IMMUNOHISTOCHEMICAL CHARACTERIZATION OF THE CELLULAR INFILTRATES IN SJOGRENS-SYNDROME, RHEUMATOID-ARTHRITIS AND OSTEOARTHRITIS WITH SPECIALREFERENCE TO CALPROTECTIN-PRODUCING CELLS

The aim of this study was to analyse the nature of infiltrating cells in minor salivary glands of patients with Sjogren's syndrome (SS). Fur thermore, we wanted to characterize the tissue distribution of calprot ectin-producing cells in inflamed salivary gland tissue of SS and in s ynovial tissue of patients with rheumatoid arthritis (RA) and osteoart hritis (OA). Cryostat sections of labial salivary gland tissue from pa tients with SS and synovial tissue from RA and OA patients were staine d (ABC-immunoperoxidase technique) using monoclonal antibodies (MoAbs) to T cells (CD3), monocytes/macrophages (CD14, CD68), and calprotecti n. Monocytes and macrophages were widely distributed in focal infiltra tes of salivary gland tissue from SS patients. Calprotectin markers sh owed a distinct staining of infiltrating macrophages and around blood vessel walls. In synovial tissue samples, calprotectin was expressed i n a high percentage of cells in the synovial lining, the subsynovium, and vessel walls. The percentages of cells stained for calprotectin we re significantly higher in RA than in OA and SS tissues. Antibodies to the calprotectin complex stained cells with a similar distribution as antibodies against the separate polypeptide chains of calprotectin. T he localization and differentiated expression of calprotectin in these chronic inflammatory conditions indicate a role in the inflammatory p rocess and may be an additional marker of macrophages/granulocytes in SS, RA and OA.