Analysis of renal biopsies performed in children with abnormal findings in urinary mass screening

School urinary mass screening tests are performed to make early diagnosis and provide proper treatment for chronic renal diseases. However, very few systemic analyses or studies have been reported regarding final diagnosis made on children with abnormal urinary screening results. To study the cases of renal biopsy in children detected in urinary screening. We retrospectively analysed 461 cases of renal biopsy performed on children referred to us with abnormal school urinary mass screening results who satisfied indications for renal biopsy. Pathologically abnormal findings were observed in 285 (61.8%) patients. Thin glomerular basement membrane disease was detected in 127 (27.5%) cases and IgA nephropathy in 121 (26.2%) cases. Among those 461 children, microscopic haematuria was observed in 289 (62.7%) patients, proteinuria in nine (2.0%), and both in 163 (35.4%). In addition, a statistically higher rate of pathological abnormalities on renal biopsy was noted in the group with microscopic haematuria combined with proteinuria and also in cases with more severe haematuria. School urinary mass screening has greatly contributed to diagnosing chronic renal diseases. Continuous medical observation is required when abnormal urinalysis is observed, and a more aggressive medical approach such as renal biopsy should also be performed if necessary.