Renal function and functional renal reserve in adolescents who acquired minimal change nephrotic syndrome in childhood

OBJECTIVE: The aim of this study was to evaluate glomerular filtration rate (GFR) and renal functional reserve (RR) in young patients after diagnosis of minimal change nephrotic syndrome (MCNS) during childhood. PATIENTS AND METHODS: GFR and RR were evaluated in 15 young patients (10 female) diagnosis of childhood MCNS 18.5 +/- 4 years before. Creatinine clearance (CC) was measured before and after an acute protein load to determine GFR and RR. Based on the tendency towards relapses, the study subjects were divided into two groups: Group A had less than five relapses and group B five or more relapses. Study subjects (groups A and B) and control subjects (group C) were matched for sex and age. RESULTS: Group B showed a higher GFR than groups A and C (group B = 133.9 +/- 16.26 ml/min/1.73 m2, group A = 107.91 +/- 18.19 ml/min/1.73m2; p = 0.014, group C = 113.89 +/- 13.17 ml/min/1.73m2, p = 0.015). RR was significantly lower (absolute and relative) in group B than in group C (group B = 10.9 +/- 15.46 ml/min/1.73m2, group C = 38.58 +/- 21.47 ml/min/1.73m2, p = 0.016 and group B = 8.56 +/- 11.75%, group C = 34.35 +/- 21.43%, p = 0.016, respectively). CONCLUSIONS: After childhood MCNS, young patients who presented more than five relapses showed an increase in GFR and a decrease in RR.