HBsAg is the first serological marker to appear in Hepatitis B virus (HBV) infection.

Detection by CLIA provides high sensitivity and specificity compared to conventional methods.

Clinical uses include:

Screening for Hepatitis B infection in blood donors and patients.

Diagnosing acute or chronic HBV infection.

Monitoring infectivity and disease progression.

Evaluating response to antiviral therapy.

A positive result indicates active HBV infection and potential infectivity.

Often performed alongside other HBV markers (Anti‑HBs, HBeAg, Anti‑HBc) for complete evaluation.

Analyte: Hepatitis B surface antigen (HBsAg) in serum/plasma.

Normal Result: Negative (no HBsAg detected).

Abnormal Findings:

Positive HBsAg: Indicates acute or chronic Hepatitis B infection.

Persistent positivity (>6 months): Suggests chronic HBV carrier state.

Clinical Use:

Provides a sensitive screening tool for HBV infection.

Helps prevent transmission via blood transfusion.

Supports monitoring and management of Hepatitis B patients.