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Flow cytometric measurements of TB‐specific T cells comparing with QuantiFERON‐TB gold
Author(s) -
Won Dong Il,
Park Jung Ran
Publication year - 2010
Publication title -
cytometry part b: clinical cytometry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.646
H-Index - 61
eISSN - 1552-4957
pISSN - 1552-4949
DOI - 10.1002/cyto.b.20503
Subject(s) - flow cytometry , cytokine , antigen , medicine , interferon gamma , tuberculosis , intracellular , tumor necrosis factor alpha , cytometry , immunology , cd3 , microbiology and biotechnology , biology , pathology , cd8 , biochemistry
Background: Interferon‐γ (IFN‐γ) release assays and the detection of IFN‐γ synthesis in the cytoplasm of activated CD4+ T cells by flow cytometry have recently been used for tuberculosis (TB) diagnosis. The aim of this study was to compare the performance of IFN‐γ assay between ELISA (QuantiFERON‐TB Gold, QFT) and intracellular cytokine flow cytometry (ICCFC), and to investigate the significance of an optimal gating strategy in ICCFC. Methods: The CD4+ T cell response to TB antigens was measured using the intracellular cytokine staining technique and four color FC (CD3, CD4, IFN‐γ, and tumor necrosis factor‐α (TNF‐α)) on whole blood samples. The results were compared with those of QFT. Results: Regarding sensitivity in the TB group, patients in the QFT positive TB group ( N = 22) were all ICCFC positive and 9 patients (64%) in the QFT negative TB group ( N = 14) were ICCFC positive. In all test tubes ( N = 72), sensitivity of “targeted” gating for TNF‐α+ IFN‐γ+ CD4+ T cells was significantly higher than customary gating (72%, 54%, respectively, P = 0.001). Conclusions: The diagnostic sensitivity of ICCFC was further confirmed to be much higher than that of QFT. In the ICCFC analysis, TNF‐α+ IFN‐γ+ CD4+ T cells should be sequentially gated through appropriately defined regions, minimizing interferents and reflecting characteristics of light scatter and marker expressions of CD4+ T cells activated by TB antigens. © 2009 Clinical Cytometry Society