Nephrotic syndrome in the 1st year of life

Abstract

Among the various primary conditions which may be associated with a nephrotic syndrome at birth or within the 1st year of life, the best known is the congenital nephrotic syndrome of finnish type (CNF) characterized by irregular pseudocystic dilatation of proximal tubules. This disease, very frequent in Finland, is often familial with an autosomal recessive mode of inheritance. Patients are steroid resistant, but the cause of death is usually not uraemia but infection or severe diarrhoea with electrolyte imbalance. The second condition is idiopathic nephrosis including minimal change disease, diffuse mesangial proliferation and focal segmental glomerular sclerosis. As opposed to CNF, infants with "early onset nephrosis" may respond to steroid therapy as older children do and may even recover. However, there are no histopathological criteria which allow the certain differentiation of idiopathic nephrosis from CNF. The third condition is diffuse mesangial sclerosis (DMS), a clinicopathological entity which can occur as an isolated finding or be associated with male pseudohermaphroditism and/or Wilms' tumour (Drash syndrome). From a morphological point of view, DMS is easy to differentiate from CNF because of the characteristic pattern of involvement of the glomeruli. From a clinical point of view, the nephropathy, almost always characterized by a nephrotic syndrome, has two distinct features: it is most often diagnosed in the first 2 years of life and it progresses rapidly to end-stage renal failure, which usually occurs before the age of 3 years. The clinical findings in 36 patients with DMS are presented. The nephropathy was isolated in 22 infants and associated with male pseudohermaphroditism and/or Wilms' tumour in 14.(ABSTRACT TRUNCATED AT 250 WORDS)

Genetic Basis of Congenital and Infantile Nephrotic Syndromes

“…1 Mutations were detected in 17 individuals (56.7% overall; 93.3% and 20.0% of patients with congenital and infantile nephrotic syndrome, respectively), in the WT1 (n ϭ 8), NPHS1 (n ϭ 6), LAMB2 (n ϭ 2), and NPHS2 (n ϭ 1) genes; no polymorphisms were detected in the PLCE1 gene [2][3][4][5] (Table 1). The frequency of mutations in patients with congenital nephrotic syndrome was similar to those of 2 large studies of European 7 (84.8%) and multiethnic 8 (81.3%) cohorts.…”

Immunohistochemical Analysis of Molecular Events in Tubulo-Interstitial Fibrosis in a Mouse Model of Diffuse Mesangial Sclerosis(ICGN Strain).

“…In particular, diffuse mesangial sclerosis (DMS) is one of the NS-related disorders and histopathologically characterized by mesangial expansion in more than 80% of glomeruli. Habib et al described that tubular dilatation and interstitial expansion was impressive in cases with renal failure [13,14]. This observation raised a possibility that tubulo-interstitial lesions could be a key predictor for diagnosis of DMS patients, although it may be difficult to determine whether the non-glomerular lesions cause or reflect renal dysfunction.…”

Síndrome nefrótica primária grave em crianças: descrição clínica e dos padrões histológicos renais de seis casos

“…Outros casos ocorreram após os dois anos de idade (2,7,10,12) , conforme relatado nos casos 3 e 4. Uma grande proporção de pacientes desenvolve hipertensão (4) , e a insuficiência renal evolui para doença crônica em meses a anos (2-4, 7, 9, 12, 16, 18) .…”

“…A ausência de microcistos tubulares não afasta a doença, pois os microcistos tubulares são achados histológicos em 75% dos casos (2,16) . No entanto, os microcistos tubulares são alterações inespecíficas e podem aparecer na esclerose mesangial difusa (16) .…”

“…A forma de herança da síndrome nefrótica idiopática não está esclarecida, mas o risco de ter outros irmãos afetados é maior nas famílias com crianças que apresentaram síndrome nefrótica no primeiro ano de vida (2) . Há casos secundários a processos infecciosos, como hepatites B e C, vírus da imunodeficiência humana, malária, citomegalovírus, rubéola, sífilis e toxoplasmose (4,13,16) , e causas pesquisadas e não confirmadas nos casos 5 e 6.…”