ANTISALIVARY ANTIBODIES IN PRIMARY SJOGRENS-SYNDROME

Earlier studies have described an antibody that recognized salivary du ctal epithelium in sera from 15-50% of patients with primary Sjogren's syndrome; however, the specific salivary antigen in those studies was not identified The present study further investigated this unknown sa livary antigen. Twenty-nine of 31 patients (94%) with primary Sjogren' s syndrome demonstrated IgG antinuclear antibodies that bound to an ep ithelial cell line with ductal characteristics derived from a human sa livary gland. Seventy-seven percent of these patients had serum antibo dies that bound to ductal cells of normal human parotid tissue after f ormalin fixation. Western blots of cell extracts, immunofluorescence, and adsorption studies indicated that SS-A/Ro and SS-B/La were the ant igens recognized in the salivary cell line. The pattern of fluorescenc e seen when anti-SS-B/La bound to normal parotid tissue was identical to the fluorescence pattern of the anti-salivary ductal antibodies des cribed in earlier literature.