High levels of complement fixing antibodies against cytomegalovirus in patients with primary Sjögren's syndrome.

Antibodies to cytomegalovirus (CMV) were examined in sera from 21 consecutive patients with primary Sjögren's syndrome (SS) and 19 consecutive patients with secondary SS, using a complement fixation (CF) test and an antibody capture enzyme-linked immunosorbent assay (ELISA). Sera from 15 CMV-negative subjects, 15 CMV-positive subjects, 3 patients with primary CMV infection and 3 patients with recurrent CMV infection served as controls. The prevalence of CMV antibodies in the patients with primary and secondary SS was found similar to the prevalence known to occur in the normal adult population. Unrelated to clinical parameters, 5 patients with primary SS (24%) had high levels of CF antibodies against CMV. Ig class antibodies to CMV were not elevated in these 5 patients. Preferential production of CF antibodies to CMV may be a pathogenetic factor in some patients with primary SS.