[The clinical significance of aberrant HLA-DR antigen expression on thyrocytes]

500 Tru-cut thyroid tissue specimens were analyzed by ABC immunohistochemistry technique by using monoclonal antibodies specific for activated lymphocytes, cytokines and HLA-DR antigen. The study revealed that DR antigen expression on thyrocytes was positively correlated with the total number of thyroid infiltrating cells, the percentage of Tac + cells, TLiSA1 + cells, T9+ cells, interferon-r+ cells, interleukin-2+ cells, especially I2+ cells, tumor necrosis factor+ cells and also positively correlated with serum TSH, thyroid microsomal antibody, thyroid globulin antibody levels. The DR expression on thyrocytes was most intense in autoimmune thyroiditis, with subacute thyroiditis, thyrotoxicosis with thyroiditis, Graves disease, goiter following in sequence and thyroid tumor being the weakest. Thyroxine treatment can suppress DR expression on thyrocytes. Our data suggest that the extent of DR expression on thyrocytes may be regarded as a new important index for clinical diagnosis, prognosis and evaluation of the therapeutic results.