[Characterization of subepidermal immune deposits in clinically unchanged skin in patients with lupus erythematosus (SLE)].

Subepidermal immune deposits containing IgG and C3 by 9 patients suffering from SLE were exposed to extreme excess of antigens in order to solubilize tissue-bound immune complexes. Sections of 4 micron were incubated at room temperature either with calf thymus DNA (0.3-30 mg/ml) or with human gamma-globulin (HGG) (1.6-16 mg/ml). The sections thus pretreated were compared with "native" samples by means of direct immunofluorescence technique. Only HGG resulted in drastic removal of IgG deposits along the dermoepidermal junction. DNA proved to be ineffective; deposits of C3 remained uninfluenced. Our results are discussed in the light of the composition of the subepidermal immune complex in SLE.