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)