Anti-heat shock proteins autoantibodies in autoimmune thyroiditis. Preliminary study

No data are currently available on the humoral autoimmune response against self heat shock proteins (hsps) possibly occurring in patients suffering from autoimmune thyroid disorders. Therefore, a preliminary research was carried out to assess whether anti-self hsps autoantibodies are present in human autoimmune thyroiditis (AIT). Serum samples from 14 patients with AIT were tested both in western blotting and in ELISA for antibody binding to protein extracts of human cultured cells (both unstimulated and heat-shocked) as well as to purified hsp 73 and hsp 72. It was found that 7 out 14 (50%) patients with AIT have autoantibodies of the IgM isotype strongly reacting with hsps 73/72. By contrast, autoantibodies to hsps 73/72 were detected only occasionally in sera from patients suffering from non-autoimmune thyroid disorders (1 out 11) as well as in sera from healthy individuals (2 out 9). No obvious clinical differences were detected between AIT patients who had autoantibodies to hsps 72/73 and those who did not. Clearly, more patients would have to be examined to determine whether the anomalous anti-hsps 73/72 autoimmune response occurring in a significant proportion of patients with AIT is in some way related to the pathogenesis and/or to the progression of the disease.