Improving T-Cell Assays for the Diagnosis of Latent TB Infection: Potential of a Diagnostic Test Based on IP-10

Background There is a need for simple tools such as the M.tuberculosis specific IFN-γ release assays (IGRA) to improve diagnosis of M.tuberculosis-infection in children. The aim of the study was to evaluate the performance of an IP-10 and IL-2 based tests for the diagnosis of M.tuberculosis-infection in recently exposed children from Nigeria. Methodology and Principal Findings Samples were obtained from 59 children at high risk of infection with M.tuberculosis (contacts of adults with smear and culture-positive tuberculosis) and 61 at low risk (contacts of smear-negative/culture-positive tuberculosis or community controls). IP-10 and IL-2 was measured in plasma after stimulation of whole-blood with M.tuberculosis specific antigens and mitogen. Previously developed criteria for positive IP-10 and IL-2 tests were used and the diagnostic performances of the IP-10 and IL-2 tests were compared with the Quantiferon In-Tube (QFT-IT) and the Tuberculin Skin Tests (TST). In response to M.tuberculosis specific antigens, the high-risk children expressed significantly higher levels of IP-10 (1358 pg/ml[IQR 278–2535 pg/ml]) and IL-2 (164 pg/ml[11–590 pg/ml]) than low risk groups 149 pg/ml(25–497 pg/ml), and 0 pg/ml(0–3 pg/ml), respectively. There was excellent agreement (>89%,k>0.80) between IP-10, IL-2 tests and QFT-IT, better than with TST (>74%,k>0.49). The IP-10 and IL-2 responses were strongly associated with M.tuberculosis exposure and with grade of infectiousness of the index cases (p<0.0001). IP-10, IL-2, and TST but not QFT-IT was associated with age of the child in the low risk groups (p<0.02). Conclusions/Significance IP-10 is expressed in high levels and results of the IP-10 test were comparable to the QFT-IT. IL-2 was released in low amounts in response to the antigens and not in response to the mitogen therefore IL-2 seems a less useful marker. We have demonstrated that IP-10 and possibly IL-2 could be alternative or adjunct markers to IFN-γ in the diagnosis infection with M.tuberculosis.

[1]  J. Yim,et al.  Discrepancy between the tuberculin skin test and the whole-blood interferon gamma assay for the diagnosis of latent tuberculosis infection in an intermediate tuberculosis-burden country. , 2005, JAMA.

[2]  C. Dye,et al.  Global tuberculosis control: surveillance planning financing. WHO report 2003. , 2003 .

[3]  R. Locksley,et al.  IL-23 and IL-17 in the establishment of protective pulmonary CD4+ T cell responses after vaccination and during Mycobacterium tuberculosis challenge , 2007, Nature Immunology.

[4]  G. Maartens,et al.  Effect of HIV-1 infection on T-Cell-based and skin test detection of tuberculosis infection. , 2007, American journal of respiratory and critical care medicine.

[5]  T. Kawabe,et al.  Evaluation of interferon-gamma, interferon-gamma-inducing cytokines, and interferon-gamma-inducible chemokines in tuberculous pleural effusions. , 2005, The Journal of laboratory and clinical medicine.

[6]  H. Bozkurt,et al.  Change in Serum Concentrations of Interleukin-2 and Interferon-γ during Treatment of Tuberculosis , 2004, The Journal of international medical research.

[7]  Alberto Mantovani,et al.  IFN-γ-inducible protein 10 and pentraxin 3 plasma levels are tools for monitoring inflammation and disease activity in Mycobacterium tuberculosis infection , 2005 .

[8]  M. Pai,et al.  Meta-analysis: New Tests for the Diagnosis of Latent Tuberculosis Infection: Areas of Uncertainty and Recommendations for Research , 2007, Annals of Internal Medicine.

[9]  P. Klenerman,et al.  Dynamic Relationship between IFN-γ and IL-2 Profile of Mycobacterium tuberculosis-Specific T Cells and Antigen Load1 , 2007, The Journal of Immunology.

[10]  M. Stoler,et al.  Bronchoalveolar neutrophils, interferon gamma-inducible protein 10 and interleukin-7 in AIDS-associated tuberculosis , 2007, Clinical and experimental immunology.

[11]  R. Pardi,et al.  Macrophages exposed to Mycobacterium tuberculosis release chemokines able to recruit selected leucocyte subpopulations: focus on gammadelta cells. , 2003, Immunology.

[12]  W. El-Sadr,et al.  Sensitivity Analysis and Potential Uses of a Novel Gamma Interferon Release Assay for Diagnosis of Tuberculosis , 2006, Journal of Clinical Microbiology.

[13]  R. Adegbola,et al.  Large-scale evaluation of enzyme-linked immunospot assay and skin test for diagnosis of Mycobacterium tuberculosis infection against a gradient of exposure in The Gambia. , 2004, Clinical infectious diseases : an official publication of the Infectious Diseases Society of America.

[14]  L. Fabbri,et al.  Use in routine clinical practice of two commercial blood tests for diagnosis of infection with Mycobacterium tuberculosis: a prospective study , 2006, The Lancet.

[15]  Jeffrey N. Martin,et al.  Comparison of an interferon-gamma release assay with tuberculin skin testing in HIV-infected individuals. , 2007, American journal of respiratory and critical care medicine.

[16]  Tsutomu Kawabe,et al.  Evaluation of interferon-γ, interferon-γ-inducing cytokines, and interferon-γ–inducible chemokines in tuberculous pleural effusions , 2005 .

[17]  Jeffrey N. Martin,et al.  Comparison of an Interferon-γ Release Assay with Tuberculin Skin Testing in HIV-infected Individuals , 2007 .

[18]  E. Vicaut,et al.  Explosion of tuberculin-specific Th1-responses induces immune restoration syndrome in tuberculosis and HIV co-infected patients , 2006, AIDS.

[19]  T. Eguale,et al.  Human T cell responses to the ESAT-6 antigen from Mycobacterium tuberculosis. , 1999, The Journal of infectious diseases.

[20]  R. Pardi,et al.  Macrophages exposed to Mycobacterium tuberculosis release chemokines able to recruit selected leucocyte subpopulations: focus on γδ cells , 2003 .

[21]  L. Cuevas,et al.  Use of purified protein derivative to assess the risk of infection in children in close contact with adults with tuberculosis in a population with high Calmette-Guérin bacillus coverage. , 2001, The Pediatric infectious disease journal.

[22]  G. Schoolnik,et al.  Comparative genomics of BCG vaccines by whole-genome DNA microarray. , 1999, Science.

[23]  P. Ravn,et al.  Latent Tuberculosis in HIV positive, diagnosed by the M. Tuberculosis Specific Interferon-γ test , 2006, Respiratory research.

[24]  J. Walrath,et al.  Resident Th1-like effector memory cells in pulmonary recall responses to Mycobacterium tuberculosis. , 2005, American journal of respiratory cell and molecular biology.

[25]  Kristian Kofoed,et al.  CXCL10/IP-10 release is induced by incubation of whole blood from tuberculosis patients with ESAT-6, CFP10 and TB7.7. , 2007, Microbes and infection.

[26]  R. Wilkinson,et al.  QuantiFERON-TB Gold: state of the art for the diagnosis of tuberculosis infection? , 2006, Expert review of molecular diagnostics.

[27]  P. Andersen,et al.  Specific immune-based diagnosis of tuberculosis , 2000, The Lancet.

[28]  L. Cuevas,et al.  Risk for Tuberculosis among Children , 2006, Emerging infectious diseases.

[29]  A. Ramsay,et al.  Comparison of scanty AFB smears against culture in an area with high HIV prevalence. , 2005, The international journal of tuberculosis and lung disease : the official journal of the International Union against Tuberculosis and Lung Disease.

[30]  R. Joshi,et al.  Sensitivity of a Whole-Blood Interferon-Gamma Assay Among Patients with Pulmonary Tuberculosis and Variations in T-Cell Responses During Anti-Tuberculosis Treatment , 2007, Infection.

[31]  R. Adegbola,et al.  Comparison of Enzyme-Linked Immunospot Assay and Tuberculin Skin Test in Healthy Children Exposed to Mycobacterium tuberculosis , 2006, Pediatrics.

[32]  W. El-Sadr,et al.  Results of a tuberculosis-specific IFN-gamma assay in children at high risk for tuberculosis infection. , 2006, The international journal of tuberculosis and lung disease : the official journal of the International Union against Tuberculosis and Lung Disease.

[33]  W. Rom,et al.  Cytokine gene activation and modified responsiveness to interleukin-2 in the blood of tuberculosis patients. , 1993, The Journal of infectious diseases.

[34]  J. Farber.  Mig and IP‐10: CXC chemokines that target lymphocytes , 1997, Journal of leukocyte biology.

[35]  P. Andersen,et al.  Comparison of tuberculin skin test and new specific blood test in tuberculosis contacts. , 2004, American journal of respiratory and critical care medicine.

[36]  Madhukar Pai,et al.  Systematic Review: T-Cellbased Assays for the Diagnosis of Latent Tuberculosis Infection: An Update , 2008, Annals of Internal Medicine.

[37]  J. Lundgren,et al.  Prospective Evaluation of a Whole-Blood Test Using Mycobacterium tuberculosis-Specific Antigens ESAT-6 and CFP-10 for Diagnosis of Active Tuberculosis , 2005, Clinical Diagnostic Laboratory Immunology.