Abstract
In this article, the authors use the term “overlaps” to refer to the coexistence of
primary biliary cirrhosis (PBC) with another autoimmune condition that involves the
liver or extrahepatic organs. Diagnosing PBC-autoimmune hepatitis (PBC-AIH) overlap
syndrome remains a challenge, especially because there is still no consensus on the
most appropriate diagnostic criteria. The prevalence of this condition varies considerably
among series of PBC patients, and its treatment demands a combination of ursodeoxycholic
acid and immunosuppressive drugs. Overlap syndrome between PBC and primary sclerosing
cholangitis is described in exceptional cases. About one in three PBC patients have
a concomitant extrahepatic autoimmune disease, which may include rheumatological,
endocrinological, gastrointestinal, pulmonary, or dermatological conditions. Overlaps
raise several questions, about whether they share much the same genetic susceptibility,
as is generally assumed. The pathogenesis of these conditions includes the production
of both innate and adaptive immune responses targeting cholangiocytes as well as different
extrahepatic tissues. In this sense, overlaps in PBC represent a continuous spectrum
of autoimmunity involving liver and extrahepatic tissues.
Keywords
primary biliary cirrhosis - autoimmune hepatitis - overlap syndrome - Sjögren syndrome
- Hashimoto thyroiditis
