Age-related increase of focal lymphocytic infiltration in the human submandibular glands

Histopathological studies were made on the submandibular glands, obtained from 207 autopsy cases of patients, ranging in age from 40-98 years who had not had collagen diseases. Focal lymphocytic infiltration of the submandibular glands was more frequently seen in the cases of patients over 70 years (80.3%) than in those of under 70 years (53.8%). Generally, the incidence of focal lymphocytic infiltration showed a trend to gradual increase with age. Immunohistochemically, a predominance of T cells (60-80%) was found in submandibular lesions with the majority (60-70%) belonging to the Leu 3a+ subset (Helper/Inducer) and with less than 20% belonging to the Leu 2a+ subset (Cytotoxic/Suppressor). The percentage of Leu 2a+ subset was found to increase in the lesion of the periacinar area, and the acinar parenchyma appeared gradually to be damaged by the infiltrating lymphocytes. The findings in the present study suggest that focal lymphocytic infiltration in submandibular glands is a focal sign of immunological disorder, based on the autoimmunity associated with aging.