Establishment of standardised SLA/LP immunoassays: specificity for autoimmune hepatitis, worldwide occurrence, and clinical characteristics

Background: Antibodies to soluble liver antigen/liver pancreas (SLA/LP) are specific markers of autoimmune hepatitis. Their target antigen has recently been cloned. Aims: To establish standardised immunoassays using the recombinant antigen, and to assess the frequency and significance of seropositivity in patients from different countries. Methods: An enzyme linked immunoassay was developed using purified recombinant antigen and validated by testing sera from 200 healthy blood donors and 1026 patients with various liver and non-liver diseases. The assay was then applied to 454 sera from 419 patients with autoimmune hepatitis from different countries. All sera were also tested by inhibition …