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BACKGROUND: Nephrotic syndrome (NS) is a common pediatric kidney disease, yet current treatments for complicated NS are only partially effective and have significant toxicity. There is no Food and Drug Administration (FDA)- or European Medicines Agency (EMA)-approved safe and effective treatment for NS. Thiazolidinediones (TZDs) have been shown to reduce proteinuria in both diabetic and non-diabetic kidney disease and in preclinical studies to directly protect podocytes from injury and reduce proteinuria. Here, we report on the potential utility of the addition of the TZD pioglitazone (PIO) to enhance proteinuria reduction in 8 children and young adults with steroid dependent NS and steroid resistant NS. METHODS: Clinical data were analyzed in comparable time periods before and after the addition of PIO to their medical regimens. Eight NS patients with minimal change NS (n = 2), focal segmental glomerulosclerosis (FSGS) (n = 4), or collapsing FSGS (n = 2) were evaluated. RESULTS: Prior to PIO initiation, all children and young adults had already received multiple immunosuppressive medications (mean = 3.75). Five of eight patients (63%; "Responders") had notable proteinuria reduction within 1 month of PIO initiation (62% reduction; P = 0.04) and normalization within 6 months (97% reduction; P = 0.04). PIO-related benefits among the responders included notable increases in serum albumin (2.5 to 3.7 g/dl; P = 0.08), dramatic reductions in hospitalizations for IV albumin infusions and diuresis (11 to 0; P < 0.01), and considerable reduction in total immunosuppression (43% reduction; P > 0.1). Importantly, no patients experienced any adverse events attributable to PIO during a total of 136 patient-months of treatment. CONCLUSIONS: While confirmatory safety and efficacy studies are needed, these findings suggest pioglitazone (a non-immunosuppressive drug) may be useful to enhance proteinuria reduction in some children and young adults with complicated NS. A higher resolution version of the Graphical abstract is available as Supplementary information.
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Glomerulosclerose Segmentar e Focal , Síndrome Nefrótica , Adulto Jovem , Humanos , Criança , Síndrome Nefrótica/complicações , Síndrome Nefrótica/tratamento farmacológico , Pioglitazona/uso terapêutico , Glomerulosclerose Segmentar e Focal/complicações , Proteinúria/etiologia , Proteinúria/complicações , Esteroides/uso terapêuticoRESUMO
Primary Coenzyme Q10 deficiency is a rare mitochondriopathy with a wide spectrum of organ involvement, including steroid-resistant nephrotic syndrome mainly associated with disease-causing variants in the genes COQ2, COQ6 or COQ8B. We performed a systematic literature review, PodoNet, mitoNET, and CCGKDD registries queries and an online survey, collecting comprehensive clinical and genetic data of 251 patients spanning 173 published (47 updated) and 78 new cases. Kidney disease was first diagnosed at median age 1.0, 1.2 and 9.8 years in individuals with disease-causing variants in COQ2, COQ6 and COQ8B, respectively. Isolated kidney involvement at diagnosis occurred in 34% of COQ2, 10.8% of COQ6 and 70.7% of COQ8B variant individuals. Classic infantile multiorgan involvement comprised 22% of the COQ2 variant cohort while 47% of them developed neurological symptoms at median age 2.7 years. The association of steroid-resistant nephrotic syndrome and sensorineural hearing loss was confirmed as the distinctive phenotype of COQ6 variants, with hearing impairment manifesting at average age three years. None of the patients with COQ8B variants, but 50% of patients with COQ2 and COQ6 variants progressed to kidney failure by age five. At adult age, kidney survival was equally poor (20-25%) across all disorders. A number of sequence variants, including putative local founder mutations, had divergent clinical presentations, in terms of onset age, kidney and non-kidney manifestations and kidney survival. Milder kidney phenotype was present in those with biallelic truncating variants within the COQ8B variant cohort. Thus, significant intra- and inter-familial phenotype variability was observed, suggesting both genetic and non-genetic modifiers of disease severity.
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Síndrome Nefrótica , Ataxia , Estudos de Associação Genética , Humanos , Doenças Mitocondriais , Debilidade Muscular , Mutação , Síndrome Nefrótica/diagnóstico , Esteroides , Ubiquinona/deficiênciaRESUMO
Primary Coenzyme Q10 (CoQ10) deficiency is an ultra-rare disorder caused by defects in genes involved in CoQ10 biosynthesis leading to multidrug-resistant nephrotic syndrome as the hallmark kidney manifestation. Promising early results have been reported anecdotally with oral CoQ10 supplementation. However, the long-term efficacy and optimal prescription remain to be established. In a global effort, we collected and analyzed information from 116 patients who received CoQ10 supplements for primary CoQ10 deficiency due to biallelic pathogenic variants in either the COQ2, COQ6 or COQ8B genes. Median duration of follow up on treatment was two years. The effect of treatment on proteinuria was assessed, and kidney survival was analyzed in 41 patients younger than 18 years with chronic kidney disease stage 1-4 at the start of treatment compared with that of an untreated cohort matched by genotype, age, kidney function, and proteinuria. CoQ10 supplementation was associated with a substantial and significant sustained reduction of proteinuria by 88% at 12 months. Complete remission of proteinuria was more frequently observed in COQ6 disease. CoQ10 supplementation led to significantly better preservation of kidney function (5-year kidney failure-free survival 62% vs. 19%) with an improvement in general condition and neurological manifestations. Side effects of treatment were uncommon and mild. Thus, our findings indicate that all patients diagnosed with primary CoQ10 deficiency should receive early and life-long CoQ10 supplementation to decelerate the progression of kidney disease and prevent further damage to other organs.
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Doenças Mitocondriais , Síndrome Nefrótica , Ubiquinona , Ataxia/tratamento farmacológico , Suplementos Nutricionais , Humanos , Rim/patologia , Doenças Mitocondriais/tratamento farmacológico , Debilidade Muscular/tratamento farmacológico , Mutação , Síndrome Nefrótica/complicações , Síndrome Nefrótica/tratamento farmacológico , Síndrome Nefrótica/genética , Proteinúria/diagnóstico , Proteinúria/tratamento farmacológico , Esteroides/uso terapêutico , Ubiquinona/análogos & derivados , Ubiquinona/deficiência , Ubiquinona/uso terapêuticoRESUMO
Multinational studies have reported monogenic etiologies in 25%-30% of children with steroid-resistant nephrotic syndrome. Such large studies are lacking in Asia. We established Deciphering Diversities: Renal Asian Genetics Network (DRAGoN) and aimed to describe the genetic and clinical spectrums in Asians. We prospectively studied a cohort of 183 probands with suspected genetic glomerulopathies from South and Southeast Asia, of whom 17% had positive family history. Using multi-gene panel sequencing, we detected pathogenic variants in 26 (14%) probands, of whom one-third had COL4A4 or COL4A5 variants (n = 9, 5%). Of those with COL4A5 defects, only 25% had features suggestive of Alport syndrome. Besides traditional predictors for genetic disease (positive family history and extrarenal malformations), we identified novel predictors, namely older age (6.2 vs. 2.4 years; p = 0.001), hematuria (OR 5.6; 95% CI 2.1-14.8; p < 0.001), and proteinuria in the absence of nephrotic syndrome (OR 4.6; 95% CI 1.8-11.8; p = 0.001) at first manifestation. Among patients who first presented with proteinuria without nephrotic syndrome, the genetic diagnostic rates were >60% when a second risk factor (positive family history or extrarenal manifestation) co-existed. The genetic spectrum of glomerulopathies appears different in Asia. Collagen IV genes may be included in sequencing panels even when suggestive clinical features are absent.
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Nefrite Hereditária , Síndrome Nefrótica , Povo Asiático/genética , Criança , Colágeno Tipo IV/genética , Feminino , Humanos , Masculino , Mutação , Nefrite Hereditária/diagnóstico , Síndrome Nefrótica/genética , ProteinúriaRESUMO
Epigenetic regulation of gene expression has a crucial role allowing for the self-renewal and differentiation of stem and progenitor populations during organogenesis. The mammalian kidney maintains a population of self-renewing stem cells that differentiate to give rise to thousands of nephrons, which are the functional units that carry out filtration to maintain physiological homeostasis. The polycomb repressive complex 2 (PRC2) epigenetically represses gene expression during development by placing the H3K27me3 mark on histone H3 at promoter and enhancer sites, resulting in gene silencing. To understand the role of PRC2 in nephron differentiation, we conditionally inactivated the Eed gene, which encodes a nonredundant component of the PRC2 complex, in nephron progenitor cells. Resultant kidneys were smaller and showed premature loss of progenitor cells. The progenitors in Eed mutant mice that were induced to differentiate did not develop into properly formed nephrons. Lhx1, normally expressed in the renal vesicle, was overexpressed in kidneys of Eed mutant mice. Thus, PRC2 has a crucial role in suppressing the expression of genes that maintain the progenitor state, allowing nephron differentiation to proceed.
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Diferenciação Celular/fisiologia , Epigênese Genética/fisiologia , Regulação da Expressão Gênica no Desenvolvimento/fisiologia , Néfrons/embriologia , Complexo Repressor Polycomb 2/biossíntese , Células-Tronco/metabolismo , Animais , Proteínas com Homeodomínio LIM/biossíntese , Proteínas com Homeodomínio LIM/genética , Camundongos , Camundongos Transgênicos , Mutação , Néfrons/citologia , Complexo Repressor Polycomb 2/genética , Células-Tronco/citologia , Fatores de Transcrição/biossíntese , Fatores de Transcrição/genéticaRESUMO
BACKGROUND: Decline in skills and knowledge among patients and/or caregivers contributes to peritoneal-dialysis (PD)-related peritonitis. Re-training is important, but no guidelines exist. We describe the implementation of a structured re-training program to decrease peritonitis rates. METHODS: This is a prospective quality improvement study involving pediatric patients on long-term home automated PD at National University Hospital, Singapore, between 2012 and 2018. With increasing peritonitis rates, systematic root cause analysis was performed, and based on the contributory factors identified, a structured re-training program was implemented from 2015. This was conducted in 5 cycles, each consisting of 4 modules (hand hygiene, exit site care, peritonitis, and PD troubleshooting). RESULTS: Peritonitis rates were analyzed in 2 phases: Phase 1 (2012-2014) when no re-training was performed and Phase 2 (2016-2018) after re-training was instituted. Fifty-nine patients were included. Of these, 45 patients were in Phase 1, 32 in Phase 2, and 18 in both phases. Peritonitis rates decreased from 0.37 ± 0.67 episodes per patient-year in Phase 1 to 0.13 ± 0.32 episodes per patient-year in Phase 2. After adjusting for age at kidney failure onset, PD vintage, years of nursing experience, and the average patient-to-nurse ratio over the study period for each patient, the adjusted peritonitis rates decreased by 0.38 episodes per patient-year (95% CI, 0.09 to 0.67, p = 0.011) from Phase 1 to Phase 2. CONCLUSION: Despite an improvement in staffing ratio, peritonitis rates only improved significantly after intensive structured re-training was instituted.
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Falência Renal Crônica , Diálise Peritoneal , Peritonite , Criança , Humanos , Diálise Peritoneal/efeitos adversos , Peritonite/etiologia , Peritonite/prevenção & controle , Estudos Prospectivos , Melhoria de Qualidade , Estudos RetrospectivosRESUMO
Circulating factors have been implicated in the pathogenesis of minimal change disease (MCD), and may have direct effects on cholesterol metabolism. This study investigated the pathogenesis of hypercholesterolemia in an IL-13 overexpression rat model of MCD prior to the onset of proteinuria, so as to establish the direct contribution of IL-13, especially with regard to hepatic cholesterol handling. In this model of MCD, the temporal relationship between hypercholesterolemia and proteinuria was first identified. Plasma proprotein convertase subtilisin/kexin type 9 (Pcsk9) and liver ATP-binding cassette sub-family G member 5 (Abcg5) were measured using ELISA. Liver Ldlr and liver X receptor alpha (Lxra) were quantified with Western blot. Abcg5-mediated cholesterol efflux in IL-13-stimulated rat primary hepatocytes was measured using taurocholate as cholesterol acceptor. The role of Lxra was validated using a luciferase assay in Lxre-luciferase-transfected IL-13-stimulated hepatocytes. IL-13-transfected rats developed hypercholesterolemia prior to proteinuria, with 35% of rats hypercholesterolemic but only 11% proteinuric by Day 20 (P = 0.04). These pre-proteinuric hypercholesterolemic rats showed elevations in total and LDL-cholesterol, but not hypertriglyceridemia or hepatic steatosis. The hypercholesterolemia was associated with increased hepatic Pcsk9 synthesis and enhanced circulating Pcsk9 levels, which correlated strongly with plasma total cholesterol (r = 0.73, P<0.001). The hypercholesterolemia was also contributed by decreased Abcg5 expression and activity, due to reduced Lxra expression. Lxra expression correlated with plasma total cholesterol levels (r = -0.52, P = 0.01), and overexpression of pLxra in rat hepatocytes abrogated the IL-13-mediated down-regulation of Lxre-driven gene expression. In conclusion, we have shown that IL-13 induced changes in hepatic cholesterol handling in a cytokine-induced rat model of MCD, resulting in hypercholesterolemia which can precede the onset of proteinuria.
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Colesterol/metabolismo , Hipercolesterolemia/metabolismo , Interleucina-13/metabolismo , Fígado/metabolismo , Nefrose Lipoide/metabolismo , Membro 5 da Subfamília G de Transportadores de Cassetes de Ligação de ATP/metabolismo , Animais , Colesterol/sangue , Modelos Animais de Doenças , Regulação para Baixo , Hipercolesterolemia/sangue , Hipercolesterolemia/complicações , Lipoproteínas/metabolismo , Receptores X do Fígado/metabolismo , Masculino , Nefrose Lipoide/sangue , Nefrose Lipoide/complicações , Pró-Proteína Convertase 9/metabolismo , Proteinúria/complicações , Proteinúria/metabolismo , Ratos Wistar , Proteínas de Ligação a Elemento Regulador de Esterol/metabolismoRESUMO
BACKGROUND: A lack of consensus exists as to the timing of kidney biopsy in children with steroid-dependent nephrotic syndrome (SDNS) where minimal change disease (MCD) predominates. This study aimed at examining the applicability of a biomarker-assisted risk score model to select SDNS patients at high risk of focal segmental glomerulosclerosis (FSGS) for biopsy. METHODS: Fifty-five patients with SDNS and biopsy-proven MCD (n = 40) or FSGS (n = 15) were studied. A risk score model was developed with variables consisting of age, sex, eGFR, suPAR levels and percentage of CD8+ memory T cells. Following multivariate regression analysis, total risk score was calculated as sum of the products of odds ratios and corresponding variables. Predictive cut-off point was determined using receiver operator characteristics (ROC) curve analysis. RESULTS: Plasma suPAR levels in FSGS patients were significantly higher, while percentage of CD45RO+CD8+CD3+ was significantly lower than in MCD patients and controls. ROC analysis suggests the risk score model with threshold score of 16.7 (AUC 0.84, 95% CI 0.72-0.96) was a good predictor of FSGS on biopsy. The 100% PPV cut-off was >24.0, while the 100% NPV was <13.3. CONCLUSION: A suPAR and CD8+ memory T cell percentage-based risk score model was developed to stratify SDNS patients for biopsy and for predicting FSGS.
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Anti-Inflamatórios/uso terapêutico , Biópsia , Glomerulosclerose Segmentar e Focal/patologia , Rim/patologia , Síndrome Nefrótica/patologia , Prednisolona/uso terapêutico , Adolescente , Estudos de Casos e Controles , Criança , Pré-Escolar , Feminino , Glomerulosclerose Segmentar e Focal/etiologia , Humanos , Subpopulações de Linfócitos , Masculino , Síndrome Nefrótica/complicações , Síndrome Nefrótica/etiologia , Receptores de Ativador de Plasminogênio Tipo Uroquinase/sangue , Medição de RiscoRESUMO
The risk of acute kidney injury (AKI) in hospitalized critically ill neonatal populations without primary renal disease continues to be high, in both term and premature infants. Observational studies have revealed high rates of chronic kidney disease (CKD) in survivors of neonatal AKI. Proposed mechanisms underlying the progression of CKD following AKI include nephron loss and hyperfiltration, vascular insufficiency and maladaptive repair mechanisms. Other factors, including prematurity and low birth weight, have an independent relationship with the development of CKD, but they may also be positive effect modifiers in the relationship of AKI and CKD. The large degree of heterogeneity in the literature on AKI in the neonatal population, including the use of various AKI definitions and CKD outcomes, has hampered the medical community's ability to properly assess the relationship of AKI and CKD in this vulnerable population. Larger prospective cohort studies with control groups which utilize recently proposed neonatal AKI definitions and standardized CKD definitions are much needed to properly quantify the risk of CKD following an episode of AKI. Until there is further evidence to guide us, we recommend that all neonates with an identified episode of AKI should have an appropriate longitudinal follow-up in order to identify CKD at its earliest stages.
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Injúria Renal Aguda/complicações , Progressão da Doença , Insuficiência Renal Crônica/etiologia , Injúria Renal Aguda/diagnóstico , Injúria Renal Aguda/fisiopatologia , Estudos de Casos e Controles , Estado Terminal , Humanos , Lactente , Recém-Nascido de Peso Extremamente Baixo ao Nascer , Recém-Nascido , Recém-Nascido Prematuro , Doenças do Prematuro , Unidades de Terapia Intensiva Neonatal , Glomérulos Renais/patologia , Estudos Longitudinais , Estudos Observacionais como Assunto , Modelos de Riscos Proporcionais , Insuficiência Renal Crônica/fisiopatologiaRESUMO
Our established interleukin-13 (IL-13) overexpression rat model of minimal change-like nephropathy provided a platform to study the molecular signalling pathways in T-helper 2 (Th2) cytokine associated minimal change nephrotic syndrome (MCNS). We hypothesized that IL-13 may act directly on podocytes, causing podocyte foot process effacement and hence proteinuria in our rat model of minimal change-like nephropathy. The present study aimed firstly to delineate the glomerular 'gene signature' associated with IL-13-mediated dysregulation of podocyte-related proteins, and subsequently to investigate the role of the differentially regulated genes (DEGs) in IL-13-mediated podocyte injury. Glomerular transcriptional profile of IL-13-overexpressed rats showed characteristic features of podocyte injury with 87% of podocyte-related genes being significantly down-regulated. Gene expression of Vav1 was shown to be highly up-regulated in the glomeruli of IL-13-overexpressed rats and pathway analysis of the DEGs suggested a possible novel role of Vav1 in podocyte cytoskeleton remodelling. Immunofluorescence examination demonstrated glomerular expression of Vav1 in rats which co-localized with synaptopodin, confirming podocyte expression. However, positive staining for the phosphorylated form of Vav1 (p-Vav1) was only seen in IL-13-overexpressed rats. Moreover, in vitro IL-13 stimulation of human podocytes resulted in phosphorylation of Vav1. This was associated with Rac1 activation and actin cytoskeleton rearrangement, which was abrogated in Vav1 knockdown podocytes. In conclusion, we have demonstrated the role of Vav1-Rac1 pathway characterized by phosphorylation of Vav1, activation of Rac1 and the subsequent actin cytoskeleton rearrangement in IL-13-induced podocyte injury, possibly explaining the podocyte foot process effacement seen in our IL-13 overexpression rat model.
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BACKGROUND: While the appearance of red clots in the dialyzer is a common phenomenon in every hemodialysis unit, the occurrence of white thrombi in the tubing is relatively rare. CASE PRESENTATION: We describe an adolescent male with recurrent white thrombi formation in the hemodialysis tubing. This patient had chronic renal failure from focal segmental glomerulosclerosis, but was no longer nephrotic at the time of the thrombi formation. He had a history of recurrent thrombosis of his vascular access. However, no pro-thrombotic risk factors could be identified. White particulate matter, measuring 1 to 3mm in size, and adherent to the arterial and venous blood tubing lines was found during the rinse back of a hemodialysis session. This was associated with a 60% decrease in his platelet count. Light microscopic examination of the deposits revealed the presence of platelet aggregates. He subsequently developed thrombosis of his arteriovenous graft six hours later. The white thrombi recurred at the next dialysis session, as well as six months later. These episodes occurred regardless of the type of dialysis machine or tubing, and appeared to resolve with an increase in heparin dose. CONCLUSION: Recurrent white thrombi formation can occur in the hemodialysis tubing of a patient with no identifiable pro-thrombotic factors. The white thrombi may be a harbinger of arteriovenous graft thrombosis and may be prevented by an increase in heparin dose.
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Falência Renal Crônica/terapia , Diálise Renal/efeitos adversos , Diálise Renal/instrumentação , Trombose/etiologia , Adolescente , Glomerulosclerose Segmentar e Focal/complicações , Humanos , Falência Renal Crônica/etiologia , Masculino , Recidiva , Dispositivos de Acesso Vascular/efeitos adversosRESUMO
INTRODUCTION: Health-related quality of life (HRQoL) studies demonstrate the impact of end-stage renal disease (ESRD) on the physical and psychosocial development of children. While several instruments are used to measure HRQoL, few have standardized domains specific to pediatric ESRD. This review examines current evidence on self and proxy-reported HRQoL among pediatric patients with ESRD, based on the Pediatric Quality of Life Inventory (PedsQL) questionnaires. METHODS: Following PRISMA guidelines, we conducted a systematic review and meta-analysis on HRQoL using the PedsQL 4.0 Generic Core Scale (GCS) and the PedsQL 3.0 ESRD Module among 5- to 18-year-old patients. We queried PubMed, Embase, Web of Science, CINAHL, and Cochrane databases. Retrospective, case-controlled, and cross-sectional studies using PedsQL were included. FINDINGS: Of 435 identified studies, 14 met inclusion criteria administered in several countries. Meta-analysis demonstrated a significantly higher total HRQoL for healthy patients over those with ESRD (SMD:1.44 [95% CI: 0.78-2.09]) across all dimensional scores. In addition, kidney transplant patients reported a significantly higher HRQoL than those on dialysis (PedsQL GCS, SMD: 0.33 [95% CI: 0.14-0.53]) and (PedsQL ESRD, SMD: 0.65 [95% CI: 0.39-0.90]) concordant with parent-proxy reports. DISCUSSION: Patients with ESRD reported lower HRQoL in physical and psychosocial domains compared with healthy controls, while transplant and peritoneal dialysis patients reported better HRQoL than those on hemodialysis. This analysis demonstrates the need to identify dimensions of impaired functioning and produce congruent clinical interventions. Further research on the impact of individual comorbidities in HRQoL is necessary for developing comprehensive, integrated, and holistic treatment programs.
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Falência Renal Crônica , Qualidade de Vida , Humanos , Falência Renal Crônica/terapia , Falência Renal Crônica/psicologia , Criança , Adolescente , Pré-Escolar , Masculino , Inquéritos e Questionários , Feminino , Diálise Renal/métodos , Diálise Renal/psicologiaRESUMO
BACKGROUND: Initiating continuous renal replacement therapy (CRRT) in infants exposes them to the dual hemodynamic challenges of high circuit extracorporeal volumes and potential membrane reactions, in the case of acrylonitrile AN69 membranes. The use of the new Prismaflex HF20 membrane in hemodynamically unstable low-body-weight infants on inotropic support has not been reported. TREATMENT: We describe the use of the HF20 (Gambro Lundia AB, Lund, Sweden) membrane in four low-body-weight infants (2.3 to 5.4 kg) with multi-organ dysfunction syndrome who were critically ill in the Pediatric Intensive Care Unit (PICU), hemodynamically unstable, and on inotropes. We were able to achieve target volume loss in all infants without compromising their hemodynamic status. Mean arterial pressures were maintained between 39 and 57 mmHg. The relatively low circuit volume of the HF20 set (60 ml) obviated the need for blood prime in the majority; however, when blood prime was required, there was no adverse reaction with the polyarylethersulfone (PAES) membrane. Solute clearance in these small infants was efficient with correction of metabolic acidosis and electrolyte abnormalities. Excellent circuit lifespan (56.3 ± 32.3 h) was observed. CONCLUSIONS: CRRT using the HF20 membrane is safe and hemodynamically well tolerated in high-risk, unstable low-body-weight infants with cardiac dysfunction on multiple inotropes.
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Injúria Renal Aguda/terapia , Peso Corporal , Cardiotônicos/uso terapêutico , Hemodiafiltração/instrumentação , Hemodinâmica/efeitos dos fármacos , Membranas Artificiais , Insuficiência de Múltiplos Órgãos/terapia , Polímeros , Sulfonas , Injúria Renal Aguda/diagnóstico , Injúria Renal Aguda/fisiopatologia , Pressão Arterial/efeitos dos fármacos , Cardiotônicos/efeitos adversos , Estado Terminal , Desenho de Equipamento , Oxigenação por Membrana Extracorpórea , Hemodiafiltração/efeitos adversos , Humanos , Lactente , Unidades de Terapia Intensiva Pediátrica , Insuficiência de Múltiplos Órgãos/diagnóstico , Insuficiência de Múltiplos Órgãos/fisiopatologia , Resultado do TratamentoRESUMO
Long-term humoral immunity is mediated by short-lived plasma cells (replenished by memory B cells) and long-lived plasma cells. Their relative contributions are uncertain for immunity to SARS-CoV-2, especially given the widespread use of novel mRNA vaccines. Yet, this has far-reaching implications in terms of the need for regular booster doses in the general population and perhaps even revaccination in patients receiving B cell-depleting therapy. We aimed to characterise anti-SARS-CoV-2 antibody titres in patients receiving Rituximab following previous SARS-CoV-2 vaccination. We recruited 10 fully vaccinated patients (age: 16.9 ± 2.52 years) with childhood-onset nephrotic syndrome, not in relapse, receiving Rituximab for their steroid/calcineurin-inhibitor sparing effect. Antibodies to SARS-CoV-2 spike (S) and nucleocapsid (N) proteins were measured immediately prior to Rituximab and again ~6 months later, using the Roche Elecys® Anti-SARS-CoV-2 (S) assay. All ten patients were positive for anti-S antibodies prior to Rituximab, with six patients (60%) having titres above the upper limit of detection (>12,500 U/mL). Following Rituximab therapy, there was a reduction in anti-S titres (p = 0.043), but all patients remained positive for anti-S antibodies, with five patients (50%) continuing to have titres >12,500 U/mL. Six patients (60%) were positive for anti-N antibodies prior to Rituximab. Following Rituximab therapy, only three of these six patients remained positive for anti-N antibodies (p = 0.036 compared to anti-S seroreversion). Humoral immunity to SARS-CoV-2 is likely to be mediated in part by long-lived plasma cells.
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Paracrine signaling between podocytes and glomerular endothelial cells through vascular endothelial growth factor A (VEGFA) maintains a functional glomerular filtration barrier. Heparan sulfate proteoglycans (HSPGs), located on the cell surface or in the extracellular matrix, bind signaling molecules such as VEGFA and affect their local concentrations, but whether modulation of these moieties promotes normal crosstalk between podocytes and endothelial cells is unknown. Here, we found that the transcription factor Wilms' Tumor 1 (WT1) modulates VEGFA and FGF2 signaling by increasing the expression of the 6-O-endosulfatases Sulf1 and Sulf2, which remodel the heparan sulfate 6-O-sulfation pattern in the extracellular matrix. Mice deficient in both Sulf1 and Sulf2 developed age-dependent proteinuria as a result of ultrastructural abnormalities in podocytes and endothelial cells, a phenotype similar to that observed in children with WT1 mutations and in Wt1(+/-) mice. These kidney defects associated with a decreased distribution of VEGFA in the glomerular basement membrane and on endothelial cells. Collectively, these data suggest that WT1-dependent sulfatase expression plays a critical role in maintaining the glomerular filtration barrier by modulating the bioavailability of growth factors, thereby promoting normal crosstalk between podocytes and endothelial cells.
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Glomérulos Renais/enzimologia , Sulfatases/metabolismo , Sulfotransferases/metabolismo , Proteínas WT1/metabolismo , Animais , Comunicação Celular , Fator 2 de Crescimento de Fibroblastos/metabolismo , Regulação da Expressão Gênica , Heterozigoto , Humanos , Camundongos , Camundongos da Linhagem 129 , Camundongos Endogâmicos C57BL , Mutação , Permeabilidade , Regiões Promotoras Genéticas , Fator A de Crescimento do Endotélio Vascular/metabolismoRESUMO
Advances in kidney genomics in the past 20 years has opened the door for more precise diagnosis of kidney disease and identification of new and specific therapeutic agents. Despite these advances, an imbalance exists between low-resource and affluent regions of the world. Individuals of European ancestry from the United States, United Kingdom, and Iceland account for 16% of the world's population, but represent more than 80% of all genome-wide association studies. South Asia, Southeast Asia, Latin America, and Africa together account for 57% of the world population but less than 5% of genome-wide association studies. Implications of this difference include limitations in new variant discovery, inaccurate interpretation of the effect of genetic variants in non-European populations, and unequal access to genomic testing and novel therapies in resource-poor regions. It also further introduces ethical, legal, and social pitfalls, and ultimately may propagate global health inequities. Ongoing efforts to reduce the imbalance in low-resource regions include funding and capacity building, population-based genome sequencing, population-based genome registries, and genetic research networks. More funding, training, and capacity building for infrastructure and expertise is needed in resource-poor regions. Focusing on this will ensure multiple-fold returns on investments in genomic research and technology.
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Estudo de Associação Genômica Ampla , Insuficiência Renal Crônica , Humanos , Estados Unidos , América Latina , África/epidemiologia , Genômica , Insuficiência Renal Crônica/genéticaRESUMO
Peritonitis- and catheter-related infections due to nontuberculous mycobacteria (NTM) including Mycobacterium abscessus have been reported among adults on peritoneal dialysis (PD). There is no recommended antimicrobial regimen for the treatment of M. abscessus peritonitis. Clofazimine has emerged as an important adjuvant antimicrobial treatment of M. abscessus lung infection. We report, to our knowledge, the first case of M. abscessus PD peritonitis in a child treated successfully using clofazimine as a novel adjuvant therapy to amikacin and clarithromycin. Her clinical features were similar to those of bacterial peritonitis, but she had persistence of symptoms and high inflammatory markers despite empirical therapy for peritonitis. Bacterial culture of PD effluent became positive for M. abscessus after 5 days. There was complete symptom resolution after 6 days of multidrug therapy. Due to ototoxicity, amikacin was discontinued after 6 weeks, while clarithromycin and clofazimine were continued for 9 months to ensure complete pathogen eradication before a planned renal transplant. A high index of suspicion in refractory or culture-negative cases is important for the diagnosis of NTM peritonitis. Multidrug therapy is recommended for M. abscessus infections. Clofazimine was chosen as a novel adjunct antimicrobial because of its pharmacokinetics, ease of administration, cost-effectiveness, and lack of serious adverse events.
Assuntos
Infecções por Mycobacterium não Tuberculosas , Mycobacterium abscessus , Diálise Peritoneal , Peritonite , Adulto , Criança , Clofazimina/uso terapêutico , Quimioterapia Combinada , Feminino , Humanos , Hansenostáticos/uso terapêutico , Infecções por Mycobacterium não Tuberculosas/diagnóstico , Infecções por Mycobacterium não Tuberculosas/tratamento farmacológico , Diálise Peritoneal/efeitos adversos , Peritonite/diagnóstico , Peritonite/tratamento farmacológico , Peritonite/etiologiaRESUMO
Rituximab is an important second line therapy in difficult nephrotic syndrome (NS), especially given toxicity of long-term glucocorticoid or calcineurin inhibitor (CNI) use. However, clinical response to rituximab is heterogenous. We hypothesized that this was underpinned by immunological differences amongst patients with NS. We recruited a cohort of 18 subjects with glucocorticoid-dependent or glucocorticoid-resistant childhood-onset minimal change NS who received rituximab either due to CNI nephrotoxicity, or due to persistent glucocorticoid toxicity with inadequate response to cyclophosphamide or CNIs. Immunological subsets, T-cell activation assays and plasma cytokines were measured at baseline and 6-months post-rituximab. Time to relapse was bifurcated: 56% relapsed within one year ("early relapse"), while the other 44% entered remission mainly lasting ≥3 years ("sustained remission"). At baseline, early relapse compared to sustained remission group had lower regulatory T-cells (Tregs) [2.94 (2.25, 3.33)% vs 6.48 (5.08, 7.24)%, P<0.001], PMA-stimulated IL-2 [0.03 (0, 1.85)% vs 4.78 (0.90, 9.18)%, P=0.014] and IFNγ [2.22 (0.18, 6.89)% vs 9.47 (2.72, 17.0)%, P=0.035] levels. Lower baseline Treg strongly predicted early relapse (ROC-AUC 0.99, 95% CI 0.97-1.00, P<0.001). There were no differences in baseline plasma cytokine levels. Following rituximab, there was significant downregulation of Th2 cytokines in sustained remission group (P=0.038). In particular, IL-13 showed a significant decrease in sustained remission group [-0.56 (-0.64, -0.35)pg/ml, P=0.007)], but not in the early relapse group. In conclusion, early relapse following rituximab is associated with baseline reductions in Treg and T-cell hyporesponsiveness, which suggest chronic T-cell activation and may be useful predictive biomarkers. Sustained remission, on the other hand, is associated with downregulation of Th2 cytokines following rituximab.
Assuntos
Nefrose Lipoide/tratamento farmacológico , Rituximab/uso terapêutico , Linfócitos T Reguladores/efeitos dos fármacos , Adolescente , Adulto , Inibidores de Calcineurina/uso terapêutico , Criança , Pré-Escolar , Citocinas/sangue , Feminino , Glucocorticoides/uso terapêutico , Humanos , Ativação Linfocitária/efeitos dos fármacos , Masculino , Nefrose Lipoide/imunologia , Recidiva , Rituximab/farmacologia , Linfócitos T Reguladores/imunologia , Adulto JovemAssuntos
Infecções por Vírus Epstein-Barr , Herpesvirus Humano 4/imunologia , Falência Renal Crônica/cirurgia , Transplante de Rim , Transtornos Linfoproliferativos , Segunda Neoplasia Primária , Adolescente , Linfócitos B/imunologia , Infecções por Vírus Epstein-Barr/etiologia , Infecções por Vírus Epstein-Barr/imunologia , Infecções por Vírus Epstein-Barr/terapia , Feminino , Humanos , Falência Renal Crônica/imunologia , Transtornos Linfoproliferativos/etiologia , Transtornos Linfoproliferativos/imunologia , Transtornos Linfoproliferativos/terapia , Transtornos Linfoproliferativos/virologia , Segunda Neoplasia Primária/etiologia , Segunda Neoplasia Primária/imunologia , Segunda Neoplasia Primária/terapia , Segunda Neoplasia Primária/virologia , Linfócitos T/imunologiaRESUMO
Chronic peritoneal dialysis (PD) for children in Singapore was instituted in 1988 at the National University Hospital with adult nurses providing dialysis services during the first 10 years. In 1998, a specialist pediatric dialysis nursing team was recruited. This study was conducted to determine the impact of dialysis nursing service on PD-related outcomes during the two nursing periods. Comparing the adult (group 1) and pediatric (group 2) nursing periods, the peritonitis rate was significantly higher in group 1 (RR 1.90; 95%CI 1.27-2.84), and this association did not weaken after adjusting for age, gender, and exit site infections. Exit site infection rate (RR 2.16; 95%CI 1.44-3.23), risk of peritonitis during the first year (RR 3.65; 95%CI 1.68-7.90), and multiple peritonitis attacks (RR 2.45; 95%CI 1.32-4.55) were higher in group 1. The peritonitis rates for adult patients cared for by the same adult nurses declined sharply from 1.05 episodes per patient-year between 1989 and 1992 to 0.41 episodes per patient-year between 1995 and 1997, however the corresponding pediatric rates did not change (1.48 to 1.06 episodes per patient-year, respectively) until the second era when specialized pediatric nurses were available. In conclusion, establishment of a specialist pediatric dialysis nursing team resulted in significant improvement in infection-related PD outcomes.