Anti-nucleosome autoantibodies as markers for autoimmune hepatitis and their correlation with disease activity

Aim: To assess the prevalence of autoantibodies against nucleosomes (anti-nucleosome Ab) in patients with autoimmune hepatitis (AIH), examine the correlation between anti-nucleosome Ab and disease activity, and evaluate the effectiveness of anti-nucleosome Ab in predicting relapse.

Methods: We analyzed serum anti-nucleosome Ab levels in 38 patients with AIH by enzyme-linked immunosorbent assay, and assessed their correlation with clinical characteristics.

Results: Anti-nucleosome Ab levels were significantly higher in AIH, but not in patients with chronic hepatitis B (n = 20) or chronic hepatitis C (n = 20), compared to healthy controls (n = 15). The positive prevalence of anti-nucleosome Ab was 71.1% in AIH. Anti-nucleosome Ab levels were significantly lower during remission compared to that during flares within the same patients with AIH. Total bilirubin levels were significantly higher in patients with anti-nucleosome Ab levels of 53.7 U/mL or more compared to those with less than 53.7 U/mL at disease onset. Analysis of the reduction in anti-nucleosome Ab by immunosuppressive therapy in 16 AIH patients revealed that age at disease onset was significantly lower and IgG levels and relapse rates were significantly higher in patients with a reduction rate of less than 35% compared to those with a reduction rate 35% or more. The International Autoimmune Hepatitis Group score and γ-globulin levels were also higher in patients with reduction rates of less than 35% (borderline significance).

Conclusion: Anti-nucleosome Ab in AIH patients may be useful markers not only for disease diagnosis, but also for activity assessment and relapse prediction.