Baseline characteristics of the cohort.

Background/Objective
Primary Focal and Segmental glomerulosclerosis (FSGS) is one of the most common causes of idiopathic nephrotic syndrome. Our aim was to describe a large cohort of patients with primary FSGS, identify risk factors associated with worse renal survival and assess the impact of different immunosuppressive regiments on renal survival.
Methods
This was a historical cohort study of adults who were diagnosed with primary FSGS from March 26, 1982, to September 16, 2020. The primary outcome was progression to ESRD.
Results
We included 579 patients. The mean age was 46 (±15) years of age, with 378 (65%) males and median 24-hour proteinuria was 3.8 (2–6) g. In multivariable analysis only eGFR (HR: 0.97 per ml/min increase, 95% CIs 0.95–0.98) and remission status (complete remission (HR: 0.03, 95% CIs 0.003–0.22) and partial remission (HR: 0.28, 95% CIs 0.13–0.61) compared to no remission) were associated with renal survival. Among patients who received immunosuppression compared to those that did not, there was a higher percentage of complete remission (121 (41%) vs. 40 (24%), p<0.001), and higher percentage of relapses (135 (64%) vs. 27 (33%), p<0.001). Immunosuppression and its type (glucocorticoids vs. cyclosporine ± glucocorticoids) were not associated with renal survival.
Conclusion
In primary FSGS, complete and partial remission were associated with improved renal survival. Further randomized studies are needed to assess the efficacy of different therapeutic agents and guide treatment.