[Review of overlap syndromes in autoimmune liver diseases. Diagnostic and therapeutic difficulties].

Overlap syndromes are biochemical, serological, histological and radiological overlaps across the classic autoimmune liver diseases in the presence of autoimmun hepatitis and primary biliary cirrhosis or primary sclerosing cholangitis. The exact prevalence of the disease is not known, but it may vary between 5% and 20%. Because it has no generally accepted diagnostic criteria, clinical signs, biochemical, serological, radiological and histological findings are evaluated together. Treatment depends on the predominant feature of the overlap syndrome; ursodeoxycholic acid and/or immunsuppressive (corticosteroid) treatment are used, based on observations from retrospective, non-randomized studies.