Evaluation of autoimmune liver disease antibodies in hepatitis patients

by Namsoo Kim, Sinyoung Kim, Jong Rak Choi, Younhee Park

Background/aims

Autoimmune hepatitis (AIH) is characterized by the presence of auto-antibodies and high blood immunoglobulin G (IgG) levels. In this study, the line immunoassay (LIA) was designed to assess various autoantibodies.

Methods

In total, 1371 patients who underwent autoimmune liver disease antibody testing between July 2019 and November 2022 were enrolled. Autoantibodies including antinuclear antibody (ANA) and anti-mitochondrial antibody (AMA) were tested, and clinical data were collected. Statistical analyses were performed by categorizing the data based on diagnosis and IgG quantification separately. A scoring system was applied to identify individuals with AIH. Patients were also classified into the AIH and non-AIH groups.

Results

The positivity rate for ANA was 80.2% in the AIH group. The IgG-high group had a high likelihood of the presence of detectable autoantibodies, with anti-Ro-52 being the most frequently detected antibody using LIA. The "Consider AIH" and "AMA" groups had 3–4 times more patients in the IgG-high group than in the "Not Considered" group.

Conclusions

Among autoantibodies, the prevalence of ANA was the highest. As per LIA results, anti-Ro-52 was the most prevalent. AIH cannot be diagnosed based on IgG levels alone and must be distinguished via autoantibody testing. Therefore, extensive testing, including autoantibodies, IgG, ANA, and liver enzyme levels, will help accurately diagnose AIH.