**PBC criteria**:
1) serum ALP levels at least two times the upper limit of normal values or serum GGT levels as least five times the upper limit of normal values
2) a positive test for AMA
3) a liver biopsy specimen showing florid bile duct lesions |

**AIH criteria**:
1) serum ALT levels at least five times the upper limit of normal values
2) serum IgG levels at least two times the upper limit of normal values or a positive test for SMA
3) a liver biopsy showing moderate or severe periportal or periseptal lymphocytic piecemeal necrosis |

**PBC-AIH overlap syndrome**: both 2 out of 3 PBC criteria are met and 2 out of 3 AIH criteria are met either simultaneously or consecutively |