Connective tissue diseases and the liver.

Connective tissue diseases such as systemic lupus erythematosus (SLE), rheumatoid arthritis, Sjögren's syndrome, and scleroderma are systemic disorders that may have an autoimmune basis. The system manifestations vary, and there is frequent overlap among the syndromes. Liver involvement in patients with connective tissue diseases has been well documented but is generally considered rare. Although advanced liver disease with cirrhosis and liver failure is rare in patients with connective tissue diseases, clinical and biochemical evidence of associated liver abnormalities is common. Previous treatment with potentially hepatotoxic drugs or coincident viral hepatitis has usually been implicated as the main causes of liver disease in patients with connective tissue diseases. However, even after careful exclusion of these etiologies, the question remains whether to classify the patient as having a primary liver disease with associated autoimmune, clinical, and laboratory features or as having liver disease as a manifestation of generalized connective tissue disease. The main example of this pathogenetic dilemma is autoimmune hepatitis and SLE-associated hepatitis, which have been regarded as two different entities, although they have features in common of autoimmune syndromes. Several clinical and histopathologic features have been used to discriminate autoimmune hepatitis from SLE, a relevant diagnostic exercise because complications and therapy are quite different. Although hepatic steatosis and abnormal results on biochemical liver function tests are the most common hepatic abnormalities associated with connective tissue diseases, other less frequent abnormalities have been noted, such as nodular regenerative hyperplasia, portal vein obliteration and portal hypertension, features of primary biliary cirrhosis, and rarely portal fibrosis with abnormal lobular architecture. Vascular disorders of the liver also have been described, such as Budd-Chiari syndrome. Histologic assessment may reveal a variety of subclinical liver diseases. The aim of this contribution is to review the current published data regarding liver involvement in connective tissue diseases.