and a worldwide consensus on management and follow-up is lacking. In this consensus statement, the Italian Society of Pediatric Nephrology summarizes the current knowledge on CSK and presents recommendations for its management, including diagnostic approach, nutritional and lifestyle habits, and follow-up. We recommend that any antenatal suspicion/diagnosis of CSK be confirmed by neonatal ultrasound (US), avoiding the routine use of further imaging if no other anomalies of kidney/urinary tract are detected. A CSK without additional abnormalities is expected to undergo compensatory enlargement, which should be assessed by US. We recommend that urinalysis, but not blood tests or genetic analysis, be routinely performed at diagnosis in infants and children showing compensatory enlargement of the CSK. Extrarenal malformations should be searched for, particularly genital tract malformations in females. An excessive protein and salt intake should be avoided, while sport participation should not be restricted. We recommend a lifelong follow-up, which should be tailored on risk stratification, as follows: low risk: CSK with compensatory enlargement, medium risk: CSK without compensatory enlargement and/or additional CAKUT, and high risk: decreased GFR and/or proteinuria, and/or hypertension. We recommend that in children at low-risk periodic US, urinalysis and BP measurement be performed; in those at medium risk, we recommend that serum creatinine also be measured; in high-risk children, the schedule has to be tailored according to kidney function and clinical data.

Diagnosis and management of urinary tract infections in children aged 2 months to 3 years in the Italian emergency units: the ItaUTI study.

Urinary tract infections (UTIs) are among the most frequent bacterial diseases in infants and children. Physician adherence to recommendations is notoriously often poor, but no data are available on UTIs management in the emergency setting. In this multicenter national study, we investigated the policies regarding UTIs management in children aged 2 months to 3 years in Italian emergency units. Between April and June 2021, directors of the emergency units were invited to answer an online survey on the following items: diagnostic approach to children with fever without an apparent source, therapeutic approach to UTIs, the use of kidney and urinary tract ultrasound, and the criteria for hospitalization. A total of 121 (89%) out of 139 of invited units participated in the study. Overall, units manage children with a suspected or confirmed UTI according to available recommendations for most of the items. However, in almost 80% (n = 94) of units, a sterile perineal bag is used to collect urine for culture. When urine is collected by cathether, heterogeneity exists on the threshold of bacterial load considered for UTI diagnosis. Conclusions: Available recommendations on UTIs in children are followed by Italian emergency units for most of the items. However, the methods to collect urine specimens for culture, one of the crucial steps of the diagnostic work-up, often do not align with current recommendations and CFU thresholds considered for diagnosis largely vary among centers. Efforts should be addressed to validate and implement new child and family friendly urine collection techniques. What is Known: • Several guidelines are published on the management of children with suspected or confirmed urinary tract infection. • No data are available on the management of pediatric urinary tract infections in the emergency setting. What is New: • Almost 80% of the Italian emergency units employ a sterile perineal bag to collect urine for culture. • Diagnostic CFU thresholds largely vary among centers.