Neutralization enzyme immunoassay for influenza virus

Area of Science:

• Virology
• Immunology
• Diagnostic Assay Development

Background:

• Influenza A (H3N2) virus poses a significant public health challenge.
• Accurate and timely detection of influenza virus infection is crucial for patient management.
• Existing diagnostic methods may have limitations in sensitivity or accessibility.

Purpose of the Study:

• To develop and validate a novel neutralization enzyme immunoassay (N-EIA) for detecting antibody titer increases in patients infected with influenza A (H3N2).
• To assess the performance of the N-EIA compared to a standard diagnostic method.

Main Methods:

• Development of a neutralization enzyme immunoassay (N-EIA) using influenza A (H3N2) virus and LLC-MK2 cells.
• Demonstration of replicated virus using a virus-specific enzyme-labeled monoclonal antibody.
• Measurement of decreased absorbance values after preincubation of virus with patient sera to determine neutralization titers.

Main Results:

• The N-EIA successfully detected antibody titer rises in sera from patients with influenza A (H3N2) infection.
• Preincubation of virus with convalescent sera resulted in decreased absorbance values, enabling neutralization titer calculation.
• Results from the N-EIA showed a strong correlation (r = 0.83) with the standard hemagglutination inhibition test using paired serum samples from 10 patients.

Conclusions:

• The developed N-EIA is a viable method for detecting antibody titer increases in influenza A (H3N2) virus infections.
• The N-EIA demonstrates good concordance with the established hemagglutination inhibition test.
• This assay offers a potential alternative for diagnosing influenza A (H3N2) infections.