As shown in Table 2, the reactivity of IgA antibodies in BD sera was 9–12 %, in culture-positive AE sera 35–45 % (p < 0.001), in GBS sera 48–55 % (p < 0.001), in RA sera 34–40 % (p < 0.05) and in IBD sera it was 26–31 % (p < 0.05). This evidence concerns the gene CD79A and Behcet disease.