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Tuberculosis (TB) remains a leading cause of death globally. Identifying the factors associated with mortality during hospitalization for TB is crucial for improving patient outcomes. This study aimed to investigate the potential risk factors, including T-SPOT.TB test results and routine laboratory markers of inflammation, associated with death during hospitalization due to TB. A retrospective analysis was conducted on 244 hospitalized TB patients. Demographic data, clinical characteristics, T-SPOT.TB results, and laboratory parameters were collected. Univariate and multivariate analyses were performed to identify independent risk factors for in-hospital mortality. Among the patients, 206 survived and 38 died during hospitalization. Multivariate analysis revealed that age (HR: 1.08, 95% CI: 1.02–1.15, p = 0.001), a negative T-SPOT.TB test result (HR: 4.01, 95% CI: 1.78–9.01, p < 0.001), elevated C-reactive protein (CRP) levels (HR: 1.04, 95% CI: 1.01–1.08, p = 0.007), and increased neutrophil-to-lymphocyte ratio (NLR) (HR: 1.04, 95% CI: 1.00–1.07, p = 0.025) were independent risk factors for mortality. This study identified age, a negative T-SPOT.TB result, elevated CRP levels, and a high NLR as significant independent risk factors for death in hospitalized TB patients. These findings underscore the importance of these parameters in the risk stratification and management of hospitalized TB patients. Further research is warranted to elucidate the mechanisms behind these associations and to validate these results in different populations. [ABSTRACT FROM AUTHOR]

Human immunodeficiency virus (HIV) infected individuals are at increased risk of developing active tuberculosis (TB). TB incidence remains higher than in non-HIV subjects after antiretroviral therapy (ART) initiation. This study was conducted to estimate the prevalence of positive IGRA, reflecting latent tuberculosis infection and/or a history of active TB, in HIV-infected individuals after ART initiation in Japan. Two IGRAs (Interferon (IFN)-γ release assays), QuantiFERON®-TB Gold Plus (QFT-Plus) and T-Spot®. TB (TSPOT), were used. We also analyzed the TB associated risk factors for the IGRAs results and the role of CD4+ T-cells, CD8+ T-cells and NK cells for producing IFN-γ. We also analyzed the risk factors for positive IGRA responses and the role of CD4+ T-cells, CD8+ T-cells and NK cells for producing IFN-γ. One hundred eight-four subjects were prospectively enrolled. Median age was 49 years. The positivity rates of QFT-Plus and TSPOT were 7.6% [95%CI 4.6–12.4] and 2.7% [95%CI 1.2–6.2], respectively, with significant difference. TB-associated risk factors and NK cells ≥300/μL were selected as independently significant factors by multivariate logistic regression. The NK cell count revealed significant linear regression with IFN-γ production responding to TB-specific antigens. The prevalence of positive IGRAs was 2.7%–7.6%. QFT-Plus would be practical for a higher positivity rate and reflect TB risk factors. The innate immune system, referring to IFN-γ production, plays an important role in the immune response to TB-specific antigens even after initiating ART. [ABSTRACT FROM AUTHOR]

The interferon-gamma release assay (IGRA) is useful for diagnosing Mycobacterium tuberculosis infections, especially in countries where Bacille Calmette–Guérin vaccinations are performed. However, reproducibility of the IGRA is unclear, as recent data suggest high IGRA conversion and reversion rates in serial tests among healthcare workers. This longitudinal study aimed to evaluate reproducibility of T-SPOT.TB for screening M. tuberculosis infections in Japan. Results of T-SPOT.TB tests performed between April 2014 and March 2016 at two hospitals in Yokohama, Japan, where the incidence of tuberculosis was 18.0 per 100,000 population in 2014, were analyzed. In total, 3890 T-SPOT.TB tests were included. Overall, positive and negative test rates were 8.4% and 87.6%, respectively. Among 373 serial tests within two years, conversion and reversion rates were only 1.1% and 12.5%, respectively. Almost all patients who were initially negative (98.9%) remained so. There was no statistically significant difference between the outcomes observed at the two hospitals. The conversion rate of T-SPOT.TB in Japan is as low as that recently reported in other countries where the incidence of tuberculosis is low. These data indicate that T-SPOT.TB is a reproducible tuberculosis screening tool at local hospitals in areas with a moderate incidence of tuberculosis. [ABSTRACT FROM AUTHOR]

• Xpert and T-SPOT.TB tests were vigorously evaluated for rapid diagnosis of BJTB. • The Xpert had a higher specificity and a lower sensitivity than the T-SPOT.TB test. • The Xpert and T-SPOT. TB tests demonstrated medium concordance in diagnosing BJTB. • The T-SPOT.TB combined with the Xpert can improve the accuracy of diagnosis of BJTB. We evaluated the application value of Xpert MTB/RIF and T-SPOT.TB in the diagnosis of bone and joint tuberculosis. One hundred two patients with suspected bone and joint tuberculosis (BJTB) were admitted to Zhengzhou Orthopaedics Hospital, Henan, China from April 2018 to February 2019. The Xpert MTB/RIF and T-SPOT.TB tests were performed using pus specimens and peripheral blood, respectively. The diagnostic performance of Xpert MTB/RIF and T-SPOT.TB tests was evaluated on the basis of the composite reference standard (CRS). A Total of 73 suspected BJTB were enrolled and categorized, including 12 confirmed BJTB, 27 probable BJTB and 34 non-BJTB. When CRS was used as the reference, the specificity, PPV and NLR values of the Xpert MTB/RIF assay were significantly higher than those of the T-SPOT.TB assay (97.1% vs. 82.4%, p < 0.05; 96.7% vs. 85.4%, p < 0.05; 0.26 vs. 0.12, p < 0.05). However, the sensitivity, NPV and PLR values of the T-SPOT. TB assay were significantly higher than those of the Xpert MTB/RIF assay (89.7% vs. 74.4%, p < 0.05; 87.5% vs. 76.7%, p < 0.05; 5.08 vs. 2.52, p < 0.05). The AUCs from Xpert MTB/RIF and T-SPOT. TB tests were 0.857 and 0.860, respectively. However, the difference was not statistically significant. The Xpert MTB/RIF and T-SPOT. TB tests demonstrated medium concordance in diagnosing BJTB. The sensitivity of T-SPOT.TB test combined with the specificity of Xpert MTB/RIF not only shorten the time of diagnosis but also improve the accuracy of diagnosis of BJTB and reduce the misdiagnosis rate. Therefore, they are useful for early diagnosis of BJTB. [ABSTRACT FROM AUTHOR]

The aim of this study was to evaluate the diagnostic performance of T-SPOT. TB for tuberculous lymphadenitis. Suspected tuberculous lymphadenitis patients between September 2010 and September 2018 who had both peripheral blood T-SPOT. TB test and lymph node biopsy were retrospectively enrolled in this study. The cutoff value of T-SPOT. TB test for peripheral blood was set as 24 spot forming cell (SFC)/106 periphreral blood monocyte cell (PBMC) according to the instruction of testing kits. The gold standard for diagnosis of TBL was the combination of microbiology results, histopathology results and patient's response to anti-TB treatment. Diagnostic efficacy of T-SPOT. TB was evaluated, including sensitivity, specificity, accuracy, predictive values, and likelihood ratio. Among 91 patients who met the inclusion criteria, we excluded 8 cases with incomplete clinical information and 6 cases who lost to follow-up. According to the gold standard, there were 37 cases of true TBL (9 confirmed TBL and 28 probable TBL), 30 cases of non-TBL, and 10 cases of clinically indeterminate diagnosis who were excluded from the final analyses. The T-SPOT. TB tests yielded 43 cases of positive response and 24 cases of negative response. The sensitivity, specificity, accuracy, positive predictive value (PPV), negative predictive value (NPV), positive likelihood ratio (PLR) and negative likelihood ratio (NLR) of peripheral blood T-SPOT. TB for diagnosing TBL were 89.2%, 66.7%, 79.1%, 76.7%, 83.3%, 2.68 and 0.16, respectively. The number of SFCs of T-SPOT. TB in TBL patients [432(134-1264)/106 PBMCs] was higher than that in non-TBL patients [0 (0–30)/106 PBMCs] with a significant difference (Z=-5.306, P <0.001). T-SPOT. TB is a rapid and simple diagnostic test for TBL with a high sensitivity and negative predictive value. [ABSTRACT FROM AUTHOR]

• In contrast to HIV-related tuberculosis, evaluations of the influence of hepcidin in non-HIV-related tuberculosis have been limited. • Non-HIV tuberculosis patients with higher hepcidin levels required a longer time to become culture-negative in this study. • The effect of hepcidin on time for culture to culture-negative was the most relevant in other clinical factors using multivariate analysis. • The negative correlation between hepcidin levels and spot numbers in the positive control wells of the T-SPOT.TB assay was identified. • Hepcidin reduced interferon-gamma production in a dose-dependent manner on in vitro examination with Jurkat cells stimulated with PHA. A major regulatory peptide in iron metabolism, hepcidin, has been shown to predict mortality in HIV-infected tuberculosis patients. The aim of this study was to evaluate whether plasma hepcidin levels on admission can be used to predict the treatment outcome of patients with smear-positive pulmonary tuberculosis (PTB) without HIV co-infection. In this prospective observational study, a total of 35 PTB patients with Mycobacterium tuberculosis -positive sputum smears were enrolled. The relationship between plasma hepcidin levels on admission and the time period to sputum culture-negative was explored. Plasma hepcidin levels of PTB patients were significantly higher than those of healthy subjects (p < 0.001). A positive correlation between hepcidin level on admission and the period until culture-negative was also observed (r = 0.46, p = 0.006). Furthermore, the hepcidin level showed a negative correlation with spot numbers in the positive control wells of the T-SPOT.TB assay; thus the effect of the peptide on interferon-gamma production in T cells was explored. Hepcidin reduced interferon-gamma gene transcription and interferon-gamma production in a dose-dependent manner in Jurkat cells stimulated with phytohaemagglutinin, an antigen non-specific stimulation. These findings indicate that hepcidin alters immunological reactions against M. tuberculosis infection and has an influence on the outcomes of PTB patients without HIV co-infection. [ABSTRACT FROM AUTHOR]

Renal transplant recipients are at increased risk of reactivating latent tuberculosis infection (LTBI) and developing active tuberculosis. QuantiFERON®-TB Gold Plus (QFT-Plus) has two TB-specific antigens tubes (TB1 and TB2). TB1 elicits CD4 T-cell response, and TB2 elicits both CD4 and CD8 T-cells responses, with expected increased sensitivity. The aim of this study was to estimate the prevalence of LTBI in renal transplant recipients in Japan. We conducted a cross-sectional study by using two interferon-γ release assays (IGRAs), QFT-Plus and T-SPOT®. TB (TSPOT). One hundred thirty-five recipients were prospectively enrolled. The median age was 49 years (range: 20 to 79). The positivity rates of QFT-Plus and TSPOT were 5.9% (95%CI 3.0–11.3) and 3.7% (95%CI 1.6–8.4), respectively, with no significant difference. The concordance rate was 95.5% (κ coefficient, 0.76). Age of 60 years and higher was related to the higher positivity rate in both QFT-Plus and TSPOT. The positivity rates of TB1 and TB2 were 5.1% (95%CI 2.5–10.2) and 5.9% (95%CI 3.0–11.2), respectively, with no significant difference. The concordance rate was 99.3% (κ coefficient, 0.93). TB2 did not show a higher positivity rate compared with TB1. The estimated prevalence of LTBI by using the both IGRAs was 3.7–5.9% in renal transplant recipients. These results were equivalent to the IGRAs positivity rate in the general Japanese population, even under the condition of immunosuppressive therapy. In consideration of the higher risk of developing active TB from LTBI, we can use both IGRAs as acceptable tools for LTBI diagnosis in renal transplant recipients. [ABSTRACT FROM AUTHOR]

Objectives: Biologic agents are used against rheumatic diseases, however, they increase the risk of developing severe infections and diseases such as tuberculosis. We aimed to determine the benefits of IP-10 detection to diagnose latent tuberculosis infection (LTBI) in patients with inflammatory rheumatic diseases on different immunosuppressive drug regimens, and compare these results with IFN-γ detection.Materials and Methods: We included 64 patients with inflammatory rheumatic diseases. We used QuantiFERON Gold In-Tube (QFN-G-IT) and T-SPOT.TB to detect IFN-γ production, and an in-house ELISA for IP-10 detection from the previous QFN-G-IT stimulated samples. We assessed the combined use of IFN-γ release assays (IGRAs) and IP-10 test, and analyzed the influence of immunotherapy on the tests performance.Results: We obtained 34.9% positive results by T-SPOT.TB, 25.0% by QFN-G-IT and 31.3% by IP-10 test. The combined use of IGRAs and IP-10 detection increased significantly the amount of positive results (p < 0.0001). Treatment intake had no significant effect on in vitro tests (p > 0.05).Conclusions: IP-10 and IFN-γ detection is comparable and their combined use could increase the number of positive results in the diagnosis of LTBI in rheumatic patients. The tested assays were not influenced by rheumatoid immunosuppressive therapy. Thus, IP-10 could be of use in the development of new and improved LTBI diagnostic tools. [ABSTRACT FROM AUTHOR]

The aim of this study was to evaluate the diagnostic value of the cerebrospinal fluid (CSF) T-SPOT.TB test for the diagnosis of TB meningitis (TBM). A retrospective analysis of 96 patients with manifested meningitis was conducted; T-SPOT.TB test was performed for diagnosing TBM to determine the diagnostic sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV). A receiver operating characteristic (ROC) curve was also drawn to assess the diagnostic accuracy. The sensitivity, specificity, PPV, and NPV of CSF T-SPOT.TB test were 97.8%, 78.0%, 80.3%, and 97.5%, respectively, for 52 patients (54.2%) of the 96 enrolled patients. The area under the curve (AUC) was 0.910, and the sensitivities of CSF T-SPOT.TB for patients with stages I, II, and III of TBM were 96.7%, 97.2%, and 98.9%, respectively. CSF T-SPOT.TB test is a rapid and accurate diagnostic method with higher sensitivity and specificity for diagnosing TBM. [ABSTRACT FROM AUTHOR]

Interferon-γ release assays, including T-SPOT. TB (TSPOT) and QuantiFERON Gold In-Tube (QFT), are important diagnostic tools for tuberculosis infection, but little work has been done to study the performance of these tests in populations prioritized for tuberculosis testing in the United States, especially those other than health care personnel. Participants were enrolled as part of a large, prospective cohort of people at high risk of tuberculosis infection or progression to tuberculosis disease. All participants were administered a tuberculin skin test, TSPOT, and QFT test. A subset of participants had their QFT (n = 919) and TSPOT (n = 885) tests repeated when they returned to get their tuberculin skin test read 2 to 3 days later (repeat study). A total of 531 participants had a TSPOT performed twice on the same sample taken at the same time (split study). The QFT repeat test interpretations were discordant (one test positive and the other negative) for 6.4% of participants (59 of 919), and the TSPOT tests were discordant for 60 of 885 participants in the repeat study (6.8%) and 41 of 531 participants in the split study (7.7%). There was a high degree of variability in the quantitative test results for both QFT and TSPOT, and discordance was not associated with both test results being near the established cut-offs. Furthermore, the proportion of discordance was similar when comparing participants in both the TSPOT repeat and TSPOT split studies. Both QFT and TSPOT were 6% to 8% discordant. The results should be interpreted with caution, particularly when seeing a conversion or reversion in serial testing. [ABSTRACT FROM AUTHOR]

Tuberculous infection of T cell spot test (T-SPOT.TB) and adenosine deaminase (ADA) have a high diagnostic value in pleural effusion for tuberculous pleurisy. However, there were major differences in existing research in regard to the clinical application of the two trials. Therefore, we conducted a meta-analysis to systematically evaluate the diagnostic value of T-SPOT.TB and ADA. Pubmed, Web of Science and Embase databases were searched to compare diagnosis of tuberculous pleurisy by T-SPOT.TB and ADA. The search period was from inception to August 31, 2021. Statistical analyses were performed using Meta-disc 1.4, Revman 5.4 and Stata 16.0. Pooled sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), and diagnostic odds ratio (DOR) were determined. Summary receiver operating characteristic (SROC) curves and the area under the curve (AUC) were used to summarize overall diagnostic performance. 10 qualified original research studies were included, with a total of 2075 patients, of which were 1391 tuberculous pleurisy and 684 non-tuberculous pleurisy. The pooled estimates of diagnostic accuracy of T-SPOT.TB were as follows: sensitivity, 0.88 (95% CI: 0.86–0.90; I 2 = 92.7%); specificity, 0.79 (95% CI: 0.76–0.82; I 2 = 93.7%); PLR, 4.49 (95% CI: 2.29–8.80; I 2 = 94.9%); NLR, 0.15 (95% CI: 0.08–0.30; I 2 = 94.3%), DOR, 35.72 (95% CI: 11.15–114.47; I 2 = 91.5%). The AUC for SROC was 0.9283 (95% CI: 0.8912–0.9654). The pooled estimates of diagnostic accuracy of ADA were as follows: sensitivity, 0.65 (95% CI: 0.62–0.67; I 2 = 98.2%); specificity, 0.90 (95% CI: 0.88–0.92; I 2 = 69.4%); PLR, 6.12 (95% CI: 4.71–7.96; I 2 = 11.9%); NLR, 0.33 (95% CI: 0.12–0.89; I 2 = 99.5%), DOR, 23.18 (95% CI: 12.75–42.14; I 2 = 66.7%). The AUC for SROC was 0.9208 (95% CI: 0.9029–0.9387). Both T-SPOT.TB and ADA had high value in the diagnosis of tuberculous pleurisy. The sensitivity of T-SPOT.TB was higher than ADA, but the specificity of ADA was higher than T-SPOT.TB. On the whole, T-SPOT. TB had similar diagnostic accuracy to ADA. • The pooled sensitivity of T-SPOT.TB was higher than that of ADA, but the pooled specificity of T-SPOT.TB was lower than that of ADA. • Both T-SPOT.TB and ADA in pleural effusion had high diagnostic value for TB pleurisy. [ABSTRACT FROM AUTHOR]

Summary Objective In this study, we have performed a direct comparison between both T-cell based assays (QFN-G-IT and T-SPOT.TB) and TST in patients with psoriasis taking different immunosuppressant drug-regimens. Methods We have prospectively studied 103 patients with moderate-to-severe psoriasis who required latent tuberculosis infection (LTBI) screening before starting systemic immunosuppressive treatment or during its sustained use. Results Overall number of positive results was 16.5%, 17.5% and 8.7% using T-SPOT.TB, QFN-G-IT and TST, respectively. Differences in the percentage of positive results between TST with T-SPOT.TB and QFN-G-IT were significant ( p = 0.005 and p = 0.008, respectively). A total of 24.3% of the subjects enrolled were positive for at least one of the three tests performed. Sixteen patients with negative TST (17%) were positive for one of the two IGRAs. We obtained seven indeterminate results by T-SPOT.TB and two by QFN-G-IT. Seven patients with negative TST presented indeterminate results by either of two IFN-γ assays. Positive TST, T-SPOT.TB and QFN-G-IT results were not affected by clinical therapeutic profile. Conclusions Our results reveal that in vitro assays are useful methods for LTBI diagnosis in patients with psoriasis, suggesting that they might be less influenced by immunosuppression than TST. [ABSTRACT FROM AUTHOR]

Summary: Objectives: To assess whether Interferon-γ release assays (IGRAs) reduce the number of people considered for tuberculosis (TB) preventive treatment without increasing subsequent active disease. Methods: Longitudinal studies with both tuberculin skin test (TST) and IGRAs were identified through a PubMed search. Reductions in diagnosis of TB infection and increases in incident TB in people considered not infected, using IGRAs either instead of TST or as a confirmatory test (two-step approach), were assessed. Results: In comparison with TST alone, the pooled reductions in diagnosis of TB infection obtained with IGRAs were 16.7% and 5.8% at 5 and 10 mm cut-offs respectively, and 24.5% and 12.4% at 5 and 10 mm respectively with the two-step approach. Compared with TST alone, incident TB among people considered not infected increased with the two-step approach (0.94% with T-SPOT®.TB and 1.1% with QuantiFERON®-TB Gold In-Tube) in one of seven studies in high-income countries. In middle- and low-income countries, two of four studies presented increases (0.08 and 0.03 per 100 patient-years respectively) with the two-step approach. Conclusions: In high-income countries, the use of IGRAs, either instead of TST or as confirmatory test reduces the number of people considered for preventive treatment, without a significant risk of subsequent active disease. [ABSTRACT FROM AUTHOR]

Summary: Background: There is limited information on the prevalence of latent tuberculosis infection (LTBI) and the risk factors among contacts of pulmonary TB, which might contribute significantly to TB burden and therefore become the major concern for TB control in Shanghai, China. Methods: A total of 45 diagnosed TB patients from each of 7 Shanghai districts were chosen and approximately 3 contacts per case were randomly selected. A structured questionnaire was used to acquire socio-demographic information and to assess the degree of exposure to index cases. LTBI screening was performed by T-SPOT.TB assay. Results: Of 969 enrolled contacts, 39% were men, average age was 45 ± 19.1 years, and 76.3% were household contacts. LTBI was identified in 29.6% of subjects. Those contacting smear-positive TB patients were 2.24 times (95%CI, 1.586–3.162) more likely to develop LTBI than those otherwise; household contact significantly increased the likelihood of LTBI by 1.52 times (95%CI, 1.061–2.180). Furthermore, among household contacts, the risk of LTBI was higher in spouses and first-degree relatives and increased with age and contact duration. Conclusions: A high prevalence of LTBI was observed among the TB contacts in Shanghai, highlighting the need of intervention among the household contacts and those contacting smear-positive TB patients. [ABSTRACT FROM AUTHOR]

Summary: Objectives: Longitudinal studies in household contacts to identify subgroups at risk of active tuberculosis are lacking. Methods: Household contacts of pulmonary tuberculosis patients were prospectively enrolled to receive chest radiography, sputum studies, and T-SPOT.TB assay at initial visit. Repeat examinations every 6 months for 3 years, and 4-month rifampin preventive therapy for T-SPOT.TB-positive contacts were provided. We investigated factors predicting T-SPOT.TB-positivity and active pulmonary tuberculosis. Results: 583 contacts were enrolled with a follow-up duration of 20.7 ± 9.4 months. 176 (30.2%) were T-SPOT.TB-positive initially and 32 (18.2%) of them received preventive therapy. Old age, living in the same room/house with the index case, the index case having a high smear grade (3+ ∼ 4+) and pulmonary cavitation were associated with T-SPOT.TB-positivity. Active tuberculosis developed in 9 T-SPOT.TB-positive contacts; risk factors included T-SPOT.TB-positivity without preventive therapy, living in the same room, and the index case being ≤50 years or female. 108 (61.4%) T-SPOT.TB-positive contacts had repeat examinations. Forty-five had T-SPOT.TB reversion and none of them developed active tuberculosis. Conclusion: Household contacts who are T-SPOT.TB-positive and live in the same room as the index case are at risk of active tuberculosis and require preventive therapy and close follow-up. [ABSTRACT FROM AUTHOR]

Summary: Background: The clinical manifestations of extrapulmonary tuberculosis (E-TB) vary according to site of disease, so we tested the hypothesis that IFN-γ producing T-cell responses also vary in parallel. Therefore we conducted a prospective, blinded, observational study to evaluate the diagnostic performance of blood T-SPOT.TB according to the various sites of E-TB. Methods: From April 2008 to August 2010, all patients with suspected E-TB were enrolled at a tertiary hospital in an intermediate TB-burden country. Final diagnosis in patients with suspected E-TB was classified by clinical category. Results: A total of 368 patients with suspected E-TB were enrolled; 196 (53%) were classified as having TB, including 119 (32%) with confirmed TB, 34 (9%) probable TB, and 43 (12%) possible TB; the remaining 172 (47%) were classified as not having TB. After excluding patients with possible TB, the T-SPOT.TB was more sensitive in patients with chronic forms of E-TB such as lymph node or osteoarticular TB (93%, 95% CI 83%–97%) than in patients with acute forms of E-TB such as TB meningitis or miliary TB (79%, 95% CI 66%–87%, P = 0.03). Conclusions: The diagnostic performance of the blood T-SPOT.TB differs among patients with various clinical manifestations of E-TB. [ABSTRACT FROM AUTHOR]

Abstract: The aim of this study was to compare the diagnostic performance of 2 interferon-γ release assays, an enzyme-linked immunospot assay (T-SPOT.TB; Oxford Immunotec Ltd., Oxford, UK) and the QuantiFERON-TB Gold in-Tube assay (QFT-GIT; Cellestis Ltd., Carnegie, Australia), in patients with suspected active tuberculosis (TB). From October 2009 to October 2011, a total of 200 patients with suspected TB were enrolled. Clinical and microbiological characteristics of the patients were collected and blood samples were obtained for T-SPOT.TB and QFT-GIT assays. Among the 200 subjects, 98 (49%) had culture-confirmed TB, 18 (9%) had probable TB, and the remaining 84 (42%) subjects did not have TB. The sensitivity, specificity, positive predictive value, and negative predictive value for active TB diagnosis by the T SPOT. TB were 83%, 71%, 81%, and 75%, respectively. For QFT-GIT, the sensitivity, specificity, positive predictive value, and negative predictive value for active TB diagnosis were 66%, 76%, 80%, and 62%, respectively. The QFT-GIT assay resulted in more indeterminate and false-negative results than the T-SPOT.TB assay, especially in immunocompromised patients. In conclusion, T-SPOT.TB had a higher sensitivity and resulted in fewer indeterminate results than the QFT-GIT assay for diagnosing active TB. [Copyright &y& Elsevier]

• High (90%) agreement between QuantiFERON-TB® Gold Plus on LIAISON® XL and T-SPOT.TB • 3% major discrepancies, half of which were false negative results with T-SPOT.TB • Equal proportion (3%) of indeterminate results obtained with both methods The current study compared the QuantiFERON-TB® Gold Plus on LIAISON® XL to the T-SPOT.TB for the diagnosis of latent Mycobacterium tuberculosis infection on 125 patient samples. A high agreement of qualitative results (90%) was observed between both methods with 3% major discrepancies, half of which were false negative results with the T-SPOT.TB. [ABSTRACT FROM AUTHOR]

Summary: Healthcare workers have an increased risk of tuberculosis infection compared with the general population. There have been few attempts to quantify the prevalence of latent tuberculosis infection amongst German healthcare workers, due to inadequacy of the current tuberculin skin test (TST). Therefore, it was our aim to investigate the prevalence of latent tuberculosis in this cohort using a tuberculosis-specific ELISpot (T-SPOT®.TB) test and to compare the performance of this test to that of the TST. Ninety-five healthy participants working in departments of radiology were examined by ELISpot, lymphocyte transformation test and TST. For cellular in-vitro tests, tuberculosis-specific peptides and purified protein derivate (PPD) were used as antigens. These tests were combined with a questionnaire on prior tuberculosis exposure. Out of 95 healthcare workers, only one (1%) was defined as positive by T-SPOT.TB, 92 (97%) by PPD–ELISpot, 78 (82%) by PPD–lymphocyte transformation test and 32 (34%) by TST. Multivariate analysis showed that the TST was significantly affected (P <0.0001 and P =0.001, respectively) by foreign birth and prior skin testing. The T-SPOT.TB test results were independent of foreign birth, prior skin testing and prior vaccination against tuberculosis. In contrast to the TST, T-SPOT.TB appears to be an accurate and useful tool to track tuberculosis infection in this at-risk group. With only one of 95 participants having acquired latent tuberculosis, these preliminary results argue for a low incidence of latent tuberculosis in German radiologists. [Copyright &y& Elsevier]

Abstract: The development of in vitro blood tests that measure the delayed hypersensitivity reaction developed after contact with Mycobacterium tuberculosis will change progressively the diagnosis of M. tuberculosis infection. These blood assays (Quantiferon TB GoldTM, Cellestis, Australia; T-SPOT.TBTM, Oxford Immunotec, United Kingdom) use specific, complex M. tuberculosis antigens (ESAT-6 and CFP-10), whereas the intra-dermal Mantoux test is done with tuberculin, a complex mixture of more than 200 antigens. ESAT-6 and CFP-10 are absent from all the BCG vaccine strains used throughout the world. Significant improvement in the specificity with equivalent or increased sensitivity of the in vitro tests compared to the Mantoux test will lead eventually to replacement of the latter. [Copyright &y& Elsevier]

Abstract: The development of in vitro blood tests that measure the delayed hypersensitivity reaction developed after contact with Mycobacterium tuberculosis will change progressively the diagnosis of M. tuberculosis infection. These blood assays (Quantiferon TB Gold TM , Cellestis, Australia; T-SPOT.TB TM , Oxford Immunotec, United Kingdom) use specific, complex M. tuberculosis antigens (ESAT-6 and CFP-10), whereas the intradermal Mantoux test is done with tuberculin, a complex mixture of more than 200 antigens. ESAT-6 and CFP-10 are absent from all the BCG vaccine strains used throughout the world. Significant improvement in the specificity with equivalent or increased sensitivity of the in vitro tests compared to the Mantoux test will lead eventually to replacement of the latter. [Copyright &y& Elsevier]

Abstract: The sensitivity of QuantiFERON-TB GOLD In-Tube was measured in 104 subjects with recent (≤2 years) and remote Mycobacterium tuberculosis infection using tuberculin skin test conversion as the reference standard. The sensitivity was not significantly different between the 2 groups (33% versus 20%, P = 0.3). This finding suggests interferon-γ release assays may not be more sensitive for diagnosis of recent than remote infection. Longitudinal studies are needed to validate this finding. [Copyright &y& Elsevier]