title: Membranous Nephropathy: Quantifying Remission Duration on Outcome.
abstract: Although change in proteinuria has been proposed as a surrogate for long-term prognosis in membranous nephropathy (MGN), variability in proteinuria levels and lag between these changes and acceptable end points, such as ESRD, has limited its utility. This cohort study examined the prognostic significance of remission duration in 376 patients with biopsy-proven idiopathic/primary MGN who achieved a remission after a period of nephrotic-range proteinuria. We defined complete remission (CR), partial remission (PR), and relapse as proteinuria ≤0.3, 0.4-3.4, and ≥3.5 g/d after CR or PR, respectively. The exposure variable was the remission status of patients at fixed landmarks (3, 6, 12, 24, and 36 months) after the date of first remission. The primary outcome was ESRD or 50% reduction in eGFR. We fitted Cox proportional hazards models to examine the association of remission status at each landmark and the primary end point. Persistent remission associated with unadjusted hazard ratios for the primary outcome that ranged by landmark from 0.35 (95% confidence interval, 0.20 to 0.61) to 0.56 (95% confidence interval, 0.31 to 1.04). Separate analyses for PR and CR yielded similar results. After adjustment, maintaining remission associated with significantly reduced risk of the primary outcome at all landmarks. Durable remissions associated with improved renal survival. Although the longer the remission, the greater the improvement, patients with remission durations as short as 3 months had improved renal prognosis compared with patients who relapsed. This study validates and quantifies PR and CR as surrogates for long-term outcome in MGN.
authors.affiliation: Division of Nephrology, Department of Medicine, University Health Network, University of Toronto, Toronto, Ontario, Canada; and daniel.cattran@uhn.ca.
authors.forename: Daniel C
authors.initials: DC
authors.lastname: Cattran
authors.affiliation: Division of Nephrology, Department of Medicine, University Health Network, University of Toronto, Toronto, Ontario, Canada; and.
authors.forename: Esther D
authors.initials: ED
authors.lastname: Kim
authors.affiliation: Division of Nephrology, Department of Medicine, University Health Network, University of Toronto, Toronto, Ontario, Canada; and.
authors.forename: Heather
authors.initials: H
authors.lastname: Reich
authors.affiliation: Division of Nephrology, Department of Medicine, Sunnybrook Health Science Center, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Michelle
authors.initials: M
authors.lastname: Hladunewich
authors.affiliation: Division of Nephrology, Department of Medicine, University Health Network, University of Toronto, Toronto, Ontario, Canada; and.
authors.forename: S Joseph
authors.initials: SJ
authors.lastname: Kim
mesh_terms: D015331:Cohort Studies; D005260:Female; D015433:Glomerulonephritis, Membranous / Q000150:complications / Q000628:therapy*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D011507:Proteinuria / Q000209:etiology / Q000628:therapy; D012074:Remission Induction; D013997:Time Factors; D016896:Treatment Outcome
keywords: clinical nephrology; glomerulonephritis; membranous nephropathy; proteinuria; renal progression; survival