Supplementary Material for: Bifunctional T-Cell-Derived Cytokines for the Diagnosis of Tuberculosis and Treatment Monitoring

Background: Diagnosis and treatment monitoring of patients with tuberculosis remain challenging. Objective: We have evaluated whether Mycobacterium-specific interferon (IFN)-γ and interleukin (IL)-2 bifunctional cytokine immune response assays improve the diagnosis of and correlate to treatment response in pulmonary tuberculosis. Methods: Early secretory antigenic target (ESAT)6/culture filtrate protein 10 (CFP10), microsomal triglyceride transfer protein 65 (MTP65) and the purified protein derivative (PPD) tuberculin-specific immune profiles were investigated in peripheral blood mononuclear cells from 19 patients with culture-confirmed tuberculosis and 23 healthy community controls (HCCs; 82.6% with latent M. tuberculosis infection) using a novel fluorescence-based dual-colour enzyme-linked immunospot (EliSpot) technology (FluoroSpot). Results: The frequency of ESAT6/CFP10-induced IFN-γ+IL-2- producing cells was elevated (p Conclusions: The addition of antigen-specific IL-2 production to IFN-γ responses by EliSpot in IFN-γ release assays increases diagnostic sensitivity for active tuberculosis.