Publications by authors named "Luisa Murer"

92 Publications

Results of the PROPINE randomized controlled study suggest tapering of prednisone treatment for relapses of steroid sensitive nephrotic syndrome is not necessary in children.

Kidney Int 2021 02 2;99(2):475-483. Epub 2020 Nov 2.

Division of Nephrology and Dialysis, Department of Pediatric Subspecialties, Bambino Gesù Children's Hospital-IRCCS, Rome, Italy. Electronic address:

Corticosteroid-related toxicity in children with steroid-sensitive nephrotic syndrome is primarily related to the cumulative dose of prednisone. To optimize treatment of relapses, we conducted the PROPINE study, a multicentric, open-label, randomized, superiority trial. Seventy-eight relapsing children aged 3-17 years who had not received steroid-sparing medications during the previous 12 months were randomized to receive, from day five after remission, either 18 doses of 40 mg/m of prednisone on alternate days (short arm), or the same cumulative dose tapered over double the time (long arm). Patients were monitored with an ad-hoc smartphone application, allowing daily reporting. The primary outcome was the six-month relapse rate at which time, 23/40 and 16/38 patients had relapsed in the long and short arms, respectively (no significant difference). Additionally, 40/78 patients were also enrolled in a secondary crossover study and were allocated to the opposite arm. Altogether, at six months, the relapse rate was 32/40 and 28/40 in the long and short arms, respectively (no significant difference). A post-hoc analysis excluding 30 patients treated with low-dose prednisone maintenance therapy failed to show significant differences between the two arms. No differences in adverse events, blood pressure and weight gain were observed. Thus, our data do not support the prescription of prolonged tapering schedules for relapses of steroid-sensitive nephrotic syndrome in children.
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http://dx.doi.org/10.1016/j.kint.2020.09.024DOI Listing
February 2021

Summary of Expert Opinion on the Management of Children With Chronic Kidney Disease and Growth Failure With Human Growth Hormone.

Front Endocrinol (Lausanne) 2020 2;11:587. Epub 2020 Sep 2.

Unit of Dialysis, IRCCS Istituto Giannina Gaslini, Genoa, Italy.

The management of children and adolescents with chronic kidney disease (CKD) and growth failure candidate for recombinant human growth hormone therapy (rhGH) is based on an appraisal of the literature established on a 2006 consensus statement and 2019 Clinical practice recommendations. The performance of these guidelines has never been tested. The objective of this study was to establish the level of adherence to international guidelines based on the 2006 consensus and the 2019 criteria that lead to the initiation of growth hormone treatment by both pediatric endocrinologists and pediatric nephrologists. A multidisciplinary team of pediatric endocrinologists and pediatric nephrologists, members of the Italian Society of Pediatric Endocrinology or of the Italian Society of Pediatric Nephrology, discussed and reviewed the main issues related to the management of pediatric patients with CKD who need treatment with rhGH. Experts developed 11 questions focusing on risk assessment and decision makings in October 2019 and a survey was sent to forty pediatric endocrinologists ( = 20) and nephrologists ( = 20) covering the whole national territory. The results were then analyzed and discussed in light of current clinical practice guidelines and recent recommendations. Responses were received from 32 of the 40 invited specialists, 17 of whom were pediatric endocrinologists (42.5%) and 15 pediatric nephrologists (37.5%). Although all the centers that participated in the survey agreed to follow the clinical and biochemical diagnostic work-up and the criteria for the treatment of patients with CKD, among the Italian centers there was a wide variety of decision-making processes. Despite current guidelines for the management of children with CKD and growth failure, its use varies widely between centers and rhGH is prescribed in a relatively small number of patients and rarely after kidney transplantation. Several raised issues are not taken into account by international guidelines and a multidisciplinary approach with mutual collaboration between specialists will improve patient care based on their unmet needs.
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http://dx.doi.org/10.3389/fendo.2020.00587DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7493742PMC
September 2020

Continuous kidney replacement therapy in critically ill neonates and infants: a retrospective analysis of clinical results with a dedicated device.

Pediatr Nephrol 2020 09 21;35(9):1699-1705. Epub 2020 May 21.

International Renal Research Institute of Vicenza, Vicenza, Italy.

Background: Providing extracorporeal renal support to neonates and infants involves a number of technical and clinical issues, possibly discouraging early utilization. This report aims to describe a multicenter experience of continuous kidney replacement therapy (CKRT) delivery to small infants using a device specifically designed for this age group.

Methods: A retrospective cohort analysis of all patients treated with the Carpediem™ machine (Bellco-Medtronic, Mirandola, Italy) in 6 centers between June 2013 and December 2016.

Results: Twenty-six neonates and small infants received 165 CKRT sessions in convective modality. Median age at neonatal intensive care unit admission 1 day (IQR 1-11), median body weight 2.9 kg (IQR 2.2-3.6). Median circuit duration 14 h (IQR 10-22), with delivered/prescribed time ratio of 84%. CKRT was conducted using 4 Fr (27%), 5 Fr (35%), 6.5 Fr (11%), and 7 Fr (3%) vascular access, and with umbilical and peripheral accesses (11% each) allowing overall median blood flow of 4.5 ml/kg/min (IQR 3.4-6) and median effluent flow rate 35 ml/kg/h (IQR 28-42). Circuits were primed with normal saline in 58% of treatments, colloids in 31%, and packed red blood cells in 11%. No serious adverse events directly related to machine application were reported by any center. Twenty-five (96%) patients survived their CKRT course and 13 patients (50%) survived to ICU discharge.

Conclusions: CKRT in neonates was easy to initiate and conduct when performed with small central vascular accesses coupled with this device. A dedicated technology for infant CKRT delivery enables patients to be safely treated avoiding technical complications. Graphical abstract.
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http://dx.doi.org/10.1007/s00467-020-04562-yDOI Listing
September 2020

Genetic Analyses in Dent Disease and Characterization of CLCN5 Mutations in Kidney Biopsies.

Int J Mol Sci 2020 01 14;21(2). Epub 2020 Jan 14.

Laboratory of Histomorphology and Molecular Biology of the Kidney, Clinical Nephrology, Department of Medicine-DIMED, University of Padua, 35128 Padua, Italy.

Dent disease (DD), an X-linked renal tubulopathy, is mainly caused by loss-of-function mutations in CLCN5 (DD1) and OCRL genes. CLCN5 encodes the ClC-5 antiporter that in proximal tubules (PT) participates in the receptor-mediated endocytosis of low molecular weight proteins. Few studies have analyzed the PT expression of ClC-5 and of megalin and cubilin receptors in DD1 kidney biopsies. About 25% of DD cases lack mutations in either CLCN5 or OCRL genes (DD3), and no other disease genes have been discovered so far. Sanger sequencing was used for CLCN5 gene analysis in 158 unrelated males clinically suspected of having DD. The tubular expression of ClC-5, megalin, and cubilin was assessed by immunolabeling in 10 DD1 kidney biopsies. Whole exome sequencing (WES) was performed in eight DD3 patients. Twenty-three novel CLCN5 mutations were identified. ClC-5, megalin, and cubilin were significantly lower in DD1 than in control biopsies. The tubular expression of ClC-5 when detected was irrespective of the type of mutation. In four DD3 patients, WES revealed 12 potentially pathogenic variants in three novel genes (SLC17A1, SLC9A3, and PDZK1), and in three genes known to be associated with monogenic forms of renal proximal tubulopathies (SLC3A, LRP2, and CUBN). The supposed third Dent disease-causing gene was not discovered.
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http://dx.doi.org/10.3390/ijms21020516DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7014080PMC
January 2020

Reverse Phenotyping after Whole-Exome Sequencing in Steroid-Resistant Nephrotic Syndrome.

Clin J Am Soc Nephrol 2020 01 12;15(1):89-100. Epub 2019 Dec 12.

Department of Clinical and Experimental Biomedical Sciences "Mario Serio,"

Background And Objectives: Nephrotic syndrome is a typical presentation of genetic podocytopathies but occasionally other genetic nephropathies can present as clinically indistinguishable phenocopies. We hypothesized that extended genetic testing followed by reverse phenotyping would increase the diagnostic rate for these patients.

Design, Setting, Participants, & Measurements: All patients diagnosed with nephrotic syndrome and referred to our center between 2000 and 2018 were assessed in this retrospective study. When indicated, whole-exome sequencing and filtering of 298 genes related to CKD were combined with subsequent reverse phenotyping in patients and families. Pathogenic variants were defined according to current guidelines of the American College of Medical Genetics.

Results: A total of 111 patients (64 steroid-resistant and 47 steroid-sensitive) were included in the study. Not a single pathogenic variant was detected in the steroid-sensitive group. Overall, 30% (19 out of 64) of steroid-resistant patients had pathogenic variants in podocytopathy genes, whereas a substantial number of variants were identified in other genes, not commonly associated with isolated nephrotic syndrome. Reverse phenotyping, on the basis of a personalized diagnostic workflow, permitted to identify previously unrecognized clinical signs of an unexpected underlying genetic nephropathy in a further 28% (18 out of 64) of patients. These patients showed similar multidrug resistance, but different long-term outcome, when compared with genetic podocytopathies.

Conclusions: Reverse phenotyping increased the diagnostic accuracy in patients referred with the diagnosis of steroid-resistant nephrotic syndrome.
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http://dx.doi.org/10.2215/CJN.06060519DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6946071PMC
January 2020

Sex and age as determinants for high blood pressure in pediatric renal transplant recipients: a longitudinal analysis of the CERTAIN Registry.

Pediatr Nephrol 2020 03 7;35(3):415-426. Epub 2019 Dec 7.

Department of Pediatric Kidney, Liver and Metabolic Diseases, Hannover Medical School, Carl-Neuberg-Str. 1, 30625, Hannover, Germany.

Background: High prevalence of arterial hypertension is known in pediatric renal transplant patients, but how blood pressure (BP) distribution and control differ between age groups and whether sex and age interact and potentially impact BP after transplantation have not been investigated.

Methods: This retrospective analysis included 336 pediatric renal transplant recipients (62% males) from the Cooperative European Pediatric Renal Transplant Initiative Registry (CERTAIN) with complete BP measurement at discharge and 1, 2 and 3 years post-transplant.

Results: At discharge and 3 years post-transplant, arterial hypertension was highly prevalent (84% and 77%); antihypertensive drugs were used in 73% and 68% of the patients. 27% suffered from uncontrolled and 9% from untreated hypertension at 3 years post-transplant. Children transplanted at age < 5 years showed sustained high systolic BP z-score and received consistently less antihypertensive treatment over time. Younger age, shorter time since transplantation, male sex, higher body mass index (BMI), high cyclosporine A (CSA) trough levels, and a primary renal disease other than congenital anomalies of the kidney and urinary tract (CAKUT) were significantly associated with higher systolic BP z-score. Sex-stratified analysis revealed a significant association between high CSA and higher systolic BP in older girls that likely had started puberty already. An association between BP and estimated glomerular filtration rate was not detected.

Conclusions: BP control during the first 3 years was poor in this large European cohort. The description of age- and sex-specific risk profiles identified certain recipient groups that may benefit from more frequent BP monitoring (i.e. young children) or different choices of immunosuppression (i.e. older girls).
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http://dx.doi.org/10.1007/s00467-019-04395-4DOI Listing
March 2020

Post-transplant recurrence of steroid resistant nephrotic syndrome in children: the Italian experience.

J Nephrol 2020 Aug 15;33(4):849-857. Epub 2019 Oct 15.

Pediatric Nephrology, Dialysis and Transplant Unit, Department of Clinical Sciences and Community Health, Fondazione IRCCS Ca' Granda-Ospedale Maggiore Policlinico, University of Milan, via della Commenda, 9, 20122, Milan, Italy.

Background: Steroid resistant nephrotic syndrome (SRNS) is a frequent cause of end stage renal disease in children and post-transplant disease recurrence is a major cause of graft loss.

Methods: We identified all children with SRNS who underwent renal transplantation in Italy, between 2005 and 2017. Data were retrospectively collected for the presence of a causative gene mutation, sex, histology, duration of pre-transplant dialysis, age at onset and transplant, HLA matching, recurrence, therapy for recurrence, and graft survival.

Results: 101 patients underwent a first and 22 a second renal transplant. After a median follow-up of 58.5 months, the disease recurred on the first renal transplant in 53.3% of patients with a non-genetic and none with a genetic SRNS. Age at transplant > 9 years and the presence of at least one HLA-AB match were independent risk factors for recurrence. Duration of dialysis was longer in children with relapse, but did not reach statistical significance. Overall, 24% of patients lost the first graft, with recurrence representing the commonest cause. Among 22 patients who underwent a second transplant, 5 suffered of SRNS recurrence. SRNS relapsed in 5/9 (55%) patients with disease recurrence in their first transplant and 2 of them lost the second graft.

Conclusions: Absence of a causative mutation represents the major risk factor for post-transplant recurrence in children with SRNS, while transplant can be curative in genetic SRNS. A prolonged time spent on dialysis before transplantation has no protective effect on the risk of relapse and should not be encouraged. Retransplantation represents a second chance after graft loss for recurrence.
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http://dx.doi.org/10.1007/s40620-019-00660-9DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7381476PMC
August 2020

Acute Kidney Injury in Critically Ill Children: A Retrospective Analysis of Risk Factors.

Blood Purif 2020 5;49(1-2):1-7. Epub 2019 Aug 5.

Division of Pediatrics, Department of Medicine, University of Udine, Udine, Italy,

Introduction: Children admitted to paediatric intensive care unit (PICU) are at risk of acute kidney injury (AKI). However, few paediatric studies have focused on the identification of factors potentially associated with the development of this condition. The aim of our study was to assess the incidence rate of AKI, identify risk factors, and evaluate clinical outcome in a large sample of critically ill children.

Methods: This retrospective observational study was conducted including patients admitted to our PICU from January 2014 to December 2016. AKI was defined according to Kidney Disease: Improving Global Outcome criteria.

Results: A total of 222 PICU patients out of 811 (27%) had AKI (stage I 39%, stage II 24%, stage III 37%). The most common PICU admission diagnoses in AKI cases were heart disease (38.6%), respiratory failure (16.8%) and postsurgical non-cardiac patients (11%). Hypoxic-ischaemic was the most frequent cause of AKI. Significant risk factors for AKI following multivariate analysis were age >2 months (OR 2.43; 95% CI 1.03-7.87; p = 0.05), serum creatinine at admission >44 µmol/L (OR 2.23; 95% CI 1.26-3.94; p = 0.006), presence of comorbidities (OR 1.84; 95% CI 1.03-3.30; p = 0.04), use of inotropes (OR 2.56; 95% CI 1.23-5.35; p= 0.012) and diuretics (OR 2.78; 95% CI 1.49-5.19; p = 0.001), exposure to nephrotoxic drugs (OR 1.66; 95% CI 1.01-2.91; p= 0.04), multiple organ dysfunction syndrome (OR 2.68; 95% CI 1.43-5.01; p = 0.002), and coagulopathy (OR 1.89; 95% CI 1.05-3.38, p = 0.03). AKI was associated with a significant longer PICU stay (median LOS of 8 days, interquartile range [IQR] 3-16, versus 4 days, IQR 2-8, in non-AKI patients; p < 0.001). The mortality rate resulted tenfold higher in AKI than non-AKI patients (12.6 vs. 1.2%; p < 0.001).

Conclusions: The incidence of AKI in critically ill children is high, with an associated increased length of stay and risk of mortality. In the PICU setting, risk factors of AKI are multiple and mainly associated with illness severity.
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http://dx.doi.org/10.1159/000502081DOI Listing
December 2020

Acute dialysis in children: results of a European survey.

J Nephrol 2019 Jun 4;32(3):445-451. Epub 2019 Apr 4.

Nephrology and Dialysis Unit, Pediatric Subspecialties Department, Institute for Scientific Research, Bambino Gesù Children's Hospital, Piazza S. Onofrio 4, 00165, Rome, Italy.

The number of children with acute kidney injury (AKI) requiring dialysis is increasing. To date, systematic analysis has been largely limited to critically ill children treated with continuous renal replacement therapy (CRRT). We conducted a survey among 35 European Pediatric Nephrology Centers to investigate dialysis practices in European children with AKI. Altogether, the centers perform dialysis in more than 900 pediatric patients with AKI per year. PD and CRRT are the most frequently used dialysis modalities, accounting for 39.4% and 38.2% of treatments, followed by intermittent HD (22.4%). In units treating more than 25 cases per year and in those with cardiothoracic surgery programs, PD is the most commonly chosen dialysis modality. Also, nearly one quarter of centers, in countries with a gross domestic product below $35,000/year, do not utilize CRRT at all. Dialysis nurses are exclusively in charge of CRRT management in 45% of the cases and pediatric intensive care nurses in 25%, while shared management is practiced in 30%. In conclusion, this survey indicates that the choice of treatment modalities for dialysis in children with AKI in Europe is affected by the underlying ethiology of the disease, organization/set-up of centers and socioeconomic conditions. PD is utilized as often as CRRT, and also intermittent HD is a commonly applied treatment option. A prospective European AKI registry is planned to provide further insights on the epidemiology, management and outcomes of dialysis in pediatric AKI.
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http://dx.doi.org/10.1007/s40620-019-00606-1DOI Listing
June 2019

An Ex Vivo Test of Complement Activation on Endothelium for Individualized Eculizumab Therapy in Hemolytic Uremic Syndrome.

Am J Kidney Dis 2019 07 7;74(1):56-72. Epub 2019 Mar 7.

Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Clinical Research Center for Rare Diseases Aldo e Cele Daccò and Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Bergamo, Italy; Unit of Nephrology and Dialysis, Azienda Socio-Sanitaria Territoriale Papa Giovanni XXIII, Bergamo, Italy; L. Sacco Department of Biomedical and Clinical Sciences, University of Milan, Milan, Italy.

Rationale & Objective: Although primary atypical hemolytic uremic syndrome (aHUS) is associated with abnormalities in complement genes and antibodies to complement factor H, the role of complement in secondary aHUS remains debatable. We evaluated the usefulness of an ex vivo test to: (1) detect complement activation within the endothelium in primary and secondary aHUS, (2) differentiate active disease from remission, (3) monitor the effectiveness of eculizumab therapy, and (4) identify relapses during eculizumab dosage tapering and after discontinuation of treatment.

Study Design: Case series.

Setting & Participants: 121 patients with primary aHUS and 28 with secondary aHUS. Serum samples were collected during acute episodes, following remission, and during eculizumab treatment and were assessed using a serum-induced ex vivo C5b-9 endothelial deposition test.

Results: Serum-induced C5b-9 deposition on cultured microvascular endothelium was quantified by calculating the endothelial area covered by C5b-9 staining; values were expressed as percentage of C5b-9 deposits induced by a serum pool from healthy controls. Testing with adenosine diphosphate-activated endothelium demonstrated elevated C5b-9 deposits for all untreated patients with aHUS independent of disease activity, while testing with unstimulated endothelium demonstrated deposits only in active disease. Similar findings were observed in secondary aHUS. Serum-induced C5b-9 deposits on activated and unstimulated endothelium normalized during eculizumab treatment. 96% (22/23) of patients receiving eculizumab at extended 3- or 4-week dosing intervals demonstrated normal C5b-9 deposits on activated endothelium, despite most patients having CH50Eq (serum complement activity) > 20 UEq/mL, indicating that adequate complement control was achieved even with incomplete blockade of circulating C5. During eculizumab dosage tapering or after treatment discontinuation, all patients experiencing relapses versus only 6% (1/17) of those in stable remission had elevated C5b-9 deposits on unstimulated endothelium.

Limitations: The C5b-9 endothelial deposition test can be performed in only specialized laboratories. Findings on eculizumab dosage tapering need to be confirmed with longitudinal monitoring of C5b-9 deposition.

Conclusions: The C5b-9 endothelial deposition assay may represent an advance in our ability to monitor aHUS activity and individualize therapy.
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http://dx.doi.org/10.1053/j.ajkd.2018.11.012DOI Listing
July 2019

Treatment and long-term outcome in primary distal renal tubular acidosis.

Nephrol Dial Transplant 2019 06;34(6):981-991

Department of Paediatric Nephrology, Great Ormond Street Hospital for Children, NHS Foundation Trust, London, UK.

Background: Primary distal renal tubular acidosis (dRTA) is a rare disorder, and we aimed to gather data on treatment and long-term outcome.

Methods: We contacted paediatric and adult nephrologists through European professional organizations. Responding clinicians entered demographic, biochemical, genetic and clinical data in an online form.

Results: Adequate data were collected on 340 patients (29 countries, female 52%). Mutation testing had been performed on 206 patients (61%); pathogenic mutations were identified in 170 patients (83%). The median (range) presentation age was 0.5 (0-54) years and age at last follow-up was 11.0 (0-70.0) years. Adult height was slightly below average with a mean (SD score) of -0.57 (±1.16). There was an increased prevalence of chronic kidney disease (CKD) Stage ≥2 in children (35%) and adults (82%). Nephrocalcinosis was reported in 88%. Nephrolithiasis was more common with SLC4A1 mutations (42% versus 21%). Thirty-six percent had hearing loss, particularly in ATP6V1B1 (88%). The median (interquartile range) prescribed dose of alkali (mEq/kg/day) was 1.9 (1.2-3.3). Adequate metabolic control (normal plasma bicarbonate and normocalciuria) was achieved in 158 patients (51%), more commonly in countries with higher gross domestic product (67% versus 23%), and was associated with higher height and estimated glomerular filtration rate.

Conclusion: Long-term follow-up from this large dRTA cohort shows an overall favourable outcome with normal adult height for most and no patient with CKD Stage 5. However, 82% of adult patients have CKD Stages 2-4. Importance of adequate metabolic control was highlighted by better growth and renal function but was achieved in only half of patients.
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http://dx.doi.org/10.1093/ndt/gfy409DOI Listing
June 2019

Haemodiafiltration use in children: data from the Italian Pediatric Dialysis Registry.

Pediatr Nephrol 2019 06 5;34(6):1057-1063. Epub 2019 Jan 5.

Dialysis Unit, Paediatric Nephrology and Dialysis Department, G Gaslini Children Hospital, Genoa, Italy.

Background: High volume haemodiafiltration (HDF) is associated with better survival than conventional haemodialysis (HD) in adults, but data concerning its use in children are lacking. The aim of this study was to assess the prevalence of paediatric HDF use and its associated factors in recent years in Italy.

Methods: We retrospectively reviewed the files of patients from the Italian Pediatric Dialysis Registry's database who were registered between January 1, 2004 and December 31, 2016 and treated with extracorporeal dialysis for at least 6 months, looking in particular at modality and its associated factors.

Results: One hundred forty-one out of 198 patients were treated exclusively with bicarbonate HD (71.2%), 57 with HDF (28.8%). Patients treated with HDF were younger (median 9.7 vs 13.2 years, p = 0.0008), were less often incident patients (52.6% vs 75.9%, p = 0.0031), had longer duration of the HD cycle (26.9 vs 20.8 months, p = 0.0036) and had a longer time to renal transplantation (32 vs 25 months, p = 0.0029) than those treated with bicarbonate HD only. The percentage of patients treated with HDF increased with dialysis vintage (16.9% at 6 months, 38.1% after more than 2 years of dialysis). The use of HDF was stable over time and was more common in the largest centres.

Conclusions: Over the observation period, HDF use in Italy has been limited to roughly a quarter of patients on extracorporeal dialysis, in particular to those with high dialysis vintage, younger age or a long expected waiting time to renal transplantation.
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http://dx.doi.org/10.1007/s00467-018-4184-zDOI Listing
June 2019

Choice of Catheter Size for Infants in Continuous Renal Replacement Therapy: Bigger Is Not Always Better.

Pediatr Crit Care Med 2019 03;20(3):e170-e179

Department of Nephrology, Dialysis and Transplantation, San Bortolo Hospital, Viale Ferdinando Rodolfi 37, Vicenza, Italy.

Objectives: Renal replacement therapy in infants and small children is the treatment of choice for severe oligoanuric renal dysfunction, with an increasing consensus that early initiation might contribute to preventing acute kidney injury complications. Safer renal replacement therapy devices specifically designed for neonates may contribute to ameliorating outcomes and increasing chances of survival. One of the crucial factors to achieve an effective renal replacement therapy in small infants is adequate vascular access. The interaction of small size central vascular catheters with renal replacement therapy devices has never been investigated. The aim of this study was to characterize both the operating conditions and performance of three different central vascular catheters sizes (4F, 5F, and 7F) connected to two different extracorporeal blood circulation models (adult and pediatric). The rheologic performance of each vascular access size in combination with the adult and pediatric renal replacement therapy models was described.

Design: Series of experimental extracorporeal circulation circuit tests were conducted with different setups. A two-roller pump was used to simulate a standard adult dialysis machine, whereas a small three-roller pump served as pediatric renal replacement therapy device.

Setting: A pressure-flow setup aimed to collect pressure and flow values under different test conditions. A second experiment focused on hemolysis estimation induced by the extracorporeal system. Hemolysis exclusively induced by the 4F catheter was also evaluated. Finally, our data were applied to estimate the optimal catheter size theoretically capable of delivering adequate doses basing on anthropometric data (patient weight and cannulation site) in absence of direct ultrasound vessel measurement.

Subjects: In vitro tests conducted on simulated extracorporeal circuit models of continuous pediatric and neonatal renal replacement therapy.

Interventions: None.

Measurements And Main Results: When 4F and 5F catheters are used, maximal blood flows within safe circuit pressures can be set at the values of 13 and 29 mL/min, respectively, when a small pump is used. Differently, when using adult roller pumps, only maximal flows of 10 and 20 mL/min are reached. However, hemolysis is higher when using a three-roller pump compared with the two-roller. The clinical impact of this increased hemolytic burden is likely not relevant.

Conclusions: Small size central vascular catheters display optimal rheologic performances in terms of pressures and flows particularly when the renal replacement therapy device is equipped with pumps proportional to central vascular catheters sizes, and even when relatively high blood flows are set. This is achieved at the risk of a higher hemolysis rate.
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http://dx.doi.org/10.1097/PCC.0000000000001825DOI Listing
March 2019

Continuous Veno-Venous Hemodialysis Using the Cardio-Renal Pediatric Dialysis Emergency MachineTM: First Clinical Experiences.

Blood Purif 2019 31;47(1-3):149-155. Epub 2018 Oct 31.

Department of Nephrology, Dialysis, and Transplantation, International Renal Research Institute, San Bortolo Hospital, Vicenza, Italy.

We report the first worldwide experience with continuous veno-venous hemodialysis (CVVHD) in children using the last generation Cardio-Renal Pediatric Dialysis Emergency Machine (CARPEDIEM)TM device. Thirteen children received 1,008 h of CVVHD during 95 sessions, using a 0.15 (n = 7) or a 0.25 m2 (n = 6) hemofilter. The median weight was 3 kg (interquartile range [IQR] 2.5-6.2). In 10 patients, CVVHD was conducted using a 5 Fr double-lumen central vascular access, whereas in 3 children, bigger sizes were used (6.5 and 8 Ch). The median prescribed Qb was 17 mL/min (IQR 10-29.5), with a median Qd of 10 mL/min. Circuits were primed with 5% albumin in 12 out of 13 patients, using anticoagulation with heparin in all 13 cases. The median delivered/prescribed time ratio yielded a 100% result (95-100%). The most common cause for "downtime" was clotting that however occurred in only 3% of all treatments. Survivals at continuous renal replacement therapy discontinuation and ICU discharge were 100 and 69% respectively. The CARPEDIEMTM machine allowed successful delivery of diffusive blood purification modality to very small patients, using small catheters, no blood primes, and excellent concordance between delivered and prescribed treatment duration.
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http://dx.doi.org/10.1159/000494437DOI Listing
May 2019

Epidemiology of and Risk Factors for BK Polyomavirus Replication and Nephropathy in Pediatric Renal Transplant Recipients: An International CERTAIN Registry Study.

Transplantation 2019 06;103(6):1224-1233

Department of Pediatrics I, University Children's Hospital, Heidelberg, Germany.

Background: BK polyomavirus-associated nephropathy (BKPyVAN) constitutes a serious cause of kidney allograft failure, but large-scale data in pediatric renal transplant recipients and a comprehensive analysis of specific risk factors are lacking.

Methods: We analyzed the data of 313 patients in the Cooperative European Pediatric Renal Transplant Initiative Registry, with an observation period of 3.3 years (range, 1-5). The net state of immunosuppressive therapy was assessed by the modified Vasudev score.

Results: Presumptive BKPyVAN (defined as sustained [>3 wk] high-level BK viremia >10 copies/mL) within 5 years posttransplant occurred in 49 (15.8%) of 311 patients, and biopsy-proven BKPyVAN in 14 (4.5%) of 313. BKPyV viremia was observed in 115 (36.7%) of 311 patients, of whom 11 (9.6%) of 115 developed viremia late, that is, after the second year posttransplant. In 6 (12.5%) of 48 patients with high-level viremia and in 3 (21.4%) of 14 with BKPyVAN, this respective event occurred late. According to multivariable analysis, BKPyV viremia and/or BKPyVAN were associated not only with a higher net state of immunosuppression (odds ratio [OR], 1.3; P < 0.01) and with tacrolimus-based versus ciclosporin-based immunosuppression (OR, 3.6; P < 0.01) but also with younger recipient age (OR, 1.1 per y younger; P < 0.001) and obstructive uropathy (OR, 12.4; P < 0.01) as primary renal disease.

Conclusions: Uncontrolled BKPyV replication affects a significant proportion of pediatric renal transplant recipients and is associated with unique features of epidemiology and risk factors, such as young recipient age, obstructive uropathy, and overall intensity of immunosuppressive therapy. BKPyV surveillance should be considered beyond 2 years posttransplant in pediatric patients at higher risk.
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http://dx.doi.org/10.1097/TP.0000000000002414DOI Listing
June 2019

Could the interaction between LMX1B and PAX2 influence the severity of renal symptoms?

Eur J Hum Genet 2018 11 4;26(11):1708-1712. Epub 2018 Jul 4.

Laboratory of Immunopathology and Molecular Biology of the Kidney, Department of Women's and Children's Health, University of Padova, Padua, Italy.

Nail Patella syndrome (NPS) is a rare autosomal dominant disease characterized by varying degrees of patella, nail, and elbows dysplasia and also ocular and renal congenital abnormalities. The renal involvement, ranging from hematuria and proteinuria to end-stage renal disease, is present in 22-60% of NPS cases. Heterozygous variants in LMX1B are known to be responsible of NPS and it has been hypothesized that the variable expressivity is due to the interaction of LMX1B with other developmental genes. We reported a case of co-presence of LMX1B and PAX2 variants in a child with extrarenal manifestation of NPS and end-stage renal disease but congenital bilateral renal hypodysplasia and vesicoureteral reflux. The LMX1B variant was de novo, whereas the PAX2 variant was inherited from the mother that had bilateral renal hypoplasia although in presence of only a mild chronic kidney disease. The molecular interaction between LMX1B and PAX2 has been already reported in vitro and this finding suggest that the worst renal NPS phenotype of our patient could be due to the defective expression of these two genes during nephrogenesis. In conclusion, our finding suggests that PAX2 may act as modifier gene in Nail Patella phenotype.
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http://dx.doi.org/10.1038/s41431-018-0213-4DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6189091PMC
November 2018

Outcome of renal transplantation in small infants: a match-controlled analysis.

Pediatr Nephrol 2018 06 13;33(6):1057-1068. Epub 2018 Mar 13.

Department of Paediatrics I, University Children's Hospital, Heidelberg, Germany.

Background: Infants with a body weight of less than 10 kg are often not considered to be suitable candidates for renal transplantation (RTx). The objective of this study was to evaluate this arbitrary weight threshold for pediatric RTx.

Methods: We conducted a multicenter, retrospective, match-controlled cohort study on infants weighing less than 10 kg at time of engrafting (low-weight group [LWG], n = 38) compared to a matched control group (n = 76) with a body weight of 10-15 kg, using data from the first 2 years post-transplant derived from the CERTAIN Registry.

Results: Patient survival was 97 and 100% in the LWG and control groups, respectively (P = 0.33), and death-censored graft survival was 100 and 95% in the LWG and control groups, respectively (P = 0.30). Estimated glomerular filtration rate at 2 years post-transplant was excellent and comparable between the groups (LWG 77.6 ± 34.9 mL/min/1.73 m; control 74.8 ± 29.1 mL/min/1.73 m; P = 0.68). The overall incidences of surgery-related complications (LWG 11%, control 23%; P = 0.12) and medical outcome measures (LWG 23%, control 36%, P = 0.17) were not significantly different between the groups. The medical outcome measures included transplant-related viral diseases (LWG 10%, control 21%; P = 0.20), acute rejection episodes (LWG 14%, control 29%; P = 0.092), malignancies (LWG 3%, control 0%; P = 0.33) and arterial hypertension (LWG 73%, control 67%; P = 0.57).

Conclusions: These data suggest that RTx in low-weight children is a feasible option, at least in selected centers with appropriate surgical and medical expertise.
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http://dx.doi.org/10.1007/s00467-018-3895-5DOI Listing
June 2018

A propensity-matched comparison of hard outcomes in children on chronic dialysis.

Eur J Pediatr 2018 Jan 16;177(1):117-124. Epub 2017 Nov 16.

Dialysis Unit, Department of Pediatrics, IRCCS Giannina Gaslini, Genoa, Italy.

Data concerning outcomes of children on hemodialysis (HD) and peritoneal dialysis (PD) are scarce and frequently derived from single-center experiences. We sought to compare survival and transplantation rates in a large cohort of PD and HD patients. We extracted all patients initiating dialysis under 16 years of age between 2004 and 2013 from the Italian Registry of Pediatric Chronic Dialysis. Patients on PD were propensity-matched to those on HD based on gender, age, primary cause of ESRD, and the number of co-morbidities. Stratified Cox proportional hazard models were used to compare outcomes by dialysis modality. Three hundred ten patients were matched from 452 incident patients. In the unmatched cohort, PD patients were younger, more likely to be diagnosed with CAKUT, and had a higher urine output than HD patients. In the propensity-matched cohort, covariates were balanced between the two groups. At 2 years, the cumulative hazard ratio for death was similar (CHR 0.95, 95% CI 0.17-5.20) for HD relative to PD patients; and at 5 years, the CHR was lower for HD patients (0.22 95% CI 0.16-0.29). The cumulative incidence of transplantation at 3 years after dialysis initiation was 60.9% in HD patients and 59.7% in PD patients, with a CHR of 1.03 (95% CI 0.73-1.45).

Conclusions: Pediatric PD and HD patients have distinct characteristics. After controlling for treatment-selection biases, children selected to start on PD or HD exhibit a similar mortality risk during the first 2 years on treatment, after which this risk increases in PD children. What is Known: • Few studies have compared hard outcomes in children on maintenance dialysis. • Children started on different dialysis modalities have distinct characteristics that impact on survival. What is New: • After controlling for treatment-selection biases, children selected to start dialysis on PD or HD exhibit a similar mortality risk during the first 2 years on treatment, after which this risk appears to be increased in PD children. • An "integrative care" approach should be used in children on PD, switching them to HD when PD-related morbidity tends to increase.
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http://dx.doi.org/10.1007/s00431-017-3040-7DOI Listing
January 2018

Cluster Analysis Identifies Distinct Pathogenetic Patterns in C3 Glomerulopathies/Immune Complex-Mediated Membranoproliferative GN.

J Am Soc Nephrol 2018 01 13;29(1):283-294. Epub 2017 Oct 13.

IRCCS-Istituto di Ricerche Farmacologiche Mario Negri, Clinical Research Center for Rare Diseases Aldo e Cele Daccò, Ranica Bergamo, Italy.

Membranoproliferative GN (MPGN) was recently reclassified as alternative pathway complement-mediated C3 glomerulopathy (C3G) and immune complex-mediated membranoproliferative GN (IC-MPGN). However, genetic and acquired alternative pathway abnormalities are also observed in IC-MPGN. Here, we explored the presence of distinct disease entities characterized by specific pathophysiologic mechanisms. We performed unsupervised hierarchical clustering, a data-driven statistical approach, on histologic, genetic, and clinical data and data regarding serum/plasma complement parameters from 173 patients with C3G/IC-MPGN. This approach divided patients into four clusters, indicating the existence of four different pathogenetic patterns. Specifically, this analysis separated patients with fluid-phase complement activation (clusters 1-3) who had low serum C3 levels and a high prevalence of genetic and acquired alternative pathway abnormalities from patients with solid-phase complement activation (cluster 4) who had normal or mildly altered serum C3, late disease onset, and poor renal survival. In patients with fluid-phase complement activation, those in clusters 1 and 2 had massive activation of the alternative pathway, including activation of the terminal pathway, and the highest prevalence of subendothelial deposits, but those in cluster 2 had additional activation of the classic pathway and the highest prevalence of nephrotic syndrome at disease onset. Patients in cluster 3 had prevalent activation of C3 convertase and highly electron-dense intramembranous deposits. In addition, we provide a simple algorithm to assign patients with C3G/IC-MPGN to specific clusters. These distinct clusters may facilitate clarification of disease etiology, improve risk assessment for ESRD, and pave the way for personalized treatment.
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http://dx.doi.org/10.1681/ASN.2017030258DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5748907PMC
January 2018

Usefulness of Tc-dimercaptosuccinic acid renal scan in the diagnosis and follow-up of acute tubulointerstitial nephritis in children.

Clin Kidney J 2017 Oct 12;10(5):655-660. Epub 2017 Jun 12.

Nephrology, Dialysis and Transplant Unit, Department of Women's and Children's Health, University-Hospital of Padova, Padova, Italy.

Background: Symptoms and signs of acute tubulointerstitial nephritis (ATIN) are nonspecific; therefore, renal biopsy is often necessary to clarify the diagnosis. The aim of this study was to evaluate the use of Tc-dimercaptosuccinic acid (DMSA) scintigraphy in the diagnosis and follow-up of ATIN.

Methods: We retrospectively reviewed the charts of five patients (nine renal units) with a median age of 14 years who underwent DMSA scan after a clinical and/or biopsy-proven diagnosis of ATIN. The exam was performed within 1 month after disease onset and repeated at a median time of 12 months after the acute phase.

Results: DMSA renal scans performed during the acute phase allowed the discovery of suggestive findings, including diffuse reduction of the renal uptake of radionuclide and presence of multiple 'cold' focal lesions in a corticomedullary distribution. The follow-up scintigraphy resulted normal in two patients who were treated with steroids and in one patient who presented a mild renal dysfunction in the acute phase. By contrast, the control scan showed persistent renal damage in one patient who was further readmitted because of hypertension and in one renal transplanted patient who presented a Stage 3 acute kidney injury in the acute phase.

Conclusions: DMSA renal scan might be a reliable tool for an early non-invasive diagnosis of ATIN in children and might be particularly useful in those patients who are not candidates for a kidney biopsy. Moreover, DMSA scan gives accurate follow-up evaluation, as it allows monitoring of the evolution of acute renal parenchymal inflammation with potential risk of renal scar formation. Due to the small sample size, our findings warrant further validation in a larger study.
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http://dx.doi.org/10.1093/ckj/sfx041DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5622892PMC
October 2017

Therapeutic Plasma Exchange in Neonates and Infants: Successful Use of a Miniaturized Machine.

Blood Purif 2017 31;44(2):100-105. Epub 2017 Mar 31.

Nephrology, Dialysis and Transplant Unit, Department of Woman's and Child's Health, University-Hospital of Padova, Padova, Italy.

Therapeutic plasma exchange (TPE) in neonates and small infants is a treatment method at the forefront that may become a potentially life-saving procedure in a wide array of severe conditions. Indications for TPE in the pediatric population have been mainly derived from adult literature, with neonatal hyperbilirubinemia being the most notable exception. The only alternative to TPE in small pediatric patients is manual blood exchange transfusion, which, however, bears an unacceptably high risk of severe complications. Still, technical issues due to extracorporeal circulation in neonates have burdened TPE so far, since machines developed for adults require a relatively large blood volume to operate. We in this study, describe our preliminary experience of TPE for treating 2 potentially life-threatening conditions in neonatal age. To overcome the aforementioned limitations, plasmapheresis was performed in both cases using a machine specifically designed for patients weighing less than 10 kg.
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http://dx.doi.org/10.1159/000470827DOI Listing
July 2018

Erratum to: Viral load of EBV DNAemia is a predictor of EBV-related post-transplant lymphoproliferative disorders in pediatric renal transplant recipients.

Pediatr Nephrol 2017 10;32(10):2001

Pediatric Nephrology and Renal Transplant Unit, Bambino Gesù Children's Hospital-IRCCS, Piazza S. Onofrio 4, 00165, Rome, Italy.

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http://dx.doi.org/10.1007/s00467-017-3752-yDOI Listing
October 2017

Long-Term Outcome of Steroid-Resistant Nephrotic Syndrome in Children.

J Am Soc Nephrol 2017 Oct 31;28(10):3055-3065. Epub 2017 May 31.

Division of Pediatric Nephrology, University Center for Pediatrics and Adolescent Medicine, Heidelberg, Germany;

We investigated the value of genetic, histopathologic, and early treatment response information in prognosing long-term renal outcome in children with primary steroid-resistant nephrotic syndrome. From the PodoNet Registry, we obtained longitudinal clinical information for 1354 patients (disease onset at >3 months and <20 years of age): 612 had documented responsiveness to intensified immunosuppression (IIS), 1155 had kidney biopsy results, and 212 had an established genetic diagnosis. We assessed risk factors for ESRD using multivariate Cox regression models. Complete and partial remission of proteinuria within 12 months of disease onset occurred in 24.5% and 16.5% of children, respectively, with the highest remission rates achieved with calcineurin inhibitor-based protocols. Ten-year ESRD-free survival rates were 43%, 94%, and 72% in children with IIS resistance, complete remission, and partial remission, respectively; 27% in children with a genetic diagnosis; and 79% and 52% in children with histopathologic findings of minimal change glomerulopathy and FSGS, respectively. Five-year ESRD-free survival rate was 21% for diffuse mesangial sclerosis. IIS responsiveness, presence of a genetic diagnosis, and FSGS or diffuse mesangial sclerosis on initial biopsy as well as age, serum albumin concentration, and CKD stage at onset affected ESRD risk. Our findings suggest that responsiveness to initial IIS and detection of a hereditary podocytopathy are prognostic indicators of favorable and poor long-term outcome, respectively, in children with steroid-resistant nephrotic syndrome. Children with multidrug-resistant sporadic disease show better renal survival than those with genetic disease. Furthermore, histopathologic findings may retain prognostic relevance when a genetic diagnosis is established.
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http://dx.doi.org/10.1681/ASN.2016101121DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5619960PMC
October 2017

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.

Ital J Pediatr 2017 Apr 21;43(1):41. Epub 2017 Apr 21.

Institute of Maternal and Child Health IRCCS "Burlo Garofolo", Department of Pediatrics, Trieste, Italy.

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.
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http://dx.doi.org/10.1186/s13052-017-0356-xDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5399429PMC
April 2017

Viral load of EBV DNAemia is a predictor of EBV-related post-transplant lymphoproliferative disorders in pediatric renal transplant recipients.

Pediatr Nephrol 2017 08 9;32(8):1433-1442. Epub 2017 Mar 9.

Pediatric Nephrology and Renal Transplant Unit, Bambino Gesù Children's Hospital-IRCCS, Piazza S. Onofrio 4, 00165, Rome, Italy.

Background: Post-transplant lymphoproliferative disorder (PTLD) is a severe complication of solid organ transplantation that can be classified into two major subtypes, namely, early lesions and non-early lesions, based on histopathological findings. In the vast majority of cases, proliferating cells are B lymphocytes and, most frequently, proliferation is induced by Epstein-Barr virus (EBV) infection.

Methods: The aim of our study was to evaluate the natural history of EBV infection and its possible evolution toward PTLD in a pediatric cohort of patients who received a renal transplant between January 2000 and December 2013. A total of 304 patients were evaluated for this study, of whom 103 tested seronegative for EBV at transplantation.

Results: Following transplantation, 50 of the 103 seronegative patients (48.5%) developed a first EBV infection, based on the results of PCR assays for EBV DNA, with 19 of these patients ultimately reverting to the negative state (<3000 copies/ml). Among the 201 seropositive patients only 40 (19.9%) presented a reactivation of EBV. Non-early lesions PTLD was diagnosed in ten patients, and early lesions PTLD was diagnosed in five patients. In all cases a positive EBV viral load had been detected at some stage of the follow-up. Having a maximum peak of EBV viral load above the median value observed in the whole cohort (59,909.5 copies/ml) was a significant and independent predictor of non-early lesions PTLD and all PTLD onset.

Conclusions: A high PCR EBV viral load is correlated with the probability of developing PTLD. The definition of a reliable marker is essential to identify patients more at risk of PTLD and to personalize the clinical approach to the single patient.
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http://dx.doi.org/10.1007/s00467-017-3627-2DOI Listing
August 2017

The genetic and clinical spectrum of a large cohort of patients with distal renal tubular acidosis.

Kidney Int 2017 05 21;91(5):1243-1255. Epub 2017 Feb 21.

Department of Biomedical Experimental and Clinical Sciences "Mario Serio", University of Florence, Florence, Italy; Medical Genetics Unit, Meyer Children's University Hospital, Florence, Italy. Electronic address:

Primary distal renal tubular acidosis is a rare genetic disease. Mutations in SLC4A1, ATP6V0A4, and ATP6V1B1 genes have been described as the cause of the disease, transmitted as either an autosomal dominant or recessive trait. Particular clinical features, such as sensorineural hearing loss, have been mainly described in association with mutations in one gene instead of the others. Nevertheless, the diagnosis of distal renal tubular acidosis is essentially based on clinical and laboratory findings, and the series of patients described so far are usually represented by small cohorts. Therefore, a strict genotype-phenotype correlation is still lacking, and questions about whether clinical and laboratory data should direct the genetic analysis remain open. Here, we applied next-generation sequencing in 89 patients with a clinical diagnosis of distal renal tubular acidosis, analyzing the prevalence of genetic defects in SLC4A1, ATP6V0A4, and ATP6V1B1 genes and the clinical phenotype. A genetic cause was determined in 71.9% of cases. In our group of sporadic cases, clinical features, including sensorineural hearing loss, are not specific indicators of the causal underlying gene. Mutations in the ATP6V0A4 gene are quite as frequent as mutations in ATP6V1B1 in patients with recessive disease. Chronic kidney disease was frequent in patients with a long history of the disease. Thus, our results suggest that when distal renal tubular acidosis is suspected, complete genetic testing could be considered, irrespective of the clinical phenotype of the patient.
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http://dx.doi.org/10.1016/j.kint.2016.12.017DOI Listing
May 2017

Renal transplantation in sensitized children and young adults: a nationwide approach.

Nephrol Dial Transplant 2017 01;32(1):191-195

Italian National Transplant Centre, Italian National Institute of Health (ISS), Rome, Italy.

Background: High levels of preformed anti-HLA antibodies dramatically diminish renal transplant outcomes. Most desensitization programmes guarantee good intermediate outcomes but quite disappointing long-term prognosis. The search for a fully compatible kidney increases time on the waiting list.

Methods: In February 2011, a nationwide hyperimmune programme (NHP) was begun in Italy: all available kidneys are primarily proposed to highly sensitized patients with a panel reactive antibody above 80%. In this manuscript, we evaluate the outcome of paediatric patients transplanted with this approach.

Results: Twenty-one patients were transplanted. Complete data are available for 20 patients. Mean age at transplantation was 14.5 years [standard deviation (SD) ± 5.5)]. Mean time on the waiting list was 29.3 months (SD ± 27.5). Median follow-up was 29.2 months (range: 11.2-59.3). The average number of HLA mismatches in these patients was 2.3 versus 3.7 in 48 standard patients transplanted in the same period (P < 0.001). Only one graft was lost. Two cases of humoral rejection occurred and were successfully treated. No cellular rejection was reported. Median creatinine clearance was 84, 88, 77 and 77 mL/min/1.73 m 2 respectively 1, 6, 12 and 24 months after transplant.

Conclusions: Transplantation of sensitized patients avoiding prohibited antigens is feasible, at least in a selected cohort of patients. In order to be able to further improve this approach, which in our opinion is very successful, it would be necessary to expand the donor pool, possibly increasing the number of countries participating in the programme. In this series, time on the waiting list did not increase significantly. This allocation policy should ideally lead to an outcome comparable to that expected in standard patients, which is particularly desirable in young patients who have the longest life expectancy. Since long-term results of desensitization programmes are not (yet) convincing, we suggest that these programmes should be reserved for selected cases where compatible organs cannot be found within a reasonable time span.
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http://dx.doi.org/10.1093/ndt/gfw369DOI Listing
January 2017

Outcome of childhood-onset full-house nephropathy.

Nephrol Dial Transplant 2017 Jul;32(7):1194-1204

Division of Nephrology and Dialysis, Children's Hospital Bambino Gesù, IRCCS, Rome, Italy.

Background: Patients with full-house nephropathy (FHN) present renal lesions that are indistinguishable from those of lupus nephritis (LN) but lack the systemic features necessary to meet diagnostic criteria for systemic lupus erithematosus (SLE). Some have been reported to develop a delayed SLE with time. The clinical outcome of children having FHN without SLE has never been reported.

Methods: Children with biopsy-proven FHN were selected after excluding SLE cases by the absence of America College of Rheumatology criteria. The proportion of patients with complete (proteinuria <0.5 g/day) or partial remission (proteinuria ≤50% from baseline), relapse (estimated glomerular filtration rate <25% and/or proteinuria ≥50% from baseline) and progression to Stage III chronic kidney disease (CKD) was described according to age and gender groups with the Kaplan-Meier curve and compared with the Log-rank test. Entity of treatment was summarized by a score at induction (0-6 months) and maintenance (6-18 months). Cox-regression model was performed to test predictors of remission, relapse and progression to CKD.

Results: Among 42 patients (28 pre-pubertal) who met the inclusion criteria, 39 (92.9%) achieved partial and 32 (76.2%) complete remission of nephropathy over 2.78 and 7.51 months of follow-up. At 10 years, the probability of progressing to CKD was 4.8%. Of those achieving remission, 18% had a renal flare mainly within 4 years after remission. Pre-pubertal males achieved complete remission more frequently than other patients but often relapsed; pre-pubertal females were treated more aggressively. Cox-regression analysis did not find independent predictors of remission or relapse.

Conclusions: The outcome of the patients with FHN we investigated was encouraging. Recurrences are limited to the first 4 years following diagnosis, allowing progressive withdrawal of immunosuppression in patients achieving remission. Evaluation of risk factors for adverse outcome is necessary especially in pre-pubertal children.
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http://dx.doi.org/10.1093/ndt/gfw230DOI Listing
July 2017

Lessons from genetics: is it time to revise the therapeutic approach to children with steroid-resistant nephrotic syndrome?

J Nephrol 2016 Aug 21;29(4):543-50. Epub 2016 May 21.

Nephrology and Dialysis Unit, Meyer Children's Hospital, Florence, Italy.

Primitive nephrotic syndrome is one of the most common glomerular diseases in childhood and represents the clinical manifestation of various pathologic changes in the kidney. In children, nephrotic syndrome is classified based on the initial response to empiric corticosteroid treatment, which is considered as the best predictor of patients' final outcome. The advent of next-generation sequencing technology showed that genetic alterations in structural genes of the podocyte can be recognized in a significant proportion of not only familial or syndromic patients with steroid-resistant nephrotic syndrome (SRNS), but also of sporadic cases, raising the question of whether it is time to update current protocols of patient care. In this review, we discuss the implications derived from several studies describing a high prevalence in children with SRNS of pathogenic mutations in a group of genes and their unresponsiveness to immunosuppressive therapy. We propose a diagnostic and therapeutic algorithm to reduce the exposure to immunosuppressants in individuals with unresponsive forms of the disease, sparing patients the untoward side effects of prolonged ineffective treatments, and at the same time guaranteeing the optimal immunosuppressive or other new therapy in potentially responsive patients.
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http://dx.doi.org/10.1007/s40620-016-0315-4DOI Listing
August 2016

CVVHD treatment with CARPEDIEM: small solute clearance at different blood and dialysate flows with three different surface area filter configurations.

Pediatr Nephrol 2016 10 30;31(10):1659-65. Epub 2016 Apr 30.

International Renal Research Institute of Vicenza (IRRIV), Vicenza, Italy.

Background: The CARdiorenal PEDIatric EMergency (CARPEDIEM) machine was originally designed to perform only continuous venovenous hemofiltration (CVVH) in neonatal and pediatric patients. In some cases, adequate convective clearance may not be reached because of a limited blood flow. In such conditions, the application of diffusive clearance [continuous venovenous hemodialysis (CVVHD)] would help optimize blood purification. In this study, the CARPEDIEM™ machine was modified to enable the circulation of dialysis through the filter allowing testing of the performance of CARPEDIEM™ machine in CVVHD.

Methods: Three different polyethersulfone hemodialyzers (surface area = 0.1 m(2), 0.2 m(2), and 0.35 m(2), respectively) were tested in vitro with a scheduled combination of plasma flow rates (Qp = 10-20-30 ml/min) and dialysis fluid flow rate (Qd = 5-10-15 ml/min). Three sessions were performed in co-current and one in counter-current configuration (as control) for each filter size. Clearance was measured from the blood and dialysate sides and results with mass balance error greater than 5 % were discarded.

Results: Urea and creatinine clearances for each plasma/dialysate combination are reported: clearance increase progressively for every filter proportionally to plasma flow rates. Similarly, clearances increase progressively with dialysate flow rates at a given plasma flow. The clearance curve tends to present a steep increase for small increases in plasma flow in the range below 10 ml/min, while the curve tends to plateau for values averaging 30 ml/min. As expected, the plateau is reached earlier with the smaller filter showing the effect of membrane surface-area limitation. At every plasma flow, the effect of dialysate flow increase is evident and well defined, showing that saturation of effluent was not achieved completely in any of the experimental conditions explored. No differences (p > 0.05 for all values) were obtained in experiments using whole blood instead of plasma or using co-current versus counter-current dialysate flow configuration.

Conclusions: Although plasma flow and filter surface give an important contribution to the level of clearance urea and creatinine, it appears evident that dialysate flow plays an essential role in the blood purification process, justifying the use of CVVHD versus CVVH in case of high dialysis dose requirement and/or limited blood flow rate.
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http://dx.doi.org/10.1007/s00467-016-3397-2DOI Listing
October 2016