Hepatitis B surface antigen (HBsAg)
- Appears during incubation period (1-6 months), 2-7 weeks prior to symptoms.
- Peaks when the patient is most ill.
- Becomes undetectable in 3-6 months.
- Indicates infection – recent or chronic.
Hepatitis B surface antibody (anti-HBs or HBsAb)
- Arises once the acute disease has resolved.
- Sometimes, not detectable unless until weeks or months after HBsAg has disappeared. This gap is called “window” period.
- Indicates, immunity (by vaccination or infection).
Hepatitis B core antibody (anti-HBc or HBcAb)
- Anti-HBc IgM and elevated serum transaminases also appear shortly before the symptom onset.
- Over the next few months, anti-HBc IgM is replaced with an IgG component.
- IgM = Recent (Acute) infection
- IgG = Chronic infection
Hepatitis B e-antigen (HBeAg)
- Shortly after HBsAg appears, HBeAg and HBV DNA can be detected in the serum and are markers of the acute viral replication.
- Predictor of infectivity.
Hepatitis B e-antibody (anti-HBe or HBeAb)
- Anti-HBe appears shortly after HBeAg vanishes and indicates subsiding viral activity.
- Predictor of low infectivity.
|Never infected (susceptible)||–||–||–||–||–|
|Incubation period||+ (1st to appear)||–||IgM (shortly before symptom onset)||+||–|
|Prodrome, Acute disease||+||–||IgM||+||+/-|
|Chronic active hepatitis B||+||–||IgG||+||–|
|Chronic non-active hepatitis B||+||–||IgG||–||+|
|Immune due to Vaccination||–||+||–||–||–|
|Immune due to Natural infection||–||+||IgG||–||+/-|
|False positive or infection in remote past||–||–||IgG||–||–|