Clinical investigation of Primary Biliary Cirrhosis (PBC) patients showed an elevated frequency of rheumatic disorders, as well as their frequent appearance in asymptomatic PBC. Anticentromere region antibodies in PBC patients were pathognomonic for concomitant complete or incomplete CREST syndrome. These antibodies were only found on the HEp2 cell substrate. The constant finding of immune-complexes (IC) with IgM antibody component suggests that they play a role in the pathogenesis of PBC. No statistically significant correlation was found between the amount and classes of circulating IC, HLA class I antigens and rheumatic disorders during PBC.