RESUMO
BACKGROUND: Small cohort studies have reported high parathyroid hormone (PTH) levels in patients with Bartter syndrome and lower serum phosphate levels have anecdotally been reported in patients with Gitelman syndrome. In this cross-sectional study, we assessed PTH and phosphate homeostasis in a large cohort of patients with salt-losing tubulopathies. METHODS: Clinical and laboratory data of 589 patients with Bartter and Gitelman syndrome were provided by members of the European Rare Kidney Diseases Reference Network (ERKNet) and the European Society for Paediatric Nephrology (ESPN). RESULTS: A total of 285 patients with Bartter syndrome and 304 patients with Gitelman syndrome were included for analysis. Patients with Bartter syndrome type I and II had the highest median PTH level (7.5 pmol/L) and 56% had hyperparathyroidism (PTH >7.0 pmol/L). Serum calcium was slightly lower in Bartter syndrome type I and II patients with hyperparathyroidism (2.42 versus 2.49 mmol/L; P = .038) compared to those with normal PTH levels and correlated inversely with PTH (rs -0.253; P = .009). Serum phosphate and urinary phosphate excretion did not correlate with PTH. Overall, 22% of patients had low serum phosphate levels (phosphate-standard deviation score < -2), with the highest prevalence in patients with Bartter syndrome type III (32%). Serum phosphate correlated with tubular maximum reabsorption of phosphate/glomerular filtration rate (TmP/GFR) (rs 0.699; P < .001), suggesting renal phosphate wasting. CONCLUSIONS: Hyperparathyroidism is frequent in patients with Bartter syndrome type I and II. Low serum phosphate is observed in a significant number of patients with Bartter and Gitelman syndrome and appears associated with renal phosphate wasting.
Assuntos
Síndrome de Bartter , Síndrome de Gitelman , Hiperparatireoidismo , Criança , Humanos , Síndrome de Gitelman/complicações , Hormônio Paratireóideo , Síndrome de Bartter/complicações , Estudos Transversais , Fosfatos , Homeostase , CálcioRESUMO
PURPOSE: Hardikar syndrome (MIM 612726) is a rare multiple congenital anomaly syndrome characterized by facial clefting, pigmentary retinopathy, biliary anomalies, and intestinal malrotation, but with preserved cognition. Only four patients have been reported previously, and none had a molecular diagnosis. Our objective was to identify the genetic basis of Hardikar syndrome (HS) and expand the phenotypic spectrum of this disorder. METHODS: We performed exome sequencing on two previously reported and five unpublished female patients with a clinical diagnosis of HS. X-chromosome inactivation (XCI) studies were also performed. RESULTS: We report clinical features of HS with previously undescribed phenotypes, including a fatal unprovoked intracranial hemorrhage at age 21. We additionally report the discovery of de novo pathogenic nonsense and frameshift variants in MED12 in these seven individuals and evidence of extremely skewed XCI in all patients with informative testing. CONCLUSION: Pathogenic missense variants in the X-chromosome gene MED12 have previously been associated with Opitz-Kaveggia syndrome, Lujan syndrome, Ohdo syndrome, and nonsyndromic intellectual disability, primarily in males. We propose a fifth, female-specific phenotype for MED12, and suggest that nonsense and frameshift loss-of-function MED12 variants in females cause HS. This expands the MED12-associated phenotype in females beyond intellectual disability.
Assuntos
Deficiência Intelectual , Complexo Mediador/genética , Deficiência Intelectual Ligada ao Cromossomo X , Retinose Pigmentar , Adulto , Colestase , Fissura Palatina , Feminino , Genes Ligados ao Cromossomo X , Humanos , Deficiência Intelectual/genética , Deficiência Intelectual Ligada ao Cromossomo X/genética , Fenótipo , Adulto JovemRESUMO
BACKGROUND: Chronic kidney disease (CKD) in children is a pro-inflammatory condition leading to a high morbidity and mortality. Accumulation of organic metabolic waste products, coined as uraemic toxins, parallels kidney function decline. Several of these uraemic toxins are protein-bound (PBUT) and gut-derived. Gut dysbiosis is a hallmark of CKD, resulting in a state of increased proteolytic fermentation that might be counteracted by dietary fibre. Data on fibre intake in children with CKD are lacking. We aimed to assess dietary fibre intake in a paediatric CKD cohort and define its relationship with PBUT concentrations. METHODS: In this multi-centre, cross-sectional observational study, 61 non-dialysis CKD patients (9 ± 5 years) were included. Dietary fibre intake was assessed through the use of 24-h recalls or 3-day food records and coupled to total and free levels of 4 PBUTs (indoxyl sulfate (IxS), p-cresyl sulfate (pCS), p-cresyl glucuronide (pCG) and indole acetic acid (IAA). RESULTS: In general, fibre intake was low, especially in advanced CKD: 10 ± 6 g/day/BSA in CKD 4-5 versus 14 ± 7 in CKD 1-3 (p = 0.017). Lower concentrations of both total (p = 0.036) and free (p = 0.036) pCG were observed in the group with highest fibre intake, independent of kidney function. CONCLUSIONS: Fibre intake in paediatric CKD is low and is even worse in advanced CKD stages. Current dietary fibre recommendations for healthy children are not being achieved. Dietary management of CKD is complex in which too restrictive diets carry the risk of nutritional deficiencies. The relation of fibre intake with PBUTs remains unclear and needs further investigation. Graphical abstract.
Assuntos
Insuficiência Renal Crônica , Uremia , Adolescente , Criança , Pré-Escolar , Estudos Transversais , Fibras na Dieta , Humanos , Toxinas Biológicas , Toxinas UrêmicasRESUMO
BACKGROUND: Nephropathic cystinosis, a hereditary lysosomal storage disorder caused by dysfunction of the lysosomal cotransporter cystinosin, leads to cystine accumulation and cellular damage in various organs, particularly in the kidney. Close therapeutic monitoring of cysteamine, the only available disease-modifying treatment, is recommended. White blood cell cystine concentration is the current gold standard for therapeutic monitoring, but the assay is technically demanding and is available only on a limited basis. Because macrophage-mediated inflammation plays an important role in the pathogenesis of cystinosis, biomarkers of macrophage activation could have potential for the therapeutic monitoring of cystinosis. METHODS: We conducted a 2-year prospective, longitudinal study in which 61 patients with cystinosis who were receiving cysteamine therapy were recruited from three European reference centers. Each regular care visit included measuring four biomarkers of macrophage activation: IL-1ß, IL-6, IL-18, and chitotriosidase enzyme activity. RESULTS: A multivariate linear regression analysis of the longitudinal data for 57 analyzable patients found chitotriosidase enzyme activity and IL-6 to be significant independent predictors for white blood cell cystine levels in patients of all ages with cystinosis; a receiver operating characteristic analysis ranked chitotriosidase as superior to IL-6 in distinguishing good from poor therapeutic control (on the basis of white blood cell cystine levels of <2 nmol 1/2 cystine/mg protein or ≥2 nmol 1/2 cystine/mg protein, respectively). Moreover, in patients with at least one extrarenal complication, chitotriosidase significantly correlated with the number of extrarenal complications and was superior to white blood cell cystine levels in predicting the presence of multiple extrarenal complications. CONCLUSIONS: Chitotriosidase enzyme activity holds promise as a biomarker for use in therapeutic monitoring of nephropathic cystinosis.
Assuntos
Cisteamina/uso terapêutico , Cistinose/sangue , Monitoramento de Medicamentos/métodos , Hexosaminidases/sangue , Ativação de Macrófagos/efeitos dos fármacos , Adolescente , Adulto , Biomarcadores , Criança , Cisteamina/farmacologia , Cistina/sangue , Cistinose/tratamento farmacológico , Feminino , Humanos , Inflamação , Interleucina-18/sangue , Interleucina-1beta/sangue , Interleucina-6/sangue , Leucócitos/química , Masculino , Adesão à Medicação , Fragmentos de Peptídeos/sangue , Estudos Prospectivos , Adulto JovemRESUMO
Cystinosis is an autosomal recessive lysosomal storage disorder characterized by the defective transport of the amino acid cystine out of the lysosome due to a deficiency of cystinosin, the lysosomal cystine transporter. Patients have lysosomal cystine accumulation in various tissues, leading to cellular stress and damage, particularly in the kidney, cornea, and other extrarenal tissues. Cysteamine, a cystine-depleting agent, improves survival and delays the progression of disease, but it does not prevent the development of either renal failure or extrarenal complications. Furthermore, the drug has severe adverse effects that significantly reduce patient compliance. Allogeneic hematopoietic stem cell transplantation (HSCT) is currently established as a therapeutic option for many inborn errors of metabolism, where the main pathologic driving factor is an enzyme deficiency. Recent studies in the cystinosis mouse-model suggested that HSCT could be a curative treatment alternative to cysteamine therapy. We treated a 16-year-old boy who had infantile cystinosis and side effects of cysteamine therapy with HSCT. We were able to demonstrate successful transfer of the wild-type cystinosin protein and CTNS mRNA to nonhematological epithelial cells in the recipient, as well as a decrease in the tissue cystine-crystal burden. This is the first report of allogeneic HSCT in a patient with cystinosis, the prototype of lysosomal membrane-transporter disorders.
Assuntos
Sistemas de Transporte de Aminoácidos Neutros/administração & dosagem , Cistinose/terapia , Células Epiteliais/metabolismo , Transplante de Células-Tronco Hematopoéticas , Adolescente , Sistemas de Transporte de Aminoácidos Neutros/genética , Sistemas de Transporte de Aminoácidos Neutros/metabolismo , Cistinose/genética , Humanos , Masculino , Mutação , Prognóstico , Transplante HomólogoRESUMO
BACKGROUND: Chronic kidney disease (CKD) in childhood is characterised by the accumulation of uraemic toxins resulting in a multisystem disorder that has a negative impact on quality of life. Childhood CKD is predominantly defined by a decrease in glomerular filtration rate, estimated (eGFR) by a single serum measurement of endogenous biomarkers, e.g. creatinine. The objective of this study was to evaluate how accurately eGFR predicts the concentration of uraemic toxins in a paediatric CKD cohort. METHODS: In 65 children (10.8 [5.1; 14.7] years) with CKD (eGFR 44 [20; 64] mL/min/1.73 m2), serum concentrations were determined of small solutes (uric acid [UA], urea, symmetric dimethylarginine [SDMA], asymmetric dimethylarginine [ADMA]), middle molecules (ß2-microglobulin [ß2M], complement factor D [CfD]) and protein-bound solutes (p-cresylglucuronide [pCG], hippuric acid, indole acetic acid, indoxyl sulphate [IxS], p-cresylsulfate [pCS] and 3-carboxy-4-methyl-5-propyl-furanpropionic acid [CMPF]). Spearman's correlation coefficients (r) were calculated to correlate uraemic toxin concentrations with three different eGFR equations, based on either serum creatinine or ß2M. RESULTS: Updated Schwartz eGFR was correlated reasonably well with concentrations of creatinine (r = -0.98), urea (rs = -0.84), SDMA (r = -0.82) and middle molecules CfD and ß2M (both rs = -0.90). In contrast, poor correlation coefficients were found for CMPF (rs = -0.32), UA (rs = -0.45), ADMA (rs = -0.47) and pCG (rs = -0.48). The other toxins, all protein-bound, had rs between -0.75 and -0.57. Comparable correlations were found between the three evaluated eGFR equations and uraemic toxin concentrations. CONCLUSIONS: This study demonstrates that eGFR poorly predicts concentrations of protein-bound uraemic toxins, UA and ADMA in childhood CKD. Therefore, eGFR only partially reflects the complexity of the accumulation pattern of uraemic toxins in childhood CKD.
Assuntos
Taxa de Filtração Glomerular , Insuficiência Renal Crônica/sangue , Insuficiência Renal Crônica/diagnóstico , Uremia/sangue , Adolescente , Arginina/análogos & derivados , Arginina/sangue , Biomarcadores/sangue , Criança , Pré-Escolar , Feminino , Humanos , Masculino , Ácido Úrico/sangueRESUMO
BACKGROUND: Total kidney volume, measured by magnetic resonance imaging (MRI), is a validated disease progression marker in adults with autosomal dominant polycystic kidney disease (ADPKD). However, in childhood, MRI is burdensome, explaining the need for alternatives. METHODS: Kidney volume (KV) was evaluated in 30 children with ADPKD, using three-dimensional ultrasound (3DUS), applying the ellipsoid method and manual contouring (KV3DUS-ellipsoid, KV3DUS-contour respectively); manual contouring on MRI (KVMRI), and the ellipsoid method on two-dimensional ultrasound (2DUS, KV2DUS). Correlations and differences were evaluated using Pearson's r and Wilcoxon signed-rank tests, and variability using Bland-Altman plots. RESULTS: All ultrasound volumetry methods showed significantly lower mean (± SD) KV (mL), compared with MRI-KV2DUS: 159 (±101); K3DUS-ellipsoid: 169 (±105); KV3DUS-contour: 185 (±110); KVMRI: 206 (±130); all p < 0.001. All had a strong correlation with KVMRI: 2DUS: r = 0.96; 3DUS-ellipsoid: r = 0.89 and 3DUS-contour: r = 0.94. Both before and after correction factor application, Bland-Altman plots showed lower variability and absolute error for KV3DUS-contour vs KV2DUS and KV3DUS-ellipsoid. CONCLUSIONS: Compared with MRI, ultrasound volumetry was prone to underestimation. However, KV3DUS-contour represents a valuable alternative for MRI in early ADPKD. Although more time-consuming, KV3DUS-contour is recommended over KV2DUS for estimation and follow-up of KV in ADPKD children, given its smaller error.
Assuntos
Imageamento Tridimensional/métodos , Rim/diagnóstico por imagem , Imageamento por Ressonância Magnética/métodos , Rim Policístico Autossômico Dominante/diagnóstico por imagem , Ultrassonografia/métodos , Adolescente , Criança , Feminino , Humanos , Processamento de Imagem Assistida por Computador/métodos , Rim/patologia , MasculinoRESUMO
OBJECTIVES: To assess health-related quality of life (HRQoL) across three renal replacement therapy modalities (preemptive transplant, non-preemptive transplant, and dialysis) in comparison with the healthy norm and other chronic health conditions, and to explore related patient factors. STUDY DESIGN: All prevalent end-stage renal disease (ESRD) patients aged 8-18 years who spent at least 6 months on their current treatment modality in the Netherlands, Belgium, and part of Germany were approached to complete the Pediatric Quality of Life Inventory 4.0 (PedsQL™) questionnaire. We determined the differences between groups on PedsQL™ mean scores, the proportion of children with an impaired HRQoL (≥ 1 SD lower than the healthy norm), the proportion of problems on individual items of the PedsQL™, and the effect of time on current treatment. Linear regression models were used to explore determinants of HRQoL. RESULTS: 192 out of 278 patients (20% preemptive transplant, 58% non-preemptive transplant, 22% dialysis) filled in the PedsQL™ (response rate 69%). Independent of treatment modality, patients had significantly lower mean scores and consequently higher proportions of impaired HRQoL on almost all domains compared to the healthy norm and other chronic health conditions. Patients with a preemptive transplant only reported higher scores on physical health compared to the other treatment modalities. Having comorbidities was the most important determinant associated with lower HRQoL scores. CONCLUSION: Dialysis and renal transplantation both have a severe impact on the HRQoL of children with ESRD. Physicians should be aware of this continuous burden. Furthermore, to develop tailored interventions for children with ESRD, qualitative studies are needed to gain more insight in the determinants of HRQoL in the different treatment modalities.
Assuntos
Falência Renal Crônica/psicologia , Transplante de Rim/psicologia , Qualidade de Vida/psicologia , Diálise Renal/psicologia , Adolescente , Criança , Estudos Transversais , Feminino , Humanos , Transplante de Rim/métodos , MasculinoRESUMO
AIMS: Despite longstanding recognition of significant age-dependent differences in drug disposition during childhood, the exact course and the underlying mechanisms are not known. Our aim was to determine the course and determinants of individual relative dose requirements, during long-term follow-up in children on tacrolimus. METHODS: This was a cohort study in a tertiary hospital with standardized annual pharmacokinetic (PK) follow-up (AUC0-12hr ) in recipients of a renal allograft (≤19 years), between 1998 and 2015. In addition, the presence of relevant pharmacogenetic variants was determined. The evolution of dose-corrected exposure was evaluated using mixed models. RESULTS: A total of 184 PK visits by 43 children were included in the study (median age: 14.6). AUC0-12h corrected for dose per kg demonstrated a biphasic course: annual increase 4.4% (CI: 0.3-8.7%) until ±14 years of age, followed by 13.4% increase (CI 8.7-18.3%). Moreover, exposure corrected for dose per m2 proved stable until 14 years (+0.8% annually; CI: -3.0 to +4.8%), followed by a steep increase ≥14 years (+11%; CI: 7.0-16.0%). Analysis according to bone maturation instead of age demonstrated a similar course with a distinct divergence at TW2: 800 (P = 0.01). Genetic variation in CYP3A4, CYP3A5, and CYP3A7 was associated with altered dose requirements, independent of age. CONCLUSIONS: Children exhibit a biphasic course in tacrolimus disposition characterized by a high and stable drug clearance until a specific phase in pubertal development (TW2: 800 at age: ±14 years), followed by an important decline in relative dose requirements thereafter. Pharmacogenetic variation demonstrated an age/puberty independent effect. We suggest a critical reappraisal of current paediatric dosing algorithms for tacrolimus and drugs with a similar disposition.
Assuntos
Imunossupressores/administração & dosagem , Transplante de Rim/métodos , Farmacogenética , Tacrolimo/administração & dosagem , Adolescente , Fatores Etários , Área Sob a Curva , Desenvolvimento Ósseo/fisiologia , Criança , Pré-Escolar , Estudos de Coortes , Citocromo P-450 CYP3A/genética , Relação Dose-Resposta a Droga , Feminino , Seguimentos , Humanos , Imunossupressores/farmacocinética , Masculino , Puberdade/fisiologia , Tacrolimo/farmacocinética , Transplante HomólogoRESUMO
BACKGROUND: Cystinosis is a rare, inherited autosomal recessive disease caused by the accumulation of free cystine in lysosomes. It is treated by the administration of cysteamine, which should be monitored by trough white blood cell (WBC) cystine measurements to ensure effective treatment. CASE-DIAGNOSIS/TREATMENT: The index case had an older brother who had previously been diagnosed with cystinosis, allowing early diagnosis of the index case at the age of 5 months. Cysteamine therapy was started at the age of 3 years; however, monitoring of WBC cystine levels did not occur on a regular basis during most of his life. Growth retardation improved after correction of electrolyte disturbances, the initiation of cysteamine therapy and treatment with recombinant human growth hormone. Renal replacement therapy was started at the age of 11 years, and renal transplantation was performed at the age of 12 years. Extra-renal cystine accumulation caused multiple endocrinopathies (including adrenal insufficiency, hypothyroidism and primary hypogonadism), neurological symptoms, pancytopenia owing to splenomegaly and portal hypertension due to nodular regenerative hyperplasia, aggravated by splenic vein thrombosis and partial portal vein thrombosis. The patient died of diffuse intra-abdominal bleeding caused by severe portal hypertension. CONCLUSION: Cysteamine treatment should be started as early as possible, and dosage should be monitored and adapted based on trough WBC cystine levels. RELEVANT INTERNATIONAL GUIDELINE: Emma F et al. (2014) Nephropathic cystinosis: an international consensus document. Nephrol Dial Transplant 29:iv87-iv94.
Assuntos
Cisteamina/administração & dosagem , Cistinose/tratamento farmacológico , Cistinose/fisiopatologia , Adolescente , Adulto , Criança , Pré-Escolar , Cistinose/complicações , Gerenciamento Clínico , Evolução Fatal , Humanos , Lactente , Recém-Nascido , Transplante de Rim , Masculino , Nefrologia , Pediatria , Linhagem , Insuficiência Renal/etiologia , Insuficiência Renal/cirurgia , Adulto JovemRESUMO
BACKGROUND: Many children with end-stage renal disease (ESRD) living in Western Europe are of non-Western European origin. They have unfavourable somatic outcomes compared with ESRD children of Western origin. In this study, we compared the Health-related Quality of Life (HRQoL) of both groups. METHODS: All children (5-18 years) with ESRD included in the RICH-Q project (Renal Insufficiency therapy in Children-Quality assessment and improvement) or their parents were asked to complete the generic version of the Paediatric Quality-of-Life Inventory 4.0 (PedsQL). RICH-Q comprises the Netherlands, Belgium and a part of Germany. Children were considered to be of non-Western origin if they or at least one parent was born outside Western-European countries. Impaired HRQoL for children with ESRD of Western or non-Western origin was defined as a PedsQL score less than fifth percentile for healthy Dutch children of Western or non-Western origin, respectively. RESULTS: Of the 259 eligible children, 230 agreed to participate. One hundred and seventy-four children responded (response rate 67%) and 55 (32%) were of non-Western origin. Overall, 31 (56%) of the ESRD children of non-Western origin, and 58 (49%) of Western origin had an impaired total HRQoL score. Total HRQoL scores of children with ESRD of Western origin and non-Western origin were comparable, but scores on emotional functioning and school functioning were lower in non-Western origin (P=0.004 and 0.01, respectively). The adjusted odds ratios (95% confidence interval) for ESRD children of non-Western origin to have impaired emotional functioning and school functioning, compared with Western origin, were 3.3(1.5-7.1) and 2.2(1.1-4.2), respectively. CONCLUSION: Children with ESRD of non-Western origin in three Western countries were found to be at risk for impaired HRQoL on emotional and school functioning. These children warrant special attention.
Assuntos
Etnicidade , Falência Renal Crônica/etnologia , Falência Renal Crônica/psicologia , Qualidade de Vida , Adolescente , Bélgica/epidemiologia , Criança , Pré-Escolar , Feminino , Alemanha/epidemiologia , Nível de Saúde , Humanos , Incidência , Falência Renal Crônica/terapia , Masculino , Países Baixos/epidemiologia , Prevalência , Prognóstico , Terapia de Substituição Renal , Estudos RetrospectivosRESUMO
INTRODUCTION: Early detection of cardiovascular disease in children with end-stage renal disease is essential in order to prevent cardiovascular morbidity and mortality in early adulthood. Tissue Doppler imaging has shown to be a promising method to detect and quantify subtle abnormalities in diastolic function. We therefore compared assessment of diastolic function by conventional echocardiography and tissue Doppler imaging. METHODS: We performed conventional echocardiography and tissue Doppler imaging in 38 children with end-stage renal disease and 76 healthy controls. We compared outcomes on parameters related to diastolic function (E/a ratio for conventional echocardiography and E/E' ratio for tissue Doppler imaging) for both groups using multiple linear regression analysis. Diastolic dysfunction was defined as E/a ratio <1 or E/E' ratio > 95th percentile for age. To assess the intra-observer reproducibility, the coefficient of variation was calculated. RESULTS: Children with end-stage renal disease had on average a lower E/a ratio (p = 0.004) and a higher mitral and septal E/E' ratio (both p < 0.001) compared with controls. In all, two children with end-stage renal disease (5%) had diastolic dysfunction according to the E/a ratio, 11 according to the mitral E/E' ratio (29%), and 16 according to the septal E/E' ratio (42%) compared with none of the controls (p = 0.109, p < 0.001, and p < 0.001, respectively). The coefficients of variation of the mitral (7%) and septal E/E' ratio (4%) were smaller than the coefficient of variation of the E/a ratio (11%). CONCLUSIONS: Tissue Doppler imaging is a more sensitive and reliable method to detect diastolic dysfunction than conventional E/a ratio in children with end-stage renal disease.
Assuntos
Diástole , Ecocardiografia Doppler/métodos , Hipertrofia Ventricular Esquerda/diagnóstico por imagem , Falência Renal Crônica/complicações , Disfunção Ventricular Esquerda/diagnóstico por imagem , Adolescente , Velocidade do Fluxo Sanguíneo , Estudos de Casos e Controles , Criança , Pré-Escolar , Estudos de Coortes , Ecocardiografia/métodos , Feminino , Humanos , Hipertrofia Ventricular Esquerda/etiologia , Modelos Lineares , Masculino , Disfunção Ventricular Esquerda/etiologiaRESUMO
Introduction: Growth failure is considered the most important clinical outcome parameter in childhood chronic kidney disease (CKD). Central to the pathophysiology of growth failure is the presence of a chronic proinflammatory state, presumed to be partly driven by the accumulation of uremic toxins. In this study, we assessed the association between uremic toxin concentrations and height velocity in a longitudinal multicentric prospective pediatric CKD cohort of (pre)school-aged children and children during pubertal stages. Methods: In a prospective, multicentric observational study, a selection of uremic toxin levels of children (aged 0-18 years) with CKD stage 1 to 5D was assessed every 3 months (maximum 2 years) along with clinical growth parameters. Linear mixed models with a random slope for age and a random intercept for child were fitted for height (in cm and SD scores [SDS]). A piecewise linear association between age and height was assumed. Results: Data analysis included data from 560 visits of 81 children (median age 9.4 years; 2/3 male). In (pre)school aged children (aged 2-12 years), a 10% increase in concurrent indoxyl sulfate (IxS, total) concentration resulted in an estimated mean height velocity decrease of 0.002 SDS/yr (P < 0.05), given that CKD stage, growth hormone (GH), bicarbonate concentration, and dietary protein intake were held constant. No significant association with height velocity was found in children during pubertal stages (aged >12 years). Conclusion: The present study demonstrated that, especially IxS contributes to a lower height velocity in (pre)school children, whereas we could not find a role for uremic toxins with height velocity during pubertal stages.
RESUMO
BACKGROUND: Evidence-based guidelines for pediatric renal transplantation (Tx) are lacking. This may lead to unwanted treatment variations. We aimed to quantify the variation in treatment policies and its consequences in daily practice in 11 centers that provide renal Tx for children in three European countries. METHODS: We surveyed Tx policies in all ten centers in the Netherlands and Belgium and one center in Germany. We compared Tx policies with the therapies actually provided and with recommendations from available published guidelines and existing literature. Information on treatment policies was obtained by a questionnaire; information on care actually provided was registered prospectively from 2007 to 2011. The clinical guidelines were identified by searches of MEDLINE and websites of pediatric nephrology organizations. RESULTS: Between centers, we found discrepancies in policies on: the minimum accepted recipient weight (8-12 kg), the maximum living and deceased donor age (50-75 and 45-60 years, respectively). HLA-match policies varied between acceptation of all mismatches to at least 1A1B1DR match donor transplantations amounting to 49 % in the Netherlands versus 26 % in Belgium (p = 0.006). CONCLUSIONS: Management policies for renal Tx in children vary considerably between centers and nations. This has a direct impact on the delivered care, and by extrapolation, on health outcome.
Assuntos
Transplante de Rim , Idoso , Bélgica , Criança , Alemanha , Teste de Histocompatibilidade , Humanos , Pessoa de Meia-Idade , Países Baixos , Guias de Prática Clínica como Assunto , Doadores de TecidosRESUMO
BACKGROUND: Cystinosis is an autosomal recessive disorder characterized by intralysosomal cystine accumulation. Growth retardation is more pronounced in cystinosis than in other chronic kidney diseases and is mostly not corrected by cysteamine. METHODS: Growth was evaluated in nine cystinosis patients, all treated with cysteamine, both after cysteamine and recombinant human growth hormone (rhGH) therapy initiation. Growth hormone (GH) secretion was studied by nocturnal GH measurements in four of nine patients and by glucagon test in four of nine patients. RESULTS: RhGH was administered to seven of nine patients. At rhGH initiation, height was below -2 SDS in five of seven patients, final height was above -2 SDS in six of seven. In two patients not treated with rhGH, final height remained below -4 SDS despite cysteamine treatment being started at the age of 6.1 and 8.1 years, respectively. Nocturnal GH secretion was normal in all patients. Glucagon tests revealed GH deficiency in one patient; two of four patients had abnormal GH peak timing. CONCLUSIONS: We present the first reported case of GH deficiency in cystinosis. Although no overt GH deficiency was detected in other patients, abnormal GH peak timing can indicate a subclinical GH secretion problem. RhGH significantly improved growth in cystinosis patients and should be initiated early in life.
Assuntos
Ritmo Circadiano , Cistinose/sangue , Transtornos do Crescimento/sangue , Hormônio do Crescimento Humano/sangue , Biomarcadores/sangue , Estatura/efeitos dos fármacos , Estudos de Casos e Controles , Criança , Pré-Escolar , Cisteamina/uso terapêutico , Cistinose/complicações , Cistinose/tratamento farmacológico , Feminino , Glucagon , Transtornos do Crescimento/tratamento farmacológico , Transtornos do Crescimento/etiologia , Terapia de Reposição Hormonal , Hormônio do Crescimento Humano/deficiência , Hormônio do Crescimento Humano/uso terapêutico , Humanos , Lactente , Masculino , Fatores de Tempo , Resultado do TratamentoRESUMO
Imbalanced colonic microbial metabolism plays a pivotal role in generating protein-bound uraemic toxins (PBUTs), which accumulate with deteriorating kidney function and contribute to the uraemic burden of children with chronic kidney disease (CKD). Dietary choices impact the gut microbiome and metabolism. The aim of this study was to investigate the relation between dietary fibre and gut-derived PBUTs in paediatric CKD. Sixty-one (44 male) CKD children (9 ± 5 years) were prospectively followed for two years. Dietary fibre intake was evaluated by either 24-h recalls (73%) or 3-day food records (27%) at the same time of blood sampling for assessment of total and free serum levels of different PBUTs using liquid chromatography. We used linear mixed models to assess associations between fibre intake and PBUT levels. We found an inverse association between increase in fibre consumption (g/day) and serum concentrations of free indoxyl sulfate (-3.1% (-5.9%; -0.3%) (p = 0.035)), free p-cresyl sulfate (-2.5% (-4.7%; -0.3%) (p = 0.034)), total indole acetic acid (IAA) (-1.6% (-3.0%; -0.3%) (p = 0.020)), free IAA (-6.6% (-9.3%; -3.7%) (p < 0.001)), total serum p-cresyl glucuronide (pCG) (-3.0% (-5.6%; -0.5%) (p = 0.021)) and free pCG levels (-3.3% (-5.8%; -0.8%) (p = 0.010)). The observed associations between dietary fibre intake and the investigated PBUTs highlight potential benefits of fibre intake for the paediatric CKD population. The present observational findings should inform and guide adaptations of dietary prescriptions in children with CKD.
Assuntos
Bactérias/metabolismo , Fibras na Dieta/administração & dosagem , Microbioma Gastrointestinal , Intestinos/microbiologia , Insuficiência Renal Crônica/dietoterapia , Toxinas Biológicas/sangue , Uremia/dietoterapia , Adolescente , Fatores Etários , Bélgica , Criança , Pré-Escolar , Disbiose , Feminino , Humanos , Lactente , Estudos Longitudinais , Masculino , Prognóstico , Estudos Prospectivos , Insuficiência Renal Crônica/sangue , Insuficiência Renal Crônica/diagnóstico , Insuficiência Renal Crônica/microbiologia , Uremia/sangue , Uremia/diagnóstico , Uremia/microbiologiaRESUMO
Because tacrolimus (Tac) has a narrow therapeutic index and highly inter- and intra-individual variable pharmacokinetic (PK) characteristics, monitoring of drug exposure is recommended, but limited data are available on the kinetics of Tac in paediatric renal transplant recipients, especially of limited sampling strategies. To investigate the correlation between Tac trough level (TL) and the 0-12 h area under the curve (AUC), and the value of abbreviated AUC monitoring, we evaluated 12 h PK profiles in 27 children at least 1 year after transplantation. There was a significant discrepancy between Tac TLs and 0-12 h AUC (r = 0.60). Every time point, different from C(0), gave a better prediction for the drug exposure, with C(4) and C(6) as best predictors (r = 0.93 and r = 0.92, respectively). The 0-12 h AUC was estimated with great precision by the use of a two- or three-point sampling strategy, and the latter is more time-point independent. In paediatric renal transplant recipients on Tac maintenance therapy, whose condition is stable, Tac TL is not a reliable tool for the estimation of drug exposure. Abbreviated monitoring, especially at three points in time, give reliable predictions of the complete 0-12 h AUC. We suggest a 0-12 h AUC of around 150 ng x h/ml for stable paediatric renal transplant recipients 1 year after transplantation and around 100 ng x h/ml in the following years. Target AUC values should be further established for paediatric transplant recipients according to the time after transplantation.
Assuntos
Imunossupressores/farmacocinética , Transplante de Rim , Rim/metabolismo , Tacrolimo/farmacocinética , Adolescente , Área Sob a Curva , Criança , Pré-Escolar , Monitoramento de Medicamentos/métodos , Humanos , LactenteRESUMO
BACKGROUND: Improved management of growth impairment might have resulted in less growth retardation after pediatric kidney transplantation (KT) over time. We aimed to analyze recent longitudinal growth data after KT in comparison to previous eras, its determinants, and the association with transplant outcome in a large cohort of transplanted children using data from the European Society for Paediatric Nephrology/European Renal Association and European Dialysis and Transplant Association Registry. METHODS: A total of 3492 patients transplanted before 18 years from 1990 to 2012 were included. Height SD scores (SDS) were calculated using recent national or European growth charts. We used generalized equation models to estimate the prevalence of growth deficit and linear mixed models to calculate adjusted mean height SDS. RESULTS: Mean adjusted height post-KT was -1.77 SDS. Height SDS was within normal range in 55%, whereas 28% showed moderate, and 17% severe growth deficit. Girls were significantly shorter than boys, but catch-up growth by 5 years post-KT was observed in both boys and girls. Children <6 years were shortest at KT and showed the greatest increase in height, whereas there was no catch-up growth in children transplanted >12. CONCLUSIONS: Catch-up growth post-KT remains limited, height SDS did not improve over time, resulting in short stature in nearly half of transplanted children in Europe.
Assuntos
Estatura/fisiologia , Transtornos do Crescimento/epidemiologia , Falência Renal Crônica/cirurgia , Transplante de Rim/efeitos adversos , Anormalidades Urogenitais/cirurgia , Refluxo Vesicoureteral/cirurgia , Adolescente , Fatores Etários , Criança , Desenvolvimento Infantil/fisiologia , Pré-Escolar , Europa (Continente)/epidemiologia , Feminino , Seguimentos , Transtornos do Crescimento/diagnóstico , Transtornos do Crescimento/etiologia , Transtornos do Crescimento/fisiopatologia , Humanos , Lactente , Recém-Nascido , Falência Renal Crônica/diagnóstico , Falência Renal Crônica/etiologia , Estudos Longitudinais , Masculino , Sistema de Registros/estatística & dados numéricos , Índice de Gravidade de Doença , Fatores Sexuais , Fatores de Tempo , Tempo para o Tratamento , Anormalidades Urogenitais/complicações , Refluxo Vesicoureteral/complicaçõesRESUMO
A girl, second child of healthy parents, was referred to the Renal Unit at the age of 9 months with haematuria (230 RBC/microl) and proteinuria (2.4 g/l). Serum creatinine was normal (0.25 mg/dl), albumin low (34 g/l) and cholesterol elevated (223 mg/dl). Physical examination showed bilateral webbing of the elbows, equinovarus of both feet and absent patellae. The clinical diagnosis of nail-patella syndrome was confirmed by demonstrating a splice mutation in the intron 5 (750 + 1 G>A) of the LMX1B gene. Treatment with enalapril for 2 years (0.1-1 mg/kg per day) did not bring about any change in urinary protein excretion. However, enalapril (1 mg/kg per day) associated with losartan (1 mg/kg per day) resulted in complete remission (proteinuria 140 mg/24 h) at the age of 7 years.
Assuntos
Bloqueadores do Receptor Tipo 1 de Angiotensina II/uso terapêutico , Inibidores da Enzima Conversora de Angiotensina/uso terapêutico , Enalapril/uso terapêutico , Losartan/uso terapêutico , Síndrome da Unha-Patela/tratamento farmacológico , Síndrome Nefrótica/tratamento farmacológico , Quimioterapia Combinada , Feminino , Humanos , Lactente , Indução de RemissãoRESUMO
Protein-bound uremic toxins (PBUTs) play a role in the multisystem disease that children on hemodialysis (HD) are facing, but little is known about their levels and protein binding (%PB). In this study, we evaluated the levels and %PB of six PBUTs cross-sectionally in a large pediatric HD cohort (n = 170) by comparing these with healthy and non-dialysis chronic kidney disease (CKD) stage 4-5 (n = 24) children. In parallel ß2-microglobulin (ß2M) and uric acid (UA) were evaluated. We then explored the impact of age and residual kidney function on uremic toxin levels and %PB using analysis of covariance and Spearman correlation coefficients (rs). We found higher levels of ß2M, p-cresyl glucuronide (pCG), hippuric acid (HA), indole acetic acid (IAA), and indoxyl sulfate (IxS) in the HD compared to the CKD4-5 group. In the HD group, a positive correlation between age and pCG, HA, IxS, and pCS levels was shown. Residual urine volume was negatively correlated with levels of ß2M, pCG, HA, IAA, IxS, and CMPF (rs -0.2 to -0.5). In addition, we found overall lower %PB of PBUTs in HD versus the CKD4-5 group, and showed an age-dependent increase in %PB of IAA, IxS, and pCS. Furhtermore, residual kidney function was overall positively correlated with %PB of PBUTs. In conclusion, residual kidney function and age contribute to PBUT levels and %PB in the pediatric HD population.