The evaluation of delayed-type hypersensitivity immune responses by the tuberculin skin test and, more recently, by ex vivo IFN-γ release assays (IGRAs) form the basis for the risk assessment for the development of tuberculosis (TB) in close contacts of infective index patients and in immunocompromised hosts. In contrast, immunodiagnosis has little value for the diagnosis of active TB so far. A report in this issue of the European Journal of Immunology [Eur J Immunol 2012. 42: 2844-2850] provides new insight into the phenotypic characteristics and selective recruitment of Ag-specific T cells to the site of the infection, as analyzed by flow cytometry, which may provide new opportunities for the immune-based diagnosis of TB in the future.
© 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.