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Interferon Gamma Release Assays for Latent Tuberculosis: What Are the Sources of Variability? J Clin Microbiol 2016; 54:845-50. [PMID: 26763969 DOI: 10.1128/jcm.02803-15] [Citation(s) in RCA: 71] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Interferon gamma release assays (IGRAs) are blood-based tests intended for diagnosis of latent tuberculosis infection (LTBI). IGRAs offer logistical advantages and are supposed to offer improved specificity over the tuberculin skin test (TST). However, recent serial testing studies of low-risk individuals have revealed higher false conversion rates with IGRAs than with TST. Reproducibility studies have identified various sources of variability that contribute to nonreproducible results. Sources of variability can be broadly classified as preanalytical, analytical, postanalytical, manufacturing, and immunological. In this minireview, we summarize known sources of variability and their impact on IGRA results. We also provide recommendations on how to minimize sources of IGRA variability.
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Slater M, Tran MC, Platt L, Luu LT, Phan HT, Pham PT, Do TB, Nguyen HT, Gaur RL, Parsonnet J, Cattamanchi A, Luo R, Nahid P, Banaei N. In vitro immunomodulation for enhancing T cell-based diagnosis of Mycobacterium tuberculosis infection. Diagn Microbiol Infect Dis 2015; 83:41-5. [PMID: 26081239 DOI: 10.1016/j.diagmicrobio.2015.05.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2015] [Revised: 04/27/2015] [Accepted: 05/03/2015] [Indexed: 11/25/2022]
Abstract
Interferon-gamma release assays have limited sensitivity for detecting latent tuberculosis infection. In this study, we determine if the addition of immunomodulators to the QuantiFERON-TB Gold In-Tube (QFT-GIT) increased test sensitivity without compromising specificity. We prospectively compared QFT-GIT results with and without incubation with 2 immunomodulators (lipopolysaccharide [LPS] and polyinosine-polycytidylic acid [PolyIC]) in 2 cohorts-113 culture-confirmed tuberculosis (TB) subjects in Hanoi, Vietnam, and 226 documented QFT-GIT-negative, low TB risk health care workers undergoing annual TB screening at a US academic institution. Sensitivity of the tests in TB subjects was 84.1% with the standard QFT-GIT and 85.8% and 74.3% after incubation with LPS and PolyIC, respectively. Specificity in low TB risk health care workers was 100% with the standard QFT-GIT by design and 86.7% with LPS and 63.3% with PolyIC. In conclusion, use of the 2 immunomodulators did not improve sensitivity of the QFT-GIT in TB patients and reduced specificity in low-risk health care workers.
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Affiliation(s)
- Madeline Slater
- Department of Medicine, Stanford University School of Medicine, Stanford, CA, USA
| | - Minh-Chi Tran
- University of California, San Francisco School of Medicine, San Francisco, CA, USA
| | - Lauren Platt
- Clinical Microbiology Laboratory, Stanford University Medical Center, Palo Alto, CA, USA
| | | | | | | | - Tam B Do
- Hanoi Lung Hospital, Hanoi, Vietnam
| | | | - Rajiv L Gaur
- Department of Pathology, Stanford University School of Medicine, Stanford, CA, USA
| | - Julie Parsonnet
- Department of Medicine, Stanford University School of Medicine, Stanford, CA, USA
| | - Adithya Cattamanchi
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, San Francisco General Hospital, University of California, San Francisco, CA, USA
| | - Robert Luo
- Department of Pathology, Stanford University School of Medicine, Stanford, CA, USA
| | - Payam Nahid
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, San Francisco General Hospital, University of California, San Francisco, CA, USA
| | - Niaz Banaei
- Department of Medicine, Stanford University School of Medicine, Stanford, CA, USA; Department of Pathology, Stanford University School of Medicine, Stanford, CA, USA; Clinical Microbiology Laboratory, Stanford University Medical Center, Palo Alto, CA, USA
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Gaur RL, Banaei N. Inoculation of QuantiFERON-TB tubes with skin microbiota causes false-positive results. Am J Respir Crit Care Med 2015; 190:834-7. [PMID: 25271749 DOI: 10.1164/rccm.201406-1041le] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Affiliation(s)
- Rajiv L Gaur
- 1 Stanford University School of Medicine Stanford, California
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Dammermann W, Bochmann D, Bentzien F, Komorowski L, Steinhagen K, Ullrich S, van Lunzen J, Lüth S. CMV specific cytokine release assay in whole blood is optimized by combining synthetic CMV peptides and toll like receptor agonists. J Immunol Methods 2014; 414:82-90. [PMID: 25450001 DOI: 10.1016/j.jim.2014.10.011] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2014] [Revised: 10/21/2014] [Accepted: 10/23/2014] [Indexed: 12/26/2022]
Abstract
BACKGROUND Interferon gamma release assays (IGRAs) are widely used to detect pathogen specific cellular immunity. Cytomegalovirus (CMV) is the foremost problematic viral infection in immunocompromised patients such as transplant or HIV infected patients. CMV antibody ELISAs are not able to predict CMV specific cellular immunity during immunosuppression. We developed a CMV specific IGRA comparing synthetic CMV peptides, native lysate and recombinant antigen. In addition, TLR agonists were tested to enhance CMV antigen immunogenicity. METHODS 397 healthy controls (HC) were stratified according to CMV IgM and IgG serostatus and subsequently tested for IFNγ- and IL2-secretion in whole blood after challenge with synthetic, native or recombinant CMV antigens and TLR agonists by ELISA. The selected TLR agonists were lipopolysaccharide (LPS), lipoteichoic acid (LTA), peptidoglycan (PGN), zymosan (Zym), polyinosinic-polycytidylic acid (Poly(I:C)), flagellin (Fla), R848, loxoribine (Lox) and bropirimine (Bro). RESULTS Synthetic pp65 peptides elicited strong IFNγ responses in CMV seropositive, but not seronegative HC (6418 vs. 13 pg/ml). Native lysates and recombinant pp65 induced equally high IFNγ responses in seropositive (35,877 and 26,428 pg/ml) and increased background IFNγ expression in seronegative HC (43 and 1148 pg/ml). Diagnostic sensitivity and specificity with regard to anti-CMV serology reached 100% for synthetic pp65 and native CMV lysate, but 57% and 100% for recombinant pp65, respectively. TLR agonists LTA and Poly(I:C) augmented IFNγ responses after challenge with synthetic pp65 peptide, native lysate or recombinant pp65 in seropositive HC. Seronegative HC remained unaffected. IL2 production was negligible compared to IFNγ. CONCLUSION IGRAs using synthetic CMV peptides or native lysate showed the best cytokine signal to noise ratio compared to recombinant antigen and TLR agonists LTA and Poly(I:C) constitute potential costimulating reagents.
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Affiliation(s)
- Werner Dammermann
- Department of Medicine, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, 20246 Hamburg, Germany.
| | - David Bochmann
- Department of Medicine, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, 20246 Hamburg, Germany
| | - Frank Bentzien
- Department of Transfusion Medicine, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, 20246 Hamburg, Germany
| | - Lars Komorowski
- Institute of Experimental Immunology, Euroimmun AG, Seekamp 31, 23560 Lübeck, Germany
| | - Katja Steinhagen
- Institute of Experimental Immunology, Euroimmun AG, Seekamp 31, 23560 Lübeck, Germany
| | - Sebastian Ullrich
- Department of Anatomy and Experimental Morphology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Jan van Lunzen
- Department of Medicine, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, 20246 Hamburg, Germany
| | - Stefan Lüth
- Department of Medicine, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, 20246 Hamburg, Germany
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Gamma interferon release assays for detection of Mycobacterium tuberculosis infection. Clin Microbiol Rev 2014; 27:3-20. [PMID: 24396134 DOI: 10.1128/cmr.00034-13] [Citation(s) in RCA: 560] [Impact Index Per Article: 56.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Identification and treatment of latent tuberculosis infection (LTBI) can substantially reduce the risk of developing active disease. However, there is no diagnostic gold standard for LTBI. Two tests are available for identification of LTBI: the tuberculin skin test (TST) and the gamma interferon (IFN-γ) release assay (IGRA). Evidence suggests that both TST and IGRA are acceptable but imperfect tests. They represent indirect markers of Mycobacterium tuberculosis exposure and indicate a cellular immune response to M. tuberculosis. Neither test can accurately differentiate between LTBI and active TB, distinguish reactivation from reinfection, or resolve the various stages within the spectrum of M. tuberculosis infection. Both TST and IGRA have reduced sensitivity in immunocompromised patients and have low predictive value for progression to active TB. To maximize the positive predictive value of existing tests, LTBI screening should be reserved for those who are at sufficiently high risk of progressing to disease. Such high-risk individuals may be identifiable by using multivariable risk prediction models that incorporate test results with risk factors and using serial testing to resolve underlying phenotypes. In the longer term, basic research is necessary to identify highly predictive biomarkers.
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Pai M, Banaei N. Occupational screening of health care workers for tuberculosis infection: tuberculin skin testing or interferon-γ release assays? Occup Med (Lond) 2014; 63:458-60. [PMID: 24097956 DOI: 10.1093/occmed/kqt105] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- Madhukar Pai
- McGill International TB Centre & Department of Epidemiology & Biostatistics, McGill University, Montreal, Quebec, Canada
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Brookes RH, Hakimi J, Ha Y, Aboutorabian S, Ausar SF, Hasija M, Smith SG, Todryk SM, Dockrell HM, Rahman N. Screening vaccine formulations for biological activity using fresh human whole blood. Hum Vaccin Immunother 2014; 10:1129-35. [PMID: 24401565 PMCID: PMC4896559 DOI: 10.4161/hv.27657] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Understanding the relevant biological activity of any pharmaceutical formulation destined for human use is crucial. For vaccine-based formulations, activity must reflect the expected immune response, while for non-vaccine therapeutic agents, such as monoclonal antibodies, a lack of immune response to the formulation is desired.
During early formulation development, various biochemical and biophysical characteristics can be monitored in a high-throughput screening (HTS) format. However, it remains impractical and arguably unethical to screen samples in this way for immunological functionality in animal models. Furthermore, data for immunological functionality lag formulation design by months, making it cumbersome to relate back to formulations in real-time. It is also likely that animal testing may not accurately reflect the response in humans.
For a more effective formulation screen, a human whole blood (hWB) approach can be used to assess immunological functionality. The functional activity relates directly to the human immune response to a complete formulation (adjuvant/antigen) and includes adjuvant response, antigen response, adjuvant-modulated antigen response, stability, and potentially safety.
The following commentary discusses the hWB approach as a valuable new tool to de-risk manufacture, formulation design, and clinical progression.
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Affiliation(s)
- Roger H Brookes
- Department of Bioprocess Research and Development; Formulation and Stability Platform; Sanofi Pasteur; Toronto, ON Canada
| | - Jalil Hakimi
- Department of Bioprocess Research and Development; Formulation and Stability Platform; Sanofi Pasteur; Toronto, ON Canada
| | - Yukyung Ha
- Department of Bioprocess Research and Development; Formulation and Stability Platform; Sanofi Pasteur; Toronto, ON Canada
| | - Sepideh Aboutorabian
- Department of Bioprocess Research and Development; Formulation and Stability Platform; Sanofi Pasteur; Toronto, ON Canada
| | - Salvador F Ausar
- Department of Bioprocess Research and Development; Formulation and Stability Platform; Sanofi Pasteur; Toronto, ON Canada
| | - Manvi Hasija
- Department of Bioprocess Research and Development; Formulation and Stability Platform; Sanofi Pasteur; Toronto, ON Canada
| | - Steven G Smith
- Faculty of Infectious and Tropical Diseases; Department of Immunology and Infection; London School of Hygiene and Tropical Medicine; London, UK
| | - Stephen M Todryk
- Department of Applied Sciences; Faculty of Health & Life Sciences; Northumbria University; Newcastle upon Tyne, UK
| | - Hazel M Dockrell
- Faculty of Infectious and Tropical Diseases; Department of Immunology and Infection; London School of Hygiene and Tropical Medicine; London, UK
| | - Nausheen Rahman
- Department of Bioprocess Research and Development; Formulation and Stability Platform; Sanofi Pasteur; Toronto, ON Canada
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Toll like receptor 2 agonists lipoteichoic acid and peptidoglycan are able to enhance antigen specific IFNγ release in whole blood during recall antigen responses. J Immunol Methods 2013; 396:107-15. [DOI: 10.1016/j.jim.2013.08.004] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2013] [Revised: 07/31/2013] [Accepted: 08/06/2013] [Indexed: 01/10/2023]
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Impact of blood volume, tube shaking, and incubation time on reproducibility of QuantiFERON-TB gold in-tube assay. J Clin Microbiol 2013; 51:3521-6. [PMID: 23966505 DOI: 10.1128/jcm.01627-13] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Gamma interferon (IFN-γ) release assays (IGRAs) are functional assays used serially to measure the efficacy of novel tuberculosis (TB) vaccines and to screen health care workers for latent tuberculosis infection (LTBI). However, studies have shown nonreproducible IGRA results. In this study, we investigated the effects of blood volume (0.8, 1.0, and 1.2 ml), tube shaking (gentle versus vigorous), and incubation duration (16, 20, and 24 h) on the reproducibility of QuantiFERON-TB Gold In-Tube (QFT-GIT) results for 50 subjects (33 uninfected and 17 infected). The median IFN-γ TB response (TB antigen [Ag] minus nil value) was significantly higher with 0.8 ml blood (1.04 IU/ml) than with 1.0 ml (0.85 IU/ml; P = 0.002) or 1.2 ml (0.49 IU/ml; P < 0.001) for subjects with LTBI. Compared with 0.8 ml (11.8%), there were larger proportions of false-negative results with 1.0 ml (29.4%; P = 0.2) and 1.2 ml (41.2%; P = 0.05) of blood for infected subjects. Blood volume did not significantly change the proportions of positive results in uninfected controls. Compared with gentle shaking, vigorous shaking increased the median IFN-γ response in nil (0.04 versus 0.06 IU/ml; P < 0.001) and TB Ag (0.12 versus 0.24 IU/ml; P = 0.004) tubes and increased TB responses (TB Agvigorous minus nilgentle) (0.02 versus 0.08 IU/ml; P = 0.004). The duration of incubation did not have a significant impact on the proportion of positive results in uninfected or infected subjects. This study identified blood volume and tube shaking as novel preanalytical sources of variability which require further standardization in order to improve the quality and reproducibility of QFT-GIT results.
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