What Does a Positive HEV Antibody Test Mean?

Hepatitis E virus (HEV) is the causative agent of hepatitis E, a disease characterized by a single-stranded RNA genome. The clinical symptoms and epidemiological features of hepatitis E are very similar to those of hepatitis A. Like hepatitis A, hepatitis E is generally a self-limiting acute liver disease.

The hepatitis E virus contains specific surface antigens that can stimulate the human immune system to produce antibodies, including IgG, IgM, and IgA. These antibodies play a crucial role in diagnosing HEV infection at different stages. In the early phase of infection, IgM antibodies are typically detectable in most patients, making them highly significant for early diagnosis. High levels of IgM antibodies can be identified in serum during the acute phase of the illness.

As the body begins to recover, the levels of IgM antibodies tend to decline or disappear altogether. At this stage, IgG antibodies become more prominent in the bloodstream. A positive IgG result often suggests a past infection. However, if the IgG antibody titer in the recovery phase is at least four times higher than during the acute phase, it strongly indicates a recent HEV infection, which is diagnostically relevant.

For accurate clinical interpretation, both IgG and IgM antibodies are usually tested together. This dual testing approach helps healthcare providers better understand the stage and nature of the infection. Most hospitals in China currently use enzyme-linked immunosorbent assay (ELISA) methods to detect these specific antibodies. ELISA is known for its high specificity and reliability in identifying HEV-related antibodies.

In summary, interpreting HEV antibody results requires careful evaluation of both IgG and IgM levels, as each reflects different phases of the immune response. Proper testing and analysis are essential for an accurate diagnosis of hepatitis E.