Figure 1.

Basal keratinocytes can express TSHR and TG, which can be recognized by TRAb and TGAb in HT patients; circulating TPOAb may cross-react with unknown proteins on keratinocyte membranes. Once bound to the targets on the keratinocyte surface, thyroid autoantibodies may trigger apoptosis of basal keratinocytes. Antigen-presenting cells phagocytose the apoptotic bodies from basal keratinocytes and present them to T helper cells, which in turn stimulate cytotoxic T cells against basal keratinocytes. Activated CD8+ cytotoxic T cells can release chemokines that attract additional lymphocytes and other immune cells into the developing OLP lesion.