Table 1.

International Society of Nephrology/Renal Pathology Society classification of lupus nephritis

Class I	Minimal mesangial lupus nephritis
Class II	Mesangial proliferative lupus nephritis
Class III	Focal lupus nephritis (<50% glomeruli)
III(A)	Active lesions
III(A/C)	Active and chronic lesions
III(C)	Chronic lesions
Class IV	Diffuse lupus nephritis (>50% glomeruli)
	Diffuse segmental (IV-S) or global (IV-G)
IV(A)	Active lesions
IV(A/C)	Active and chronic lesions
IV(C)	Chronic lesions
Class V	Membranous lupus nephritis
Class VI	Advanced sclerosing lupus nephritis (≥90% globally sclerosed glomeruli without residual activity)

Adapted with premission from Weening et al. [9].