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Hepatitis A test: serum IgM antibodies to HAV
Last reviewed: 05.07.2025
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IgM antibodies to HAV are normally absent in serum.
Viral hepatitis A ( Hepatitis A ) is an acute viral infection. The causative agent is the hepatitis A virus (HAV). The HAV genome is represented by single-stranded RNA. The hepatitis A virus contains a single antigen (HAV-Ag). The proportion of viral hepatitis A in the total incidence of viral hepatitis is 70-80%. In the structure of viral hepatitis A morbidity, children make up up to 80%, and the bulk are preschoolers and primary school students.
Reliable confirmation of the diagnosis of viral hepatitis A is carried out by serological methods - detection of an increase in the level of specific antibodies (anti-HAV) belonging to IgM (anti-HAV IgM). In viral hepatitis A, an increase in the titer of antibodies related to IgM begins in the incubation period, 5-10 days before the first symptoms of the disease, and progresses rapidly. By the time the patient initially contacts a doctor, the level of anti-HAV IgM has reached high enough values to be detected by the ELISA method. It is generally accepted that anti-HAV IgM in patients appears at the beginning of clinical manifestations of the disease and persists for up to 6 months after the infection. A year after the infection, anti-HAV IgM is not detected in the blood.
Determination of anti-HAV IgM is the main test for the specific diagnosis of viral hepatitis A.
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