Autoimmune hepatitis

Circulating autoantibodies have come to play a significant role in the diagnosis of AIH. They occur in the majority of patients, although their role in pathogenesis is debatable. There is no clear correlation between the disease activity or prognosis and the antibody titer.

The following autoantibodies are associated with AIH: antibodies against cell nuclei (ANA), native DNA, smooth muscles (ASMA, most important target antigen: F-actin), SLA/LP, liver-kidney microsomes (LKM-1, target antigen: cytochrome P450 IID6) and liver cytosolic antigen type 1 (LC-1, target antigen: formiminotransferase cyclodeaminase). Of all of the antibodies, autoantibodies against SLA/LP, which can today be detected by various EUROIMMUN enzyme immunoassays, have the highest specificity for AIH. Anti-SLA/LP antibodies occur in AIH either alone or together with other autoantibodies. Their prevalence is only between 10% and 30%, but the predictive value is almost 100%. Furthermore, high concentrations of antibodies against smooth muscles (ASMA) indicate AIH. A large part of the antibodies is directed against conformational epitopes of F-actin, which are best preserved in frozen tissue sections or tissue cells. In contrast to other ASMA, antibodies against F-actin are a very specific marker for type I AIH. In addition to the determination on triple sections of rat tissue (liver, kidney, stomach; LKS), the cell line VSM47 (vascular smooth muscle) allows to easily and clearly differentiate the microfilamentous (MF) fluorescence patterns from non-MF patterns, thus facilitating the diagnosis of type I AIH using indirect immunofluorescence tests. Our EUROLINE Autoimmune Liver Diseases profiles are multiparametric line blots that enable efficient confirmation of all relevant autoantibodies.