Correlation of in vitro and in vivo tests for cell-mediated immunity in the dog.

Using tuberculin (purified protein derivative) as the test antigen, 29 dogs with different vaccination histories were tested with the lymphocyte transformation (LT) assay, the indirect agarose leukocyte migration inhibition (LMI) assay, and the skin test for delayed type hypersensitivity. All three tests were done simultaneously on each dog. The LT assay results were found to correlate well (r = 0.88) with the skin test results, whereas LMI results were found to correlate poorly (r = 0.55) with the skin test results. It was concluded that the LT assay is a more reliable measure of cell mediated immunity in the dog than is the LMI assay.