T cell subpopulations in the labial minor salivary gland histopathologic lesion of Sjögren's syndrome.

The majority of T cells constituting the focal lymphocytic infiltrates in the labial minor salivary glands of patients with Sjögren's syndrome bear the helper phenotype (CD4); activation is expressed by class II (HLA-DR) MHC products. In our immunohistologic study of snap frozen minor salivary gland biopsies from 16 patients with primary Sjögren's syndrome, it was shown that the majority (77%) of the infiltrating T cells exhibit the memory helper/inducer phenotype (UCHL-1) and express LFA-1 molecules. In addition most of the T cells express the alpha beta receptor while only 2.8% express the gamma delta receptor. Our findings suggest that these T cell infiltrates in patients with primary Sjögren's syndrome may explain the intense B lymphocyte hyperreactivity observed in the exocrine glands of patients with Sjögren's syndrome.