High prevalence of autoantibodies in hepatitis A infection: the impact on laboratory profiles

Abstract

Aims: In the absence of IgM antibodies against hepatitis A virus (HAV), HAV infections can be regarded as autoimmune hepatitis when they show positive autoantibodies by indirect immunofluorescence and lack other viral markers. The aim of this study was to evaluate the prevalence, titres and impact of autoantibodies in Korean patients with HAV infection.

Methods: The study involved a retrospective review of the electronic medical records of 73 patients with HAV at Konkuk University Hospital from August 2005 to September 2008. The presence and pattern of anti-nuclear antibody, anti-smooth muscle antibody, anti-mitochondrial antibody and anti-liver/kidney microsomal antibody were assessed by indirect immunofluorescence on Hep-2 cells and mouse/kidney sections.

Results: Of the 73 patients with hepatitis A, 65 (89.0%) showed positive indirect immunofluorescence tests. Of note, most of the positive tests (95.5%) showed a cytoplasmic pattern with filamentous staining of cytoplasmic fibres. There was no significant difference between groups in age or sex. In patients positive for autoantibodies, alanine aminotransferase and leucocyte count were significantly higher, while the increase in globulin was not statistically significant. In terms of titres, globulin was significantly higher in patients with > or =1:160 titres than in those with < or =1:80 titres (mean (SD) 3.4 (0.5) versus 2.8 (0.4) g/dl, respectively; p = 0.000).

Conclusions: The study demonstrated a high prevalence of anticytoplasmic autoantibodies in patients with acute hepatitis A. These data would be useful to aid interpretation of indirect immunofluorescence testing in patients with acute hepatitis, especially in areas with a high prevalence of HAV.