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.
ABSTRACT
BCG Purified Protein Derivative (BCG-PPD)was isolated and purified from BCG Culture filtrate by trichloroacetic acid and ammonium sulfate methods. The purity of BCG-PPD was Similar to PPD-S(international standard) and PPD-C(China), but more than that of PPD-CT68 (Canada)and PPD-RT23(Danish). The Delayed-Type Hyperseusitivity(DTH) to BCG-PPD was more sensitivity than other PPD on BCG vaccinated guinea pigs, but less sensitivity than other PPD on Mycobacterium tuberculosis infected guinea pigs. The conversion rate and induration diameter to BCG-PPD was higher than PPD in 333 of 12 weeks after BCG vaccination newborns, but lower than that of other PPD in 97 tuberculosis patients. It was shown that DTH reaction to PPD was more sensitivity in Mycobacteria homogeneous strain vaccinated individual than Mycobacteria heterogeneous strain vaccinated individual. It was demonstrated that BCG-PPD was better than other PPD on observation conversion rates and induration diameter of BCG vaccinated individual. It maybe help to identification BCG vaccinated or tuberculosis infected with DTH of BCG-PPD and PPD in same individual.