Serum IgG, IgM, and IgA levels in ankylosing spondylitis.

Using immunoelectrophoresis, Mackiewicz and Fenrych (1961) found broader and more intense IgM precipitation lines in sera from patients with ankylosing spondylitis (AS). Kriegel, Burger, Kapp, and Alexopulos (1969) determined Ig levels in AS by single-radial immunodiffusion (Mancini, Vaerman, Carbonara, and Heremans, 1964) and reported a rise of the IgA level. Using the same technique, Langness, Banavsky, Alexopulos, Kriegel, and Burger (1971) found increased IgG and IgA serum levels in patients with AS. These authors did not consider the frequency distribution of the results nor the age distribution of the groups investigated. We have determined the IgG, IgM, and IgA concentration in AS with the linear plate immunodiffusion technique (Wieme and Veys, 1970; Veys, 1971), and have compared the results with the Ig levels found in a normal population (Veys, Wieme, and Vuylsteek, in press) and in patients with rheumatoid arthritis (Veys, 1971). The patients with AS were then subdivided into groups to look for correlations between Ig levels and duration and activity of the disease.