AN IMMUNOHISTOCHEMICAL STUDY OF IMMUNOLOGICAL PHENOMENA IN MINOR SALIVARY-GLANDS IN PATIENTS WITH SJOGRENS-SYNDROME

Using different monoclonal antibodies, we performed an immunofluoresce nt technique on labial salivary glands in order to investigate the imm unological phenomena involved in Sjogren's syndrome (SS). An aberrant expression of HLA-DR molecules was detected on cytoplasm of epithelial labial salivary cells in 9 out of 19 (47%) patients, with SS. No such expression was found in 8 patients without SS or in 3 normal controls . HLA-DQ molecules were demonstrated also in two out of ten SS patient s without HLA-DR. A lymphocytic infiltration was not correlated with t he expression of class II molecules. T cells bearing gamma delta recep tors were not detected. The intracellular adhesion molecules (ICAM-1) and lymphocyte function associated antigen-1 (LFA-1) were not found on epithelial glandular salivary cells of patients and controls. In conc lusion, these data suggested that the absence of ICAM-1 and LFA-1 in s alivary cells and the absence of infiltrating T cells bearing gamma de lta receptors exclude their immunopathogenetic role in SS; moreover, t hese data demonstrated that the aberrant expression of HLA class II mo lecules on epithelial salivary cells of patients with SS is not a phen omenon correlated with the lymphocytic infiltration.