Anti-mitochondrial antibodies (AMA) occur in over 90% of primary biliary cirrhosis cases, 3-11% of
chronic active hepatitis patients and are absent in patients with extrahepatic biliary obstruction and in
other liver diseases.
Anti-smooth muscle antibodies (ASMA) in high titer (>160) occur in the majority of cases of chronic
active hepatitis and in intermediate titers (40-80) in acute viral hepatitis. Occasionally they may occur in
cases of primary biliary cirrhosis where they are also found in intermediate titers. The significance of
titers of 20-40 is doubtful since these titers may occur in normal
Seropositivity for anti-LKM-1 antibodies is consistent with a diagnosis of Autoimmune Hepatitis (AIH) type 2. Anti-LKM-1 antibodies serve as a serologic marker for AIH type 2 and typically occur in the absence of ASMA and antinuclear antibodies. Patients with AIH type 2 more often tend to be young, female, and have severe disease that responds well to immunosuppressive therapy.
If the anti-LKM-1 test is negative, but ASMA and/or ANA are positive, then the person likely has AIH type 1