Low level rubella immunity detected by ELISA and specific lymphocyte transformation

Area of Science:

• Immunology
• Virology
• Vaccinology

Background:

• Low or undetectable hemagglutination-inhibition (HAI) rubella titers can raise questions about immunity levels.
• Assessing both humoral and cell-mediated immunity is crucial for a comprehensive understanding of rubella protection.

Purpose of the Study:

• To investigate the immune status of individuals with low or undetectable rubella HAI titers.
• To compare the efficacy of ELISA and HAI tests in detecting rubella-specific antibodies and immune response.

Main Methods:

• Enzyme-Linked Immunosorbent Assay (ELISA) for antibody detection.
• Analysis of IgG presence in sucrose gradient separated serum fractions.
• Assessment of lymphocyte transformation (stimulation index) for cell-mediated immunity.

Main Results:

• ELISA detected rubella antibodies in individuals with low/undetectable HAI titers, confirmed by IgG presence and lymphocyte response.
• Individuals with natural rubella infection and low HAI titers showed positive ELISA results and significant lymphocyte stimulation.
• Rubella vaccinees with low/undetectable HAI titers also demonstrated ELISA positivity, with detectable IgG and lymphocyte reactivity.

Conclusions:

• The ELISA test is more sensitive than the HAI test for detecting rubella antibodies, especially in individuals with low titers.
• ELISA positivity correlates with the presence of specific IgG and a functional cell-mediated immune response.
• These findings suggest that ELISA provides a more accurate assessment of rubella immunity in specific populations.