Lymphoid complement of the human salivary glands: function and pathology.

In normal human salivary glands the Duct-Associated Lymphoid Tissue (DALT) is poorly developed. In contrast, in the course of autoimmune disorders, typified by Sjögren's syndrome (SS), organized lymphoid accumulations are formed around the ducts. B cell-dependent zones with secondary follicles and T cell-dependent zones with HEV are detected in these lymphoid structures. In addition, the duct epithelium is infiltrated by abundant lymphocytes. A persistent antigenic stimulation may lead to development of B-cell Mucosa-Associated Lymphoid Tissue (MALT) lymphomas that, in low-grade cases, maintain the lobular organization of normal and of SS salivary glands.