Prevalence and significance of autoantibodies in patients with non-alcoholic steatohepatitis

Goals: The aim of this study is to evaluate the prevalence and the clinical and histologic correlates of autoantibodies in patients with nonalcoholic steatohepatitis (NASH). Background: Antinuclear antibodies (ANA) and anti-smooth muscle antibodies (ASMA) have been identified in patients with NASH. The significance of autoantibodies in NASH is uncertain. Study: Clinical data from patients with a histologic diagnosis of NASH at a university hospital in Chicago, Illinois between January 1999 and April 2003 were reviewed retrospectively. Seventy-four patients who were tested for autoantibodies and had no history of alcohol abuse or a systemic autoimmune disease were included. Demographic information and laboratory data were collected. Autoantibody titers greater than or equal to1:40 were considered positive. A single pathologist reviewed all liver biopsies and scored features of NASH and identified characteristics of autoimmune hepatitis. Results: Thirty-four percent of patients with NASH had positive ANA titers and 6% were ASMA positive. Demographic and laboratory parameters did not differ by ANA status, except that women were more frequently ANA positive then men (P = 0.01). The severity of steatosis, inflammation, and fibrosis on liver biopsy were similar in the ANA positive and negative groups. Only 15% of ANA positive patients with NASH had a plasma cell infiltrate on liver biopsy and there was no difference in the frequency of histologic features of autoimmune hepatitis between ANA positive and negative patients. Conclusions: Antinuclear antibodies are common in patients with NASH and most frequently represent a nonspecific antibody response that is not associated with the pattern or severity of injury on liver biopsy.