Evolution of nephrotic-associated focal segmental glomerulosclerosis and relation to the glomerular tip lesio11See Editorial by Haas,P. 1188.

Evolution of nephrotic-associated focal segmental glomerulosclerosis and relation to the glomerular tip lesion.BackgroundSeveral entities or variants within focal segmental glomerulosclerosis (FSGS) have been described, but their changes with time and interrelationships are undetermined.MethodsChanges with time were studied in two series of segmental sclerosing lesions in the nephrotic syndrome, one of 22 specimens from ten patients in a trial, the other of 176 specimens from 121 consecutive patients.ResultsThe earliest lesions were probably all at the tubular origin, equivalent to the tip variant of FSGS. In some patients, lesions remained at this site, but progression to renal failure was accompanied by morphologic progression, with development of lesions at various sites, equivalent to FSGS, not otherwise specified (NOS). Progression was more likely if there were large lesions, abnormal mesangium, and extensive acute tubular damage. Patients with lesions at the tubular origin at presentation had a shorter duration of symptoms and less chronic renal damage than those with multiple lesions, were more likely to have a complete response of the nephrotic syndrome, and were less likely to progress to renal failure. Recurrent nephrotic syndrome occurred in 12 of 14 allografts at risk, and was usually accompanied by lesions at the tubular origin, then multiple lesions.ConclusionAt least some patients with FSGS (NOS) have evolved from the tip variant. The tip variant has been considered a distinct entity. Another interpretation is that it includes two conditions, one an early form of classic FSGS, and the other closely related to minimal change nephropathy (MCN), equivalent to the glomerular tip lesion as originally defined