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Updated: May 29, 2026
Application of Long-term cultured Interferon-γ Enzyme-linked Immunospot Assay for Assessing Effector and Memory T Cell Responses in Cattle
Published on: July 11, 2015
Comparative study of IFNγ and antibody tests for feline tuberculosis
Shelley G Rhodes1, Danielle Gunn-Mooore, Maria Laura Boschiroli
1TB Research Group, Animal Health and Veterinary Laboratories Agency, Surrey KT15 3NB, United Kingdom. shelley.rhodes@ahvla.gsi.gov.uk
Insights
The interferon-gamma (IFNγ) test and rapid antibody tests show high specificity for feline tuberculosis. The IFNγ test demonstrates promising sensitivity for Mycobacterium bovis and TB Complex infections, aiding in diagnosis and monitoring treatment.
Area of Science:
- Veterinary Medicine
- Immunology
- Microbiology
Background:
- Tuberculosis (TB) in domestic cats presents diagnostic challenges.
- Ante mortem diagnosis is crucial for disease control and management.
- Existing serological tests have limitations in sensitivity and specificity.
Purpose of the Study:
- To compare the diagnostic performance of the cell-based interferon-gamma (IFNγ) test against serological rapid antibody tests for feline tuberculosis.
- To evaluate the utility of these tests in differentiating Mycobacterium bovis and other TB Complex infections.
- To explore the potential of the IFNγ test as a monitoring tool for TB chemotherapy.
Main Methods:
- Comparison of IFNγ assay with STAT-PAK and DPP VetTB rapid antibody tests in 62 culture-confirmed TB cats and controls.
- Antibody specificity analysis using multi-antigen print immunoassay (MAPIA) in rapid test-positive cats.
- Longitudinal testing of one cat undergoing TB chemotherapy for suspected M. bovis infection.
Main Results:
- All tests demonstrated excellent specificity (100%).
- IFNγ test sensitivity was 70-100% for M. bovis and TB Complex infections.
- Rapid tests showed 90% sensitivity for M. bovis but lower (up to 46.2%) for M. microti.
- Positive IFNγ response to ESAT6/CFP10 aided in differentiating pathogenic from less-pathogenic TB Complex.
Conclusions:
- The IFNγ test and rapid antibody tests are highly specific for feline tuberculosis.
- The IFNγ test shows encouraging sensitivity for M. bovis and TB Complex, with potential for differential diagnosis.
- Preliminary data suggest the IFNγ test may serve as a valuable tool for monitoring TB chemotherapy response in cats.
Abstract:
This study describes the comparison of the cell-based interferon-gamma (IFNγ) test with serological rapid antibody tests (STAT-PAK and DPP VetTB) for the ante mortem testing of tuberculosis in domestic cats. The antibody specificities of rapid antibody test-positive cats were further discerned using multi-antigen print immunoassay. A total of 62 cats with culture-confirmed Mycobacterium bovis, Mycobacterium microti, Mycobacterium avium and Mycobacterium malmoense, as well as negative controls and dangerous-contact cats were tested. Tests were also applied longitudinally to one further cat undergoing TB chemotherapy for suspected M. bovis infection. Our data from this small study show excellent test specificity (100% for all tests) and encouraging levels of test sensitivity for M. bovis and TB Complex infections (IFNγ 70-100% depending upon test interpretation criteria; rapid tests both 90% for M. bovis infection and up to 46.2% for M. microti infection). The differential diagnosis of very pathogenic TB Complex (M. bovis, Mycobacterium tuberculosis), as opposed to less-pathogenic TB Complex (M. microti) was possible where positive responses to the protein cocktail ESAT6/CFP10 were observed (80% of M. bovis-infected cats in this study showed positive IFNγ responses to ESAT6/CFP10, while 20% had antibody responses to ESAT6/CFP10 using MAPIA). Finally, preliminary data from a longitudinal study of one M. bovis-exposed cat with a positive IFNγ test pre-treatment suggest that a decrease in bacterial burden may be reflected in the IFNγ response, and thus the IFNγ test may provide a monitor for TB chemotherapy.
