[Immunohistochemical studies of mononuclear cellular infiltrates of papillary, follicular and anaplastic thyroid cancers]

The mononuclear cellular infiltrate of thyroid neoplasms was examined by immunohistochemical techniques and compared to normal thyroid (control 1) and untreated Graves' disease tissue (control 2). Using a panel of monoclonal antibodies T-, B cells and macrophage antigens as well as the expression of activation-associated antigens and of MHC class II molecules were examined. In comparison to control 1 an increase of positive cells could be detected in carcinomas. This increase was significant for CD3+ and CD8+ T cells, for CD4+ macrophages and for HLA-DP+ cells in all types of carcinomas. In addition, in anaplastic carcinomas a significant increase of B cells, RM3/1+ macrophages, IL-2R+, ICAM-1+ and HLA-DQ+ cells was observed as well as of HLA-DR+ cells in follicular and of CD4+ T cells in papillary carcinomas. A comparison with control 2 revealed a significant increase of CD4+ cells (T cells and macrophages) in papillary and of CD8+ and RM3/1+ cells in anaplastic carcinomas. Our findings, an obvious increase of cell populations and of an upregulated expression of activation-associated antigens on these cells, indicated an immunological reaction caused by neoplastic thyrocytes. Further functional studies are however necessary.