Is kidney biopsy necessary in children with idiopathic nephrotic syndrome?

Aim: To investigate the need, in the Northern European setting, to perform kidney biopsy in children with steroid‐sensitive nephrotic syndrome. Methods: In this retrospective study 124 individuals aged 1–18 years with idiopathic nephrotic syndrome, followed in the paediatric hospitals in southern Sweden from 1999 to 2018, were included. Results: There was a median follow‐up time of 6.5 (0.2–16.8) years. The majority (92%) of children were steroid‐sensitive and of them, 60.5% were frequently relapsing or steroid‐dependent. Microscopic haematuria was found at onset in 81.1% and hypertension in 8.7%. At least one kidney biopsy was performed in 93 (75%). The most common indication was a steroid‐dependent or relapsing course (58.4%). One of 79 steroid‐sensitive children had another histological diagnosis than minimal change nephropathy 1.3%, 95% confidence interval (0.002, 0.068). Bleeding occurred after eight biopsies (6.6%). Twenty individuals (30.7%) were transferred to adult units, 18 still on immunosuppression. Conclusion: We have in our cohort of unselected children with idiopathic nephrotic syndrome confirmed that a kidney biopsy rarely gives important medical information in steroid‐sensitive children without any other complicating factor and that the liberal policy of kidney biopsy in the Nordic countries safely can be changed. [ABSTRACT FROM AUTHOR]