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We provided proof of the principle of the existence of chromatin-like structures (EV-chromatin) in AML-sEVs, and we have shown that EV-chromatin could communicate with BM-MSCs and modulate their behavior. We identified non-mutational p53 inactivation involving MDM2 and potentially S100 proteins (associated with EV-chromatin) as a mechanism by which AML-EV-chromatin regulates the proliferation of BM-MSCs. 1g), we have demonstrated that sEVs transfer chromatin-like structures (we termed EV-chromatin), in which many proteins are associated with EV-DNA. [Extracted from the article]

Podocytes are highly specialized cells playing a key role in the filtration function of the kidney. A damaged podocyte ultrastructure is associated with a reorganization of the actin cytoskeleton and accompanied with a loss of adhesion to the glomerular basement membrane leading to proteinuria in many forms of glomerular diseases, e.g. nephrotic syndrome. If the first-line therapy with glucocorticoids fails, alternative immunosuppressive agents are used, which are known to have the potential to stabilize the actin cytoskeleton. A new option for preventing relapses in steroid dependent nephrotic syndrome is the monoclonal antibody rituximab, which, in addition to its B-cell depleting effect, is assumed to have direct effects on podocytes. We here provide data on the non-immunological off-target effects of the immunosuppressant rituximab on podocyte structure and dynamics in an in vitro puromycin aminonucleoside model of podocyte injury. A conditionally immortalized human podocyte cell line was used. Differentiated podocytes were treated with puromycin aminonucleoside and rituximab. Our studies focussed on analyzing the structure of the actin cytoskeleton, cellular adhesion and apoptosis using immunofluorescence staining and protein biochemistry methods. Treatment with rituximab resulted in a stabilization of podocyte actin stress fibers in the puromycin aminonucleoside model, leading to an improvement in cell adhesion. A lower apoptosis rate was observed after parallel treatment with puromycin aminonucleoside and rituximab visualized by reduced nuclear fragmentation. Consistent with this data, Western-blot analyses demonstrated that rituximab directly affects the caspase pathways by inhibiting the activation of Caspases-8, -9 and -3, suggesting that rituximab may inhibit apoptosis. In conclusion, our results indicate an important role of the immunosuppressant rituximab in terms of stability and morphogenesis of podocytes, involving apoptosis pathways. This could help to improve therapeutical concepts for patients with proteinuria mediated by diseased podocytes. [ABSTRACT FROM AUTHOR]

Allograft-specific regulatory T cells (Treg cells) are crucial for long-term graft acceptance after transplantation. Although adoptive Treg cell transfer has been proposed, major challenges include graft-specificity and stability. Thus, there is an unmet need for the direct induction of graft-specific Treg cells. We hypothesized a synergism of the immunotolerogenic effects of rapamycin (mTOR inhibition) and plerixafor (CXCR4 antagonist) for Treg cell induction. Thus, we performed fully-mismatched heart transplantations and found combination treatment to result in prolonged allograft survival. Moreover, fibrosis and myocyte lesions were reduced. Although less CD3+ T cell infiltrated, higher Treg cell numbers were observed. Noteworthy, this was accompanied by a plerixafor-dependent plasmacytoid dendritic cells-(pDCs)-mobilization. Furthermore, in vivo pDC-depletion abrogated the plerixafor-mediated Treg cell number increase and reduced allograft survival. Our pharmacological approach allowed to increase Treg cell numbers due to pDC-mediated immune regulation. Therefore pDCs can be an attractive immunotherapeutic target in addition to plerixafor treatment. [ABSTRACT FROM AUTHOR]

Idiopathic nephrotic syndrome is the most frequent glomerular disease in children in most parts of the world. Children with steroid-sensitive nephrotic syndrome (SSNS) generally have a good prognosis regarding the maintenance of normal kidney function even in the case of frequent relapses. The course of SSNS is often complicated by a high rate of relapses and the associated side effects of repeated glucocorticoid (steroid) therapy. The following recommendations for the treatment of SSNS are based on the comprehensive consideration of published evidence by a working group of the German Society for Pediatric Nephrology (GPN) based on the systematic Cochrane reviews on SSNS and the guidelines of the KDIGO working group (Kidney Disease - Improving Global Outcomes). [ABSTRACT FROM AUTHOR]

The authors reflect on the German best practice guideline on pediatric idiopathic steroid-sensitive nephrotic syndrome (SSNS). Topics discussed include the lack of variable approach driven by expertise to the standardized alternative treatment protocol for frequently relapsing nephrotic syndrome (FRNS) and steroid-dependent nephrotic syndrome (SDNS), use of steroids for initial therapy and treatment relapse, and constant change facing the management of childhood nephrotic syndrome.

Background: Children presenting with proliferative lupus nephritis (LN) are treated with intensified immunosuppressive protocols. Data on renal outcome and treatment toxicity is scare. Methods: Twelve-month renal outcome and comorbidity were assessed in 79 predominantly Caucasian children with proliferative LN reported to the Lupus Nephritis Registry of the German Society of Paediatric Nephrology diagnosed between 1997 and 2015. Results: At the time of diagnosis, median age was 13.7 (interquartile range 11.8–15.8) years; 86% showed WHO histology class IV, nephrotic range proteinuria was noted in 55%, and median estimated glomerular filtration rate amounted to 75 ml/min/1.73 m2. At 12 months, the percentage of patients with complete and partial remission was 38% and 41%, respectively. Six percent of patients were non-responders and 15% presented with renal flare. Nephrotic range proteinuria at the time of diagnosis was associated with inferior renal outcome (odds ratio 5.34, 95% confidence interval 1.26–22.62, p = 0.02), whereas all other variables including mode of immune-suppressive treatment (e.g., induction treatment with cyclophosphamide (IVCYC) versus mycophenolate mofetil (MMF)) were not significant correlates. Complications were reported in 80% of patients including glucocorticoid toxicity in 42% (Cushingoid appearance, striae distensae, cataract, or osteonecrosis), leukopenia in 37%, infection in 23%, and menstrual disorder in 20%. Growth impairment, more pronounced in boys than girls, was noted in 78% of patients. Conclusions: In this cohort of juvenile proliferative LN, renal outcome at 12 months was good irrespectively if patients received induction treatment with MMF or IVCYC, but glucocorticoid toxicity was very high underscoring the need for corticoid sparing protocols. [ABSTRACT FROM AUTHOR]

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). [ABSTRACT FROM AUTHOR]

Background: In 2010, INF2 mutations were associated with autosomal-dominant focal segmental glomerulosclerosis (FSGS), clinically presenting with moderate proteinuria in adolescence. However, in the meantime, cases with more severe clinical courses have been described, including progression to end-stage renal disease (ESRD) during childhood. INF2 mutations in patients with isolated FSGS are clustered in exons 2 to 4, encoding the diaphanous inhibitory domain, involved in the regulation of the podocyte actin cytoskeleton.Methods: We report a family with 14 affected individuals (autosomal-dominant mode of inheritance), most of whom presented with nephrotic-range proteinuria, hypertension, and progressive renal failure. Four members received a kidney transplant without disease recurrence. Two patients underwent renal biopsy with the result of minimal-change glomerulopathy and IgA nephropathy respectively. We performed mutational analysis of ACTN4, CD2AP, COQ6, INF2, LAMB2, NPHS1, NPHS2, PLCE1, TRPC6, and WT1 in the index patient by next-generation sequencing. Additionally, in 6 affected and 2 unaffected family members target diagnostics were performed.Results: We identified a novel heterozygous mutation c.490G>C (p.(Ala164Pro) in exon 3 of the INF2 gene in the index patient and 6 additionally examined affected family members. In silico analysis predicted it as “probably damaging”. Additionally, three patients and 2 unaffected relatives harbored a novel heterozygous variant in ACTN4 (c.1149C>G, p.(Ile383Met)) with uncertain pathogenicity.Conclusion: Mutations in INF2 are associated with familial proteinuric diseases - irrespective of the presence of FSGS and in the case of rapid disease progression. Therefore, mutational analysis should be considered in patients with renal histology other than FSGS and severe renal phenotype. [ABSTRACT FROM AUTHOR]

The European Academy of Paediatrics (EAP) is dedicated to promoting healthy lifestyles for children from birth into young adulthood. Physical exercise and leisure are essential to the development of healthy bodies, strong minds, and social skills. All children, without regard to their physical or mental capacities, should be provided with the time, the leadership, the facilities, and the equipment needed to exercise through sports while enjoying playing, even competing, in an environment appropriate to their capacities and aspirations. During exercise and sports, children should be assured of a safe and an appropriate environment that protects and promotes their human rights. Top sports that engage the best competitive athletes in an age group, in a region, in a country, or in the world should provide role models and even dreams for all children. These top sports, however, are also most usually surrounded by large political, economic, and/or business interests where only the best can compete while at times exacting a too high physical and/or psychological cost for those who have survived the cut, made the grade. Alongside this more and more children are being raised in environments with fewer open spaces as well as inside a media and digital culture making significantly less room for the enjoyment of physical exercise and leisure. Children's diets have also been changed dramatically by a significant intake of calorierich foods, which often have little nutritional value and which even a child's high metabolism rates not able to burn off efficiently. Conclusion With this Resolution, the EAP is calling for a renewed look at the role of sports and leisure in the lives of children and, by implication, at the way we structure, finance, and promote sports in Europe. The EAP is also asking that this Resolution be adopted by all organizers of sports involving children and young adults in Europe (and beyond), be that on the playground, in schools, in clubs, or in professional sporting organizations. The EAP would like that every child, throughout his or her childhood years and into young adulthood, can fully participate in sports in a safe environment where winning is playing and playing is winning. [ABSTRACT FROM AUTHOR]

Background: Alport syndrome (ATS) is a progressive hereditary nephropathy characterized by hematuria and proteinuria. It can be associated with extrarenal manifestations. In contrast, thin basement membrane nephropathy (TBMN) is characterized by microscopic hematuria, is largely asymptomatic, and is rarely associated with proteinuria and end-stage renal disease. Mutations have been identified in the COL4A5 gene in ATS and in the COL4A3 and COL4A4 genes in ATS and TBMN. To date, more than 1000 different mutations in COL4A5, COL4A3, and COL4A4 are known. Methods: In this study mutational analysis by exon sequencing and multiplex ligation-dependent probe amplification was performed in a large European cohort of families with ATS and TBMN. Results: Molecular diagnostic testing of 216 individuals led to the detection of 47 novel mutations, thereby expanding the spectrum of known mutations causing ATS and TBMN by up to 10 and 6 %, respectively, depending on the database. Remarkably, a high number of ATS patients with only single mutations in COL4A3 and COL4A4 were identified. Additionally, three ATS patients presented with synonymous sequence variants that possible affect correct mRNA splicing, as suggested by in silico analysis. Conclusions: The results of this study clearly broaden the genotypic spectrum of known mutations for ATS and TBMN, which will in turn now facilitate future studies into genotype-phenotype correlations. Further studies should also examine the significance of single heterozygous mutations in COL4A3 and COL4A4 and of synonymous sequence variants associated with ATS. [ABSTRACT FROM AUTHOR]

Background: Steroid-resistant nephrotic syndrome (SRNS) is a severe cause of progressive renal disease. Genetic forms of SRNS can present with autosomal recessive or autosomal dominant inheritance. Recent studies have identified mutations in multiple podocyte genes responsible for SRNS. Improved sequencing methods (next-generation sequencing, NGS) now promise rapid mutational testing of SRNS genes. Methods: In the present study, a simultaneous screening of ten SRNS genes in 37 SRNS patients was performed by NGS. Results: In 38 % of the patients, causative mutations in one SRNS gene were found. In 22 % of the patients, in addition to these mutations, a secondary variant in a different gene was identified. Conclusions: This high incidence of accumulating sequence variants was unexpected but, although they might have modifier effects, the pathogenic potential of these additional sequence variants seems unclear so far. The example of molecular diagnostics by NGS in SRNS patients shows that these new sequencing technologies might provide further insight into molecular pathogenicity in genetic disorders but will also generate results, which will be difficult to interpret and complicate genetic counseling. Although NGS promises more frequent identification of disease-causing mutations, the identification of causative mutations, the interpretation of incidental findings and possible pitfalls might pose problems, which hopefully will decrease by further experience and elucidation of molecular interactions. [ABSTRACT FROM AUTHOR]

In the biomedical sector, production of bioresorbable implants remains challenging due to improper dissolution rates or deficient strength of many candidate alloys. Promising materials for overcoming the prevalent drawbacks are iron-based alloys containing silver. However, due to immiscibility of iron and silver these alloys cannot be manufactured based on conventional processing routes. In this study, iron-manganese-silver alloys were for the first time synthesized by means of additive manufacturing. Based on combined mechanical, microscopic, and electrochemical studies, it is shown that silver particles well distributed in the matrix can be obtained, leading to cathodic sites in the composite material. Eventually, this results in an increased dissolution rate of the alloy. Stress-strain curves showed that the incorporation of silver barely affects the mechanical properties. [ABSTRACT FROM AUTHOR]

Autosomal recessive polycystic kidney disease (ARPKD), although less frequent than the dominant form, is a common, inherited ciliopathy of childhood that is caused by mutations in the PKHD1-gene on chromosome 6. The characteristic dilatation of the renal collecting ducts starts in utero and can present at any stage from infancy to adulthood. Renal insufficiency may already begin in utero and may lead to early abortion or oligohydramnios and lung hypoplasia in the newborn. However, there are also affected children who have no evidence of renal dysfunction in utero and who are born with normal renal function. Up to 30 % of patients die in the perinatal period, and those surviving the neonatal period reach end stage renal disease (ESRD) in infancy, early childhood or adolescence. In contrast, some affected patients have been diagnosed as adults with renal function ranging from normal to moderate renal insufficiency to ESRD. The clinical spectrum of ARPKD is broader than previously recognized. While bilateral renal enlargement with microcystic dilatation is the predominant clinical feature, arterial hypertension, intrahepatic biliary dysgenesis remain important manifestations that affect approximately 45 % of infants. All patients with ARPKD develop clinical findings of congenital hepatic fibrosis (CHF); however, non-obstructive dilation of the intrahepatic bile ducts in the liver (Caroli's disease) is seen at the histological level in only a subset of patients. Cholangitis and variceal bleeding, sequelae of portal hypertension, are life-threatening complications that may occur more often in advanced cases of liver disease. In this review we focus on common and uncommon kidney-related and non-kidney-related phenotypes. Clinical management of ARPKD patients should include consideration of potential problems related to these manifestations. [ABSTRACT FROM AUTHOR]

Background: mTOR inhibitors (mTORI) have emerged as alternative and additive immunosuppressive agents in pediatric renal transplantation (pRTx). Their immunosuppressive, anti-proliferative, and anti-neoplastic mechanisms have been described to be effective, whereas some side effects are alarming. In particular, growth and pubertal development are of concern. The aim of this study was to look for long-term side effects of mTORI therapy in pRTx. Patients and methods: The retrospective analysis focused on side effects, growth, and pubertal development under mTORI therapy in 31 children. Eighteen children were routinely monitored for estradiol, testosterone, LH, and FSH levels. Results: The occurrence of bacterial infections, lymphoceles, myelosuppression, and the course of overall linear growth was comparable with other pediatric renal transplant cohorts. According to the clinical puberty status, all but one patient showed normal age-related development in parallel to normal serum hormone levels. Only one patient experienced cytomegaly virus infection under mTORI, no post-transplant lymphoproliferative disorders (PTLD) occurred. Conclusions: Long-term mTORI therapy is safe in pRTx. No negative impact on growth and pubertal development was observed. [ABSTRACT FROM AUTHOR]

Background: Bardet-Biedl syndrome (BBS) is a genetic disorder with obesity as one of the major phenotypic criterion, which is proposed to be of neuroendocrine origin. Therefore, disturbances in appetite-regulating hormones have been considered as causative factors. Acyl ghrelin is an orexigenic hormone, whereas its desacylated form, obestatin, and leptin have the opposite functions. Ghrelin is negatively regulated in relation to nutritional status. The aim of this study was to evaluate the impact of hormone alterations on obesity development in BBS patients. Methods: Total and acylated ghrelin, obestatin, leptin and adiponectin were measured in eight children with BBS. The results were analyzed in relation to auxological parameters [body mass index (BMI), height]. Results: The mean BMI was significantly increased in BBS patients compared to the controls. Plasma levels of acylated ghrelin, total ghrelin and obestatin were slightly elevated in BBS patients compared to controls, as was the acyl/total ghrelin ratio. Leptin levels were significantly elevated in BBS patients. Conclusion: BBS patients lack the negative regulatory mechanisms of appetite-regulating hormones with respect to nutritional status and exhibit resistance to anorexigenic leptin. This results in a shift towards the orexigenic effects of this self-regulating system. These alterations may in part be responsible for the disturbed appetite regulation in BBS patients. [ABSTRACT FROM AUTHOR]

The authors reflect on the dosing of glucocorticosteroids that are used in the treatment of nephrotic syndrome. They suggest that without precise knowledge of the pathogenesis of nephrotic syndrome, optimal dosing of the drugs can not be achieved. They argue that until detailed information on the pathogenesis of the syndrome and on the molecular mechanisms of the action of immunosuppressive drugs is obtained, researchers will not be able to study which drugs are best for treating the syndrome.

Protein–energy wasting is a common problem in pediatric patients with chronic kidney disease (CKD). Disturbances in appetite-regulating hormones have been suggested as causative factors. Acyl ghrelin is a potent orexigenic hormone, whereas desacyl ghrelin and obestatin have the opposite effect. The regulation of acyl ghrelin and its anorexigenic opponents and its role in the development of CKD-associated protein–energy wasting is poorly understood. We measured total and acylated ghrelin, obestatin, leptin, and adiponectin in children with CKD ( n = 29), children undergoing hemodialysis (HD) or peritoneal dialysis (PD; n = 29), renal transplant recipients (RTx; n = 91), and healthy controls ( n = 27), and analyzed the data in relation to body mass index (BMI) and height. Patients with renal insufficiency showed lower BMI standard deviation score (SDS) values and height SDS compared with controls and RTx patients. Total ghrelin was elevated in CKD and dialyzed patients compared with controls or transplant recipients ( P < 0.001). Acyl ghrelin did not differ between groups, and the acyl ghrelin/total ghrelin ratio was reduced in uremic patients ( P < 0.05). Obestatin plasma levels were increased in patients with renal insufficiency compared with controls and RTx patients ( P < 0.01). Uremia leads to an accumulation of the anorexigenic hormones desacyl ghrelin and obestatin. Orexigens like acyl ghrelin are not elevated. A disturbed balance between anorexigenic and orexigenic hormones may influence development of CKD-associated protein–energy wasting in pediatric patients. [ABSTRACT FROM AUTHOR]

Renal cysts in childhood can be found in a variety of diseases, which can be congenital or acquired, or renal cysts may be part of a multiorgan disease or restricted to the kidneys only. Ultrasonography is the first-line diagnostic tool and is informative in many cases. However, there is a broad spectrum in the sonographic appearance of renal cysts, and family or genetic studies, a search for extrarenal organ involvement, or additional imaging modalities may be required to make a definitive diagnosis. The aim of this article is to summarize the diagnostic potential and limitations of ultrasonography and depict typical examples of the most important cystic entities. [ABSTRACT FROM AUTHOR]

The impact of cyclosporine A (CsA) therapy in patients with steroid-dependent nephrotic-syndrome (SDNS) on long-term renal function is controversial. Data beyond 5 years are rare. Long-term renal function was evaluated in children with SDNS with and without CsA therapy, especially beyond 5 years. Twenty children were treated with CsA (study group) for a mean of 5.4 ± 2.2 years (ten patients for 5–11 years). Glomerular filtration rate (GFR) was calculated before and after 3 and 12 months and at latest follow-up of therapy. Fifteen children with cyclophosphamide-treated SDNS without CsA served as controls. In the study group, GFR decreased within 12 months from 136 ± 19 to 120 ± 31, to 114 ± 14 ml/min per 1.73 m2 at latest follow-up ( p < 0.0001). Patients with CsA > 5 years had a GFR of 111 ± 14 ml/min per 1.73 m2 at latest follow-up without a GFR below 90 ml/min per 1.73 m2. No CsA toxicity was found in biopsies. In the control group, GFR dropped within 3 months, from 137 ± 27 to 130 ± 24, to 126 ± 19 ml/min per 1.73 m2 at latest follow-up ( p = 0.1). Patients with and without nephrotoxic CsA therapy showed a drop in GFR. In CsA-treated patients, GFR was about 12% lower at latest follow-up compared with patients without nephrotoxic therapy but always remained within normal range. CsA seems to be safe, even in long-term treatment for more than 5 years. [ABSTRACT FROM AUTHOR]

In developed countries, the use of living unrelated donors is restricted to purely altruistic donors who have a close and emotional relationship with the recipients. By law, commercial transplantation is illegal. Increasing shortness of donors, the excellent results of kidney transplants from spousal and living unrelated donors as well as the very low risk for the donor has been used as an argument for paid organ donation. Arguments in favour are the relief of donor-organ shortage, short waiting times for renal transplantation, economic benefits for the donor as well as the economic benefits for society by reducing the costs of dialysis by more transplants. Major arguments against are exploitation of the donor, coercion, and a growing black market. Despite the fact that different societies have different norms or reproaches that we are failing our patients and accept the death of thousands, kidney trade has created an environment of corruption and commercialisation, which brings even the cadaver transplant program into disrepute. However, denying the existence of paid organ donation does not contribute to solve the problem. A public discussion about consequences of changing ethics and human rights, rather than pragmatic solutions, is needed. [ABSTRACT FROM AUTHOR]

For the comparison of long-term outcome of the management of medical or surgical treatment of children with severe vesicoureteral reflux (VUR), children aged <11 years with non-obstructive grade III/IV reflux, previous urinary tract infection (UTI) and glomerular filtration rate (GFR) ≥70 ml/min per 1.73 m2 body surface area were recruited, and 306 were randomly allocated to receive antimicrobial prophylaxis or ureteral reimplantation. Primary endpoints were new renal scars and renal growth. Follow up, originally planned for 5 years, was extended to 10 years for 252 children, 223 of whom had follow-up imaging. Up to 5 years, 40 new urographic scars (medical 19, surgical 21) were seen. Between 5 years and 10 years, only two further scars were observed. Renal growth and UTI recurrence rate were similar, except that medically treated patients had more febrile infections. There was no difference in somatic growth, radionuclide imaging or renal function. A GFR <70 ml/min per 1.73 m2 was found in only one patient. Three patients developed hypertension requiring treatment. We conclude that, with close supervision and prompt treatment of recurrences, children entering the study with GFR ≥70 ml/min per 1.73 m2 progressed remarkably well under either medical or surgical management, emphasizing the importance of continued supervision and the entry level of renal function. [ABSTRACT FROM AUTHOR]

The clinical syndrome of oedema with proteinuria is an important cause of paediatric morbidity in sub-Saharan Africa. The aim of this study was to assess its prevalence, clinical presentation and outcome in The Gambia, where the syndrome is perceived to be common but has not previously been studied. All children admitted with oedema and proteinuria to three hospitals in the Western region of The Gambia between January 1995 and June 1998 were identified retrospectively. Hospital records were retrieved to assess admission characteristics. All traceable children were clinically reviewed, and urinalysis was performed between 3 months and 4 years after admission. Two hundred and two children who presented with proteinuria and oedema were identified, accounting for 1.2% of paediatric hospital admissions in The Gambia. Haematuria on dipstick testing was common (76.5%). Of 39 children who were traced, four (10.3%) were dead. Eighteen of the remaining 35 (51.4%) had proteinuria at follow up. Older age at first presentation was significantly associated with increased long-term morbidity. These preliminary data suggest that oedema with proteinuria may be common and could cause long-term morbidity and mortality in Gambian children. Further studies on its aetiology and treatment are warranted. [ABSTRACT FROM AUTHOR]

Background: Calcineurin inhibitors (CNI) are the main immunosuppressive drugs in solid organ transplantation. However, their use is hampered by side effects like nephrotoxicity. We report an exceptional experience with three children treated with sirolimus after combined liver and kidney transplantation with prolonged renal failure and CNI-associated nephrotoxicity. Patients and results: Two girls experienced prolonged renal graft failure after combined liver-kidney transplantation for 11 and 12 weeks. Repeated biopsies did not show any rejection but did exhibit tubular damage and acute CNI-toxicity. A boy with hyperoxaluria after liver and (a third) renal transplantation experienced acute renal graft failure after an early steroid-resistant rejection. All children were switched to sirolimus-based immunosuppression and cessation of CNI therapy, which was followed by rapid improvement of renal function. Rejection of liver or kidney did not occur after CNI withdrawal. Sirolimus was commenced with 3 mg/m2/day in two doses and resulted in reasonable drug exposure. However, drug monitoring was required to adjust sirolimus dosage. Summary: Prolonged renal failure after transplantation with severe CNI toxicity may be salvaged successfully with sirolimus-based immunosuppression. [ABSTRACT FROM AUTHOR]

Glutathione-S-transferases (GST) play a central role in the inactivation of toxic drugs like cyclophosphamide (CP). These enzymes depict several polymorphisms with altered activity, and it has been shown that different polymorphisms influence the risk of malignancies and the outcome after chemotherapy. To prove the hypothesis that CP efficacy in children with nephrotic syndrome is influenced by polymorphic expression of GSTs, the genotype of 26 patients was analyzed and correlated with the outcome after CP treatment. All 26 children with steroid-sensitive nephrotic syndrome and frequent relapses or steroid dependency were treated with CP at a mean age of 6.7±4.0 years. CP was given in a dose of 2 mg/kg/day for 12±1 week. GST-M1, GST-P1 and GST-T1 polymorphisms were detected by PCR. In patients with GST-M1 null polymorphism, a significantly better rate of sustained remission was seen than in patients with the heterozygous or homozygous GST-M1 wildtype (0 versus 29%,P<0.01). In contrast, children with GST-P heterozygous or homozygous polymorphism had a significantly lower rate of sustained remission compared to homozygous wildtype (7 versus 38%,P<0.02). The GST-T1 genotype did not influence the outcome after CP treatment (P=0.32). Patients with the combination of GST-M1 null and GST-P1 wildtype did not relapse in 50%, compared to 6% in other children (P<0.01). We conclude that the polymorphic expression of GST-M1 and -P1 did significantly influence the long-term remission rate after CP treatment of steroid-sensitive nephrotic syndrome in children. Whereas GST-M1 null will increase cyclophosphamide efficacy, GST-P1 polymorphism seems to be related to enhanced susceptibility to further relapses. [ABSTRACT FROM AUTHOR]

Cyclosporine (CsA) monitoring using abbreviated area under the curve or 2-h blood concentration (C2 h) has been shown to predict total drug exposure in adult renal transplantation. However, pediatric experience is limited. Since 1998, we have monitored C2 h in 45 children (age 10.6±4.7 years) during the first 6 weeks after transplantation. In 22 a 4-h CsA profile (AUC0-4h) was available and C2 h in the remaining 23 patients. In addition CsA profiles from 24 children transplanted before 1998 were used to calculate the correlation between single time points and AUC0-4h. The best correlation between AUC0-4h and a single time point was seen with C2 h (r2=0.89). C0 h did not predict AUC0-4h reliably (r2=0.27). C2 h showed the lowest prediction error (10.0±9.6%). No dependency on age could be detected. In the first 3 months following transplantation, rejection was observed in 9 of 45 patients (20%). Glomerular filtration rate remained stable within the first 5 years after transplantation. In conclusion, in the early phase after renal transplantation, C2h can be used to predict drug exposure within the whole pediatric age group and should be evaluated in prospective trials. [ABSTRACT FROM AUTHOR]

Arterial hypertension is common in pediatric renal allograft recipients. While the causes are multifactorial, including chronic graft rejection, immunosuppressive therapy, and renal vascular disorders, the effect of hypertension on renal allograft function is detrimental. As in adults, if not treated early and aggressively, hypertension may lead to cardiovascular damage and graft failure. Pathophysiological changes in the arteries and kidney after renal transplantation and the impact of receptor regulation have not been studied extensively in children. For identifying children with hypertension following renal transplantation casual blood pressure measurements do not accurately reflect average arterial blood pressure and circadian blood pressure rhythm. Ambulatory 24-h blood pressure monitoring should regularly be applied in transplant patients. The purpose of this review is to analyze pathophysiological aspects of risk factors for arterial hypertension and underline the importance of regular blood pressure monitoring and early therapeutic intervention. [ABSTRACT FROM AUTHOR]

Cyclosporine (CsA) is a critical-dose drug for which a minor change in absorption can have important clinical implications. Generic formulations of CsA are becoming more widely available, but standard criteria for bioequivalence require only that a single study in healthy volunteers demonstrate that mean pharmacokinetic parameters fall within 80–125% of the mean values for Neoral, the reference formulation of CsA. However, CsA absorption is known to differ between healthy volunteers and transplant patients and between different types of transplant patients, such that standard bioequivalence testing may be inadequate to ensure interchangeability of CsA formulations in all patients. The limited available clinical evidence has shown that stable renal transplant patients receiving Neoral have a significant reduction in mean CsA trough level after transfer to the Cicloral formulation. Mean pharmacokinetic values have been reported as equivalent following transfer to Gengraft in one study, but mean CsA trough fell and mean serum creatinine rose significantly in a separate trial. The only clinical outcomes data available are from a retrospective study of de novo renal transplant patients, which reported a significantly higher incidence of biopsy-proven acute rejection in patents receiving Gengraf versus Neoral (39% versus 25%, P<0.05). Until robust clinical data demonstrate that different formulations of CsA are interchangeable, it is advisable to prescribe CsA by brand, and any transfer to a different CsA formulation should be undertaken with close supervision and only at the direction of the transplant physician. [ABSTRACT FROM AUTHOR]

Cyclosporine absorption profiling uses either the area under the concentration curve in the first 4 h post dose, AUC(0–4), or the concentration 2 h post dose (C2) to optimize immunosuppression in adult kidney and liver transplantation. We characterized C2 versus AUC(0–4) relationships over time after transplant and across transplant indications in 56 pediatric transplant patients. There were 36 kidney transplant patients aged 9.7±3.9 years. Nineteen of these patients were studied in the de novo period on day 7 post transplant and 17 in the maintenance phase more than 1 year post transplant. In addition, 20 liver transplant patients aged 8.9±4.2 years were studied in the maintenance phase. All patients had five blood samples collected over the 12-h dose interval that were analyzed by validated assay methods at a central laboratory. Pediatric C2 values were 1,463±658 ng/ml for de novo kidney, 954±322 ng/ml for maintenance kidney, and 619±339 ng/ml for maintenance liver transplant patients. C2 was a strong predictor of AUC(0–4) in all three pediatric groups, with coefficients of determination (r[sup 2]) ranging from 0.861 to 0.936. Although data were limited from the de novo period, the C2 versus AUC(0–4) regression was consistent over time after transplant and between transplant indications, with a regression slope of 2.50 in de novo kidney, 2.54 in maintenance kidney, and 2.76 in maintenance liver transplant recipients. These slopes were also comparable to that in adult maintenance kidney transplant patients (2.60). In conclusion, C2 versus AUC(0–4) relationships demonstrated consistency over time (de novo vs. maintenance phase), between transplant indications (kidney vs. liver), and across age groups (pediatric vs. adult patients). Average C2 values achieved with current pediatric cyclosporine dosing practices cluster around the target C2 ranges recommended for adults. [ABSTRACT FROM AUTHOR]

Steroid-sensitive nephrotic syndrome often follows a relapsing course with a substantial number of patients requiring cytotoxic therapy with cyclophosphamide (CP). However, the long-term success of CP treatment is difficult to predict. We retrospectively evaluated 106 patients after CP to identify parameters associated with sustained remission. The overall rate of cumulative sustained remission was 24% after 10 years. No gender difference was found. Several factors were significantly correlated with the rate of sustained remission: age at CP therapy (remission 34% versus 9% in children older or younger than 5.5 years, P<0.01), frequently relapsing versus steroid-dependent status (54% versus 17%, P<0.05), leukopenia under CP treatment (44% in children with leukopenia versus 19% in children without leukopenia, P<0.05), and a cumulative dosage per body surface area (BSA) of more or less than 5,040 mg/m[SUP2] (45% versus 11%, P<0.01). In contrast, the cumulative dosage per kilogram body weight had no significant influence on long-term remission (23% in children with >168 mg/kg versus 26% in children with <168 mg/kg, P>0.05). The current concept of CP treatment of steroid-sensitive nephrotic syndrome is less effective in pre-school children. CP therapy should be re-evaluated on a BSA-adjusted regimen. [ABSTRACT FROM AUTHOR]

OBJECTIVES: Progressive familial intrahepatic cholestasis (PFIC) usually presents with pruritus, jaundice, hepatomegaly, and growth failure. A group of PFIC is recognized by marked elevation of total serum bile acids, decreased serum apolipoprotein A-1, and high-density lipoprotein, but normal γ-glutamyltranspeptidase and cholesterol. Although medical therapy generally fails, partial external biliary diversion (DIV) has been used with promising results for cholestasis. However, little has been reported of its effect on linear growth, synthetic liver function, and lipid metabolism. METHODS: DIV was performed on six noncirrhotic children with PFIC, all suffering from severe pruritus and cholestasis, refractory to medical treatment. Stature was below -1 (median, -2.3) standard deviation score (SDS) for height in all cases. All patients had markedly enhanced bile acids (307 ± 72 µml/L), markedly decreased high-density lipoprotein (20 ± 7 mg/dl), and apolipoprotein A-1 (58 ± 37 mg/dl). but normal γ-glutamyltranspeptidase and cholesterol. In addition, cholinesterase activity, monoethylglycin-exylidide test, and Fischer's ratio indicated a significantly reduced synthetic liver function in all children but the youngest. RESULTS: After DIV, all patients were consistently relieved of pruritus, and experienced normalization of all liver function tests, including cholinesterase activity, monoethylgly-cinexylidide test, and Fischer's ratio, as well as the serum lipid profile within 1 yr. In addition, a marked catch-up growth (median, +1.3 SDS) was evident after 1 yr in all cases. CONCLUSIONS: This report shows an excellent result of DIV in noncirrhotic PFIC patients and compares favorably with other reports. All patients experienced complete remission, including normalization of synthetic liver function and lipid metabolism. For the first time we have shown that DIV can also be associated with an accelerated growth in these patients. [ABSTRACT FROM AUTHOR]

In 1989, 22 children (11 boys, 11 girls aged 8-23 years) with nephropathic cystinosis, who had received a total of 28 renal allografts over the previous 14 years, were reviewed. Nineteen were alive, of whom 17 had functioning grafts 5 months to 13 years after transplantation. The mean serum creatinine level in these 17 was 135 μmol/l. Patient and graft survival did not differ from non-cystinotic children. Persistent hypothyroidism was found in 3 patients, transient diabetes mellitus in 1, severely disturbed vision in 1 and brain atrophy in 11. Arterial hypertension was present in 16 patients. Growth retardation was universal, although in 4 patients on cyclosporin A post-transplant catch-up growth occurred. Five patients over 15 years completed puberty. Readjustment in terms of school performance was good but was less good for psychosocial development. None of the patients had ever been treated with cystine-depleting agents; the data will therefore provide a historical control group with which to compare the results from a group treated with these agents. [ABSTRACT FROM AUTHOR]

Many factors must be considered for the effective and safe use of cyclosporin A (CsA) in paediatric nephrology. Detailed knowledge of the variable bioavailability, tissue distribution, and metabolism, as well as causes which lead to their alteration are necessary. Factors which affect the activity of the mixed function oxidase system cytochrome P-450 must be considered, i. e. liver dysfunction and many drugs. Precise knowledge of the CsA determination method and the spectrum of metabolites is essential. In children with renal transplants, a body surface area-related dose will better meet the dose requirements than a body weight related-dose. For drug level monitoring whole blood rather than plasma should be used, and the parent drug level should be the main determinant; elevated metabolite levels may be important in suspected nephrotoxicity or liver dysfunction. Pharmacokinetic profiles are necessary to discover absorption problems or increased CsA clearance rates which necessitate shorter dosing intervals. In children with steroid-dependent minimal change nephrotic syndrome, remission without steroids is maintained as long as CsA is given. The appropriate starting dosage is 150 mg/m per day; trough level monitoring is mandatory to prevent nephrotoxicity and to confirm adequate immunosuppressive drug levels which should be 80-160 ng/ml (parent drug level). Although the benefit of CsA has been reported in some cases of lupus erythematosus, its use should be restricted to severe cases only until its efficacy and safety has been confirmed in controlled trials. [ABSTRACT FROM AUTHOR]

Eight children with terminal renal insufficiency on continuous ambulatory peritoneal dialysis were followed for 12 months to evaluate laboratory parameters of mineral ion and bone metabolism. Calcium carbonate (range 47-295 mg/kg body weight per day) was given in combination with low doses of either vitamin D or 1,25(OHD. Blood urea nitrogen and serum phosphate concentrations remained well controlled throughout the observation period. A significant increase in serum calcium levels from 2.35±0.18 to 2.61±0.22 mmol/l (mean ± SD) was observed during the first 6 months. Alkaline phosphatase activity and mid-C-regional parathyroid hormone, both indirect parameters of bone metabolism, revealed no evidence of severe secondary hyperparathyroidism. Our data indicate that calcium carbonate may be sufficient to induce relative hypercalcaemia in uraemic children, and thus reduce the risk of developing renal osteodystrophy. Unwanted side-effects of vitamin D preparations, i. e. increased intestinal phosphate absorption and hypercalcaemia after successful renal transplantation, may thus be avoided. [ABSTRACT FROM AUTHOR]

The association of a spondylo-epiphyseal dysplasia and growth failure with the nephrotic syndrome was found in three boys. Renal biopsy performed on two revealed focal and segmental glomerulosclerosis. The nephrotic syndrome occurred at the age of 3-7 years, leading to end-stage renal failure in all patients. Growth failure persisted after successful renal transplantation. This association may represent a distinct disease entity. [ABSTRACT FROM AUTHOR]

It is well established that plasma phosphate (Pp) is largely determined by the renal phosphate threshold, which is best described by the maximal rate of tubular phosphate reabsorption divided by the glomerular filtration rate (Tm/GFR). For its clinical assessment either direct phosphate loading with simultaneous measurement of GFR is performed, or the nomogram described by Walton and Bijvoet is used. In order to test the validity of the two methods, we compared in 20 infants and 31 children the fasting values of phosphate reabsorption [endogenous phosphate reabsorption/inulin clearance (T/C) and T] with those obtained after phosphate loading [maximal phosphate reabsorption (Tm) and Tm/C], and both with those derived from the nomogram. In addition the fasting T/C of 50 infants and 143 children could be compared with the nomogram. The results demonstrate that the directly measured T/C was the same as the directly measured Tm/C and that the measured Tm/C was correctly estimated by the nomogram. However, the comparison of fasting T/C with nomogram-derived values showed a systematic error, by which the latter values were higher than those measured. The discrepancy was due to the splay of the phosphate titration curve, which was found by Bijvoet when the ratio of phosphate clearance (C) corrected for GFR (C/GFR) fell below 0.2. The incorporation of this splay in the nomogram could not be confirmed by data measured in our children. It is concluded that fasting T is already 'maximal' and that, therefore, no phosphate loading is necessary to estimate Tm. Furthermore, there is no evidence of a major splay, which makes the nomogram incompatible below a C/GFR ratio of 0.2. For clinical assessment we recommend use of the formula Tm/GFR=P−(U×P/U) where P, U, P and U refer to the plasma and urinary concentration of phosphate and creatinine respectively. This formula can be applied easily without the need to collect timed urinary specimens and is independent of the phosphate load. [ABSTRACT FROM AUTHOR]

The renal handling of uric acid during cyclosporin A (CyA) treatment was investigated by clearance studies using 24-h urine collections in 28 paediatric renal transplant recipients (CyA group), and the results were compared with those of 19 renal transplanted children treated with azathioprine and prednisolone (AZA group), 35 children with chronic renal failure (CRF) and 10 children with normal renal function (N group). Serum uric acid levels were significantly higher in the CyA group (567±156 μmol/l) compared with the AZA group (378±98), the CRF group (415±119) and the N group (290±68). Mean uric acid clearances in each group measured 3.9±2.8 ml/min per 1.73 m (CyA), 5.6±3.4 (AZA), 4.0±2.2 (CRF) and 8.4±3.7 (N). Calculation of the net tubular uric acid reabsorption per millilitre glomerular filtration rate revealed a significantly increased value of 0.53±0.15 μmol/ml in the CyA group ( P<0.01) compared with 0.34±0.08, 0.29±0.15 and 0.27±0.07 μmol/l for the AZA, CRF and N groups respectively. We therefore conclude that CyA treatment is associated with an increased net tubular reabsorption of uric acid, which may lead to hyperuricaemia. [ABSTRACT FROM AUTHOR]

Thirty-two pediatric renal transplant patients receiving cyclosporin and 34 receiving azathioprine treatment (historical controls) were investigated for the occurrence of rejection episodes; their clinical symptoms and findings, time of onset, influence of donorship, relation to cyclosporin blood levels and graft function outcome were also studied. In the cyclosporin group, four grafts were lost in the 2nd year, while in the azathioprine group five grafts were lost within the first 5 weeks after transplantation due to acute irreversible rejection. Clinical signs of rejection episodes under cyclosporin were mild and usually presented a silent increase of serum creatinine. First rejection episodes occurred later in patients treated with cyclosporin than in azathioprine-treated patients (50% probability after 7 weeks as opposed to 2 weeks). The percentage of patients receiving cyclosporin who had experienced no rejection episodes was 18,8% as opposed to 11,8% of patients receiving azathioprine. The lowest incidence of rejection episodes was observed in patients with living related grafts receiving cyclosporin treatment, 75% of whom were free of rejection episodes after 2 years. Cyclosporin blood levels below 400 ng/ml were observed in 74% of rejection episodes. Biopsies were often used to differentiate between cyclosporin nephrotoxicity and rejection when the cyclosporin levels were above 400 ng/ml. Both treatment groups exhibited a parallel decline in graft function, which correlated with the number of rejection episodes. [ABSTRACT FROM AUTHOR]

An 11-year-old boy with recurrent nephritis due to tubulointerstitial nephritis associated with uveitis (TINU syndrome) was treated with cyclosporin A (CSA) to induce sustained remission. CSA was introduced as a steroid-sparing drug because of extreme obesity (body mass index 32 kg/m²). Although the boy did not complain of any clinical symptoms, eye inspection after 7 months revealed bilateral disk edema with retinal bleeding and the patient developed cerebrospinal hypertension. Pseudotumor cerebri was diagnosed by measuring the intracranial pressure (31 cmH2O) and normal computer tomography and brain magnetic resonance imaging. Cessation of CSA therapy and treatment with mycophenolate mofetil led to resolution within 12 weeks. [ABSTRACT FROM AUTHOR]

Abscess formation is a rare cause of febrile illness in childhood but always has to be considered in such clinical presentations. Belonging to the resident flora of the oropharyngeal region, Fusobacteria are known to cause local infections; from here they may extend to other sites via the bloodstream or are aspirated into the lung (Lemierre disease). We report on two boys with Lemierre disease due to infection by Fusobacteria in monoculture causing two different clinical phenotypes. Case 1 presented with a large subphrenic abscess and pneumonic infiltration of the right middle lobe. Primary focus of infection was periodontal disease. Case 2 presented with a life-threatening septicaemia due to a retropharyngeal abscess and perforated otitis media followed by osteomyelitis of the atlas and thrombosis of the left sigmoid sinus and internal jugular vein. Conclusion: Fusobacteria should be considered in any abscess formation in children. A thorough examination of the oropharyngeal region as a possible site of primary manifestation is mandatory. [ABSTRACT FROM AUTHOR]

Patients with chronic renal failure exhibit multiple endocrine, gastrointestinal and cardiovascular abnormalities, many of which may be explained by alterations of adenylyl cyclase (AC) responsiveness and/or G-protein expression. Since such alterations were previously reported, e.g., for platelets of adult chronic renal failure patients undergoing hemodialysis treatment (HD), we have investigated whether children with chronic renal failure undergoing HD exhibit similar alterations. Eleven uremic children undergoing HD were compared with 11 age-matched healthy controls. Platelet AC activity was determined in the absence (basal) and presence of a receptor agonist, direct G-protein activators and direct AC stimulators. G-protein α-subunits were measured by quantitative immunoblotting. Basal and stimulated platelet AC and immunoreactivity for platelet G-protein αsubunits did not significantly differ between HD and control children. We conclude that HD in children is associated with much smaller, if any, abnormalities of blood cell signal transduction than in adult patients. We speculate that quality of dialysis, age, and underlying disease might differentially influence blood cell signal transduction cascades. [ABSTRACT FROM AUTHOR]

Recently, a new oral microemulsion formulation of cyclosporin A (CsA) - Neoral (Sandoz, Basle, Switzerland) - with a higher bioavailability has become available. Ten stable paediatric renal transplant recipients with excessive variations in CsA trough levels with the original Sandimmun (Sandoz, Basle, Switzerland) preparation were switched to Neoral on a 1∶1 basis. Pharmacokinetic studies revealed impaired absorption of Sandimmun, in six patients. Compared with equal doses of Sandimmun, the 8-h area under the concentration-time curve increased from 1,422 to 2,657 ng×h/ml and the peak concentration rose from 319 to 824 ng/ml ( P<0.01). In six patients with Sandimmun malabsorption, conversion on a 1∶1 basis led to a reduction in creatinine clearance which was reversible after dose reduction by 9%-25%. With trough levels at the lower end of the present target range, creatinine clearance stabilised around pre-conversion values. [ABSTRACT FROM AUTHOR]

Fourteen patients (aged 5.9-22.1 years) undergoing continuous ambulatory or cycling peritoneal dialysis were treated with recombinant human erythropoietin (rhEPO), which was given intravenously once a week at a dosage of 300 units/kg. The mean haematocrit level increased from 18.5% to 27.5% and the reticulocyte count from 19‰ to 62‰ within 1 month. After an average time of 3.1 months rhEPO dosage could be adjusted to 100 units/kg per week to keep the haematocrit level at 30%. Only 1 patient had an exacerbation of hypertension, which required a dosage reduction; other side-effects were not noted. [ABSTRACT FROM AUTHOR]

Mammalian kidneys constantly filter large amounts of liquid, with almost complete retention of albumin and other macromolecules in the plasma. Breakdown of the three-layered renal filtration barrier results in loss of albumin into urine (albuminuria) across the wall of small renal capillaries, and is a leading cause of chronic kidney disease. However, exactly how the renal filter works and why its permeability is altered in kidney diseases is poorly understood. Here we show that the permeability of the renal filter is modulated through compression of the capillary wall. We collect morphometric data prior to and after onset of albuminuria in a mouse model equivalent to a human genetic disease affecting the renal filtration barrier. Combining quantitative analyses with mathematical modelling, we demonstrate that morphological alterations of the glomerular filtration barrier lead to reduced compressive forces that counteract filtration pressure, thereby resulting in capillary dilatation, and ultimately albuminuria. Our results reveal distinct functions of the different layers of the filtration barrier and expand the molecular understanding of defective renal filtration in chronic kidney disease.