Systemic lupus erythematosus. Studies of the antibodies bound to skin.

Systemic lupus erythematosus is characterized by antibodies demonstrable by immunofluorescence on the renal glomeruli and at the basement membrane area of both normal and involved skin. Acid eluates from glomeruli and from normal-appearing skin of three patients with systemic lupus erythematosus contained an antinuclear antibody. This antibody fixes complement and produces a mixed immunofluorescent pattern. Anti-deoxyribonucleic acid or antiextractable nuclear antigen antibodies may be present. This antibody is concentrated on the skin and glomerular basement membrane in proportion to the total serum IgG concentration. In two cases the skin eluate contains, in addition to the antinuclear antibody, a basement membrane antibody that fixes complement, gives a linear immunofluorescent pattern, and appears to be similar (although not identical) to the pemphigoid antibody.