Stability of hepatitis B surface antigen over time: implications for studies using stored sera

Area of Science:

• Hepatology
• Virology
• Clinical Chemistry

Background:

• Quantitative hepatitis B surface antigen (HBsAg) measurements are increasingly used in chronic hepatitis B management.
• The stability of HBsAg levels in stored sera is crucial for reliable disease monitoring but has not been well-established.

Purpose of the Study:

• To prospectively assess the stability of hepatitis B surface antigen (HBsAg) levels in frozen sera stored for one year.

Main Methods:

• 105 fresh serum samples were divided into five aliquots.
• One aliquot was tested at baseline; the others were stored at -20°C and tested at 3, 6, 9, and 12 months.
• HBsAg levels were measured using the Elecsys HBsAg II assay.

Main Results:

• HBsAg levels showed no significant overall difference across the 12-month storage period.
• High correlations were observed between consecutive time points (r > 0.987, P < 0.001).
• Over 99% of samples exhibited less than a 1-log change in HBsAg levels after 12 months.

Conclusions:

• Hepatitis B surface antigen (HBsAg) levels are stable in frozen sera for up to 12 months.
• Stored sera can be reliably used for accurate quantitative HBsAg measurements in chronic hepatitis B management.