[Importance of gamma-interferon and DR expression in autoimmune thyroid disease]

The purpose of this paper is to study some of the mechanisms by which antigen presentation, one of the first steps in the immune process, is modulated. Three different experiments are performed: a) Using thyroid tissue from patients operated on for Graves' Disease, spontaneous HLA-DR and TPO antigen expressions were measured through the Cytotoxicity Assay; these findings were correlated with the presence of antiTPO in the sera of these patients. It was found that only patients whose thyroid tissue spontaneously expressed both antigens had circulating antiTPO in their sera, thus demonstrating that dual expression is basic for antibody production. b) Blood samples from other Graves' patients were obtained; peripheral lymphocytes were isolated and cultured in complete media for 5 days, then supernatant was separated and IFN-g concentration was measured by a sandwich type RIA; the same procedure was done in 12 normal controls in order to compare the results. It was found that lymphocytes from Graves' patients secreted significantly more IFN-g than normal controls (20.9 +/- 13.54 U/ml vs 3.7 +/- 3.22 U/ml respectively, p < 0.001) confirming that they were sensitized, so this determination could be used as a marker of immune process, if other infectious conditions are excluded; also it was found that IFN-g hypersecretion persists once hyperthyroidism has been treated, pointing out that the immune abnormality is still present.(ABSTRACT TRUNCATED AT 250 WORDS)