The diagnosis of lupus nephritis
lupus nephritis depends on blood tests, urinalysis, X-rays, ultrasound scans of the kidneys, and a kidney biopsy. On urinalysis, a nephritic picture is found and red blood cell casts, red blood cells and proteinuria is found. The World Health Organization has divided lupus nephritis into five stages based on the biopsy. This classification was defined in 1982 and revised in 1995.
Class I is minimal mesangial glomerulonephritis which is histologically normal on light microscopy but with mesangial deposits on electron microscopy. It constitutes about 5% of cases of lupus nephritis.Kidney failure is very rare in this form
Class II is based on a finding of mesangial proliferative lupus nephritis. This form typically responds completely to treatment with corticosteroids. It constitutes about 20% of cases. Kidney failure is rare in this form.
Class III is focal proliferative nephritis and often successfully responds to treatment with high doses of corticosteroids. It constitutes about 25% of cases. Kidney failure is uncommon in this form.
Class IV is diffuse proliferative nephritis. This form is mainly treated with corticosteroids and immunosuppressant drugs. It constitutes about 40% of cases. Kidney failure is common in this form.
Class V is membranous nephritis and is characterized by extreme edema and protein loss. It constitutes about 10% of cases. Kidney failure is uncommon in this form.