Kidney in lupus erythematosus.

The pathologic abnormalities present in patients with SLE have been classified as follows: minimal lupus nephritis, mild (focal) proliferative lupus nephritis, severe (diffuse) proliferative lupus nephritis, and membranous lupus nephritis. Changes in individual patients from one form of nephritis to another are observed infrequently. Pathologic evidence of activity is usually present in patients with hematuria, although it may be found in patients with no evidence of clinical renal disease. Complement components and titer of antibody to native DNA may be helpful in estimating disease activity.