Biotin-related proteins of 70 and 72 kDa in gallbladder bile in primary biliary cirrhosis

Primary biliary cirrhosis (PBC) is an autoimmune liver disease characterize d by serum antimitochondrial antibody mainly reacting with inner lipoyl dom ain of E2 subunit of pyruvate dehydrogenase (PDC-E2). Lipoyl domain of PDC- E2 has sequence homologies with biotinylated site of biotin enzymes. This b iotin-related protein and the C355.1 reactive antigen were surveyed by West ern blotting in gallbladder bile samples from 27 patients with PBC and from 23 patients with other hepatobiliary disease. Biotin-related proteins of 7 0 and 72 kDa were detected in 89% of PBC samples, whereas it was infrequent ly detected in 48% of control samples (P < 0.01). C355.1 reactive antigen o f 64 kDa was detected in 22% of PBC samples and 8.7% of control samples (P > 0.01). This biotin-related proteins of 70 and 72 kDa may refer to the pat hogenesis of PBC. (C) 1999 Elsevier Science Ireland Ltd. All rights reserve d.