Expression of cyclooxygenase-1 (COX-1) in labial salivary glands of Sjogren's syndrome

COX plays an important role in inflammatory diseases such as rheumatoid art hritis. To determine the role of COX in Sjogren's syndrome (SS), we examine d COX expression in the salivary glands of SS patients. We examined 15 pati ents with SS and two normal subjects. Labial salivary gland tissue samples were analysed immunohistochemically using anti-COX-1 and COX-2 antibodies. All biopsy samples from 15 patients with SS were stained for COX-1. In cont rast, COX-1 immunostaining was not detected in normal salivary gland tissue s. Co-expression of COX-1 and CD68 was confirmed by mirror section techniqu e and double antibody immunostaining. This finding indicated that COX-1-exp ressing cells in SS salivary glands were infiltrating macrophages. In contr ast to COX-1 staining, only a little COX-2 immunostaining was observed in s alivary gland tissues from SS patients. These data suggest that COX-1 expre ssion on infiltrating macrophages may contribute to the inflammatory proces s of salivary glands in SS.