Table 4: Original World Health Organization [WHO] classification of lupus nephritis. Modified from: Churg J, Sobin LH: Renal Disease: Classification and Atlas of Glomerular Disease, Tokyo, Igaku-Shoin, 1982.

Pathologic Class Renal Morphology
Class I Normal glomeruli: but immune deposits are noted by immunofluorescence and electron microscopy
Class II Mesangial alterations only a)        No mesangial hypercellularity, but mesangial immune deposits are seen b)       Mesangial matrix and cellular hypertrophy with immune deposits
Class III Focal, proliferative glomerulonephritis: <50% glomeruli affected.
Class IV Diffuse glomerulonephritis: >50% glomeruli affected. Severe mesangial, endocapillary, or mesangio-capillary proliferation and/or extensive subendothelial deposits]
Class V Membranous glomerulonephritis
Class VI Advanced glomerulosclerisis