Figure 1.

Immunohistochemical staining for HLA class I and VP1 in thyroid tissue samples from GD patients and controls. HLA class I and VP1 was found in more GD samples than controls. A, Positive HLA class I staining (brown color) in thyroid follicular cells in a new GD sample. B, Negative HLA class I staining in a control sample. C, Globally positive VP1 staining (brown color) in thyroid follicular cells in a chronic GD sample. D, Negative VP1 staining in a control sample. All samples stained with a standard horseradish peroxidase immunohistochemistry protocol. GD, Graves disease; HLA, human leukocyte antigen; VP1, enteroviral capsid protein 1.