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 > or = 1:40 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.