Focal segmental glomerulosclerosis in children with idiopathic nephrotic syndrome. A report of the Southwest Pediatric Nephrology Study Group.

Clinicopathologic correlations were examined in 75 children with focal segmental glomerulosclerosis (FSGS) associated with idiopathic nephrotic syndrome. The biopsy specimens of all patients were examined by electron microscopy (69 patients) or immunofluorescence microscopy (67 patients) in addition to light microscopy. Fifty-three patients (group A) had FSGS diagnosed on their first biopsy; 22 patients (group B) had one to three previous biopsies showing minimal glomerular changes or mesangial hypercellularity prior to the demonstration of FSGS on a subsequent biopsy. Considerable homogeneity between the diagnostic biopsy features in the two groups was evident. Diffuse mesangial hypercellularity and IgM deposition were found in a similar percentage of each group, but these features did not correlate with each other. To date, the mean duration of follow-up for the entire group has been 57 months (range, 7 to 217 months): 21% have developed ESRD, 23% have a decreased GFR but not ESRD, 37% have persistent proteinuria only, 11% are in remission, and 8% have been lost to follow-up. No morphologic or clinical features have been predictive of outcome during this relatively short period of followup. The frequency of chronic renal failure and ESRD has been similar in groups A and B. These data suggest that the clinical outcome in children with FSGS is poor in many patients, whether the diagnosis is established on an initial or subsequent renal biopsy specimen.