RÉSUMÉ
PURPOSE: Present study has been undertaken to determine the distribution of various renal diseases causing asymptomatic hematuria in children and to evaluate the benefit of doing renal biopsy in these children. METHODS: Study population consisted of 146 children with asymptomatic primary hematuria who had been admitted to the pediatric department of Kyungpook National University Hospital for the past 4 years from 1999 to 2002. In 122 out of 146 cases, renal biopsy was performed percutaneously and in 24 out of 146 cases, diagnosed as idiopathic hypercalciuria, oral calcium loading test was performed. RESULTS: The age(mean+/-SD) at onset or discovery of hematuria of the 146 children included in this study was 8.0+/-3.2 years and the proportion of boys and girls was 54.8% and 45.2%, respectively. In 76 out of 146 cases(52%), asymptomatic hematuria was first diagnosed by school urinalysis screening. The proportion of histopathologic findings based on 122 biopsies was as follows : Thin Glomerular Basement Membrane(TGBM) 73 cases(50%); IgA nephropathy 20 cases(14%); Alport syndrome 6 cases(4%); Membranous Glomerulonephropathy(MGN) 4 cases(3%); Membranoproliferative Glomerulonephritis(MPGN) 2 cases(1%); IgA nephropathy with TGBM 3 cases(2%); "normal" glomeruli 14 cases(10%). Twenty four cases (16%) were diagnosed as idiopathic hypercalciuria. During follow-up periods, 15% of 146 cases became hematuria-free and renal function did not deteriorate in any cases. CONCLUSION: Unless hematuric children manifest poor prognostic indicators for renal survival, we would recommend long term regular follow-up prior to a renal biopsy.