Analysis of Isolated Proteinuria on School Urinary Mass Screening

ABSTRACT

PURPOSE: The urinary mass screening program in school aged population has been performed since 1981, but the consensus on the follow-up schedule and the management of isolated proteinuria has not been reached yet. The aim of this study was to investigate the cause of isolated proteinuria and to propose a guideline for the treatment and follow-up afterwards. Methods: The medical records of 114 cases of isolated proteinuria detected through the analysis of urinary mass screening and evaluated at the pediatric outpatient clinic of Asan Medical Center from January 1990 to July 2001 have been reviewed. RESULTS: The classification of isolated proteinuria was as follows. Transient proteinuria 32%, orthostatic proteinuria 65%, persistent proteinuria 3%. In orthostatic proteinuria group, daytime and nighttime proteinuria were 319.2+/-89.1 mg/dL and 56.5+/-6.1 mg/dL. In persistent proteinuria group, daytime and nighttime proteinuria were 1140+/-40.5 mg/dL and 289+/-8 mg/dL. After 30 month follow-up, 2 cases of persistent proteinuria were needed renal biopsy and 1 case revealed focal segmental glomerular sclerosis. In all cases, serum creatinine, albumin and complements levels were normal. In the orthostatic proteinuria group, no significant renal diseases were detected. CONCLUSION: Since most of the isolated proteinuria detected through the school urinary mass screening were orthostatic proteinuria or transient proteinuria, initially aggressive diagnostic method such as renal biopsy is not needed and regular follow-up with quantitation of proteinuria is warranted.