To investigate the roles of T cells accumulating around the bile ducts, we analyzed the clonality of alphabeta T cell populations in the livers of patients with PBC by size spectratyping and sequencing of the T cell receptor (TCR) Vbeta transcripts.TCR Vbeta spectratyping of PBC patients showed several skewed complementarity determining region 3 (CDR3) size patterns suggestive of clonal predominance as well as Gaussian-like patterns suggestive of polyclonal expansion.