Table 2.

The Oxford classification of IgA nephropathy (according to ref. [28])

Histological variable	Description
Mesangial hypercellularity	M0 < 50% of glomeruli showing mesangial hypercellularity M1 > 50% of glomeruli showing mesangial hypercellularity
Endocapillary hypercellularity	E0 absent E1 present
Segmental glomerulosclerosis/adhesion	S0 absent S1 present presence or absence of podocyte hypertrophy/tip lesions in biopsies with S1
Tubular atrophy/interstitial fibrosis	T0 ≤ 25% of the cortical area affected by tubular atrophy or interstitial fibrosis T1 26–50% of the cortical area affected by tubular atrophy or interstitial fibrosis T2 > 50% of the cortical area affected by tubular atrophy or interstitial fibrosis
Cellular/fibrocellular crescents	C0 absent C1 present in at least one glomerulus C2 present in > 25% of glomeruli

Modified with permission from Elsevier Ltd.©