A Correlative Evaluation of the Diagnostic Importance of Adaptive Cell-Mediated Tests in Bovine Tuberculosis

Marina SPINU

Abstract


Knowledge of the immune responses which develop in cattle following infection with
Mycobacterium bovis is essential both to the understanding of disease pathogenesis and to the
logical development of immune-dependent tools, such as diagnostic tests and vaccines, which
can be used to combat the disease (Pollock et al., 2001). The early, preclinical stages of
bovine TB can be detected in live animals by the use of tests of cellular immunity (the skin, cinterferon
and lymphocyte transformation tests)(de la Rua-Domenech et al., 2006). In
tuberculosis, both macrophages and lymphocytes are sensitized to tuberculin, which in low
concentrations is capable of inducing their activation both in vivo and in vitro. This study
aimed to evaluate the diagnostic relevance of monitoring adaptive cell-mediated responses
such as skin test (IDR), gamma interferon (IFN) synthesis (Bovigam TM, ELISA test), in
vitro blast transformation test (RPMI 1640 medium, 72 h incubation) and leukocyte migration
inhibition tests (RPMI 1640 medium, 18 h incubation) to avian and bovine tuberculins. The
skin test was performed on 79 Romanian spotted adult bovine, aged 5 to 10 years. Blood
samples on heparin (50 IU/ml) were taken from the 34 IDR positive animals (1.14±0.83 mm
and 7.28±1.58 mm responses to avian and bovine tuberculin, respectively, accompanied by
local edema) and subjected to the other cell mediated immunity tests. Correlation coefficients
between the tests were calculated. No significant correlation between the IDR and IFN for
the bovine tuberculin, yet a strong positive correlation (p<0.001) for the avian tuberculin were
obtained, suggesting the independent variation of the two indicators. Both IDR - leukocyte
migration (r = 0.513, p< 0.01) and IDR-blast transformation (r = 0.592, p< 0.001) correlations
were positive and statistically significant, when bovine tuberculin was used. We concluded
that the latter two tests could be used when specific sensitization to M. tuberculosis bovine
subtype is to be detected in IDR positive animals.

Keywords


tuberculosis, bovine, diagnosis, cellular immunity

Full Text:

PDF


DOI: http://dx.doi.org/10.15835/buasvmcn-vm:67:2:6035


University of Agricultural Sciences and Veterinary Medicine
3-5 Manastur St., 400372 Cluj-Napoca
Romania
Tel: +40-264-596.384 | Fax: +40-264-593.792
biroupublicatii@usamvcluj.ro