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
ALP: Alkaline Phosphatase; GGT: Gamma-glutamyl Transpeptidase; AMA: Antimitochondrial Antibodies; ALT: Alanine Transaminase; IgG: Immunoglobulin G; SMA: Smooth Muscle Antibodies
Table 1: Paris criteria [10].