Prevalence of Yersinia plasmid-encoded outer protein (Yop) class-specific antibodies in patients with Hashimoto's thyroiditis

Objective To investigate the prevalence of class-specific antibodies (IgG, IgA) to Yersinia enterocolitica a plasmid-encoded outer proteins (Yops) in patients with diagnosed Hashimoto's thyroiditis. Methods Seventy-one patients with Hashimoto'S disease, 464 healthy blood do nors and 250 patients with non-postinfectious rheumatic disorders (matched controls) were tested for class-specific antibodies to Yops. Anti-Yop antib odies were determined by ELISA and Western blot. Results The prevalence of class-specific antibodies to Yops as determined b y ELISA was 14-fold higher (20 of 71; 28.2%) in people with Hashimoto's thy roiditis than in the two control groups. These results were confirmed by th e Western blot, with 16 positive sera, three equivocal and one negative. Conclusions There is strong clinical and seroepidemiologic evidence for an immunopathologic causative relationship between Yersinia enterocolitica inf ection and Hashimoto's thyroiditis. Further investigation concerning the me chanisms involved and the possible effects of antibacterial chemotherapy on the outcome of Hashimoto's disease is warranted.