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QuantiFERON-TB test; interferon gamma release assay (IGRA)

Indications: - screening for tuberculosis - patients who have received BCG* - patients unlikely to return to have tuberculin skin test read* * otherwise tuberculin skin testing is recommended [9] * more specific than tuberculin skin testing in patients with a history of BCG vaccination * the BCG vaccine does not affect QuantiFERON-TB test results [15] Contraindications: - diagnosis of tuberculosis - evaluation of reactivation of latent tuberculosis* (obtain chest X-ray) - avoid routine combination of tuberculin skin test with interferon gamma release assay [9] * once positive, test remains positive after treatment for active tuberculosis or latent tuberculosis Principle: - measures release of interferon-gamma from lymphocytes in heparinized blood incubated with two or three tuberculous antigens & control antigens - after exposure to active tuberculosis, 8-10 weeks before negative QuantiFERON-TB test is reliable - indeterminant test < 8 weeks after exposure should be repeated at 8-10 weeks - chest X-ray reserved for positive test FDA-approved. Advantages: - no need for 2nd visit - results available in 24 hours - appears to better identify latent tuberculosis that is likely to progress than tuberculin skin test [6,7] - negative predictive value > 99%, > than skin testing - preferred method of tuberculosis screening for patients who have received BCG either as vaccine or as cancer chemotherapy [8,9] Disadvantages: - false positives: - 10 of 14 hospital employees in whom latent TB seemed unlkely, repeat testing was negative - healthcare employees who test positive, often test negative on repeat testing [11] - baseline false positives among healthcare workers more frequent (3.8%) than tuberculin skin testing (1.8%) [12] - test conversion* among healthcare workers more frequent (6.1%) than with tuberculin skin testing (0.9%) [12] - false positives in low-risk patients - low CD4 counts in patients with HIV1 infection interfere with ability to react with positive control thus rendering results of testing indeterminate [9] * no association between test conversion & exposure to tuberculosis [12] Method: includes positive control Management: - rule out active TB, prior to treatment of latent TB - chest X-ray indicated for positive QuantiFERON-TB test

Related

tuberculosis

General

laboratory tests for tuberculosis gamma-interferon in blood

References

  1. Journal Watch 21(23):185, 2001 Mazurek GH et al Comparison of a whole-blood interferon gamma assay with tuberculin skin testing for detecting latent Mycobacterium tuberculosis infection. JAMA 286:1740, 2001 PMID: 11594899
  2. Mazurek GH, Villarino ME; CDC. Guidelines for using the QuantiFERON-TB test for diagnosing latent Mycobacterium tuberculosis infection. Centers for Disease Control and Prevention. MMWR Recomm Rep. 2003 Jan 31;52(RR-2):15-8. PMID: 12583541 - Gerberding JL et al, MMWR 2005; 54/RR-15:1 The Centers for Disease Control and Prevention (CDC) Guidelines for using the QuantiFERON-TB Gold test for detecting Mycobacterium tuberculosis infection, United States http://www.cdc.gov/mmwr/PDF/rr/rr5415.pdf
  3. Ferrara G et al, Use in routine clinical practice of two commercial blood tests for diagnosis of infection with Mycobacterium tuberculosis. Lancet 2006; 367:1328 PMID: 16631911
  4. de Perio MA et al Cost-effectiveness of interferon gamma release assays vs tuberculin skin tests in health care workers. Arch Intern Med 2009 Jan 26; 169:179. PMID: 19171815
  5. Cellestis Limited, Carnegie, Victoria, Australia
  6. Diel R et al. Negative and positive predictive value of a whole-blood interferon-gamma-release assay for developing active tuberculosis: An update. Am J Respir Crit Care Med 2011 Jan 1; 183:88 PMID: 20802162 - Lange C and Rieder HL. Intention to test is intention to treat. Am J Respir Crit Care Med 2011 Jan 1; 183:3. PMID: 21193782
  7. Fong KS et al. Challenges of interferon-gamma release assay conversions in serial testing of health-care workers in a TB control program. Chest 2012 Jul 1; 142:55. PMID: 22796839 - Diel R, Loddenkemper R, Nienhaus A. Predictive value of interferon-gamma release assays and tuberculin skin testing for progression from latent TB infection to disease state: a meta-analysis. Chest. 2012 Jul;142(1):63-75 PMID: 22490872 - Loddenkemper R, Diel R, Nienhaus A. To repeat or not to repeat-that is the question!: Serial testing of health-care workers for TB infection. Chest. 2012 Jul;142(1):10-1. doi: 10.1378/chest.12-0045. PMID: 22796831
  8. Mazurek GH, Jereb J, Vernon A, LoBue P et al Updated guidelines for using Interferon Gamma Release Assays to detect Mycobacterium tuberculosis infection - United States, 2010. MMWR Recomm Rep. 2010 Jun 25;59(RR-5):1-25. PMID: 20577159 corresponding NGC guideline withdrawn Jan 2016
  9. Medical Knowledge Self Assessment Program (MKSAP) 16, 17 American College of Physicians, Philadelphia 2012, 2015
  10. Ponce de Leon D, Acevedo-Vasquez E, Alvizuri S et al Comparison of an interferon-gamma assay with tuberculin skin testing for detection of tuberculosis (TB) infection in patients with rheumatoid arthritis in a TB-endemic population. J Rheumatol. 2008 May;35(5):776-81. Epub 2008 Apr 1. PMID: 18398944
  11. Slater ML et al. Challenges with QuantiFERON-TB gold assay for large-scale, routine screening of U.S. healthcare workers. Am J Respir Crit Care Med 2013 Oct 15; 188:1005 PMID: 23978270
  12. Dorman SE et al. Interferon-gamma release assays and tuberculin skin testing for diagnosis of latent tuberculosis infection in healthcare workers in the United States. Am J Respir Crit Care Med 2014 Jan 1; 189:77 PMID: 24299555
  13. McMullen SE et al. Performance of QuantiFERON-TB Gold and tuberculin skin test relative to subjects' risk of exposure to tuberculosis. Clin Infect Dis 2014 May 1; 58 PMID: 24585559 http://cid.oxfordjournals.org/content/58/9/1260
  14. Centers for Disease Control and Prevention Interferon-Gamma Release Assays (IGRAs) - Blood Tests for TB Infection. http://www.cdc.gov/tb/publications/factsheets/testing/igra.htm
  15. Yamcy JR, Melchert VE QuantiFERON-TB Gold+ for the Diagnosis of Mycobacterium tuberculosis Infection American Family Physician 2021. Feb 1;103(3):177-178 PMID: 33507050 https://www.aafp.org/pubs/afp/issues/2021/0201/p177.html#afp20210201p177-b6 - Haas MK, Belknap RW. Diagnostic tests for latent tuberculosis infection. Clin Chest Med. 2019;40(4):829-837 PMID: 31731987