Significance of antibodies to soluble liver antigen/liver pancreas: a large French study

Antibodies to soluble liver antigen (SLA)/liver pancreas (LP) are generally considered as highly specific diagnostic markers of type 1 auto-immune hepatitis (AIH-1), and are particularly useful in patients without conventional antibodies. However, the presence of anti-SLA/LP in type 2 auto-immune hepatitis (AIH-2), primary sclerosing cholangitis (PSC) and hepatitis C has recently been reported. The aim was thus to describe the characteristics of anti-SLA/LP-positive patients in the largest series reported to date. Sera were selected from the period between 1998 and 2005, based on the presence of antibodies to SLA/LP detected by two methods. The clinical status of patients was determined from their medical records. Eighty-one anti-SLA/LP-positive patients with available clinical data were included: 89% (72/81) had a diagnosis of AIH-1, including 10 (12%) associated with cholestatic diseases (primary biliary cirrhosis in seven cases and PSC in three cases). Six patients (7%) suffered from another liver disease: hepatitis C (n=3) and drug-induced hepatitis (n=3). No specific diagnosis was made in three patients. Antibodies to SLA/LP are of a major diagnostic value for AIH-1, including paediatric forms and overlap syndromes with cholestatic diseases, but are not found in association with anti-liver/kidney/microsome type 1 or antibodies to liver cytosol type 1. They are rarely present in other liver diseases such as hepatitis C and drug-induced hepatitis.