Apoptosis and cell proliferation: the paradox of salivary glands in sjögren’s disease

Abstract

Aim: To assess apoptosis and proliferation in salivary glands of patients with primary Sjögren’s syndrome. Methods: Studies were performed in twenty four minor salivary glands from patients with primary Sjögren’s syndrome and an equal number of controls. Apoptosis was studied by immunohistochemistry using monoclonal antibodies anti-Fas, FasL and Caspase 3 and apoptotic features by TUNEL. Proliferation was assessed with monoclonal anti-PCNA and anti-Ki67 antibodies. Results: All salivary glands from Sjögren’s display apoptotic molecules along the epithelia of salivary ducts, and in a smaller amount in acinar tissue. The presence of Caspase 3, Fas/FasL was concordant with the expression of apoptosis by TUNEL. Proliferation markers were encountered in inflammatory emigrant cells, but not in ductal epithelia nor in acini. Control biopsies poorly expressed apoptotic or proliferation markers. Conclusion: Present data suggests that the ductal epithelial and acinar cells of salivary glands from Sjögren’s disease patients exhibit increased apoptosis. Proliferation was mainly observed in infiltrating lymphoid cells. Both events constitute a biological paradox related to the inflammatory process of salivary glands in Sjögren’s disease.