Cutaneous vessel immune deposits in rheumatoid arthritis.

A study to determine the presence of immune deposits in the cutaneous vessels of normal-appearing skin was made in 39 patients with rheumatoid arthritis. Immune deposits in skin vessels were found in 20 of the 32 patients with seropositive rheumatoid arthritis. The frequency of such immune deposits was only slightly higher in patients with clinical vasculitis than in those without such vasculitis. There was an association among the presence of immune deposits in skin vessels, presence of antinuclear antibodies, and elevated serum levels of IgM and IgA. The major immunoreactants detected were IgM and C3. The presence of immune deposits in skin vessels does not differentiate seropositive rheumatoid aptients who have clinical vasculitis from those who do not have clinical vasculitis.