Immunohistologic markers of immune activation and changes of glycosylationof serum proteins in primary Sjogren's syndrome

Objective To assess the possible correlations between the immune activation of certai n surface antigens at the lip salivary gland (LSG) level, and changes in gl ycosylation of serum proteins in primary Sjogren's syndrome (SS). Methods LSG biopsy samples were obtained from 22 SS patients (mean age 56.3 years; mean disease duration 70.8 months) and prepared for immunohistochemical ana lysis using murine monoclonal antibodies for interleukin-2 receptor (IL-2R) (CD25) and for the class II major histocompatibility antigen HLA-DR. The g lycosylation of serum proteins was evaluated in all patients by an enzyme-l inked lectin assay (ELLA) using concanavalin A (Con A). Results In LSG specimens the presence of IL-2R was observed at the infiltrating lev el, mainly periductally, in 13 (59%) cases and on the epithelial cells of 1 4 (64%) patients. In 13 out of 22 SS patients (59%) a marked positivity bot h of the infiltrates and of the epithelium was found for anti-HLA-DR monocl onal antibody. The degree of expression of different antigens on LSG sample s was correlated with their histologic class according to Tarpley evaluatio n. The positivity for IL-2R and HLA-DR molecules on glandular tissues was c orrelated. A significant increase in the total Con A reactivity of serum pr oteins was found in those patients expressing IL-2R and HLA-DR antigens on LSG specimens. Conclusions The co-expression of IL-2R and HLA-DR antigens on both the epithelium and i nfiltrates of LSG is consistent with a participation of these cells in the immune process of SS. Moreover changes in the glycosylation of serum protei ns seem to be related to the presence of these immunoactivation markers of the disease at the LSG level, suggesting that the control of protein glycos ylation could be mediated by the same mechanisms involved in the tissue dam age of SS.