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Background: Autosomal dominant polycystic kidney disease (ADPKD) is the most common monogenic cause of renal failure. For several decades, ADPKD was regarded as an adult-onset disease. In the past decade, it has become more widely appreciated that the disease course begins in childhood. However, evidence-based guidelines on how to manage and approach children diagnosed with or at risk of ADPKD are lacking. Also, scoring systems to stratify patients into risk categories have been established only for adults. Overall, there are insufficient data on the clinical course during childhood. We therefore initiated the global ADPedKD project to establish a large international pediatric ADPKD cohort for deep characterization. Methods: Global ADPedKD is an international multicenter observational study focusing on childhood-diagnosed ADPKD. This collaborative project is based on interoperable Web-based databases, comprising 7 regional and independent but uniformly organized chapters, namely Africa, Asia, Australia, Europe, North America, South America, and the United Kingdom. In the database, a detailed basic data questionnaire, including genetics, is used in combination with data entry from follow-up visits, to provide both retrospective and prospective longitudinal data on clinical, radiologic, and laboratory findings, as well as therapeutic interventions. Discussion: The global ADPedKD initiative aims to characterize in detail the most extensive international pediatric ADPKD cohort reported to date, providing evidence for the development of unified diagnostic, follow-up, and treatment recommendations regarding modifiable disease factors. Moreover, this registry will serve as a platform for the development of clinical and/or biochemical markers predicting the risk of early and progressive disease. Keywords: ADPKD, ADPedKD Registry, children, longitudinal

Background: Pediatric kidney transplantations are rarely performed, and there is limited knowledge about the diversity in current clinical practices across Europe. This study aims to explore the utility of clinical snapshot studies in identifying these disparities, establishing a foundation for future snapshot studies and standardization efforts., Methods: A pilot clinical snapshot study was conducted, with invitations extended to all 109 pediatric kidney transplant centres in Europe. Each participating centre provided pre-, peri-, and postoperative data concerning their most recent thirty transplantations. The primary outcomes encompassed the evaluation of disparities in donor-recipient selection, surgical techniques, post-operative drainage procedures, and immunosuppressive therapy protocols. Secondary outcomes involved the analysis of rejection rates, incidence of infections, and graft survival., Results: The study involved 439 patients from fifteen centres (14%) in twelve countries, with varying transplant volumes (range 1-29 transplantations per year) and follow-up periods. Significant differences were found among centres in terms of donor types, cold and warm ischemia time, pre-emptive transplant rates, and kidney transplant drainage methods. The rate of living donors varied between 3% and 90% and the median duration of cold ischemia ranged was 770 min after deceased donation and 147 min after living donation. Basiliximab was the dominant induction therapy, yet steroid withdrawal varied widely. Infection, rejection, and graft survival rates also varied significantly between centres., Conclusion: This study revealed substantial variation in clinical practices among European centres performing pediatric kidney transplantations. These findings could serve as a stimulus for international dialogue and collaboration., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (© 2024 Oomen L, Bootsma-Robroeks, Bouts, Carbonell Pradas, Gander, Kienzl-Wagner, König, Pereira, Dunand, Mosca, Pac, Podracka, Prytula, Sangermano, Vitkevic, Zieg, van der Zanden, Feitz and de Wall.)

Introduction: Hepatocyte nuclear factor 1-beta ( HNF1B ) gene variants or the chromosome 17q12 deletion (17q12del) represent the most common monogenic cause of developmental kidney disease. Although neurodevelopmental disorders have been associated with the 17q12del, specific genotype-phenotype associations with respect to kidney function evolution have not yet been fully defined. Here, we aimed to determine whether 17q12del or specific HNF1B variants were associated with kidney survival in a large patient population with HNF1B disease., Methods: This was a retrospective observational study involving 521 patients with HNF1B disease from 14 countries using the European Reference Network for rare kidney diseases with detailed information on the HNF1B genotype ( HNF1B variants or the 17q12del). Median follow-up time was 11 years with 6 visits per patient. The primary end point was progression to chronic kidney disease (CKD) stage 3 (estimated glomerular filtration rate [eGFR] < 60 ml/min per 1.73 m 2 ). Secondary end points were the development of hypomagnesemia or extrarenal disorders, including hyperuricemia and hyperglycemia., Results: Progression toward CKD stage 3 was significantly delayed in patients with the 17q12del compared to patients with HNF1B variants (hazard ratio [HR]: 0.29, 95% confidence interval [CI]: 0.19-0.44, P  < 0.001). Progression toward CKD stage 3 was also significantly delayed when HNF1B variants involved the HNF1B Pit-1, Oct-1, and Unc-86 homeodomain (POU h ) DNA-binding and transactivation domains rather than the POU-specific domain (POU s ) DNA-binding domain (HR: 0.15 [95% CI: 0.06-0.37), P  < 0.001 and HR: 0.25 (95% CI: 0.11-0.57), P  = 0.001, respectively). Finally, the 17q12del was positively associated with hypomagnesemia and negatively associated with hyperuricemia, but not with hyperglycemia., Conclusion: Patients with the 17q12del display a significantly better kidney survival than patients with other HNF1B variants; and for the latter, variants in the POU s DNA-binding domain lead to the poorest kidney survival. These are clinically relevant HNF1B kidney genotype-phenotype correlations that inform genetic counseling., (© 2024 International Society of Nephrology. Published by Elsevier Inc.)

Integrin Subunit Alpha 8 gene (ITGA8) encodes an integrin chain that is known to be critical in the early stage of the kidney development. Bi-allelic pathogenic variants in ITGA8 are associated with bilateral renal agenesis, as well as anomalies involving urogenital system. Here, we report two unrelated patients presenting with slowly progressing chronic kidney disease associated with bilateral renal hypodysplasia carrying homozygous loss of function variants in the ITGA8 gene. These results broaden the clinical and genotypic spectrum of ITGA8 defects, revealing the high and unexpected degree of phenotypic heterogeneity of this autosomal recessive disease. Our study emphasizes the usefulness of Next-Generation Sequencing in unraveling the genetic cause of chronic kidney disease of unknown etiology, and raises the question of genetic modifiers involved in the variation of the phenotypes associated with autosomal recessive ITGA8 pathogenic variants., (© 2022 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Background: Kidney transplantation (KT) is the optimal treatment for children with end-stage kidney disease. The aim of this study was to evaluate the impact of preemptive kidney transplantation (PKT) and of pretransplant dialysis duration on graft survival among French pediatric kidney transplant recipients., Methods: We analyzed all first pediatric kidney-only transplantations performed in France between 1993 and 2012. A Cox multivariable model was used to investigate the association of PKT and pretransplant dialysis time with the hazard of graft failure defined as death, return to dialysis, or retransplant, whichever occurred first., Results: Patients (n = 1911) were included, of which 380 (19.8%) received a PKT. Median time of follow-up was 7.0 y. PKT was associated with a 55% reduction of the hazard of graft failure at any time after KT compared with patients transplanted after dialysis (hazard ratio, 0.45; 95% confidence interval, 0.33-0.62), after adjustment for recipient sex and age, primary kidney disease, donor age and type (living or deceased donor), number of HLA mismatches, cold ischemia time, and year of transplantation. A reduction of the hazard of graft failure was found in PKT whatever the compared duration of dialysis, even when <6 mo and whatever the dialysis modality. Results were similar in multiple sensitivity analyses., Conclusions: In France, PKT among pediatric patients is associated with a better graft survival when compared with KT after dialysis, even when <6 mo. Based on these findings, we suggest that PKT should be considered as the treatment of choice for children with end-stage kidney disease., Competing Interests: The authors declare no conflicts of interest., (Copyright © 2021 Wolters Kluwer Health, Inc. All rights reserved.)

Introduction: Tubulointerstitial nephritis (TIN) and uveitis (TINU) syndrome is a rare disease. The renal prognosis is generally thought to be better in children with TINU syndrome than in adults. However, data are scarce. We aimed to investigate the long-term renal prognosis in a French cohort of children with TINU syndrome., Methods: We performed a national retrospective study including 23 French pediatric nephrology centers enrolling patients with TINU syndrome diagnosed between January 2000 and December 2018., Results: A total of 46 patients were included (52% female, median age 13.8 years). At diagnosis of TIN, the median estimated glomerular filtration rate (eGFR) was 30.6 ml/min per 1.73 m 2 (4.9-62.8). The median time between diagnosis of uveitis and TIN was 0.4 months (-4.1; +17.1). All patients had anterior uveitis, but 12 (29%) were asymptomatic. Nearly all patients (44 of 46) received steroid treatment, and 12 patients (26%) received a second-line therapy. At last follow-up (median 2.8 years), the median eGFR was 87.5 ml/min per 1.73 m 2 (60.3-152.7) and <90 ml/min per 1.73 m 2 in 20 patients., Conclusion: In our study, nearly half of the patients had renal sequelae at last follow-up. Given the possible progression to chronic kidney disease, long-term monitoring of children with TINU syndrome is mandatory. Approximately a quarter of the children had asymptomatic uveitis suggesting all children presenting with TIN should undergo systematic ophthalmologic screening even in the absence of ocular signs., (© 2021 International Society of Nephrology. Published by Elsevier Inc.)

The prevalence of neurological involvement in patients with a deletion of or a variant in the HNF1B gene remains discussed. The aim of this study was to investigate the neuropsychological outcomes in a large cohort of children carrying either a HNF1B whole-gene deletion or a disease-associated variant, revealed by the presence of kidney anomalies. The neuropsychological development-based on school level-of 223 children included in this prospective cohort was studied. Data from 180 children were available for analysis. Patients mean age was 9.6 years, with 39.9% of girls. Among these patients, 119 carried a HNF1B deletion and 61 a disease-associated variant. In the school-aged population, 12.7 and 3.6% of patients carrying a HNF1B deletion and a disease-associated variant had special educational needs, respectively. Therefore, the presence of a HNF1B deletion increases the risk to present with a neuropsychiatric involvement when compared with the general population. On the other hand, almost 90% of patients carrying a HNF1B disease-associated variant or deletion have a normal schooling in a general educational environment. Even if these findings do not predict the risk of neuropsychiatric disease at adulthood, most patients diagnosed secondary to kidney anomalies do not show a neurological outcome severe enough to impede standard schooling at elementary school. These results should be taken into account in prenatal counseling.

To date, it is important to know more about the population of CKD stage 5 patients in order to better understand the practices of access to renal replacement therapy (RRT) or conservative treatment and to anticipate future needs. In April 2015, at the instigation of the Scientific Committee of REIN, a working group was formed to reflect on the opportunity and feasibility of a data collection on these patients. Between September 2017 and March 2018, 21 participating centers included 390 patients over a period of at least one month. The data collected included the patient's living conditions, level of study, mode of referral, clinical data and the therapeutic project. The median age at baseline was 71.4years (IQR: 58.4-80.4), 39.9% were diabetic. The median eGFR was 12mL/min/1.73m 2 (IQR: 9-14). At inclusion, 77% of the patients were already followed in nephrology, 11% had been referred by a general practitioner. For the majority of patients included (81%), there was a RRT project. In 10% of cases, there was a project of conservative care, in 5% of cases the project was not yet decided and in 7% the project had not been yet discussed. At the latest news (median time 4.0months), 35% of patients were dialyzed, 9 (2%) have been pre-emptively transplanted, 25 (6%) died, 210 (54%) were still with a CKD stage 5. Our pilot study has shown the feasibility and interest of setting up such a data collection. Such a registry will provide important public health information regarding the demographic of nephrologists and advanced practices nurses. At the local level, this information will help the department to organize themselves to set-up pre-RRT information, implementation of care pathway nurses and multidisciplinary meetings for difficult cases. However, our pilot study shows that to ensure the completeness of the collection, the tracking upstream or downstream of nephrology consultations for eligible patients is essential and therefore requires dedicated human time on site., (Copyright © 2019 Société francophone de néphrologie, dialyse et transplantation. Published by Elsevier Masson SAS. All rights reserved.)

Background: To describe the quality of life of adolescents initiating haemodialysis, to determine the factors associated with quality of life, and to assess coping strategies and their impact on quality of life., Methods: All adolescents initiating haemodialysis between September 2013 and July 2015 in French paediatric haemodialysis centres were included. Quality of life data were collected using the "Vécu et Santé Perçue de l'Adolescent et l'Enfant" questionnaire, and coping data were collected using the Kidcope questionnaire. Adolescent's quality of life was compared with age- and sex-matched French control., Results: Thirty-two adolescents were included. Their mean age was 13.9 ± 2.0 years. The quality of life score was lowest in leisure activities and highest in relationships with medical staff. Compared with the French control, index, energy-vitality, relationships with friends, leisure activities and physical well-being scores were significantly lower in haemodialysis population. In multivariate analyses, active coping was positively associated with quality of life and especially with energy-vitality, relationships with parents and teachers, and school performance. In contrast, avoidant and negative coping were negatively associated with energy-vitality, psychological well-being and body image for avoidant coping, and body image and relationships with medical staff for negative coping., Conclusions: The quality of life of haemodialysis adolescents, and mainly the dimensions of leisure activities, physical well-being, relationships with friends and energy-vitality, were significantly altered compared to that of the French population. The impact of coping strategies on quality of life seems to be important. Given the importance of quality of life and coping strategies in adolescents with chronic disease, health care professionals should integrate these aspects into care management.

Background: Recommendations for management of Finnish-type congenital nephrotic syndrome (CNS) followed by many teams include daily albumin infusions, early bilateral nephrectomy, dialysis and transplantation. We aimed to assess the treatment and outcome of patients with CNS in France., Methods: We conducted a nationwide retrospective study on 55 consecutive children born between 2000 and 2014 treated for non-infectious CNS., Results: The estimated cumulative incidence of CNS was 0.5/100 000 live births. The underlying defect was biallelic mutations in NPHS1 (36/55, 65%), NPHS2 (5/55, 7%), PLCE1 (1/55, 2%), heterozygous mutation in WT1 (4/55, 7%) and not identified in nine children (16%). Fifty-three patients (96%) received daily albumin infusions from diagnosis (median age 14 days), which were spaced and withdrawn in 10 patients. Twenty children (35%) were managed as outpatients. Thirty-nine patients reached end-stage kidney disease (ESKD) at a median age of 11 months. The overall renal survival was 64% and 45% at 1 and 2 years of age, respectively. Thirteen children died during the study period including four at diagnosis, two of nosocomial catheter-related septic shock, six on dialysis and one after transplantation. The remaining 13 patients were alive with normal renal function at last follow-up [median 32 months (range 9-52)]. Renal and patient survivals were longer in patients with NPHS1 mutations than in other patients. The invasive infection rate was 2.41/patient/year., Conclusions: Our study shows: (i) a survival free from ESKD in two-thirds of patients at 1 year and in one-half at 2 years and (ii) a significant reduction or even a discontinuation of albumin infusions allowing ambulatory care in a subset of patients. These results highlight the need for new therapeutic guidelines for CNS patients., (© The Author(s) 2018. Published by Oxford University Press on behalf of ERA-EDTA. All rights reserved.)

Background: Despite major technical improvements in the care of children requiring renal replacement therapy (RRT) before 2 years of age, the management of those patients remains challenging and transplantation is generally delayed until the child weighs 10 kg or is 2 years old. In this national cohort study, we studied patient and graft survival in children starting RRT before 2 years of age to help clinicians and parents when deciding on RRT initiation and transplantation management., Methods: All children starting RRT before 24 months of age between 1992 and 2012 in France were included through the national Renal Epidemiology and Information Network (REIN) registry. The primary endpoints were patient survival on dialysis and 10-year graft survival., Results: A total of 224 patients were included {62% boys, median age 10.5 months [interquartile range (IQR) 5.8-15.6]}. The 10-year survival rate was 84% (IQR 77-89). Suffering from extrarenal comorbidities was the only factor significantly associated with both an increased risk of death on dialysis [hazard ratio 5.9 (95% confidence interval 1.8-19.3)] and a decreased probability of being transplanted. During follow-up, 174 renal transplantations were performed in 171 patients [median age at first transplantation 30.2 (IQR 21.8-40.7) months]. The 10-year graft survival was 74% (IQR 67-81). Factors associated with graft loss in multivariate analysis were the time spent on dialysis before transplantation, donor/recipient height ratio with an increased risk for both small and tall donors and presenting two human leucocyte antigen-antigen D-related mismatches., Conclusions: This study confirms the good outcome of children starting RRT before 2 years of age. The main question remains when and how to transplant those children. Our study provides data on the optimal morphological and immunological matching in order to help clinicians in their decisions.

Background: Studies in the USA and Europe have demonstrated inequalities in adult access to renal transplants. We previously demonstrate that the centre of treatment was impacting the time to be registered on the renal waiting list. In this study, we sought to ascertain the influence of patient and centre characteristics on the probability of transplantation within 1 year after registration on the waiting list for children., Methods: We included patients <18 years awaiting transplantation from the French ESRD National Registry. The effects of patient and centre characteristics were studied by hierarchical logistic regression. Centre effects were assessed by centre-level residual variance. A descriptive survey was performed to investigate differences in the centres' practices, and linear regression was used to confirm findings of different HLA compatibility requirements between centres., Results: The study included 556 patients treated at 54 centres; 450 (80.9%) received transplants in the year after their listing. HLA group scarcity, time of inactive status during the year, pre-emptive listing and listing after age 18 were associated with lower probabilities of transplantation. Patient characteristics explained most of the variability among centres, but patients treated in paediatric centres had a lower probability of transplantation within 1 year because of higher HLA compatibility requirements for transplants., Conclusions: Although patient characteristics explained most of the inter-centre variability, harmonization of some practices might enable us to reduce some inequalities in access to renal transplantation while maintaining optimal transplant survival and chances to get a second transplant when needed., (© The Author 2014. Published by Oxford University Press on behalf of ERA-EDTA. All rights reserved.)

Background: Data on anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis are scarce in children. The current study is aimed at describing the clinical features and outcomes of childhood-onset ANCA-associated vasculitis (AAV)., Methods: We conducted a retrospective French multicentre study involving patients in whom AAV was diagnosed before the age of 18 years. Inclusion criteria were (i) granulomatosis with polyangiitis (GPA) or microscopic polyangiitis (MPA) according to classification criteria of the European League Against Rheumatism/Paediatric Rheumatology European Society, and (ii) ANCA positivity. Patient and renal survival were analysed., Results: Among 66 children included, 80% were female, 42% had GPA and 58% MPA including renal-limited vasculitis, 67% were pANCA+ and 33% cANCA+. The mean incidence of reported cases increased to 0.45 per million children/year in the period 2006-10. Median age at diagnosis was 11.5 years, and median time to diagnosis was 1 month. Initial symptoms included fever and fatigue (79%), skin lesions (41%), arthritis (42%), pulmonary (45%) and renal involvement (88%). Clinical features were similar between GPA and MPA with the exception of upper airway impairment (28%) specific of GPA. Ninety percent of the patients achieved remission after induction treatment. After a median follow-up of 5.2 years, 4 patients (6%) died, corresponding to a mortality rate of 1.2 per 100 person-years, and 22 patients (34%) developed end-stage renal disease (ESRD). Renal survival was 74, 70 and 59% at 1, 5 and 10 years, respectively. In a multivariable Cox regression model, baseline glomerular filtration rate, ethnic origin, histopathological classification and era of treatment were associated with the occurrence of ESRD. Relapse-free survival was 57% at 5 years and 34% at 10 years of follow-up. Patient and renal outcome did not significantly differ between GPA and MPA., Conclusion: Childhood-onset AAV is a rare disease characterized by female predominance, delayed diagnosis, frequent renal impairment and a high remission rate. Baseline GFR and new histopathological classification system are strong predictors of ESRD. Renal survival in childhood AAV has improved over time., (© The Author 2015. Published by Oxford University Press on behalf of ERA-EDTA. All rights reserved.)

Aims: The use of mycophenolate mofetil (MMF) in children with systemic lupus erythematosus (SLE) is increasing. However, the clinical benefit of its monitoring has been scarcely studied, and little is known about its pharmacokinetics in this context. The objectives of the present study were: (i) to describe mycophenolic acid (MPA, the active moiety of MMF) pharmacokinetics, (ii) to develop a Bayesian estimator (BE) allowing the determination AUC (area under the curve) from a limited number of blood samples and (iii) to explore the relationships between exposure indices to MPA and the clinical status in children with SLE., Methods: This was a retrospective study including 36 children with SLE, extracted from the expert system ISBA, for whom full- pharmacokinetic profiles of MPA were collected together with clinical data. A pharmacokinetic model and a BE were developed using an iterative two stage Bayesian approach. ROC curve analyses and logistic regressions were used to investigate the association of exposure and active disease., Results: A pharmacokinetic model and a BE were developed that allowed good AUC estimation performance (bias ± SD = -0.02 ± 0.15). ROC curve analyses showed that AUC/dose <0.06 and AUC <4 mg l(-1)  h were associated with a good sensitivity and specificity for active disease (78%/94% and 94%/56%, respectively). When introduced in a logistic regression model, AUC <44 mg l(-1)  h and AUC/dose <0.06 were associated with an increased risk of active disease (OR = 21.2, 95% CI 2.3, 196.1, P = 0.007 and OR = 59.5, 95% CI 5.9, 588.2, P = 0.0005 respectively]., Conclusions: The developed pharmacokinetic BE could be used to test prospectively the interest of MPA monitoring for limiting relapse of the disease or its progression., (© 2014 The British Pharmacological Society.)

Introduction: Postnatal management of prenatally detected hydronephrosis remains controversial. It has been suggested that cortical transit time (CTT) could successfully predict deterioration in children with pelvi-ureteric junction (PUJ) obstruction. We decided to conduct a retrospective study in our hydronephrosis population to evaluate whether initial CTT was significantly correlated with the need for surgery., Patients and Method: We reviewed the charts of all our patients managed for significant PUJ obstruction (>12 mm) between 2007 and 2010 and determined CTT retrospectively, on the first diuretic scan of each of these patients. We then determined the relationship between initial CTT and the need for surgery., Results: We identified 37 patients with hydronephrosis (pelvic size >12 mm) of which 26 were diagnosed prenatally. Out of 22 patients with an initial abnormal CTT, 20 underwent surgery. Out of 15 children with a normal initial CTT, 4 underwent surgery (OR 27.5 (IC95%: 4.3-174.9))., Conclusion: Initial CTT could be a reliable prognostic factor for future evolution of renal function in children with hydronephrosis. CTT is easy to determine on diuretic renal scan. A prospective trial is being devised to confirm what role it could have in the management of children with hydronephrosis., (Copyright © 2013 Journal of Pediatric Urology Company. Published by Elsevier Ltd. All rights reserved.)

We report the first studied example of wettability of conducting polymers based on poly(3,4-ethylenedioxyselenophene). Hydrocarbon 3,4-ethylenedioxyselenophene (C2H5 to C12H25) derivatives are synthesized and electropolymerized in propylene carbonate using lithium tetrafluoroborate (LiBF4) and lithium bistrifluoromethanesulfonimidate (LiTf2N) as electrolyte. Highly structured films are obtained from a C8H17 chain independent of the electrolyte used. Superhydrophobic properties with high adhesion are specifically reached if using a C12H25 chain and LiBF4. The surface morphology is porous and highly structured as the films consist of assemblies of nanofibrils., (Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Background: Rituximab (RTX) has recently showed promising results in the treatment of steroid-dependent idiopathic nephrotic syndrome (SDNS)., Methods: This was a retrospective multicenter study of 18 children treated with RTX for SDNS, with a mean follow-up of 3.2 years. RTX was introduced because of side effects or relapses during therapy with immunosuppressive agents. The children received one to four infusions of RTX during the first course of treatment, and subsequent infusions were given due to CD19-cell recovery (CD19 >1 %; 54 % of children) or relapse (41 %), as well as systematically (5 %)., Results: Treatment with RTX maintained sustained remission without relapse in 22 % of patients and increased the duration of remission in all other patients. The time between two successive relapses was 9 months in the absence of re-treatment and 24.5 months when infusions were performed at the time of CD19-cell recovery. At the last follow-up, 44.5 % of patients were free of oral drug therapy. Of those still receiving oral drugs, all doses had been decreased. No serious adverse events occurred., Conclusion: The results of this retrospective study confirm the efficacy and very good safety of RTX in the treatment of SDNS. The optimal therapeutic protocol seems to be a repeated single infusion at the time of CD19-cell recovery.

We report maternal uniparental disomy of chromosome 17 (mat UPD17) in a 2.5-year-old girl presenting infantile cystinosis. This patient was homozygous for the 57 kb deletion encompassing the CTNS gene, frequently found in patients from the European origin. The proband's mother was heterozygous for the deletion and the father did not carry the deletion. We carried out haplotype analysis with polymorphic markers spanning the whole chromosome 17. Informative markers showed the presence of two maternal alleles but no paternal allele for regions spanning the 17q arm and the proximal half of 17p, and only one maternal allele on the distal 17p arm. As deletion of half of 17p is probably not viable, these results suggest mat UPD17 with heterodisomy of 17q and proximal 17p and isodisomy of distal 17p. This is the first demonstration of mat UPD17, in particular of isodisomy 17p, in cystinosis.

We describe the case of a 14-year-old boy who presented with pulmonary embolism and who was subsequently found to have nephrotic syndrome due to lupus membranous nephropathy. He had no other signs of nephrotic syndrome or of systemic lupus erythematosus, such as edema or circulating lupus anticoagulants (antiphospholipid or anticardiolipin antibodies), and no hereditary coagulopathy. This case contributes to our understanding of unusual clinical presentations of systemic lupus erythematosus in children.

Congenital nephrotic syndrome of the Finnish type (CNF) is due to NPHS1 mutation and is responsible for a variety of urinary protein losses. We report the case of a 4-month-old girl with a particularly severe form (proteinuria approximately 150 g/l) of CNF. She developed severe non-regenerative anaemia requiring bi-monthly blood transfusions despite daily EPO (600 UI/kg) and iron supplementation. Epoetin pharmacokinetics revealed a urinary loss of 27% of the given dose within the first 24 h after IV injection. However, plasma levels remained increased after 24 h (228 UI/l). Plasma transferrin and transcobalamin levels were undetectable. Atransferrinaemia and atranscobalaminaemia seem to be responsible for disturbed erythropoiesis.

Factor H deficiency is responsible for thrombotic microangiopathy (TMA) via uncontrolled activation of the alternative pathway of the complement system. Ocular TMA has never been reported in patients with factor H abnormalities. A male patient with congenital homozygote factor H deficiency reached end-stage renal disease at the age of 10 years. Hemodialysis was uneventful for 3 years, when, suddenly, unilateral ocular pain and blurred vision occurred while he had febrile pharyngitis. Ophthalmologic examination found vitreous bleeding, elevated ocular pressure, choroidal hemorrhage (ultrasound biomicroscopy) and retinal ischemia (fluorescein angiography). C-reactive protein concentration was increased, while haptoglobin levels remained normal. We suspected that TMA due to factor H deficiency was responsible for the ocular manifestations and immediately initiated daily plasma exchanges (PEs) with fresh frozen plasma (FFP) for 10 days followed by three sessions per week. Factor H serum level increased from 6% to 82%, and C3 level normalized. Progressively, ocular pain decreased, and visual acuity and ophthalmologic findings showed improvement. When there is permanent activation of the alternative pathway in patients with end-stage renal disease (ESRD), the search for secondary targets might be of interest. In nephrectomized patients, no biological parameter can predict isolated ocular TMA. Early ophthalmologic investigation and substitution of factor H via FFP may avoid irreversible damage.