PRIMARY BILIARY-CIRRHOSIS AN EPITHELITIS - EVIDENCE OF ABNORMAL SALIVARY-GLAND IMMUNOHISTOCHEMISTRY

Primary biliary cirrhosis (PBC) is an autoimmune liver disease of unkn own etiology. Nearly 93% of patients with PBC exhibit evidence of foca l sialoadenitis. In an earlier study, we reported evidence of aberrant expression of PDC-E2, or a mimeotope, in the salivary glands of patie nts with PBC that had Sjogren's syndrome. At the time of the previous study, data was not yet available regarding patients with PBC without sicca complaints. Therefore, to investigate the extent of salivary gla nd involvement in PBC, we collected lip biopsy sections from 9 PBC pat ients diagnosed as PBC by liver biopsy, without clinical or histologic features of Sjogren's syndrome and 9 PBC patients with established Sj ogren's syndrome. Using immunohistochemical staining with both a murin e monoclonal antibody. C355.1, and a human combinatorial antibody, SP4 , we examined the ducts of these salivary glands for the presence of t he characteristic aberrant staining pattern found in patients with PBC , We report that 6/9 PBC patients fulfilling established Sjogren's syn drome criteria and 6/9 PBC patients lacking features of Sjogren's synd rome showed intense staining of the ductal epithelial cells of the sal ivary gland. These data suggest that the PBC-specific antigen recogniz ed by C355.1 and SP4 in bile duct epithelial cells is expressed aberra ntly in the salivary gland in 66% of patients with PBC, independent of Sjogren's syndrome. This finding suggests a common disease process in these two tissues. Further, expression of this molecule may be an ear ly marker of salivary gland involvement in patients with PBC.