CFP10/ESAT6 fusion protein-ELISPOT method for Mycobacterium tuberculosis infection and its diagnosis value.

The aim was to establish a method of detecting tuberculosis infection by enzyme-linked immunospot(ELISPOT)assay and evaluate the application value of CFP10/ESAT6 fusion protein for diagnosis of tuberculosis(TB).By comparing with the different experimental environment,the optimal detecting condition were identified including cell concentration,incubation period and protein antigen concentration,and ELISPOT assay was established.PPD skin test was set as control.It was found that the most appropriate conditions of ELISPOT assay were,2×105 cell/each well,20-40μg/mL CFP10/ESAT6 fusion protein as stimulus and 20 hours of incubation period.The positive rates of PPD skin test in 30 healthy persons,38 patients with non-TB diseases and 40 TB patients were 40%,0% and 72.5%,respectively.Whereas the positive rates of ELISPOT assay were 20.0%,10.5% and 92.5%,respectively.For the 40 TB patients,the sensitivities of ELISPOT in sputum-positive TB group and sputum-negative TB group were 94.4% and 90.9%,respectively.It's concluded that ELISPOT could be used to detect tuberculosis infection efficiently and it might be an important assistant method in diagnosis of tuberculosis.