Abstract :There is little known about the role of basement membrane and matrix proteins in the pathogenesis of salivary gland disease associated with Sjögren’s Syndrome (SS). Histologically, at the level of the light microscope, lymphocytic infiltration is by CD4 T cells.
Our laboratory has studied the basement membrane in salivary gland disease. Preliminary work indicates abnormalities in the major component of the basement membrane, laminin. This protein appears to be “trapped” intracellularly in the ductal and acinar epithelial cells as demonstrated by immunohistochemistry using specific monoclonal antibodies. It remains unclear whether the laminin dysregulation results from an anabolic or catabolic issue but investigations are ongoing at several levels. Preliminary transmission electron microscopic (TEM) studies on 6 patients have revealed variations in the basal lamina are suggestive of a general “narrowing” of this structure. In contrast, previously published studies report basal lamina “thickening” which is inconsistent with our observations and published data. The objective of the present study, therefore, is to attempt to resolve this discrepancy by carrying out sequential measurements on the basal lamina of ductal and acinar epithelium of diseased salivary glands by TEM from a larger group of patients (12) and compare them with controls. Results showed that there is a loss of the lamina lucida portion of the basal lamina, in spite of overall “thickening” that was characterized as structural disorganization. There was also a marked increase in intracellular acinar cell laminin, shown by immunohistochemistry and TEM, compared with healthy controls. The potential role of laminin dysregulation is discussed.