ABSTRACT
Objective To assess the potential of whole blood IFN-γassay for diagnosing mycobacterium in rhesus macaques.Methods Firstly, basic serum IFN-γconcentrations of TST-negative and -positive rhesus macaques were detected.Then, heparinized whole blood from TST-negative and-positive rhesus macaques was incubated with PBS and 200 IU bovine-PPD ( tuberculin purified protein derivative ) for about 24 h, respectively.The supernatant plasma were harvested and used to determine the concentrations of IFN-γ.The results of plasma IFN-γconcentrations and stimulation index ( SI) were used to analyze the diagnostic potential of the whole blood IFN-γassay.Results The basic serum concentrations of IFN-γfor the TST-positive monkeys were significantly higher than that of the TST-negative macaques, showing a high coefficient of variation.There was no significant effect on the production of IFN-γin the TST-negative macaques.While significantly elevation of IFN-γconcentrations was found in stimulated plasma of TST-positive macaques (P<0.01).The SI of TST-positive macaques was significantly higher than the TST-negative ones.ROC curve analysis revealed that IFN-γconcentrations and SI could be used as evaluation index of whole blood IFN-γassay.Conclusions Based on a small sample experiment we have demonstrated that whole blood IFN-γassay may be one possible auxiliary diagnostic method for tuberculin skin test.