HBsAg (hepatitis B virus surface antigen) is a component of the outer envelope of the hepatitis B virus that is the first marker of hepatitis B infection. After infection, HBsAg appears in the blood serum before the onset of clinical symptoms or changes in biochemical parameters.

Determination of HBsAg is an important step in the diagnosis of hepatitis B infection, as well as in assessing the effectiveness of treatment of chronic hepatitis B.

Indications for prescription

• Evaluation of the effectiveness of the “flexible” regimen of pegylated interferon (PegIFN) therapy
• Prediction of response to antiviral therapy (ART)
• Assessment of viral carrier status (HBsAg >1000 IU/ml)

Patient preparation rules:

• 4 hours before collection: refrain from eating, exclude fatty foods
• You can drink water
• Children under 1 year old: preferably donate before feeding or with the longest possible pause between feedings

Time frame: 24 hours