title: Remission of proteinuria improves prognosis in IgA nephropathy.
abstract: Proteinuria has been shown to be an adverse prognostic factor in IgA nephropathy. The benefit of achieving a partial remission of proteinuria, however, has not been well described. We studied 542 patients with biopsy-proven primary IgA nephropathy in the Toronto Glomerulonephritis Registry and found that glomerular filtration rate (GFR) declined at -0.38 +/- 0.61 ml/min per 1.73 m2/mo overall, with 30% of subjects reaching end-stage renal disease. Multivariate analysis revealed that proteinuria during follow-up was the most important predictor of the rate of GFR decline. Among the 171 patients with <1 g/d of sustained proteinuria, the rate of decline was 90% slower than the mean rate. The rate of decline increased with the amount of proteinuria, such that those with sustained proteinuria >3 g/d (n = 121) lost renal function 25-fold faster than those with <1 g/d. Patients who presented with > or =3 g/d who achieved a partial remission (<1 g/d) had a similar course to patients who had < or =1 g/d throughout, and fared far better than patients who never achieved remission. These results underscore the relationship between proteinuria and prognosis in IgA nephropathy and establish the importance of remission.
authors.affiliation: Division of Nephrology, University Health Network, University of Toronto, Toronto, Ontario, Canada. h.reich@utoronto.ca
authors.forename: Heather N
authors.initials: HN
authors.lastname: Reich
authors.forename: Stéphan
authors.initials: S
authors.lastname: Troyanov
authors.forename: James W
authors.initials: JW
authors.lastname: Scholey
authors.forename: Daniel C
authors.initials: DC
authors.lastname: Cattran
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D005260:Female; D005919:Glomerular Filtration Rate; D005922:Glomerulonephritis, IGA / Q000175:diagnosis / Q000628:therapy* / Q000652:urine*; D006801:Humans; D007668:Kidney / Q000473:pathology; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D011379:Prognosis; D011507:Proteinuria / Q000628:therapy*; D012074:Remission Induction; D016896:Treatment Outcome