The most reliable indicator of recent Hepatitls-B infection in a convalescing patient is -
IgM Anti HBc
IgM Anti F-IBe
HBsAg
IgGAntiHBs
Hepatitis B core antigen Hepatitis B core antigen (HBcAg) is not found in the blood, but antibody to it (anti-HBc) appears early in the illness and rapidly reaches a high titre, which subsides gradually but then persists. Anti-HBc is initially of IgM type, with IgG antibody appearing later. Anti-HBc (IgM) can sometimes reveal an acute HBV infection when the HBsAg has disappeared and before anti-HBs has developed Ref Davidson edition23rd pg874
G.I.T