Procedures
This section encapsulates the key concepts and procedures within serology, focusing on the body’s immune response, antigen-antibody interactions, and specific pathogens. It provides a structured framework for understanding the role of serological testing in diagnosing and monitoring infectious diseases
Immunoglobulin Response to Infection
- IgM: Typically the first antibody produced in response to a new infection, indicating an acute or recent infection
- IgG: The most abundant antibody in serum, indicating past infection or vaccination, and providing long-term immunity
- IgA: Predominant antibody in mucosal secretions, providing localized immunity at mucosal surfaces
Antigen-Antibody Interactions
- Specificity: The ability of an antibody to bind to a specific antigen
- Affinity and Avidity: Affinity refers to the strength of a single antigen-antibody bond, while avidity describes the overall strength of the interaction
- Cross-Reactivity: The ability of an antibody to bind to similar, but not identical, antigens
- Factors Affecting Interactions: Temperature, pH, ionic strength, incubation time, and antigen/antibody concentrations
Testing Methods for Antigen-Antibody Interactions
- Agglutination: Visible clumping of particles due to antibody-antigen binding
- EIA/ELISA: Enzyme-labeled antibodies or antigens detect and quantify immune complexes
- Chemiluminescence: Chemiluminescent-labeled antibodies or antigens detect and quantify immune complexes
- Immunofluorescence: Fluorescently labeled antibodies detect antigens or antibodies in a sample
Serodiagnosis of Agents of Encephalitis
- West Nile Virus (WNV): WNV IgM (recent), WNV IgG (past), Plaque Reduction Neutralization Test (PRNT)
- St. Louis Encephalitis Virus (SLEV): SLEV IgM (recent), SLEV IgG (past), Plaque Reduction Neutralization Test (PRNT)
- La Crosse Virus (LACV): LACV IgM (recent), LACV IgG (past)
- Eastern Equine Encephalitis Virus (EEEV): EEEV IgM (recent), EEEV IgG (past)
- Western Equine Encephalitis Virus (WEEV): WEEV IgM (recent), WEEV IgG (past)
- Powassan Virus (POWV): POWV IgM (recent), POWV IgG (past)