Sjögren's Syndrome—Newer Aspects of Research, Diagnosis, and Therapy

Abstract

Recent advances in the study of Sjögren's syndrome include detection of antisalivary duct antibody (ASDA) in patients' sera, development of sensitive techniques to evaluate salivary glandular function by scintigraphy, classification of salivary glands obtained from lip biopsies according to the extent of lymphoid infiltration, and demonstration that these lymphoid cells actively synthesize significant amounts of IgG and especially of IgM, including rheumatoid factor. The syndrome presents against a broad spectrum of lymphoproliferation, from benign disease, through nonmalignant extraglandular lymphoproliferation ("pseudolymphoma"), to frankly malignant disease, either macroglobulinemia or lymphomas. The relationships between scintigraphic and histologic classification, the presence of ASDA, serum levels, and lip biopsy synthesis of IgM and rheumatoid factor, and the clinical course are discussed. Implications for therapy with immunosuppressive drugs are briefly explored. Possible mechanisms are pointed out that may help explain the pathogenesis as genetic factors leading to an immunologic imbalance between cellular and serologic response, with viral antigens playing a role.