Anti-a actinin antibodies as new predictors of response to treatment in autoimmune hepatitis type 1

Abstract

Background We reported that combined presence of autoantibodies (Abs) against filamentous-actin (AFA) and a-actinin are specific for autoimmune hepatitis type 1 (AIH-1) diagnosis. Aim To explore our data and assess whether anti-a-actinin and AFA Abs could be used as indicators of response to treatment and predictors of AIH-1 flares in a large cohort of AIH-1 patients. Methods Seven hundred and sixty-four serial serum samples of 86 consecutive AIH-1 patients, 509 pathological and 110 normal controls were tested for the presence of anti-a-actinin and AFA Abs by an in-house IgG-specific ELISA and a standardised commercially available ELISA respectively. Patients sera were divided into baseline group (active disease before treatment initiation, n = 86) and then according to treatment response into group A-responders (n = 40 patients), group B-relapsers/incomplete responders (n = 37 patients) and group C-not-treated (n = 9 patients). Results Anti-a-actinin and AFA levels were significantly higher at baseline. Double reactivity against a-actinin and AFA was associated with disease activity (OR 4.9; 95% CI: 2.79). Anti-a-actinin optical densities (ODs) before treatment decreased significantly at first remission (P < 0.05). Treatment response was associated with anti-a-actinin Abs negativity before treatment (OR 3.4; 95% CI: 1.38.9) and absence of double positivity for anti-a-actinin and AFA Abs before treatment (OR 3.8; 95% CI: 1.410.4). Responders had lower baseline levels of anti-a-actinin than relapsers and/or incomplete responders (P = 0.002). Binary logistic regression revealed lower levels of anti-a-actinin as the only independent predictors of response (P = 0.05). Conclusions Anti-a-actinin Abs at baseline appear to predict treatment response and therefore they might be used for monitoring treatment outcome in AIH-1.