title: The MEST score provides earlier risk prediction in lgA nephropathy.
abstract: The Oxford Classification of IgA nephropathy (IgAN) includes the following four histologic components: mesangial (M) and endocapillary (E) hypercellularity, segmental sclerosis (S) and interstitial fibrosis/tubular atrophy (T). These combine to form the MEST score and are independently associated with renal outcome. Current prediction and risk stratification in IgAN requires clinical data over 2 years of follow-up. Using modern prediction tools, we examined whether combining MEST with cross-sectional clinical data at biopsy provides earlier risk prediction in IgAN than current best methods that use 2 years of follow-up data. We used a cohort of 901 adults with IgAN from the Oxford derivation and North American validation studies and the VALIGA study followed for a median of 5.6 years to analyze the primary outcome (50% decrease in eGFR or ESRD) using Cox regression models. Covariates of clinical data at biopsy (eGFR, proteinuria, MAP) with or without MEST, and then 2-year clinical data alone (2-year average of proteinuria/MAP, eGFR at biopsy) were considered. There was significant improvement in prediction by adding MEST to clinical data at biopsy. The combination predicted the outcome as well as the 2-year clinical data alone, with comparable calibration curves. This effect did not change in subgroups treated or not with RAS blockade or immunosuppression. Thus, combining the MEST score with cross-sectional clinical data at biopsy provides earlier risk prediction in IgAN than our current best methods.
authors.affiliation: Division of Nephrology, University of British Columbia, Vancouver, BC, Canada; BC Provincial Renal Agency, Vancouver, BC, Canada; Centre for Health Evaluation and Outcome Sciences, St. Paul's Hospital, Vancouver, BC, Canada.
authors.forename: Sean J
authors.initials: SJ
authors.lastname: Barbour
authors.affiliation: BC Provincial Renal Agency, Vancouver, BC, Canada.
authors.forename: Gabriela
authors.initials: G
authors.lastname: Espino-Hernandez
authors.affiliation: Division of Nephrology, University of Toronto, Toronto, ON, Canada.
authors.forename: Heather N
authors.initials: HN
authors.lastname: Reich
authors.affiliation: Regina Margherita Children's University Hospital, Torino, Italy.
authors.forename: Rosanna
authors.initials: R
authors.lastname: Coppo
authors.affiliation: Oxford University Hospitals, Oxford, UK.
authors.forename: Ian S D
authors.initials: IS
authors.lastname: Roberts
authors.affiliation: The John Walls Renal Unit, Leicester General Hospital, Leicester, UK.
authors.forename: John
authors.initials: J
authors.lastname: Feehally
authors.affiliation: Division of Nephrology, University of Toronto, Toronto, ON, Canada.
authors.forename: Andrew M
authors.initials: AM
authors.lastname: Herzenberg
authors.affiliation: Division of Nephrology, University of Toronto, Toronto, ON, Canada. Electronic address: daniel.cattran@uhn.ca.
authors.forename: Daniel C
authors.initials: DC
authors.lastname: Cattran
mesh_terms: D000328:Adult; D001284:Atrophy / Q000473:pathology; D001706:Biopsy; D018450:Disease Progression; D005260:Female; D005355:Fibrosis; D005500:Follow-Up Studies; D005919:Glomerular Filtration Rate; D005922:Glomerulonephritis, IGA / Q000145:classification* / Q000473:pathology* / Q000503:physiopathology; D006801:Humans; D007668:Kidney / Q000473:pathology*; D007676:Kidney Failure, Chronic / Q000209:etiology*; D008297:Male; D050527:Mesangial Cells / Q000473:pathology; D008875:Middle Aged; D011237:Predictive Value of Tests; D011379:Prognosis; D018570:Risk Assessment / Q000379:methods
keywords: IgA nephropathy; glomerular disease; renal pathology