ABSTRACT
BACKGROUND: Proteinuria is a common finding in children. It may be due to a benign cause, but it can also represent early renal injury. Of children with persistent proteinuria noted in mass urine screening programs, 35% have a urine protein level greater than 100 mg/dl and many of them are associated with many underlying renal diseases. The aim of this study was to identify the etiology and prognosis of persistent proteinuria in children. METHODS: We collected data on urine protein from January 2011 to December 2016 in a tertiary medical center. During this 6-year period, 37,645 children received urinalysis, and 2.3% were found to have persistent proteinuria. We reviewed their medical charts for clinical diagnoses and renal function. According to the level of persistent proteinuria, we divided the children into three groups (mild, moderate, and severe). RESULTS: Most clinical diagnoses in the mild persistent proteinuria group were not readily identifiable. In the moderate and severe groups, acute kidney injury was the leading cause of significant proteinuria, followed by systemic lupus erythematosus, steroid-sensitive nephrotic syndrome, and congenital urogenital tract anomalies. There were significant differences in the rate of chronic renal insufficiency among the three groups. Prematurity with extremely low birth weight was also a major factor associated with pediatric chronic renal insufficiency. CONCLUSION: Assessing persistent proteinuria in children is important due to the diverse range of associated diseases or mortality.