Anti-HBCs are IgM, IgA and IgG, which appear and disappear sequentially in the infection, the latter may be present for a long time. Routine detection of anti-HBC can indicate one of the three or the sum of them, with IgM appearing in the first week of illness in 90% of cases. IgM positive, even if HbsAg negative, can diagnose acute hepatitis B. Conversely, IgM negative acute hepatitis, even if HbsAg positive, can be chronic HBV infection overlapping acute lesions of other pathogens IgG appears late and can remain for years. correlation, with increased detection rates in ASC, mild chronic hepatitis B, active chronic hepatitis B, and acute hepatitis B at once, and can remain high in cirrhosis.