Clinical features of liver dysfunction in collagen diseases
Liver dysfunction is not rare in patients with collagen disease. We sought to elucidate the clinical features of liver dysfunction in the presence of collagen disease. We analyzed the frequency and causes of liver dysfunction in 607 patients (rheumatoid arthritis [RA], n = 220; systemic lupus erythematosus [SLE], n = 164; systemic sclerosis [SSc], n = 47; Sjögren's syndrome [SjS], n = 44; Behçet's disease, n = 43; polymyositis/dermatomyositis [PM/DM], n = 27; vasculitis syndrome, n = 25; mixed connective tissue disease [MCTD], n = 21; and adult-onset Still's disease [AOSD], n = 16). Liver dysfunction was observed in 238 (39.2%) of 607 patients showing collagen disease. Patients with AOSD (81.3%), PM/DM (51.9%) and vasculitis syndrome (48.0%) frequently displayed liver dysfunction. Liver dysfunction in collagen diseases results from many causes; drug-induced liver injury (26.1%), fatty liver (7.6%), viral hepatitis (1.3%), autoimmune hepatitis (4.2%), primary biliary cirrhosis (15.9%) and the collagen disease itself (15.5%). Conversely, primary biliary cirrhosis was a leading cause in SSc (76.1%) and SjS (70.0%). Liver dysfunction in collagen disease tended to be mild. In addition, alanine aminotransferase levels correlated positively with ferritin levels in AOSD (R = 0.708, P < 0.05). Moreover, alkaline phosphatase levels correlated positively with C reactive protein levels in vasculitis syndrome (R = 0.833, P < 0.05). Liver dysfunction in the presence of collagen disease has various causes, and dysfunction associated with collagen disease reflects the activity of the collagen disease itself.