Studies on the immunological abnormalities in patients with Behcet's disease. Part 2. Autoantibodies and immune complexes in patients with Behcet's disease.

The incidence of various autoantibodies and immune complexes in 66 patients with Behcet's disease was studied. (1) Antilymphocyte antibody(ALA) was detected in 17(54.8%) out of 31 cases, antinuclear antibody(ANA) in 9(13.6%) out of 66 cases, antithyroglobulin antibody (TGHA) in 2(6.1%) out of 33 cases, antimicrosomal antibody(MCHA) in 5(13.9%) out of 36 cases and rheumatoid factor(RF) in 1(1.5%) out of 66 cases. These antibodies tended to be found in the incomplete type of Behcet's disease. (2) Immune complexes were detected in 1(5.3%) out of 19 cases by Clq solid-phase radioimmunoassay and in 8(42.1%) out of 19 cases by conglutinin solid-phase radioimmunoassay, demonstrating a considerable difference in sensitivity depending on the assay system. (3) Antinuclear antibody was found often in the cases without steroid therapy. The staining pattern was speckled, and the titer was low, up to 32 fold. (4) Antilymphocyte antibody was of a lower titer than SLE but. showed the same titer as the patients positive for HBs antigen. The immunoglobulin class was mainly IgM, and 6 out of 15 cases showed cytotoxicity against T cell. ALA was not inversely proportional to the peripheral blood lymphocyte count and showed low values in patients administered steroid hormone. Autoantibodies such as ALA and immune complexes were detected in patients with Behcet's disease, suggesting that the autoimmunization mechanism existed in patients with Behcet's disease. ALA was found at the high incidence of 72.2% in the incomplete type of Behcet's disease. Thus, it appears necessary to restudy this disease from the standpoint of viral infection.