Objective: To study the clinicopathologic features of different variants of primary focal segmental glomerulosclerosis (FSGS).
Methods: One hundred and two cases of FSGS were retrieved from the archival files of Peking University First Hospital during the past 6-year period. The pathologic findings were reviewed and the degrees of active and chronic changes were assessed by morphometric analysis. The histopathologic patterns were then correlated with clinical manifestations.
Results: Amongst the 102 cases of primary FSGS studied, 55.9% belonged to the NOS (not other specified) variant, while the perihilar, cellular, tip and collapsing variants accounted for 6.9%, 25.5%, 4.8% and 6.9% respectively. The level of proteinuria in the cellular and tip variants were much higher than that in the NOS variant; and the incidence of nephrotic syndrome in the tip and collapsing variants was higher than that in the other three variants (chi(2) = 12.23, P < 0.05). The activity score of the cellular and collapsing variants was also higher than that of the other three variants (P < 0.05). The interval between disease onset and renal biopsy diagnosis in the perihilar variant was longer than that in the other variants. The chronicity score of this variant was higher than that of the tip and NOS variants (P < 0.05). On the other hand, the total scores of active and chronic changes of the tip variant was lower than that of the cellular and collapsing variants (P < 0.05); and its chronic score was lower than that of the NOS and perihilar variants (P < 0.05).
Conclusions: The NOS variant is the commonest morphologic pattern seen in primary FSGS. The cellular and collapsing variants are the patterns associated with active lesions, while perihilar variant is the pattern associated with chronic lesions. The tip variant shows mild pathological changes compared with the other patterns.