Immunohistochemistry of the B-Cell Component in Lower Lip Salivary Glands of Sjoegren's Syndrome and Healthy Subjects

Serial sections of lower lip salivary gland (LSG) biopsies were examined by immunohistochemistry, using a battery of B- and partly T-related antibodies (CD5, CD20, CD21, CD27, CD38, CD45RO, CD79a, Bcl-2 and Bcl-6) in different groups of subjects: healthy controls and clinically verified smoking or nonsmoking cases of primary Sjoegren's syndrome (SS). The purpose was to characterize the B-cell pattern of the lymphocytic foci and of the tiny perivascular infiltrates preceding the development of foci. Hyperplastic tonsil was used as stain control. In normal LSG, widely dispersed CD38 super(+) and CD79a super(+) as well as some CD5 super(+) cells are a normal constituent, with lack of staining with the other antibodies. In SS-LSG, the lymphocytic foci showed staining with all the antibodies, with variable degrees of overlapping or nonoverlapping. In SS-LSG of nonsmokers, CD20 super(+) B cells make up a prominent part of the fully developed periductal lymphocytic foci, not overlapping with CD45RO. Also, CD20 super(+) B cells did not overlap in the infiltrates with colocalized CD27 super(+)-CD38 super(+) cells. CD20 super(+) B cells and CD45RO super(+) T cells also occur as minute infiltrates perivascularly in areas of no foci in SS-LSG as well as in SS smokers lacking the typical foci. Smokers lack foci, but tiny infiltrates express CD20 as well CD45R0. Our findings suggest that CD20 super(+) B cells and CD45RO super(+) T cells are early immigrants in the LSG of SS of smokers as well as nonsmokers and that another subgroup of CD27 super(+)-CD38 super(+) B cells gradually mix with the first two to form the characteristic foci in SS-LSG. The simultaneous demonstration of CD20 super(+) and CD27 super(+) B cells in SS-LSG may constitute a significant diagnostic tool. Further, the findings suggest that the early immigrating lymphocytes may have been primed at a site remote from the glands before arriving via the blood to the gland tissue.