Autoimmune hepatitis

Clinical information

Autoimmune hepatitis (AIH; previously called lupoid hepatitis, chronic active hepatitis) predominantly affects women (75 % of cases). The disease manifests by an increase in bilirubin, liver enzyme and immunoglobulin levels and by characteristic histological changes seen on liver biopsy: necrosis of the parenchyma cells with lymphocyte and plasma cell infiltration. Various autoantibodies occur as well. The disease can occur from early childhood up to old age but is most frequent in young to middle adulthood. In Western Europe the incidence of AIH is 1.9 cases per 100,000 inhabitants per year. Untreated, AIH soon develops into liver cirrhosis. However, with timely low-dose immunosuppressive therapy given consistently for the rest of the patient’s life, life expectancy is normal. Differential diagnostics should include hepatitis virus infection, ruled out by testing for the appropriate serological parameters.

Diagnostics

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 the pathogenesis is still unclear. There is also 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 2D6) and liver cytosolic antigen type 1 (LC-1, target antigen: formiminotransferase cyclodeaminase). Of all of these 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 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. The VSM47 (vascular smooth muscle) cell line allows fibrillar fluorescence patterns to be easily and reliably distinguished from non-fibrillar patterns, facilitating the diagnosis of type 1 AIH by indirect immunofluorescence. In addition, the determination on triple sections of rat tissue (liver, kidney, stomach; LKS) can be used for diagnosis. The multiparametric line blots – EUROLINE Autoimmune Liver Diseases profiles – enable efficient confirmation of all relevant autoantibodies.

Files

Autoimmune liver diseases

Serology of autoimmune hepatitis and primary biliary cholangitis

EUROLINE Profiles Autoimmune Liver Diseases