AUTOANTIBODY PANELS: LIVER
The Liver-antibody profile is a semi-quantitative membrane-fixed immunoblot assay for the serological detection of autoimmune hepatitis (AIH). By means of the simultaneous detection of antibodies against seven different antigens, the differentiation of different types of autoimmune hepatitis and the differentiation from other liver diseases is possible. The prognosis of autoimmune hepatitis can be significantly improved with the latest treatments, and so the timely diagnosis of autoimmune hepatitis is of great importance.
Through the detection of various autoantibodies this test offers a fast and reliable diagnosis of primary biliary cirrhosis (PBC), autoimmune hepatitis type 1 (AIH-1) and type 2 (AIH-2) as well as delimitation of these autoimmune disorders from other liver diseases. Probable diagnosis can be supported by demonstration of antibodies to asialoglycoprotein receptor, liver specific cytosolic antigen type 1, SLA/LP, and/or perinuclear antineutrophil cytoplasm.
Primary Biliary Cirrhosis:AMA-M2
The high sensitivity and specificity of M2 autoantibodies makes them excellent for the detection of primary biliary cirrhosis (PBC). AMA are detected in 90 to 95 % of PBC patients; and in up to 25 % of AIH patients (usually low titers). AMA-M2 are absent in 5% of PBC patients. In these cases, Sp 100 (anti-NPC) and gp210 antibodies are very diagnostically significant. Their detection is specifically indicative of primary biliary cirrhosis. PBC specific ANAs have been found more frequently in patients with advanced disease, the presence of anti-NPC is associated with accelerated progression toward advanced disease and, eventually, death
Autoimmune Hepatitis type 1 (AIH-1):Anti-SMAs (smooth muscle antibodies)
They are typical markers for AIH-1 and are detected in 87 % of AIH patients, either as the only marker of the disease, or in combination with ANA. In cases of type 1 AIH, antibodies against F-actin are predominantly detected.
Antibodies against the soluble liver antigen (SLA/LP, soluble liver antigen/liver pancreas antigen) are highly specific markers for AIH-1.
Autoimmune Hepatitis type 2 (AIH-2):
Antibodies against type 1 liver-kidney mircosomes are serological markers for the diagnosis of AIH-2. LKM-1 antibodies are also detected in up to 7 % of patients with chronic hepatitis C.
Antibodies against the liver cystolic antigen type 1 (LC-1) are specific markers found in up to 50 % of AIH-2 patients and LC-1 antibody titer correlates with the activity of the disease. These antibodies may be the only serological marker in 10 % of AIH patients.
Autoimmune Hepatitis type 3 (AIH-3):
Type 3 AIH is the least established form and has been characterized by antibodies to soluble liver antigen (anti-SLA)/LP)