Lymphocytotoxic Antibody in Sj 6 gren ' s Syndrome

The autoimmune mechanism in Sj6gren's syndrome (SjS) and the close association of this syndrome with systemic lupus erythematosus (SLE) haye been suggested in seyeTal reports. Although the pathelogical significances of Iymphecytotoxic antibody is obscurc, possible roles of this antibody in the pathogenesis of autoimmunity have been speculated. The purposes of the present study were to demonstrate lymphocytotoxic antibody, in sera of paticnts with SjS, and then to analyse various correlations of this antibody with clinical parameters of SjS, We detected cold-reactive lymphocytotoxic antibody not only in most C86.4%) of the patients with SLE, but also in many patients with SjS {51.6%; cxcluding SjS patients with SLE), rheuTnatoid arthritis (RA; Sl.6%) and myasthenia gravis (MG; 36,4%), which are considered to be autoimmune diseases. On the other hand, Iymphocytotoxic antibody was detectcd in only one (5.6%) of eighteen healthy persons. We also confirmed that the cold-reactive lymphocytotoxic antibody detected in SLE is a 2-mcrcaptoethanol sensitive and T-lymphocytotoxic antibody. Frequent dernonstration (50%) of this antibody even in SjS patients without any associated diseases supports the immunological basis of SjS as well as yirological participztion in SjS, Although this antibody did not significantly coTrelate with most of the clinical parameters in SjS patients, this antibody may become a hallmark as one of imrnunological abnormalities in SjS, even though it was produced by non-specific lymphocyte activation.