A simple method to measure antibody affinity against the hepatitis B surface antigen using a routine quantitative...

Area of Science:

• Immunology
• Virology
• Clinical Chemistry

Background:

• Hepatitis B virus (HBV) infection remains a significant global health concern.
• Assessing the immune response, particularly antibody levels and affinity, is crucial for managing HBV infection.
• Existing methods for measuring antibody affinity can be complex and time-consuming.

Purpose of the Study:

• To develop a straightforward method for quantifying antibody affinity to hepatitis B surface antigen (anti-HBs).
• To investigate the clinical significance of anti-HBs antibody affinity in patients with resolved HBV infection.
• To evaluate the utility of this new method in routine clinical laboratory settings.

Main Methods:

• Serum samples from 60 patients with resolved HBV infection were analyzed.
• Patients were categorized into 'anti-HBs-only positive' and 'anti-HBs positive with anti-HBc' groups.
• A commercial assay on the AxSYM device was used to measure total anti-HBs levels across serial dilutions.
• Relative anti-HBs antibody affinity was calculated using the mass action formula based on logarithmic transformations of antibody titers.

Main Results:

• The developed method demonstrated a statistically significant higher affinity of anti-HBs in the anti-HBs-only positive group compared to the other group (P<0.05).
• No significant difference in total antibody activity was observed between the groups (P>0.05).
• The calculated relative antibody affinity positively correlated with the absolute value of (lgU(1)-lgU(2)).

Conclusions:

• A simple and effective method for measuring anti-HBs antibody affinity using routine quantitative systems has been established.
• This method can differentiate immune responses based on antibody affinity, offering insights beyond total antibody levels.
• The findings suggest that this approach can be a valuable tool for clinical laboratories in managing patients with hepatitis B.