title: Pathologic classification of diabetic nephropathy.
abstract: Although pathologic classifications exist for several renal diseases, including IgA nephropathy, focal segmental glomerulosclerosis, and lupus nephritis, a uniform classification for diabetic nephropathy is lacking. Our aim, commissioned by the Research Committee of the Renal Pathology Society, was to develop a consensus classification combining type1 and type 2 diabetic nephropathies. Such a classification should discriminate lesions by various degrees of severity that would be easy to use internationally in clinical practice. We divide diabetic nephropathy into four hierarchical glomerular lesions with a separate evaluation for degrees of interstitial and vascular involvement. Biopsies diagnosed as diabetic nephropathy are classified as follows: Class I, glomerular basement membrane thickening: isolated glomerular basement membrane thickening and only mild, nonspecific changes by light microscopy that do not meet the criteria of classes II through IV. Class II, mesangial expansion, mild (IIa) or severe (IIb): glomeruli classified as mild or severe mesangial expansion but without nodular sclerosis (Kimmelstiel-Wilson lesions) or global glomerulosclerosis in more than 50% of glomeruli. Class III, nodular sclerosis (Kimmelstiel-Wilson lesions): at least one glomerulus with nodular increase in mesangial matrix (Kimmelstiel-Wilson) without changes described in class IV. Class IV, advanced diabetic glomerulosclerosis: more than 50% global glomerulosclerosis with other clinical or pathologic evidence that sclerosis is attributable to diabetic nephropathy. A good interobserver reproducibility for the four classes of DN was shown (intraclass correlation coefficient = 0.84) in a test of this classification.
authors.affiliation: Department of Pathology, Leiden University Medical Center, PO Box 9600, 2300 RC Leiden, The Netherlands.
authors.forename: Thijs W Cohen
authors.initials: TW
authors.lastname: Tervaert
authors.forename: Antien L
authors.initials: AL
authors.lastname: Mooyaart
authors.forename: Kerstin
authors.initials: K
authors.lastname: Amann
authors.forename: Arthur H
authors.initials: AH
authors.lastname: Cohen
authors.forename: H Terence
authors.initials: HT
authors.lastname: Cook
authors.forename: Cinthia B
authors.initials: CB
authors.lastname: Drachenberg
authors.forename: Franco
authors.initials: F
authors.lastname: Ferrario
authors.forename: Agnes B
authors.initials: AB
authors.lastname: Fogo
authors.forename: Mark
authors.initials: M
authors.lastname: Haas
authors.forename: Emile
authors.initials: E
authors.lastname: de Heer
authors.forename: Kensuke
authors.initials: K
authors.lastname: Joh
authors.forename: Laure H
authors.initials: LH
authors.lastname: Noël
authors.forename: Jai
authors.initials: J
authors.lastname: Radhakrishnan
authors.forename: Surya V
authors.initials: SV
authors.lastname: Seshan
authors.forename: Ingeborg M
authors.initials: IM
authors.lastname: Bajema
authors.forename: Jan A
authors.initials: JA
authors.lastname: Bruijn
mesh_terms: D003928:Diabetic Nephropathies / Q000145:classification* / Q000473:pathology*; D006801:Humans; D007678:Kidney Glomerulus / Q000473:pathology