Sjögren's syndrome: histologic and immunohistochemical study.

Labial salivary gland tissues from 20 patients with primary Sjögren's syndrome (group 1), 26 with the secondary type of the disease (group 2), 16 patients with the incomplete form of the disease and 10 normal controls were examined for the presence of lymphocyte infiltrates, epithelial damages and plasma cell aggregates. Activated T lymphocytes of the helper phenotype predominated in groups 1 and 2. Aberrant epithelial expression of HLA class II molecules was found in the same group of patients, while IgG- and IgM- containing plasma cells were detected.