Clasically,congenital nephrotic syndrome (CNS) is a rare kidney disorder characterised by heavy proteinuria, hypoproteinemia, and oedema starting within the first 3 month of life.Recently,studies proved that compound heterozygous mutations in the NPHS1 gene may present with later onset of steroid-resistent nephrotic syndrome, broadening the phenotypic spectrum of congenital nephrotic syndrome of the Finnish type.
We report a case of nephrotic syndrome with histopathological findings of congenital nephrosis in a 1.5 years old full-term infant. No information about the weight of placenta was recorded and prenatal course has been uneventful. Personal history was unremarkable, with normal nutritional status and statural growth. The clinical diagnosis of NS was made on the basis of nephrotic range proteinuria,hypoalbuminaemia, dyslipidemia, oligoanuria and oedema. No evidence of infection or autoimmune pathology was obtained. Renal ultrasonography presented enlarged, hyperechogenic kidneys with loss of corticomedullary differentiation. Management included high-energy and low-sodium diet, intravenous albumin infusion, ACEi and antiplatelet agent(Dipyridamole). Atypical presentation lead us to initially consider immunosuppressive drugs (iv pulse-therapy with methyl-prednisolone, afterwards Cyclosporine) but no response in his clinical state was registred, with refractory proteinuria and ascites. Prior to the availability of genetic testing, we performed percutaneous renal biopsia showing microcystic dilation of the proximal tubules suggesting congenital nephrotic syndrome of the finnish type. Studies reported a successful management of CNS with IEC and Indomethacin in combination with unilateral nephrectomy, but due to diminished digestive tolerance we decided to temporise NSAID administration and continued aggressive supportive treatment.
Management of CNS may be very challenging with a severe prognosis. Knowledge of aetiology helps in assessing management and prognosis. CNS is corticoresistent and immunosuppressive drugs may be harmful due to the already high susceptibility to infection. Treatment with ‘antiproteinuric’ medication is worth trying, as they improve clinical control and delay the start of dialysis and renal transplantation, increasing the probability of success.