Dominant TNF-α Mycobacterium Tuberculosis-specific CD4 T-cell responses discriminate between latent infection and active disease (99.10)

Abstract

Abstract Background: Diagnosis of Mtb infection requires several parameters. IFNg-release assays do not discriminate between active TB disease and latent Mtb infection. Methods: Mtb-specific T-cell responses were investigated in a test cohort of 283 subjects with known diagnosis of latent Mtb infection or active TB disease and subsequently in a validation cohort of 114 subjects with blinded clinical status. Mtb-specific T-cell responses were analyzed by polychromatic flow cytometry using ESAT-6 and CFP-10 peptide pools. Results: Mtb-specific IFNg ELISpot responses were not different between patients with active TB disease or latent Mtb infection. In contrast, the functional profile of Mtb-specific CD4 T-cell responses was significantly different between active TB disease and latent Mtb infection (ESAT-6 or CFP-10, all P<0.0001) in the test cohort. Overall, Mtb-specific CD4 T-cell responses from patients with latent Mtb infection were TNFa+IFNg+IL-2+, while single TNFa-producing Mtb-specific CD4 T-cell responses were dominant in patients with active TB disease. Using this parameter (i.e. % of single TNFa-producing cells) as a diagnostic tool in an independent cohort of 101 patients with blinded TB diagnosis, we obtained >90% concordance between the clinical and the cytokines profile in predicting active TB disease and latent Mtb infection Conclusions: Polychromatic flow cytometry is a novel and reliable laboratory tool for the timely diagnosis of acute TB disease.