Immunopathological features of primary Sjögren's syndrome.

When the immunopathological features of primary Sjögren's syndrome (SS) are outlined, three questions may be asked. Firstly, how is auto-immunity triggered off? The arguments which suggest that viruses play a role are discussed and the key role of the genetic background is emphasized. Secondly, why does the auto-immune vicious circle operate? Lymphocyte proportions, activation markers and functions are analysed in the peripheral blood and in the salivary glands. Thirdly, how do SS lesions occur? Although their physiopathological role is not well defined, a myriad of organ-specific or non organ-specific autoantibodies are observed. In addition to this B-lymphocyte polyclonal activation, apparently there is an early monoclonal proliferation in the course of the disease.