Introducing the ESAT-6 free IGRA, a companion diagnostic for TB vaccines based on ESAT-6
نویسندگان
چکیده
There is a need for an improved vaccine for tuberculosis. ESAT-6 is a cardinal vaccine antigen with unique properties and is included in several vaccine candidates in development. ESAT-6 is also the core antigen in the IFN-γ release assays (IGRA) used to diagnose latent infection, rendering IGRA tests unspecific after vaccination. This challenge has prompted the development of a companion diagnostic for ESAT-6 based vaccines, an ESAT-6 free IGRA. We screened a panel of seven potential new diagnostic antigens not recognized in BCG vaccinated individuals. Three highly recognized antigens EspC, EspF and Rv2348c were identified and combined with CFP10 in an ESAT-6 free antigen cocktail. The cocktail was prepared in a field-friendly format, lyophilized with heparin in ready-to-use vacutainer tubes. The diagnostic performance of the ESAT-6 free IGRA was determined in a cross-validation study. Compared IGRA, the ESAT-6 free IGRA induced a comparable magnitude of IFN-γ release, and the diagnostic performance was on par with Quantiferon (sensitivity 84% vs 79%; specificity 99% vs 97%). The comparable performance of the ESAT-6 free IGRA to IGRA suggests potential as companion diagnostic for ESAT-6 containing vaccines and as adjunct test for latent infection.
منابع مشابه
IGRA based diagnosis of infection and prediction of disease
Can IGRA assays, used in the highly specific and sensitive quantiFERON and T-spot tests, predict the development of disease in individuals who are infected but currently display no symptoms? High ESAT-6 reactivity may predict disease because ESAT-6 is a marker for bacterial burden. We found that vaccinated cattle for which the vaccine did not offer protection displayed high reactivity to ESAT-6...
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