To determine the utility of
steroid response in classifying childhood
nephrotic syndrome, we reviewed 119 biopsies in 92 children aged 1 to 16 years who had been followed for a mean of 7.2 years.
Steroid responses were classified as
steroid resistant,
steroid dependent, and frequent relapser as defined by the International Study of
Kidney Disease in Children. Biopsy specimens were classified as showing
focal glomerulosclerosis (FSGS) in 39 children, as showing
lipoid nephrosis in 28, and as questionable in another 25 with either focal global
sclerosis,
IgM nephropathy, or mesangial prominence and tubular changes. A strong agreement (p less than 0.01) was found between children whose FSGS was
steroid resistant and children whose
lipoid nephrosis resulted in frequent relapses. The length of the remission after
therapy with
chlorambucil or
cyclophosphamide was determined in 84 children. A significantly shorter length of remission after cytotoxic
drug therapy (p less than 0.05) was identified for patients with FSGS versus those with
lipoid nephrosis; this difference became more significant for
steroid-resistant patients in comparison with those who were
steroid dependent or were frequent relapsers (p less than 0.005). Among all
steroid-resistant patients, those with FSGS had shorter remissions than patients with other histologic changes (p less than 0.001). The data suggest that patterns of response to
corticosteroid therapy correlate with the histologic abnormality. Thus
steroid-sensitive patients need not undergo renal biopsy before receiving cytotoxic drugs.
Steroid-resistant patients would benefit from a biopsy, because the findings tend to predict the outcome.