Sjögren's syndrome (SSj) is a chronic autoimmune disorder characterized by lymphocytic infiltration of the exocrine glands with concomitant destruction of the glandular tissue, affecting predominantly salivary and lacrimal glands. The inflammatory infiltrate begins around ductal epithelial cells, extending and replacing the functional tissue. It consists predominantly of CD4+ T cells, with fewer CD8+ T cells, B cells, and plasma cells. The plasmacellular infiltrate consists of large amounts of IgG and IgM containing plasma cells. Some studies have revealed a predominant Th1 pattern of cytokines and chemokine expression in minor salivary glands of SSj patients. An increased expression of vascular endothelial and lymphocyte adhesion molecules was found on the minor salivary glands of patients with SSj. It was documented that glandular epithelial cells of SSj patients express HLA-DR antigens, and that structures resembling ectopic germinal centers were found in minor salivary glands of SSj patients. The mechanisms that initiate the inflammatory process in minor salivary glands of SSj patients remain unknown, but recent studies have shown that the glandular epithelial cells of SSj patients have a role in the pathogenesis of the disease.
Sjögren's syndrome; minor salivary glands; histopathology
