Lack of in vitro effect of antithyroid drugs upon peroxidase antigen expression in autoimmune thyroid disease Ausencia de efecto in vitro de las drogas antitiroideas sobre la expresion del antigeno peroxidasa en las enfermedades autoinmunes del tiroides.

Abstract

The aim of this study is to determine whether antithyroid drugs (ATD) act via inhibiting thyroid hormone synthesis or by interfering with the immune process which leads to autoimmune disease. Previously we had demonstrated that ATD do not affect HLA-DR and TPO antigen expressions induced by appropriate stimulus in normal thyrocytes, so we decided to study what happens when the same experiments are performed using autoimmune thyrocytes. Cultured thyroid tissue from patients operated on for Graves' Disease or Hashimoto's Thyroiditis were stimulated with TSH or TBII alone or associated with ATD; TPO antigen expression was evaluated by the Cytotoxicity Assay using human monoclonal antiTPO. When autoimmune thyrocytes were cultured and no stimulus was used or with the addition of MMI or PTU alone, very low values of TPO expression were noted (8.6 +/- 6.7, 5.0 +/- 7.1 and 4.2% +/- 2.3% respectively); if they were stimulated with TSH or TBII, a sharp rise of TPO antigen expression was detected