Classification of Lupus Nephritis

I

Minimal mesangial

Normal (although immune complexes are sometimes visible using immunofluorescence or electron microscopy)

None

Excellent

II

Mesangial proliferative

Immune complexes in the mesangium only and mesangial hypercellularity

Possibly microscopic hematuria, proteinuria, or both

Excellent

III

Focal

Endocapillary and extracapillary cellular proliferation and inflammation in < 50% of glomeruli, usually in a segmental distribution

Usually hematuria and proteinuria

Possibly hypertension, nephrotic syndrome, and elevated serum creatinine

Variable

IV

Diffuse†

Endocapillary and extracapillary cellular proliferation and inflammation in > 50% of glomeruli

Usually hematuria and proteinuria

Frequently hypertension, nephrotic syndrome, and elevated serum creatinine

Variable

V

Membranous

Thickening of the glomerular basement membrane with subepithelial and intramembranous immune complex deposition

Usually nephrotic syndrome

Sometimes microscopic hematuria or hypertension

Serum creatinine usually normal or slightly elevated

Poorly defined

VI

Advanced sclerosing

Sclerosis of > 90% of glomerular capillaries

Bland urinary sediment and end-stage kidney disease or slowly increasing serum creatinine

Poor