Complex-specific immunoglobulin M antibody patterns in humans infected with alphaviruses

Area of Science:

• Virology
• Immunology
• Epidemiology

Background:

• Alphaviruses, including eastern equine encephalitis (EEE), western equine encephalitis (WEE), Pogosta (Ockelbo), Mayaro, Ross River, and chikungunya viruses, cause significant human disease.
• Accurate and timely diagnosis is crucial for managing alphavirus infections and monitoring outbreaks.

Purpose of the Study:

• To evaluate the diagnostic utility of immunoglobulin M (IgM) antibody capture enzyme immunoassay for detecting alphavirus infections.
• To assess the specificity of IgM antibodies against homologous and heterologous alphaviruses.

Main Methods:

• Sera from human cases of EEE, WEE, Pogosta, Mayaro, Ross River, and chikungunya virus infections were tested.
• An IgM antibody capture enzyme immunoassay was employed to detect specific IgM antibodies.
• Selected sera with high IgM titers were further tested against nine heterologous alphaviruses to assess cross-reactivity.

Main Results:

• The IgM antibody capture enzyme immunoassay successfully detected diagnostically useful IgM antibody titers in infected individuals.
• Testing against heterologous alphaviruses revealed complex specificity patterns for IgM antibodies.
• The assay demonstrated potential for use in both diagnosing individual alphavirus infections and in epidemiological surveillance during outbreaks.

Conclusions:

• Immunoglobulin M (IgM) antibody testing is a valuable tool for diagnosing infections caused by various alphaviruses.
• The observed cross-reactivity highlights the importance of considering differential diagnosis in IgM testing for alphavirus infections.
• This immunoassay is suitable for clinical diagnostics and public health surveillance of alphavirus outbreaks.