16 research outputs found
Association of TB Exposure and risk factors with TST conversions: Results from multivariate logistic regression (Bolded variables reached statistical significance).
<p>Association of TB Exposure and risk factors with TST conversions: Results from multivariate logistic regression (Bolded variables reached statistical significance).</p
Characteristics of study participants who underwent repeat tuberculin testing in 2008.
<p>Characteristics of study participants who underwent repeat tuberculin testing in 2008.</p
Prevalence of risk factors & TB exposure at repeat tuberculin testing in 2008.
<p>Prevalence of risk factors & TB exposure at repeat tuberculin testing in 2008.</p
Frequency distribution of change in tuberculin skin test reactions since baseline testing (induration in mm).
<p>Frequency distribution of change in tuberculin skin test reactions since baseline testing (induration in mm).</p
Frequency distribution of tuberculin skin test reactions at annual testing in 2008 (induration in mm).
<p>Frequency distribution of tuberculin skin test reactions at annual testing in 2008 (induration in mm).</p
Association between risk factors and TST Conversions: Results of univariate logistic regression (Bolded variables reached statistical significance).
<p>Association between risk factors and TST Conversions: Results of univariate logistic regression (Bolded variables reached statistical significance).</p
Challenges in the Development of an Immunochromatographic Interferon-Gamma Test for Diagnosis of Pleural Tuberculosis
<div><p>Existing diagnostic tests for pleural tuberculosis (TB) have inadequate accuracy and/or turnaround time. Interferon-gamma (IFNg) has been identified in many studies as a biomarker for pleural TB. Our objective was to develop a lateral flow, immunochromatographic test (ICT) based on this biomarker and to evaluate the test in a clinical cohort. Because IFNg is commonly present in non-TB pleural effusions in low amounts, a diagnostic IFNg-threshold was first defined with an enzyme-linked immunosorbent assay (ELISA) for IFNg in samples from 38 patients with a confirmed clinical diagnosis (cut-off of 300pg/ml; 94% sensitivity and 93% specificity). The ICT was then designed; however, its achievable limit of detection (5000pg/ml) was over 10-fold higher than that of the ELISA. After several iterations in development, the prototype ICT assay for IFNg had a sensitivity of 69% (95% confidence interval (CI): 50-83) and a specificity of 94% (95% CI: 81-99%) compared to ELISA on frozen samples. Evaluation of the prototype in a prospective clinical cohort (72 patients) on fresh pleural fluid samples, in comparison to a composite reference standard (including histopathological and microbiologic test results), showed that the prototype had 65% sensitivity (95% CI: 44-83) and 89% specificity (95% CI: 74-97). Discordant results were observed in 15% of samples if testing was repeated after one freezing and thawing step. Inter-rater variability was limited (3%; 1out of 32). In conclusion, despite an iterative development and optimization process, the performance of the IFNg ICT remained lower than what could be expected from the published literature on IFNg as a biomarker in pleural fluid. Further improvements in the limit of detection of an ICT for IFNg, and possibly combination of IFNg with other biomarkers such as adenosine deaminase, are necessary for such a test to be of value in the evaluation of pleural tuberculosis.</p> </div
Prevalence of TB exposure and risks factors (N = 436).
<p>Prevalence of TB exposure and risks factors (N = 436).</p
Clinical characteristics of the participants (N = 436).
<p>LTBI: Latent Tuberculosis Infection; TST: Tuberculin Skin Test; TB Tuberculosis.</p