Specific antibody profile in human brucellosis.

Area of Science:

• Immunology
• Infectious Diseases
• Medical Diagnostics

Background:

• Brucellosis diagnosis relies on serological tests.
• Classic serological tests may lack sensitivity in detecting subtle immunoglobulin changes.
• Enzyme-linked immunosorbent assay (ELISA) offers a potentially more sensitive method for immunoglobulin detection.

Purpose of the Study:

• To compare the diagnostic performance of ELISA with classic serological tests for Brucella immunoglobulins.
• To evaluate the utility of different immunoglobulin isotypes (IgM, IgA, IgG) detected by ELISA in monitoring brucellosis.
• To assess the predictive value of persistent antibody titers for relapse and chronic infection.

Main Methods:

• Comparison of classic serological tests and ELISA for Brucella antibodies.
• Analysis of 761 serum samples from 75 patients with brucellosis.
• Kaplan-Meier method used to determine persistent ELISA positivity rates at 12 months post-therapy.

Main Results:

• ELISA demonstrated superior detection of serological changes compared to classic tests.
• Persistent ELISA positivity rates at 12 months post-therapy were 25% for IgM, 69% for IgA, and 89% for IgG in non-relapsed patients.
• A secondary peak of ELISA IgG and IgA was frequently observed in patients experiencing relapse.
• High IgG titers at admission or focal disease were associated with persistent high antibody titers in non-relapsed patients.

Conclusions:

• ELISA is a more effective tool than classic serological tests for monitoring immunoglobulin responses in brucellosis.
• A secondary peak in ELISA IgG and IgA serves as a reliable marker for brucellosis relapse.
• Persistent high IgG titers alone are not a sufficient predictor of chronic brucellosis infection.