INTERFERON-GAMMA AND EPITHELIAL-CELL ACTIVATION IN SJOGRENS-SYNDROME

We have examined the hypothesis that interferon-gamma (IFN-gamma) and its interaction with epithelium may play a role in the perpetuation of inflammation in Sjogren's syndrome (SS). Labial salivary gland primar y cell cultures from 16 patients with primary SS (pSS) and eight cultu res from patients with SS symptoms but histologically normal biopsies were examined for expression of HLA-DR and cytoplasmic La (SS-B). Epit helial HLA-DR expression was found in 80% of cultures from pSS patient s and 38% of those from patients not fulfilling diagnostic criteria. C ytoplasmic La was detected in 50 and 38% of cultures, respectively. Tr eatment of 14 of the cultures with IFN-gamma increased HLA-SR and cyto plasmic La expression above that of untreated cultures. Depletion of I FN-gamma using neutralizing antibody had the reverse effect. These fin dings suggest that the perpetuation of chronic inflammation of pSS may be due to the induction of HLA-DR and La antigen expression on epithe lial cells by IFN-gamma.