NPHS1 gene mutations confirm congenital nephrotic syndrome in four Brazilian cases: A novel mutation is described.

AIM: Autosomal recessive mutations in NPHS1 gene are a common cause of congenital nephrotic syndrome (CNS). The disorder is characterized by massive proteinuria that manifests in utero or in the neonatal period during the first 3 months of life. NPHS1 encodes nephrin, a member of the immunoglobulin family of cell adhesion molecules and the main protein expressed at the renal slit diaphragm. Currently, there are approximately 250 mutations described in the NPHS1 gene distributed among all nephrin domains. The main objective of this study was to perform the analysis of the NPHS1 gene in patients with congenital nephrotic syndrome in order to determine the molecular cause of the disease. METHODS: Direct sequencing of NPHS1 gene in four children was performed. RESULTS: Each patient was heterozygous for two pathogenic mutations disclosing the molecular cause of the disease in 100% of the cases. We identified six different mutations, consisting of one in-frame deletion, one frameshift, and four missense substitutions. The p.Val736Met mutation that is described here for the first time was considered pathogenic by different mutation predictive algorithms. Regardless of the type of mutation, three patients had a bad outcome and died CONCLUSIONS: Despite the small size of the cohort, this study contributed to the increasing number of deleterious mutations in the NPHS1 gene by describing a new mutation. Also, since we identified NPHS1 pathogenic mutations as the cause of the disease in all cases analyzed, it might be a frequent cause of CNS in the South Eastern region of Brazil, although the analysis of a larger sample is required to obtain more indicative epidemiological data.

NPHS2 mutations account for only 15% of nephrotic syndrome cases.

BACKGROUND: Nephrotic syndrome is traditionally classified on the basis of the response to standard steroid treatment. Mutations in more than 24 genes have been associated with nephrotic syndrome in children, although the great majority of steroid-resistant cases have been attributed to mutations in three main genes: NPHS1, NPHS2 and WT1. The aims of this study were to identify mutations in these genes more frequently reported as mutated and to characterize each variation using different in silico prediction algorithms in order to understand their biological functions. METHODS: We performed direct sequence analysis of exons 8 and 9 of WT1, 8 exons of NPHS2 and 29 exons of NPHS1, including NPHS2 and NPHS1 intron-exon boundary sequences, as well as 700 bp of the 5' UTR from both genes in 27 steroid-resistant patients aged between 3 months and 18 years. RESULTS: Analysis of the NPHS2 gene revealed four missense mutations, one frameshift mutation and three variations in the 5' UTR. Four patients presented compound heterozygosis, and four other patients presented one heterozygous alteration only. WT1 and NPHS1 gene analysis did not reveal any mutations. DISCUSSION: This is the first study focusing on genetics of SRNS in Brazilian children. Identification of mutations is important because it could influence physicians' decision on patient treatment, as patients carrying mutations can be spared the side effects of immunosuppressive therapy and ultimately could be considered for kidney transplantation from a living donor. CONCLUSIONS: After molecular analysis of the genes more frequently reported as mutated in 27 steroid-resistant nephrotic syndrome patients, we identified NPHS2 mutations confirming the hereditary character of the kidney disease in only 14.8% of patients. Therefore, the next step is to perform a next generation sequencing based analysis of glomeluropathy-related panel of genes for the remaining patients in order to search for mutations in other genes related to steroid-resistant nephrotic syndrome.

Two distinct WT1 mutations identified in patients and relatives with isolated nephrotic proteinuria.

Wilms' tumor type 1 gene (WT1) encodes a zinc-finger transcription factor that plays a key role during genitourinary development and in adult kidney. Mutations in exons 8 and 9 are associated with Denys-Drash Syndrome, whereas those occurring in the intron 9 donor splice site are associated with Frasier Syndrome. Familial cases of WT1 mutations are rare with only few cases described in the literature, whereas cases of WT1 mutations associated with isolated nephrotic proteinuria with or without focal segmental glomerular sclerosis (FSGS) are even rarer. Exons 8 and 9 of WT1 gene were analyzed in two non-related female patients and their parents. Patient 1, who presented with isolated nephrotic proteinuria and histologic pattern of FSGS, is heterozygous for the mutation c.1227+4C>T. This mutation was inherited from her mother, who had undergone kidney transplant due to FSGS. Patient 2 is heterozygous for the novel c.1178C>T transition inherited from her father. The putative effect of this nucleotide substitution on WT1 protein is p.Ser393Phe mutation located within the third zinc-finger domain. The patient and her father presented, respectively, isolated nephrotic proteinuria and chronic renal failure. These data highlight the importance of the inclusion of WT1 gene mutational analysis in patients with isolated nephrotic proteinuria, especially when similar conditions are referred to the family.

Prospective cohort analyzing risk factors for chronic kidney disease progression in children.

OBJECTIVE: To identify risk factors for chronic kidney disease progression in Brazilian children and to evaluate the interactions between factors. METHODS: This was a multicenter prospective cohort in São Paulo, involving 209 children with CKD stages 3-4. The study outcome included: (a) death, (b) start of kidney replacement therapy, (c) eGFR decrease >50% during the followup. Thirteen risk factors were tested using univariate regression models, followed by multivariable Cox regression models. The terms of interaction between the variables showing significant association with the outcome were then introduced to the model. RESULTS: After a median follow-up of 2.5 years (IQR=1.4-3.0), the outcome occurred in 44 cases (21%): 22 started dialysis, 12 had >50% eGFR decrease, seven underwent transplantation, and three died. Advanced CKD stage at onset (HR=2.16, CI=1.14-4.09), nephrotic proteinuria (HR=2.89, CI=1.49-5.62), age (HR=1.10, CI=1.01-1.17), systolic blood pressure Z score (HR=1.36, CI=1.08-1.70), and anemia (HR=2.60, CI=1.41-4.77) were associated with the outcome. An interaction between anemia and nephrotic proteinuria at V1 (HR=0.25, CI=0.06-1.00) was detected. CONCLUSIONS: As the first CKD cohort in the southern hemisphere, this study supports the main factors reported in developed countries with regards to CKD progression, affirming the potential role of treatments to slow CKD evolution. The detected interaction suggests that anemia may be more deleterious for CKD progression in patients without proteinuria and should be further studied.

NPHS2 Mutations: A Closer Look to Latin American Countries.

Nephrotic syndrome is one of the most common kidney pathologies in childhood, being characterized by proteinuria, edema, and hypoalbuminemia. In clinical practice, it is divided into two categories based on the response to steroid therapy: steroid-sensitive and steroid resistant. Inherited impairments of proteins located in the glomerular filtration barrier have been identified as important causes of nephrotic syndrome, with one of these being podocin, coded by NPHS2 gene. NPHS2 mutations are the most frequent genetic cause of steroid resistant nephrotic syndrome. The aim of this review is to update the list of NPHS2 mutations reported between June 2013 and February 2017, with a closer look to mutations occurring in Latin American countries.

WT1 Haploinsufficiency Supports Milder Renal Manifestation in Two Patients with Denys-Drash Syndrome.

Denys-Drash syndrome (DDS) is characterized by nephropathy, genital abnormalities, and predisposition to Wilms' tumor. DDS patients usually present heterozygous de novo germline WT1 mutations. The WT1 gene comprises 10 exons encoding the N-terminal transactivation and the C-terminal DNA-binding regions. Two unrelated patients with genital ambiguity and Wilms' tumor were analyzed by sequencing of the WT1 gene, and 3 mutations in exon 1 were identified of which 2 are novel. Patient 1 carried a c.555delC mutation that causes a frameshift and a premature stop codon. Patient 2 carried both c.421A>C and c.424C>T aberrations that lead to the missense p.Lys141Gln and the nonsense p.Lys142* mutation, respectively. As both patients were heterozygous for the mutations, we tested their parents who did not carry any mutation. Therefore, the 3 WT1 mutations occurred de novo in both patients. Heterozygous mutations result in WT1 haploinsufficiency as they impair protein production. They are associated with a milder DDS phenotype as observed in the patients studied here.

[Hypercalcemia and multiple osteolytic lesions in a child with disseminated paracoccidioidomycosis and pulmonary tuberculosis]. / Hipercalcemia e lesões osteolíticas múltiplas em criança com paracoccidioidomicose disseminada e tuberculose pulmonar.

OBJECTIVE: To describe the case of a child with paracoccidioidomycosis who presented hypercalcemia with multiple osteolytic lesions. DESCRIPTION: A 6-year-old boy was admitted with a one-month history of fever and hepatosplenomegaly. On admission, he looked sick, pale, and had disseminated lymphadenopathy and hepatosplenomegaly. The laboratory findings included anemia (hemoglobin = 6.8 g/dl), eosinophilia (1,222/mm3), thrombocytopenia (102,000/mm3), and hypoalbuminemia (serum albumin = 2.2 g/dl). Paracoccidioides brasiliensis was identified in bone marrow examination. In the second week after admission, the patient presented joint pain, poor activity and difficulty in walking. He presented hypercalcemia (maximum value = 14.9 mg%) and reduction in renal function, which lasted for two weeks. On the 42nd day after admission, his chest X-ray showed lytic lesions in clavicle, scapula, ribs, and humerus, with bilateral slipped capital humeral epiphysis. The patient presented nephrocalcinosis and nephrolithiasis, reduction in creatinine clearance and evidence of tubular lesions. At the end of the second month after admission, Mycobacterium tuberculosis was isolated in gastric washing. The child received treatment for paracoccidioidomycosis and tuberculosis and has not had any sequelae for 3 years. COMMENTS: The development of symptomatic hypercalcemia leading to renal lesion, associated with multiple osteolytic lesions, had never been described in paracoccidioidomycosis. Although pulmonary tuberculosis was diagnosed and could be related to hypercalcemia, the sudden onset of hypercalcemia and its normalization without specific treatment for tuberculosis suggests that bone lysis was the most important factor in the genesis of hypercalcemia.

Prospective cohort analyzing risk factors for chronic kidney disease progression in children / Coorte prospectiva que analisa os fatores de risco para progressão de doença renal crônica (DRC) em crianças

Abstract Objective: To identify risk factors for chronic kidney disease progression in Brazilian children and to evaluate the interactions between factors. Methods: This was a multicenter prospective cohort in São Paulo, involving 209 children with CKD stages 3-4. The study outcome included: (a) death, (b) start of kidney replacement therapy, (c) eGFR decrease >50% during the followup. Thirteen risk factors were tested using univariate regression models, followed by multivariable Cox regression models. The terms of interaction between the variables showing significant association with the outcome were then introduced to the model. Results: After a median follow-up of 2.5 years (IQR = 1.4-3.0), the outcome occurred in 44 cases (21%): 22 started dialysis, 12 had >50% eGFR decrease, seven underwent transplantation, and three died. Advanced CKD stage at onset (HR = 2.16, CI = 1.14-4.09), nephrotic proteinuria (HR = 2.89, CI = 1.49-5.62), age (HR = 1.10, CI = 1.01-1.17), systolic blood pressure Z score (HR = 1.36, CI = 1.08-1.70), and anemia (HR = 2.60, CI = 1.41-4.77) were associated with the outcome. An interaction between anemia and nephrotic proteinuria at V1 (HR = 0.25, CI = 0.06-1.00) was detected. Conclusions: As the first CKD cohort in the southern hemisphere, this study supports the main factors reported in developed countries with regards to CKD progression, affirming the potential role of treatments to slow CKD evolution. The detected interaction suggests that anemia may be more deleterious for CKD progression in patients without proteinuria and should be further studied.

Resumo Objetivo: Identificar os fatores de risco para progressão da DRC em crianças do Brasil e avaliar as interações entre os fatores. Métodos: Coorte prospectiva multicêntrica em São Paulo, envolvendo 209 crianças com DRC em estágios 3-4. O desfecho do estudo incluiu: a) óbito, b) início da terapia de substituição renal, c) redução de > 50% na taxa estimada de filtração glomerular (eGFR) durante o acompanhamento. Foram testados 13 fatores de risco com o modelo de regressão univariada seguido do modelo de regressão multivariado de Cox. Os termos de interação entre as variáveis mostraram associação significativa e foram introduzidos ao modelo. Resultados: Após média de acompanhamento de 2,5 anos (IIQ = 1,4 a 3,0), 44 casos (21%) apresentaram desfecho: 22 iniciaram diálise, 12 apresentaram redução de > 50% na eGFR, sete foram submetidos a transplante e três morreram. Estágio avançado de DRC no acometimento (RR = 2,16, IC = 1,14-4,09), proteinúria nefrótica (RR = 2,89, IC = 1,49-5,62), idade (RR - 1,10, IC = 1,01-1,17), escore Z da pressão arterial sistólica (RR = 1,36, IC = 1,08-1,70) e anemia (RR = 2,60, IC - 1,41-4,77) foram associados ao resultado. Foi detectada interação entre anemia e proteinúria nefrótica na primeira visita (V1) (RR = 0,25, IC = 0,06-1,00). Conclusões: Como a primeira coorte de DRC no hemisfério sul, este estudo é concordante com os principais fatores relatados em países desenvolvidos com relação à progressão da DRC, afirmando o possível papel dos tratamentos para mostrar a evolução da DRC. A interação detectada sugere que a anemia pode ser mais nociva na progressão da DRC em pacientes sem proteinúria e deve ser ainda mais estudada.

Plasmaférese como tratamento de glomeruloesclerose segmentar focal (GESF) recorrente após transplante renal. Relato de caso e revisão da literatura / Plasmapheresis as a therapy for relapsed focal segmental glomerulosclerosis (FSGS) after kidney transplantation: case report and a review of the literature

A glomerulosclerose segmentar focal (GESF) é uma doença renal caracterizada por síndrome nefrótica, com freqüente progressão para insuficiência renal terminal. Nesta fase, o transplante renal, tanto com doador cadáver como intervivos, aparece como a única opção terapêutica para esses pacientes. Contudo, após o transplante renal, a taxa de recorrência de GESF é alta, chegando até 50 por cento dos casos. Nesta situação, a causa parece estar relacionada a um "fator humoral" circulante, responsável pelo aumento da permeabilidade glomerular. A remoção desse "fator humoral", por meio da plasmaférese terapêutica, aparece como uma boa opção de tratamento para esses pacientes. Neste artigo descreveremos o caso de um paciente masculino de 12 anos de idade, com diagnóstico de glomeruloesclerose segmentar focal recorrente após transplante renal, submetido a tratamento com plasmaférese. Após cinco sessões o paciente evoluiu com melhora sustentada da função renal. O uso de plasmaférese para tratamento da glomeruloesclerose segmentar focal pré e pós-transplante renal ainda é limitado, a maioria dos estudos apresentando resultados de curto prazo ou com pequeno número de pacientes. Alguns fatores preditivos de boa resposta ao tratamento têm sido identificados por diversos autores, dentre eles o início precoce do tratamento após a recorrência e a baixa idade. O número de sessões necessárias para atingir a remissão varia bastante e deve ser determinado individualmente. Outra possibilidade apresentada pelos autores é a plasmaférese profilática, não sendo possível até agora determinar sua eficácia. O caso apresentado é um exemplo de glomeruloesclerose recorrente com ótima resposta a plasmaférese terapêutica, evidenciando o potencial dessa modalidade de tratamento nesta situação e reforçando a necessidade de mais estudos.

Focal segmental glomerulosclerosis (FSGS) is a renal disease characterized by a nephrotic syndrome frequently evolving to end-stage renal failure. At this stage, renal transplantation, using either cadaver or live donors, is the only therapeutic option. However, after renal transplantation relapse is high, at a rate of 50 percent on average. The cause seems to be related to a peripheral humoral factor responsible for increasing glomerular permeability. The clearance of this factor by apheresis is today considered a good therapeutic option. We describe the case of a 12-year-old male patient, with relapsed FSGS after renal transplantation, who was treated by plasmapheresis. After five procedures a sustained improvement in the renal function was obtained. Reports published on plasmapheresis for the treatment of FSGS before and after renal transplantation are still limited to short-term results involving a small number of patients. Some predictive factors for good responses were identified by several investigators including the early start of treatment after relapse and lower ages. The number of plasmapheretic procedures to reach remission varies widely, and should be determined on a case to case basis. Another possibility presented by some investigators is prophylactic plasmapheresis, but this still lacks evidence on efficacy. This case report is an example of FSGS with a good response to plasmapheretic procedures, showing a potential benefit of this treatment. However, further controlled studies involving a higher number of patients are necessary.

Hipercalcemia e lesões osteolíticas múltiplas em crianca com paracoccidioidomicose disseminada e tuberculose pulmonar / Hypercalcemia and multiple osteolytic lesions in a child with disseminated paracoccidioidomycosis and pulmonary tuberculosis

OBJETIVO: Descrever o caso de uma crianca com paracoccidioidomicose, que apresentou hipercalcemia associada a múltiplas lesões osteolíticas. DESCRIÇAO: Menino de 6 anos, internado com história de febre e hepatoesplenomegalia há 1 mês. A internacão, apresentava-se em regular estado geral, descorado, com linfonodomegalia generalizada e hepatoesplenomegalia. Os exames laboratoriais identificaram anemia (hemoglobina = 6,8 g/dl), eosinofilia (1.222/mm ), plaquetopenia (102.000/mm ) e hipoalbuminemia (albumina = 2,2 g/dl). Paracoccidioides brasiliensis foi identificado no mielograma. A partir da segunda semana de internacão, apresentou artralgia, hipoatividade e dificuldade à deambulacão, sendo constatada hipercalcemia (dosagem máxima de 14,9 mg por cento) e reducão da funcão renal, que duraram pouco mais de 2 semanas. No 42º dia de internacão, foram vistas, na radiografia de tórax, múltiplas lesões líticas em clavículas, escápulas, costelas e úmeros, com escorregamento epifisário de úmero bilateral. Apresentou nefrocalcinose e nefrolitíase, com reducão no clearance de creatinina e evidências de lesão tubular. No final do segundo mês de internacão, na cultura do lavado gástrico, foi identificado Mycobacterium tuberculosis. Recebeu tratamento para paracoccidioidomicose e tuberculose e está há mais de 3 anos em acompanhamento, sem nenhuma seqüela. COMENTARIOS: O desenvolvimento da hipercalcemia sintomática, levando à lesão renal e associada a lesões ósseas múltiplas e disseminadas, nunca foi descrito em paracoccidioidomicose. Embora tenha sido diagnosticada tuberculose pulmonar, que pode estar relacionada à hipercalcemia, a forma abrupta como se instalou e como se normalizou sem o tratamento específico para tuberculose sugere que a lise óssea foi o fator mais importante na gênese da hipercalcemia.

Avaliaçäo de microalbuminúria em crianças saudáveis / Evaluation of microalbuminuria in healthy children

O uso de microalbuminúria como marcador de nefropatiadiabética e como determinante da progressäo da lesäo renal tem sido largamente estudado. O presente estudotem como objetivo estudar a distribuiçäo dos valores de microalbuminúria em crianças saudáveis de 6 a 16 anos de idade, com a finalidade de se obter valor(es) crítico(s) de normalidade. Para se determinar a excreçäo urinária de albumina (AER), foram avaliadas 76 crianças de ambos os sexos, de 6 a 16 anos, com peso, altura e pressäo arterial adequados à idade e ao sexo, sem antecedente de doença renal, comcreatinina sérica e sedimento urinário normais. A AERfoi avaliada em duas amostras noturnas de urina através de radioimunoensaio. Os dados de microalbuminúria foram transformados em logaritmos para análise. Näo houve diferenças significativas entre os sexos, ocorrendo diferença significativa quanto à faixa etária. Considerando-se o percentil 95 como discriminatório, osvalores do P95 para crianças de 6 aos 11 anos, inclusive, foi de até 8,70ug/mn e para faixa dos 12 a 16 anos, inclusive, foi de até 10,85 ug/min. A partir da definiçäo dos valores discriminados de microalbuminúria para a faixa pediátrica torna-se possível utiliza-los como referência para estudos posteriores

Avaliaçäo do estado nutricional e do crescimento de crianças e adolescentes com insuficiencia renal crônica / Nutritional evaluation condition and the growth of the children and adolescent it chronic renal failure

Com o objetivo de avaliar o estado nutrticional de 43 pacientes(23M/20F), com idade de 1,6 a 20 anos, com insuficiencia renal crônica (IRC) acompanhados no Ambulatório de Nefrologia Pediátrtica da FCM da Unicamp, estudou-se o escore z dos indicadores altura/idade (A/I), peso/idade (P/I) e peso/altura (P/A). O clearance de creatininavariou de 0 a 46 ml/min/1,73 metros quadrados, sendo a mediana de 8,00. Encontram-se 41,9 poecento com escore z de A/I abaixo de -3,0 e 60,5 porcento abaixo de -2,0, e para o indicador P/A, apenas, um menor que -2,0. Esta distribuiçäo muito comprometida para a A/I e praticamente normal para P/A demonstra um estado nutricional bom, com repercussäo negativa sobre a estatura decorrente da longa duraçäo da doença. Para determinar quais fatores estariam associados com o comprometimento da estatura, foram avaliados parâmetros socioeconômicos (renda familiar per capita e escolaridade materna), clínicos (idade, sexo, raça,idade ao diagnóstico IRC, tempo de IRC, diagnóstico etiológico e tratamento) e laboratoriais (clearance de creatinina, hemoglobina, cálcio, fósforo inorgânico, fosfatase alcalina, pH e bicarbonato) em relaçäo ao indicador A/I. A distribuiçäo dos escores z de A/I apresentou diferença estatísticamente significante em relaçäo ao sexo e a etiologia, com maior comprometimento no sexo masculino e nos pacientes com cistinose.. A cistinose teria maior impacto no ccrescimento por ser uma patologia congênita com graves distúrbios metabólicos.(au)

Papel da bacterioscopia da urina como triagem na solicitação de urocultura em serviço de atenção primária / Bacterioscopy of urine and urine culture

Avaliar as correlações entre os sinais e/ou sintomas que levaram o médico a suspeitar de ITU com os resultados da leucocitúria, bacterioscopia e urocultura. Avaliar o papel da bacterioscopia como exame de triagem para a solicitação de urocultura. Foram estudas, prospectivamente, por 12 meses, todas as crianças com suspeita de infecção do trato urinário (ITU), encaminhadas de serviços de atenção primária de saúde para coleta de urocultura (98 episódios em 78 crianças de um mês a 10 anos de idade). O método de obtenção da amostra foi rigorosamente padronizado para a coleta por meio do saco coletor ou jato intermediário, reproduzindo o que habitualmente ocorre nos serviços de atenção primária. A análise da bacterioscopia foi realizada em amostra de urina não centrifugada e corada pelo método de gram. As causas mais freqüentes de indicação de pesquisa de ITU foram: baixo ganho ponderal (n=31/98), febre isolada ou associada a outros sintomas (n=28/98) e queixas urinárias (n=22/98). Somente dez uroculturas foram positivas (10,2 por cento), havendo um número significativo de amostras contaminadas (n=19/98). Os resultados da bacterioscopia demonstraram que não houve casos de falso negativo, sendo a sensibilidade do método de 84,1 por cento e a especificidade de 100 por cento. Poderia haver uma redução de 63 por cento na solicitação de urocultura em casos com suspeita clínica de ITU, recomendando a sua solicitação somente quando a bacterioscopia fosse positiva ou inconclusiva.

Abcessso cerebral na infância: relato de 10 casos / Brain abscess in childhren: A ten cases report

Objetivo: Sendo o abscesso cerebral raro na infância, com alto coeficiente de mortalidaade, o objetivo deste trabalho é o de relatar a evoluçäo clínica de 10 crianças com diagnóstico de abscesso cerebral internadas na Enfermaria de Pediatria do Hospital de Clínicas da Faculdade de Ciências Médicas da Universidade Estadual de Campinas. Métodos: No período de Janeiro de 1986 a Julho de 1995, foram revistos os prontuários dos pacientes com diagnósticos de abscesso cerebral. Na revisäo foram analisados os seguintes dados: idade, sexo, manifestaçöes clínicas, exame físico, achados de exames radiológicos, agente etiológico, tratamento, complicaçöes e evoluçäo dos pacientes. Resultados A idade das crianças variou de 2 a 13 anos (mediana 3 anos), sendo 6 do sexo feminino. Predominaram as manifestaçöes neurológicas, e dois pacientes apresentaram antecedente de infecçäo otorrinolaringológica (otite média crônica e sinusite). Outros dois pacientes eram portadores de cardiopatia congênita cianótica(Tetratologia de Fallot e estenose pulmonar com comunicaçäo interventricular). O diagnóstico e acompanhamento foi realizado com tomografia computadorizada de crânio...