Objective To establish enzyme-linked immunosorbent assays of anti-HEV IgA and to investigate its clinic significance in patients with hepatitis E.
Methods An enzyme-linked immunosorbent assays of anti-HEV IgA was established by instead of anti-human IgG with anti-human IgA in anti-HEV IgG assays came from Beijing WanT ai biological pharmacy enterprise. Anti-HEV IgA, anti-HEV IgM and anti-HEV IgG were detected in serial sera of 60 patients with HEV-RNA positive and control groups.
Results The 60 patients with HEV-RNA positive had both anti-HEV IgA and anti-HEV IgM alone. These patients were not only negative for HEV RNA but also lack anti-HEV IgG as well. Only one patient had both anti-HEV IgA and anti-HEV IgM (covert infection). Periodic serum samples obtained from 60 patients with hepatitis E were tested for HEV RNA, anti-HEV IgA, anti -HEV IgM and anti-HEV IgG. Their HEV-RNA were detectable in the serum until 1 to 40(20±11)d. But anti-HEV IgA were detectable until 1 to 150(120±23)d, anti-HEV IgM were detectable until 1 to 150(90±15)d. After two months of the onset the positive rates of anti-HEV IgA was higher than that of anti-HEV IgM(P < 0.05).
Conclusion The method to detect the antiHEV IgA is practicable. Anti-HEV IgA is longer duration than that of anti-HEV IgM and as an assistant signal to diagnose acute hepatitis E without anti-HEV IgM. Anti-HEV IgA alone or along with anti-HEV IgM is useful for serological diagnosis of hepatitis E with increased specificity.