Increased numbers of IgG-containing cells in rectal lamina propria of patients with ankylosing spondylitis.

Using an indirect immunoperoxidase technique we found the numbers of IgG-containing cells in the rectal lamina propria to be increased in patients with ankylosing spondylitis compared with controls, but not in patients with acute anterior uveitis or rheumatoid arthritis, or in the first-degree relatives of patients with ankylosing spondylitis. No differences between diagnostic groups were detected in the numbers of cells containing IgA, IgM, IgD, or IgE. The total numbers of plasma cells in the rectal lamina propria were not significantly increased. Similar increases of IgG-containing cells were not found in the duodenal lamina propria of patients with ankylosing spondylitis.