Childhood minimal change disease and focal segmental glomerulosclerosis: a continuous spectrum of disease? Pathologic study of 33 cases with long-term follow-up.

Thirty-three children with idiopathic nephrotic syndrome who underwent kidney needle biopsy were reevaluated. The male to female ratio was 2:1, and a preponderance of North-African Jewish and Arab origin over Ashkenazi Jewish origin was noted. There was a positive correlation between the severity of glomerular changes and prognosis among the 10 cases with minimal change disease (MCD) and the 23 with focal segmental glomerulosclerosis (FSGS). On long-term follow-up (mean over 11 years) chronic renal failure developed in none of 10 MCD patients, 1 of 12 FSGS patients with mild glomerular sclerosis, 1 of 7 FSGS patients with moderate glomerular sclerosis and 3 of 4 FSGS patients with severe glomerular sclerosis. Prognosis of patients with mild glomerular sclerotic lesion on light microscopy was substantially not worse than the prognosis of patients with mild glomerular alterations only on the electron microscopic study (MCD-B). Thus, both pathologically and prognostically, there was a continuous spectrum from 'pure' MCD (MCD-A) to FSGS with severe glomerular sclerosis. Glomerular changes confined to the origin of the proximal tubule ('tip' changes) were seen only in 4 patients and did not have a distinct prognostic significance. No case of peripheral location of the sclerotic segment within the glomerulus was found in our series of FSGS, and therefore no correlation between location of segmental sclerosis and prognosis was feasible.