6Liver abnormalities in connective tissue diseases

The liver is a lymphoid organ involved in the immune response and in the maintenance of tolerance to self molecules, but it is also a target of autoimmune reactions, as observed in primary liver autoimmune diseases (AILD) such as autoimmune hepatitis, primary biliary cirrhosis, and primary sclerosing cholangitis. Further, the liver is frequently involved in connective tissue diseases (CTD), most commonly in the form of liver function test biochemical changes with predominant cholestatic or hepatocellular patterns. CTD commonly affecting the liver include systemic lupus erythematosus, antiphospholypid syndrome, primary Sjögren's syndrome, systemic sclerosis, dermatomyositis, polimyositis, and anti-synthetase syndrome, while overlap syndromes between AILD and CTD may also be diagnosed. Although liver cirrhosis and failure are extremely rare in patients with CTD, unusual liver conditions such as nodular regenerative hyperplasia or Budd-Chiari syndrome have been reported with increasing frequency in patients with CTD. Acute or progressing liver involvement is generally related to viral hepatitis reactivation or to a concomitant AILD, so it appears to be fundamental to screen patients for HBV and HCV infection, in order to provide the ideal therapeutic regimen and avoid life-threatening reactivations. Finally, it is important to remember that the main cause of biochemical liver abnormalities in patients with CTD is a drug-induced alteration or coexisting viral hepatitis. The present article will provide a general overview of the liver involvement in CTD to allow rheumatologists to discriminate the most common clinical scenarios.