Hepatitis A Antibody, IgG Unit Converter

Hepatitis A Antibody, IgG measures IgG-class antibodies to the hepatitis A virus (HAV) in your blood. A reactive (positive) result indicates that your immune system has developed lasting protection against hepatitis A, either from a past infection or from vaccination.

This test is distinct from Hepatitis A IgM, which detects antibodies produced during acute or very recent infection. IgG antibodies appear later, typically a few weeks after infection onset or vaccination, and persist for life in most people.

Results are reported as a signal-to-cutoff (S/CO) ratio. A value of 1.0 or above is considered reactive, meaning IgG antibodies were detected and you are likely immune.

Anti-HAV IgG antibodies are produced by plasma cells, which are specialized B lymphocytes of the adaptive immune system. After exposure to the hepatitis A virus (through infection or vaccination), B cells recognize viral antigens, undergo class switching from IgM to IgG production, and differentiate into long-lived plasma cells in the bone marrow that secrete IgG into the bloodstream.