The Oxford classification of IgA nephropathy: rationale, clinicopathological correlations, and classification.
IgA nephropathy is the most common glomerular disease worldwide, yet there is no international consensus for its pathological or clinical classification. Here a new classification for IgA nephropathy is presented by an international consensus working group. The goal of this new system was to identify specific pathological features that more accurately predict risk of progression of renal disease in IgA nephropathy, thus enabling both clinicians and pathologists to improve individual patient prognostication. In a retrospective analysis, sequential clinical data were obtained on 265 adults and children with IgA nephropathy who were followed for a median of 5 years. Renal biopsies from all patients were scored by pathologists blinded to the clinical data for pathological variables identified as reproducible by an iterative process. Four of these variables: (1) the mesangial hypercellularity score, (2) segmental glomerulosclerosis, (3) endocapillary hypercellularity, and (4) tubular atrophy/interstitial fibrosis were subsequently shown to have independent value in predicting renal outcome. These specific pathological features withstood rigorous statistical analysis even after taking into account all clinical indicators available at the time of biopsy as well as during follow-up. The features have prognostic significance and we recommended they be taken into account for predicting outcome independent of the clinical features both at the time of presentation and during follow-up. The value of crescents was not addressed due to their low prevalence in the enrolled cohort.
University Health Network, Toronto General Research Institute, Toronto, Ontario, Canada.
Cattran
Daniel C
DC
Coppo
Rosanna
R
Cook
H Terence
HT
Feehally
John
J
Roberts
Ian S D
IS
Troyanov
Stéphan
S
Alpers
Charles E
CE
Amore
Alessandro
A
Barratt
Jonathan
J
Berthoux
Francois
F
Bonsib
Stephen
S
Bruijn
Jan A
JA
D'Agati
Vivette
V
D'Amico
Giuseppe
G
Emancipator
Steven
S
Emma
Francesco
F
Ferrario
Franco
F
Fervenza
Fernando C
FC
Florquin
Sandrine
S
Fogo
Agnes
A
Geddes
Colin C
CC
Groene
Hermann-Josef
HJ
Haas
Mark
M
Herzenberg
Andrew M
AM
Hill
Prue A
PA
Hogg
Ronald J
RJ
Hsu
Stephen I
SI
Jennette
J Charles
JC
Joh
Kensuke
K
Julian
Bruce A
BA
Kawamura
Tetsuya
T
Lai
Fernand M
FM
Leung
Chi Bon
CB
Li
Lei-Shi
LS
Li
Philip K T
PK
Liu
Zhi-Hong
ZH
Mackinnon
Bruce
B
Mezzano
Sergio
S
Schena
F Paolo
FP
Tomino
Yasuhiko
Y
Walker
Patrick D
PD
Wang
Haiyan
H
Weening
Jan J
JJ
Yoshikawa
Nori
N
Zhang
Hong
H
D000293:Adolescent; D000328:Adult; D000368:Aged; D001706:Biopsy; D002648:Child; D002675:Child, Preschool; D005260:Female; D005919:Glomerular Filtration Rate; D005922:Glomerulonephritis, IGA / Q000145:classification* / Q000208:ethnology / Q000473:pathology* / Q000503:physiopathology; D006801:Humans; D007668:Kidney / Q000473:pathology*; D007678:Kidney Glomerulus / Q000473:pathology; D008297:Male; D008875:Middle Aged