The prognosis of idiopathic nephrotic syndrome: a comparative study between the index of selectivity of proteinuria and the findings in renal biopsies.

In 20 children with idiopathic nephrotic syndrome, the morphological changes in the glomeruli were compared with the index of selectivity of proteinuria. For the determination of the index of selectivity, the clearances of IgG and transferrin were used. A high correlation was found between the morphological changes and the index values. An index of selectivity of proteinuria of 0.20 proved to be the critical value for differentiating between a steroid sensitive and a steroid resistant INS.