Interferon gamma release assays are unaffected by previous bcg vaccination. Tb and qftgit assays in patients with probable tb, where a positive result was assumed when either test was positive and a negative result was assumed when both tests were negative, the diagnostic sensitivity increased to 87. In june of 2017, qiagen released the newest version of the quantiferontb assay, referred to as the quantiferontb gold plus, or qftplus assay. Tb test results are available within one to two days. Simultaneous performance of quantiferontb gold, tspot. Blood was drawn for both assays within 14 days of starting antituberculosis treatment. This should include checking for signs and symptoms suggestive of tb disease, a chest radiograph, and, when indicated, examination of sputum or other clinical. A borderline test result tspot only also indicates an uncertain likelihood of m. In june of 2017, qiagen released the newest version of the quantiferon tb assay, referred to as the quantiferon tb gold plus, or qftplus assay. The gold plus test has been optimized in such an innovative way with the tbspecific antigens that elicit cd8 and cd4 t cell responses. A diagnosis of ltbi requires that tb disease be excluded by medical evaluation. The qftplus showed a high degree of agreement with the qftgit and tspot, with high sensitivity and specificity. Comparison of the sensitivity of quantiferontb gold in. Tb showed higher overall sensitivity than qft git 91.
Tb and quantiferon tb gold intube qftgit tests, as two commercial blood assays for diagnosing active tuberculosis atb, are not yet fully validated. Latent tuberculosis infection is a growing concern. Comparison of the sensitivity of quantiferontb gold intube. Jun 03, 2016 currently, there are two types of interferongamma release assays igras in use for the detection of tuberculosis tb infection, the quantiferon tb gold intube test gftgit and t spot. Interferongamma release assays igras blood tests for tb. Sensitivity and specificity of quantiferon tb gold plus compared with quantiferon tb gold intube and t spot. Higher specificity of tuberculin skin test compared with. There are few headtohead comparisons of the commercial gamma interferon release assays giras. Comparing quantiferontuberculosis gold, tspot tuberculosis and tuberculin skin test in hivinfected individuals from a low prevalence tuberculosis country. Comparing quantiferontb gold plus with other tests to. Comparative study between using quantiferon and tuberculin.
Quantiferon and t spot have replaced the tuberculin skin test to detect. Tb appears less specific than quantiferon tb gold and that when specificity parameters are equalized, sensitivity is very similar. In general, the pooled qftgit sensitivity is reported to be around 8084% while the tspot. The tb1 tube contains esat6 and cfp10 derived peptides tb7. Spottb assay from oxford immunotec and the quantiferontb gold intube elisa manufactured by qiagen. Tb and quantiferontb gold intube qftit assays in patients with cultureproven pulmonary tuberculosis.
However, the sensitivity decline according to age of tspot. Comparison of the sensitivity of quantiferontb gold intube and. Qftplus is an improved version of the industryleading igra for tb detection, quantiferontb gold. White blood cells from most persons that have been infected with m. Tb test is a blood test for tuberculosis tb screening performed in one visit, using one blood collection tube. Comparison of two commercially available gamma interferon. Tb assays and tst induration diameter in the 46 children with a positive tuberculin skin test 38 with tstdefined latent tb infection and 8 with tb disease. Similar to tb gold test, even a tspot test aids in confirming or ruling out tuberculosis in a patient. To the editor we read with great interest the study by mcmullen et al evaluating the performance of tuberculin skin test tst and quantiferontb gold intube qft for the assessment of tuberculosis risk among college students. Cost analysis of tuberculin skin test and the quantiferontb. As experience with the igras evolves in routine screening, the igras are endorsed with national recommendations 10. Updated guidelines for using interferon gamma release. In a metaanalysis on patients with active tb infection, sensitivities were 0. Tb and quantiferontb gold intube qftgit tests, as two commercial blood assays for diagnosing active tuberculosis atb, are not.
Similar to tb gold test, even a t spot test aids in confirming or ruling out tuberculosis in a patient. Sensitivity and specificity of quantiferon tb gold test qftgin patients with psoriasis the safety and scientific validity of this study is the responsibility of the study sponsor and investigators. We investigated both test generations in a direct headtohead comparison in a german pulmonary hospital. Tb has higher diagnostic sensitivity than quantiferontb gold, there is no statistically significant difference in specificity. Quantiferon tb gold qft is an in vitro laboratory test that measures responses to tbspecific peptide antigens in whole blood. Antigens, testing methods, and interpretation criteria differ between igras. The original quantiferontb gold qftgold assay used a cocktail of peptides to stimulate presensitized cd4 tcells to release gamma interferon.
The quantiferontb gold test qftg is a wholeblood test for use as an aid in diagnosing mycobacterium tuberculosis infection, including latent tuberculosis infection ltbi and tuberculosis tb disease. Qftgit, 52% and among hivinfected persons tspot 61%. It is available in most european countries, the united states as well as various other countries. Tb test is an in vitro diagnostic test for the detection of effector t cells that have been specifically activated by mycobacterium tuberculosis antigens and is intended for use as an aid in the diagnosis of. It should also be noted that the study of goletti and coworkers 6, which is not cited by richeldi, performed an independent comparison of both commercial tests and found little difference in outcome. Spot tb assay from oxford immunotec and the quantiferon tb gold intube elisa manufactured by qiagen. Tb was able to detect a higher number of tb infected cases. A t spot test is an invitro pathology test that aids in the detection of the presence of effector t cells that respond to stimulation of m. Tb assay versus the qftg assay 9, 18, 11, while a study in pediatric patients showed equivalent sensitivities of the tspot.
Spot using an enzymelinked immunospot elispot method. Tb test is the only blood test that has demonstrated in a pivotal clinical study both sensitivity and specificity exceeding. Updated guidelines for using interferon gamma release assays. Tb appears less specific than quantiferontb gold and that when specificity parameters are equalized, sensitivity is very similar. Dec 17, 2018 quantiferon gold plus is the new, improved version of the quantiferon gold tb test. Tuberculosis detection tb gold test or a tspot test.
Comparison of costeffectiveness between the quantiferontb. If primed by previous tb infection, lymphocytes will produce detectable amounts of gamma interferon. Quantiferontb gold qft is an in vitro laboratory test that measures responses to tbspecific peptide antigens in whole blood. Tb test is the only blood test that has demonstrated in a pivotal clinical study both sensitivity and specificity exceeding 95% and reliability in all atrisk groups the tspot. Igras have sensitivity age screened with both tst and two igra assays quantiferon gold intube test qftgit and tspot, the igras were found to have high specificity diagnosis of pulmonary tuberculosis in adults view in chinese. Pdf accuracy of quantiferontb gold test vs tuberculin skin. Extremely sensitive sensitivity refers to how well a test detects the disease. Stephan c, wolf t, goetsch u, bellinger o, nisius g, oremek g, rakus z, gottschalk r, stark s, brodt hr, et al. The quantiferon tb gold test qftg is a wholeblood test for use as an aid in diagnosing mycobacterium tuberculosis infection, including latent tuberculosis infection ltbi and tuberculosis tb disease. Its sensitivity is approximately 80% for active tb. Sensitivity and specificity of quantiferon tb gold test qft. The data supported the conclusion that the greater proportion of positive t spot.
Tb results resulted from a higher level of sensitivity in the test compared with quantiferon. Tb and quantiferontb gold intube qftgit tests, as two commercial blood assays for diagnosing active. In conclusion, i agree that the evidence base using the lalvani elispot i. Owing to contradictory reports regarding whether the results of these igras are affected by the age of the patient, we aimed to determine if these two tests have agerelated differences in sensitivity. Ivinfected outpatients from a large university hospital. Tb is a type of elispot assay used for tuberculosis diagnosis, which belongs to the group of interferon gamma release assays. Tb test is a unique, singlevisit blood test, also known as an interferongamma release assay igra for tb infection. Incidence and risk factors for a positive test reaction and the concordance. Among children who were not bcg vaccinated but had a. Among children who were not bcg vaccinated but had a positive tuberculin skin test. Comparison of the sensitivity of quantiferon tb gold intube and t spot.
Efficient unlike the tuberculin skin test tst or ppd, the tspot. The original quantiferon tb gold qft gold assay used a cocktail of peptides to stimulate presensitized cd4 t cells to release gamma interferon. Both are equally acceptable for screening latent tb in health care workers. Moreover, as mentioned above, examinees were required to take a retest in qftgit, whereas 11 examinees were required to undergo a retest in tspot including those with positive. May, 2016 quantiferontb gold it analyses interferon. Among the ifng release assays igra, quantiferon tb plus qftplus is a new generation of quantiferon tb gold in tube qftit which includes an additional antigen tube tb2. Comparison of the accuracy of quantiferon tb gold in tube vs. A modern replacement to the tuberculin skin test tst, qft provides clinicians with an accurate, reliable and efficient tool for aiding the diagnosis of tb infection. Author links open overlay panel jin takasaki a toshie manabe b eriko morino a yoshikazu muto a masao hashimoto a motoyasu iikura a shinyu izumi a haruhito sugiyama a koichiro kudo c d. Tb and quantiferon tb gold in tube qfngit tests for diagnosing mycobacterium tuberculosis infection. Tb testing the differences between quantiferon gold. Both gamma interferon tests were unaffected by prior mycobacterium bovis bcg vaccination. The tspot tb test is very good if it is going to be used in a low tb endemic. Pooled specificity was low for both igra platforms t spot, 61%.
A tspot test is an invitro pathology test that aids in the detection of the presence of effector tcells that respond to stimulation of m. Tb and quantiferon tb gold intube qftit assays in patients with cultureproven pulmonary tuberculosis. Tb was more sensitive than qfngit in diagnosing both active and latent infection. Tb showed statistically significant decreases in sensitivity according to age, and the degree of the decline was larger for qftgit than for tspot. Comparison of sensitivities of two commercial gamma. The data supported the conclusion that the greater proportion of positive tspot. Among the ifng release assays igra, quantiferontb plus qftplus is a new generation of quantiferon tb gold in tube qftit which includes an additional antigen tube tb2. The authors analyzed 15 936 tuberculosis tests from 9483 university of pennsylvania attendees and found higher. Until recently, there were just two igras with fdaclearance in the united states, including the t. In the us, up to million people have latent tuberculosis infection ltbi. Tb showed higher overall sensitivity than qftgit 91. The quantiferontb gold intube is an indirect test for m tuberculosis infection that is based on measurement of a cellmediated immune response. Quantiferon gold plus is the new, improved version of the quantiferon gold tb test.
A whole blood assay, quantiferontb gold intube qftit, cellestis ltd, australia and an enzymelinked immunospot assay elispot, tspot. One patient with uncontrolled diabetes mellitus showed negative results on all three igras. Tb oxford immunotec, oxford, united kingdom or its. Sensitivity and specificity of quantiferontb gold plus. Moreover, as mentioned above, examinees were required to take a retest in qftgit, whereas 11 examinees were required to undergo a retest in t spot including those with positive. Oct 15, 2014 to the editor we read with great interest the study by mcmullen et al evaluating the performance of tuberculin skin test tst and quantiferontb gold intube qft for the assessment of tuberculosis risk among college students. A single visit blood test for tuberculosis the tspot. Quantiferon and t spot are tests for mycobacterium.
Comparison of sensitivities of two commercial gamma interferon. There are two different igras available commercially. The specificity of the qftplus was the same as that of the qftgit and tspot 98. Equal sensitivity of the new generation quantiferontb gold. Each participant received three tests quantiferon tb gold in tube, t spot. Tb, oxford immunotec, oxford, uk were carried out according to the manufacturers guidelines and defined as positive, negative or indeterminate based on manufacturers recommended criteria. The quantiferontb gold plus qftplus assay is an in vitro diagnostic test that utilizes a peptide cocktail simulating esat6 and cfp10 proteins to stimulate cells in heparinized whole blood. Qftgit, 52% and among hivinfected persons t spot 61%. The test is manufactured by oxford immunotec in the uk. A whole blood assay, quantiferon tb gold intube qftit, cellestis ltd, australia and an enzymelinked immunospot assay elispot, t spot. Currently, there are two types of interferongamma release assays igras in use for the detection of tuberculosis tb infection, the quantiferontb gold intube test gftgit and tspot.
Tb is much larger than that with the commercial test. Quantiferontb gold intube, tst and clinical data were used to differentiate ltbi. Each participant received three tests quantiferontb goldin tube, tspot. Is the quantiferontb blood assay a good replacement for the. The tspot tb test is very good if it is going to be used in a low tb endemic country but it is laborious on the other hand the quantiferongoldin tube serves the same purpose and less laborious. The broken line indicates a tst induration of 15 mm. We conducted this study to assess agreement of test results for qftplus with those of quantiferontb gold intube qftgit. The sensitivity of both tests is higher in developed, lowincidence countries such as the u. A cocktail of 3 mycobacterial proteins esat6, cfp10, and tb 7. Sensitivity and specificity of quantiferontb gold plus compared with quantiferontb gold intube and tspot. Pooled specificity was low for both igra platforms tspot, 61%. Relationship between results of quantiferontb gold in tube and tspot.
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