CIRCULATING IGG COMPLEXES IN PRIMARY BILIARY-CIRRHOSIS - SERIAL STUDY IN 40 PATIENTS FOLLOWED FOR 2 YEARS

  • 1 January 1978
    • journal article
    • research article
    • Vol. 34  (1) , 19-27
Abstract
Several antibodies are present in sera of patients with primary biliary cirrhosis (PBC). Evidence of antigen-antibody complexes in sera of PBC were sought, assuming that some of the antibodies may circulate complexed with an antigen. The Raji [human Burkitt''s lymphoma] cell radioimmunoassay, which determines complement[c]-bound immune complexes, was used to determine the levels of such complexes in serial samples of sera from 40 patients with PBC followed for 2 yr. There were 24 patients (60%) with significantly elevated levels of circulating complexes. In most they were detected from the beginning of the study and the high levels persisted. In 7 patients whose sera initially had normal levels of complexes, the levels increased to become abnormal during the following year. These complexes sedimented at .gtoreq. 19S in most patients studied. The mean level of C3 but not C4 was lower in patients with elevated complexes than in those with normal complexes. A significant correlation was observed between the presence of elevated complexes and the severity of the inflammatory cell infiltrate surrounding intrahepatic portal tracts and serum Ig[immunoglobulin]G and IgM levels. There was also a significant correlation with titers of antimitochondrial antibody, but not with the histological stage of disease or with the collagen and Cu content of the liver. Although the method of detection of immune complexes is indirect and the antigen is unknown, the presence of such high levels of complexes suggests a possible role of immune complexes in the pathogenesis of PBC.