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systemic lupus erythematosus patients with native
DNA binding activity (nDNA-BA) in the serum and subepidermal
immunoglobulin deposits were studied to determine the relationship of the
immunoglobulin (Ig) class distribution of serum nDNA-BA to the clinical characteristics of their disease and to the Ig class present at the dermal-epidermal junction (DEJ). The patients with predominantly (86-98%)
IgM nDNA-BA in the serum had less active disease, mild or no renal involvement, and longer survival than those with predominantly (51-95%)
IgG nDNA-BA in the serum. Renal biopsies in eight patients with predominantly
IgM nDNA-BA in the serum showed relatively benign histologic changes in the kidney. In contrast, renal tissue from 23 patients with predominantly
IgG nDNA-BA showed more severe histologic changes. All patients had multiple skin biopsies. Patients with predominantly
IgM nDNA-BA consistently had only
IgM at the DEJ. Patients with predominantly
IgG nDNA-BA had
IgG, usually in association with
IgM, at the DEJ. The findings demonstrate that a minority of
systemic lupus erythematosus patients may exhibit a limited anti-nDNA response characterized by the presence of chiefly
IgM nDNA-BA in the serum and that this is reflected by the presence of mild disease and
IgM alone at the DEJ. The development of
IgG nDNA-BA is associated with more severe and active disease.