Anti-gp210 and anti-Sp100 antibodies in primary biliary cholangitis

Background and study aims: To determine the sensitivity and specificity of anti-gp210 and anti-Sp100 autoantibodies in primary biliary cholangitis (PBC) Patients and Methods: Sera of 106 PBC patients with positive anti-mitochondrial antibodies and 58 healthy blood donors were analyzed. A line immunoassay was used to evaluate the reactivity of antigp210 and anti-Sp100 antibodies. Results: The frequency of anti-gp210 and anti-Sp100 autoantibodies was 29.2% and 28.3%, respectively. Eight patients had both anti-gp210 and anti-Sp100 antibodies. Of 106 patients, 23 (21.7%) had antigp210 antibody, although not anti-Sp100 antibody, and 22 (20.7%) had anti-Sp100, although not antigp210 antibodies. Their combination increased the frequency of anti-gp210 and anti-Sp100 antibodies from 29.2% to 50% (P = 0.002) and 28.3% to 50% (P = 0.0012), respectively. In the control group, two subjects had anti-gp210 antibody and none had anti-Sp100 antibody. Thus, the specificity of anti-gp210 and anti-Sp100 antibodies was 96.5% and 100%, respectively. The positive predictive value (PPV) of antigp210 antibody was 94%; its negative predictive value (NPV) was 42.7%. The PPV and NPV of antiSp100 antibody were 100% and 43.3%, respectively. Conclusion: It is important to combine anti-gp210 and anti-Sp100 antibodies in the immunological exploration of PBC. (c) 2021 Pan-Arab Association of Gastroenterology. Published by Elsevier B.V. All rights reserved.