Progressive destruction of the intrahepatic bile ducts in patients with primary biliary cirrhosis (PBC) is thought to be mediated by cytotoxic T cells which recognize certain epitopes, such as the pyruvate dehydrogenase complex (PDC). To clarify the T-cell repertoire in PBC, we analyzed T-cell receptor (TCR) Vbeta-chain messages expressed in peripheral blood mononuclear cells (PBMCs) stimulated with PDC and in liver biopsy specimens. PBMCs from 12 PBC patients and 6 healthy controls were examined. The TCR Vbeta repertoires of unstimulated PBMCs and PBMCs stimulated with PDC purified from bovine heart were analyzed, using the reverse transcriptase-polymerase chain reaction (RT-PCR) and single-strand conformation polymorphism (SSCP). Liver biopsy specimens from 5 PBC patients were also analyzed. In the PBC patients, several different T-cell clones, some of which showed the same mobility, were evident in both the PDC-stimulated and unstimulated PBMCs, as demonstrated by SSCP analysis. In addition, TCR clonality of infiltrating lymphocytes in the liver was also observed in PBC patients, showing common clonal T-cell accumulation with that seen in PBMCs stimulated with PDC. These data indicate that common clonal T-cell accumulation specific for PDC may be present in both peripheral PBMCs and the liver of patients with PBC.