Renal histological features of school-age children with asymptomatic haematuria and/or proteinuria: a multicenter study.

Aim The risk of asymptomatic haematuria and/or proteinuria development into chronic progressive glomerulonephritis (CPG) is unclear. The indications for renal biopsy and follow-up on these asymptomatic children remain controversial. Methods A multicenter, retrospective study was performed to investigate the renal histological features of school-age children with asymptomatic urine abnormalities. Results A total of 112 asymptomatic children's renal biopsy data were studied. Most of the children (71%) received a renal biopsy because of isolated microscopic haematuria (IH), and these children were predominantly (60%) proven to have only mild lesions in the glomeruli. Approximately 30% of the children were biopsied because of asymptomatic proteinuria with or without microscopic haematuria (HP or isolated asymptomatic proteinuria (IP)), and these children were mostly (44–83%) indicated to have CPG, such as IgA nephropathy, focal segmental glomerulosclerosis, and Alport syndrome. The junior high school students had a greater percentage of HP than the primary school children. IgA nephropathy was the most common diagnosis in children who received renal biopsy because of HP. Conclusions Our findings indicate that IP and especially HP may have a high risk of development into CPG. IH, however, has a relatively low risk of severe histological lesions. Thus, IH per se might not be suggested as an indication for early renal biopsy. Long-term follow-up is necessary for these asymptomatic children.