Immunoelectron microscopy of skin in lupus erythematosus.

A multistep immunocytochemical method, utilizing horeradish peroxidase as an immunological bound marker enzyme, was employed to demonstrate in vivo fixed immunoglobulins (IgG, IgM) in the skin of three patients with CDLE and three patients with SLE. The immunoglobulin deposits were confined to the uppermost strata of the dermis, i.e. the area just below the basal lamina. Small amounts of immunoglobulin were visible within the lamina lucida and the basal lamina. Only quantitative differences were observed between deposits of immunoglobulins in CDLE and SLE. I CDLE, the reaction product covered a wider area of the superficial dermis and extended deeper down into the dermis. IgG and IgM deposits exhibited an identical fine structural morphology.