Objective: The expression of Fas antigen on ductal epithelial cells of sialoadenitis was examined in patients with Sjögren's syndrome (SS) and in normal subjects.
Methods: Minor salivary glands from the SS patients were examined by an immunohistochemical method using a new monoclonal antibody to the Fas antigen.
Results: In two patients with severe sialoadenitis, Fas was strongly expressed on the ductal epithelial cells. By contrast, the Fas antigen was not seen in the minor salivary glands of normal subjects nor in those with mild sialoadenitis.
Conclusion: This finding suggests that the Fas antigen may play a role in the pathogenesis of sialoadenitis in SS by providing a specific target for cytotoxic T cells expressing the Fas ligand.