scholarly journals Comparing the performance of QuantiFERON-TB Gold Plus with QuantiFERON-TB Gold in-tube among highly TB exposed gold miners in South Africa

2021 ◽  
Vol 5 ◽  
pp. 66
Author(s):  
Thobani Ntshiqa ◽  
Violet Chihota ◽  
Raoul Mansukhani ◽  
Lindiwe Nhlangulela ◽  
Kavindhran Velen ◽  
...  
Keyword(s):  
South Africa ◽  
Latent Tuberculosis ◽  
Prior History ◽  
Interferon Gamma Release Assay ◽  
Limited Data ◽  
History Of ◽  
Gold Miners ◽  
Release Assay ◽  
Additional Antigen ◽  
Hiv Negative

Background: QuantiFERON-TB Gold in-tube (QFT-GIT) is an interferon-gamma release assay (IGRA) used to diagnose latent tuberculosis infection. Limited data exists on performance of QuantiFERON-TB Gold-Plus (QFT-Plus), a next generation of IGRA that includes an additional antigen tube 2 (TB2) while excluding TB7.7 from antigen tube 1 (TB1), to measure TB specific CD4+ and CD8+ T lymphocytes responses. We compared the performance of QFT-Plus with QFT-GIT among highly TB exposed goldminers in South Africa. Methods: We enrolled HIV-negative goldminers in South Africa, ≥33 years with no prior history of TB disease or evidence of silicosis. Blood samples were collected for QFT-GIT and QFT-Plus. QFT-GIT was considered positive if TB1 tested positive; while QFT-Plus was positive if both or either TB1 or TB2 tested positive, as per manufacturer's recommendations. We compared the performance of QFT-Plus with QFT-GIT using Cohen’s Kappa. To assess the specific contribution of CD8+ T-cells, we used TB2−TB1 differential values as an indirect estimate. A cut-off value was set at 0.6. Logistic regression was used to identify factors associated with having TB2-TB1>0.6 difference on QFT-Plus. Results: Of 349 enrolled participants, 304 had QFT-Plus and QFT-GIT results: 205 (68%) were positive on both assays; 83 (27%) were negative on both assays while 16 (5%) had discordant results. Overall, there was 94.7% (288/304) agreement between QFT-Plus and QFT-GIT (Kappa = 0.87). 214 had positive QFT-Plus result, of whom 202 [94.4%, median interquartile range (IQR): 3.06 (1.31, 7.00)] were positive on TB1 and 205 [95.8%, median (IQR): 3.25 (1.53, 8.02)] were positive on TB2. A TB2-TB1>0.6 difference was observed in 16.4% (35/214), with some evidence of a difference by BMI; 14.9% (7/47), 9.8% (9/92) and 25.3% (19/75) for BMI of 18.5-24.9, 18.5-25 and >30 kg/m2, respectively (P=0.03). Conclusion: In a population of HIV-negative goldminers, QFT-Plus showed a similar performance to QFT-GIT.

scholarly journals Interferon Gamma Release Assay for the Identification of Latent Tuberculosis Infection in Rural and Remote Settings

2021 ◽  
Vol 1 (4) ◽  
Author(s):  
Kendra Brett ◽  
Melissa Severn
Keyword(s):  
Interferon Gamma ◽  
Clinical Utility ◽  
Latent Tuberculosis Infection ◽  
Latent Tuberculosis ◽  
Indigenous Communities ◽  
Tuberculosis Infection ◽  
Interferon Gamma Release Assay ◽  
Rural And Remote ◽  
History Of ◽  
Release Assay

There is a lack of evidence on the clinical utility of the interferon gamma release assay for identifying latent tuberculosis infection in rural and remote settings. In remote Indigenous communities with known history of bacillus Calmette-Guérin vaccination, more positive tests results were reported with the tuberculin skin test than with the interferon gamma release assay.

scholarly journals Simultaneous Adalimumab and Antitubercular Treatment for Latent Tubercular Infection: An Experience from Nepal

2019 ◽  
Vol 2019 ◽  
pp. 1-6
Author(s):  
Binit Vaidya ◽  
Shweta Nakarmi
Keyword(s):  
New York ◽  
Oral Treatment ◽  
Latent Tuberculosis ◽  
Interferon Gamma Release Assay ◽  
Ltbi Treatment ◽  
Antitubercular Treatment ◽  
Adalimumab Treatment ◽  
Release Assay ◽  
Timing Of Initiation ◽  
Economic Constraints

Introduction. In Nepal, adalimumab is the most common agent being used, but in a disease activity-based dose tapering to address the economic constraints. Another constraint is the high risk of reactivation of tuberculosis in countries with high burden, especially with the use of tumor necrosis factor blocking agents. Though there are recommendations for screening and treatment of latent tuberculosis infection (LTBI) before using adalimumab, data is not clear regarding the appropriate screening schedule and the timing of initiation of biologic therapy. Methodology. This retrospective review of prospectively followed cohort of spondyloarthropathy patients aimed to evaluate the efficacy of simultaneous initiation of adalimumab with LTBI treatment. Patients fulfilling either the modified New York criteria for ankylosing spondylitis or Assessment in SpondyloArthritis international Society criteria and who were refractory to oral treatment were screened with Mantoux (≥10mm) and interferon gamma release assay (QuantiFERON) to detected LTBI. Those who tested positive were started on rifampicin/isoniazid combination for 3 months and adalimumab treatment on the same day. The patients were followed up at 2 weeks, 4 weeks, 12 weeks, and then every 3 months for 2 years. Results. Out of 784 patients diagnosed, 92 were receiving adalimumab. LTBI was detected by positivity of either Mantoux or QuantiFERON in 29.3% patients. None of the patients with LTBI who were started on the 2 drug regime simultaneous with adalimumab developed activation of tuberculosis. However, two patients testing negative for both the tests developed tubercular pleural effusion during treatment. Conclusions. Our findings indicate that screening for LTBI should be more frequent in patients from high tuberculosis burden countries; treatment of LTBI with rifampicin/isoniazid combination for 3 months is effective in preventing reactivation even when adalimumab is started simultaneously.

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