Table 3 Revised classification lupus nephritis according to the International Society of Nephrology/Renal Pathology Society (ISN/RPS) 2003[78]
From: Renal involvement in autoimmune connective tissue diseases
Class I | Minimal mesangial lupus nephritis |
Normal glomeruli by light microscopy, but mesangial immune deposits by immunofluorescence | |
Class II | Mesangial proliferative lupus nephritis |
Purely mesangial hypercellularity of any degree or mesangial matrix expansion by light microscopy, with mesangial immune deposits | |
May be a few isolated subepithelial deposits visible by immunofluorescence or electron microscopy, but not by light microscopy | |
Class III | Focal lupus nephritis |
Active or inactive focal, segmental or global endo- or extracapillary glomerulonephritis involving <50% of all glomeruli, typically with focal subendothelial immune deposits, with or without mesangial alterations | |
Class III (A) | Active lesions: focal proliferative lupus nephritis |
Class III (A/C) | Active and chronic lesions: focal proliferative and sclerosing lupus nephritis |
Class III (C) | Chronic inactive lesions with glomerular scars: focal sclerosing lupus nephritis |
Class IV | Diffuse lupus nephritis |
Active or inactive diffuse, segmental or global endo- or extracapillary glomerulonephritis involving ≥50% of all glomeruli, typically with diffuse subendothelial immune deposits, with or without mesangial alterations. This class is divided into diffuse segmental (IV-S) lupus nephritis when ≥50% of the involved glomeruli have segmental lesions, and diffuse global (IV-G) lupus nephritis when ≥50% of the involved glomeruli have global lesions. Segmental is defined as a glomerular lesion that involves less than half of the glomerular tuft. This class includes cases with diffuse wire loop deposits but with little or no glomerular proliferation | |
Class IV-S (A) | Active lesions: diffuse segmental proliferative lupus nephritis |
Class IV-G (A) | Active lesions: diffuse global proliferative lupus nephritis |
Class IV-S (A/C) | Active and chronic lesions: diffuse segmental proliferative and sclerosing lupus nephritis |
Active and chronic lesions: diffuse global proliferative and sclerosing lupus nephritis | |
Class IV-S (C) | Chronic active lesions with scars: diffuse segmental sclerosing lupus nephritis |
Class IV-G (C) | Chronic inactive lesions with scars: diffuse global sclerosing lupus nephritis |
Class V | Membranous lupus nephritis |
Global or segmental subepithelial immune deposits or their morphologic sequelae by light microscopy and by immunofluorescence or electron microscopy, with our without mesangial alterations | |
Class V lupus nephritis may occur in combination with class III or IV in which case both will be diagnosed | |
Class V lupus nephritis show advanced sclerosis | |
Class VI | Advanced sclerosis lupus nephritis |
≥90% of glomeruli globally sclerosed without residual activity |