[Lymphocyte subsets in labial salivary gland of Sjogren's syndrome].

Using the immunohistochemical avidin-biotin-peroxidase complex (ABC) method, lymphocyte subsets in the salivary glands of 15 patients with primary Sjogren's syndrome, 7 patients with secondary Sjogren's syndrome and 4 normal controls were identified by monoclonal antibodies. The infiltrating lymphocytes were mainly T lymphocytes, the majority of which were T helper cells (Leu-3a) in SS groups. The Leu-3a/Leu-2a ratio was increased. These changes were related to the degrees of the disease. The lymphocytes of patients expressed the HLA-DR antigen (Ia). Thus genetic predisposition plays an important role in the disease. A proposed mechanism is that the deficiency of suppressor lymphocytes and the overactivity of helper lymphocytes would result in B cells becoming hyperactive. Multiple autoantibodies produced by the B cells would contribute to tissue damage, and the tissue fragments would in turn further stimulate antibody production.