Abstract
Thirteen serum samples positive for anti-centromere antibodies (ACA) were selected from patients with primary biliary cirrhosis (PBC). Each IgG subclass of ACA was examined by the indirect immunofluorescent method using monoclonal antibody to human IgG subclass. ACA of IgG1 and IgG3 subclasses were positive in almost all sera with high titers of more than 1:320. ACA of IgG2 and IgG4 subclasses were negative in 6 and 7 out of 13 sera respectively, and the antibody titers in positive sera distributed widely from 1:40 to 1:2, 560. On the otherhand, antibodies to mitochondria (AMA) which often coexisted with ACA distributed similarly in the four subclasses.
In this study, we could not find any significant correlation between IgG subclass distribution of ACA and clinical features of PBC. However predominant restriction of ACA to IgG1 and IgG3 subclasses could speculate some pathogenetic abnormalities behind PBC.
