Immunoglobulin deposits in the dermo-epidermal junction zone in patients with systemic lupus erythematosus. Rheumatoid arthritis and temporal arteritis compared by serological testing including alpha2-macroglobulin.

In biopsies from normal-looking skin, immune complexes in the dermo-epidermal junction zone were found by a direct immunofluorescence technique in 14 of 17 patients with systemic lupus erythematosus, in 6 of 12 patients with rheumatoid arthritis, but in none of 10 patients with temporal arteritis and 25 normal controls. Blood samples were obtained simultaneously from all patients and high titres of IgG organ-nonspecific antinuclear factors with complement-fixing properties were found to be closely related to systemic lupus erythematosus. IgG granulocyte-specific antinuclear factors were related with rheumatoid arthritis, while high concentrations of plasma fibrinogen were characteristic of temporal arteritis. No significant increases or differences in blood values of alpha2-macroglobulin were found between the groups and no correlation was found with deposits in the skin.