Table 1.

Definitions of pathological variables used in the Oxford classification of immunoglobulin a nephropathy

Variable	Definition	Score
Mesangial hypercellularity	< 4 Mesangial cells/mesangial area = 0	M0 < 0.5
	4-5 Mesangial cells/mesangial area = 1	M1 > 0.5
	6-7 Mesangial cells/mesangial area = 2
	> 8 Mesangial cells/mesangial area = 3
Segmental glomerulosclerosis	Any amount of the tuft involved in sclerosis, but not involving the whole tuft or the presence of an adhesion	S0 = absent
		S1 = present
Endocapillary hypercellularity	Hypercellularity due to increased number of cells within glomerular capillary lumina causing narrowing of the lumina	E0 = absent
		E1 = present
Tubular atrophy/interstitial fibrosis	Percentage of cortical area involved by the tubular atrophy or interstitial fibrosis, whichever is greater	0%-25% - T0
		26%-50% - T1
		> 50% - T2