Epithelial class II MHC antigen normally expressed by submandibular glands of elderly people.

Immunohistochemical studies were made on 81 submandibular glands obtained from over 60-year-old autopsy cases. Those patients who had had either sialolithiasis or autoimmune diseases were not included in this study. HLA-DR expression was observed in the great majority (95.1%) of the aged submandibular glands, especially on the serous acinar cells and the intercalated duct cells, regardless of the appearance of focal lymphocytic infiltration. The incidence of HLA-DP expression was slightly lower (85.2%) and HLA-DQ was much lower (42.0%) than that of HLA-DR. These data support the proposal that epithelial expression of class II antigens in aged glands is a focal sign of age-related immunological disorders.