Focal and segmental glomerulosclerosis: definition and relevance of a partial remission

Focal and segmental glomerulosclerosis (FSGS) is one of the most common primary glomerular diseases to terminate in ESRD. A complete remission (CR) confers an excellent long-term prognosis, but the quantitative benefits of partial remissions (PR) have not been defined. This study evaluated the rate of renal function decline (slope of creatinine clearance) and renal survival in nephrotic FSGS patients with CR, PR, or no remission. It also examined relapse rate from remission and its impact on outcome. Multivariate analysis included clinical and laboratory data at presentation and over follow-up, BP control, the agents used, and immunosuppressive therapy. The study cohort was 281 nephrotic FSGS patients who had a minimum of 12 mo of observation and were identified from the Toronto Glomerulonephritis Registry. Over a median follow-up of 65 mo, 55 experienced a CR, 117 had a PR, and 109 had no remission. A PR was independently predictive of slope and survival from renal failure by multivariate analysis (adjusted time-dependent hazard ratio, 0.48; 95% confidence interval, 0.24 to 0.96; P = 0.04). Immunosuppression with high-dose prednisone was associated with a higher rate of PR and CR. Relapse from PR was frequent (56%) and associated with a more rapid rate of renal function decline and worse renal survival compared with relapse-free partial remitters. Only female gender and the nadir of proteinuria during remission were associated with a sustained remission. A PR in proteinuria and its maintenance are important therapeutic targets in FSGS, with implications for both slowing progression rate and improving renal survival.