Diagnostic value of ex vivo pleural fluid interferon-gamma versus adapted whole-blood quantiferon-TB gold in tube assays in tuberculous pleural effusion

The value of single or combined use of pleural fluid interferon gamma release assay in the diagnosis of tuberculous pleurisy

OBJECTIVE

Tuberculous pleurisy (TP) is a common disease of extrapulmonary tuberculosis, but its diagnosis is challenging. Recently, studies have found that the pleural fluid interferon gamma release assay (PF-IGRA) has important diagnostic value in TP, but the sample size of these studies was small, and the conclusions were inconsistent. Therefore, this study evaluated the diagnostic value of PF-IGRA in TP through a meta-analysis.

METHODS

We conducted a literature search in multiple databases to identify studies and calculated the sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), diagnostic odds ratio (DOR), summary receiver operating characteristic (SROC) curve and area under the curve (AUC).

RESULTS

All 26 publications, including 30 case-control studies, were eventually included in the meta-analysis. The results showed that the pooled sensitivity, specificity, PLR, NLR, DOR and AUC with their 95% confidence intervals were 0.90 (0.88-0.91), 0.87 (0.85-0.89), 7.64 (4.46-13.07), 0.13 (0.09-0.19), 65.45 (32.13-133.33) and 0.9508, respectively. The subgroup analysis suggested that the sensitivity, specificity and AUC of PF-IGRA for TP in areas with a high tuberculosis burden were significantly higher than those in areas with a low tuberculosis burden. The sensitivity and AUC of the enzyme-linked immunosorbent assay method were higher than those of the enzyme-linked immunosorbent assay method for IGRA, but the specificity was similar. More importantly, PF-IGRA combined with adenosine deaminase (ADA) could increase the diagnostic value of TP.

CONCLUSIONS

The current meta-analysis indicated that PF-IGRA has high diagnostic value in diagnosing TP, especially in areas with a high TB burden. We recommended that the combination of PF-IGRA and ADA is the best way to diagnose TP.

Diagnostic Value of Interferon-Gamma Release Assays Combined with Multiple Indicators for Tuberculous Peritonitis

Objective

To investigate the diagnostic value of interferon-gamma release assays combined with multiple indicators for tuberculous peritonitis.

Methods

Patients who were admitted to the hospital due to suspected tuberculous peritonitis were prospectively included during the 30-month study period. Moreover, healthy individuals were recruited and included in the control group. All the study participants were assessed using various indexes, such as interferon-gamma release assays.

Results

A total of 180 patients with suspected tuberculous peritonitis were enrolled, and 24 were excluded. 73 patients with a confirmed diagnosis of tuberculous peritonitis were included in the tuberculous peritonitis group, 83 patients with other diseases in the other-disease control group, and 52 healthy individuals in the control group. Moreover, 83 patients in the other-disease control group and 52 participants in the control group were identified as 135 nontuberculous peritonitis patients. The area under the receiver operating characteristics curve for the QuantiFERON-TB test was 0.851 (95% confidence interval: 0.799–0.903), and the optimal cutoff value was 0.55 IU/mL, which corresponds to a sensitivity and specificity of 86.30% and 80.00%, respectively. The receiver operating characteristic curves for the combination of the QuantiFERON-TB test and the use of erythrocyte sedimentation rate, serum adenosine deaminase level, serum cancer antigen 125 level, and hypersensitive C-reactive protein level had an area under the curve of 0.859 (95% confidence interval: 0.809–0.909), with a sensitivity and specificity of 97.26% and 62.96%, respectively.

Conclusions

The combined use of the QuantiFERON-TB test and multiple indexes can significantly improve the accuracy of diagnosing tuberculous peritonitis.

Evaluation of interferon-gamma release assays in extrasanguinous body fluids for diagnosing tuberculosis: A systematic review and meta-analysis

AIMS

In this study, we conducted a meta-analysis to systematically compare the diagnostic accuracy of IGRAs performed for extrasanguinous body fluids with that performed for blood in the diagnosis of TB.

MAIN METHODS

Multiple English and Chinese databases were searched up to November 2017. Studies that complied with the guidelines for the Quality Assessment of Diagnostic Accuracy Studies and used QuantiFERON-TB Gold In-Tube and/or T-SPOT.TB (ELISPOT) assays on both blood and extrasanguinous body fluids were included. Statistical analysis was performed using Stata 12.0 software. Since publication bias is a concern in the meta-analysis of diagnostic studies, we tested for this using Begg's funnel plots.

KEY FINDING

Among the 1332 articles searched from the databases, 24 articles met the inclusion criteria, which included 1040 samples in the patient group and 1044 samples in the control group. For extrasanguinous body fluids, the pooled sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), diagnostic odds ratio (DOR), and summary receiver operating characteristic (SROC) area under the curve (AUC) were 87% (95% CI: 0.81-0.91), 89% (95% CI: 0.84-0.93), 8.22 (95% CI 5.38-12.56), 0.15 (95% CI: 0.10-0.21), 44.92 (95% CI: 25.61-78.81), and 0.94 (95% CI: 0.92-0.96), respectively. For peripheral blood, these values were 83% (95% CI: 0.79-0.87), 74% (95% CI: 0.68-0.79), 3.17 (95% CI 2.63-3.84), 0.23 (95% CI: 0.19-0.29), 12.99 (95% CI: 10.19-16.57), and 0.86 (95% CI: 0.82-0.89), respectively.

SIGNIFICANCE

IGRAs performed on extrasanguinous body fluids exhibited a better diagnostic accuracy compared with IGRAs performed on peripheral blood for diagnosing TB.

Body Fluid Interferon-γ Release Assay for Diagnosis of Extrapulmonary Tuberculosis in Adults: A Systematic Review and Meta-Analysis

The diagnosis of extrapulmonary tuberculosis (EPTB) is difficult. In recent years, T-cell interferon-γ release assays (IGRAs) are widely used in diagnosing tuberculosis. The aim of this meta-analysis is to evaluate the diagnostic accuracy of body fluid IGRAs in diagnosing EPTB. The PubMed, EMBASE, Web of Science, and Cochrane bibliographies were searched for English language articles. 22 studies met the inclusion criteria. The pooled sensitivity and specificity of body fluid IGRAs for diagnosing EPTB were 0.87 [95% confidence interval (CI): 0.83–0.92] and 0.85 (95% CI: 0.79–0.90), respectively. For the fluid T-SPOT.TB, the pooled sensitivity and specificity were 0.92 (95% CI: 0.88–0.95) and 0.85 (95% CI: 0.78–0.91), respectively. The diagnostic odds ratio (DOR) of the fluid T-SPOT.TB was 46.99 (95% CI: 13.69–161.28) for tuberculosis pleurisy, 26.46 (95% CI: 11.38–61.56) for tuberculosis peritonitis, and 97.86 (95% CI: 25.31–378.45) for tuberculosis meningitis. The application of T-SPOT. TB in the diagnosis of EPTB performed better in the body fluid than in the blood. The diagnostic values of the fluid T-SPOT.TB varied for different fluid categories. However, the utility of T-SPOT.TB was limited due to its suboptimal accuracy and higher cost compared with conventional tests.

Accuracy of the interferon-gamma release assay for the diagnosis of tuberculous pleurisy: an updated meta-analysis

Background and Objectives. The best method for diagnosing tuberculous pleurisy (TP) remains controversial. Since a growing number of publications focus on the interferon-gamma release assay (IGRA), we meta-analyzed the available evidence on the overall diagnostic performance of IGRA applied to pleural fluid and peripheral blood. Materials and Methods. PubMed and Embase were searched for relevant English papers up to October 31, 2014. Statistical analyses were performed using Stata and Meta-DiSc. Pooled sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), positive predictive value (PPV), negative predictive value (NPV) and diagnostic odds ratio (DOR) were count. Summary receiver operating characteristic curves and area under the curve (AUC) were used to summarize the overall diagnostic performance. Results. Fifteen publications met our inclusion criteria and were included in the meta analysis. The following pooled estimates for diagnostic parameters of pleural IGRA were obtained: sensitivity, 0.82 (95% CI [0.79-0.85]); specificity, 0.87 (95% CI [0.84-0.90]); PLR, 4.94 (95% CI [2.60-9.39]); NLR, 0.22 (95% CI [0.13-0.38]); PPV, 0.91 (95% CI [0.85-0.96]); NPV, 0.79 (95% CI [0.71-0.85]); DOR, 28.37 (95% CI [10.53-76.40]); and AUC, 0.91. The corresponding estimates for blood IGRA were as follows: sensitivity, 0.80 (95% CI [0.76-0.83]); specificity, 0.70 (95% CI [0.65-0.75]); PLR, 2.48 (95% CI [1.95-3.17]); NLR, 0.30 (95% CI [0.24-0.37]); PPV, 0.79 (95% CI [0.60-0.87]); NPV, 0.75 (95% CI [0.62-0.83]); DOR, 9.96 (95% CI [6.02-16.48]); and AUC, 0.89. Conclusions. This meta analysis suggested that pleural IGRA has potential for serving as a complementary method for diagnosing TP; however, its cost, high turn around time, and sub-optimal performance make it unsuitable as a stand-alone diagnostic tool. Better tests for the diagnosis of TP are required.

Interferon Gamma Release Assays for Diagnosis of Pleural Tuberculosis: a Systematic Review and Meta-Analysis

The role of interferon gamma release assays (IGRAs), although established for identifying latent tuberculosis, is still evolving in the diagnosis of active extrapulmonary tuberculosis. We systematically evaluated the diagnostic performance of blood- and pleural fluid-based IGRAs in tuberculous pleural effusion (TPE). We searched the PubMed and Embase databases for studies evaluating the use of commercially available IGRAs on blood and/or pleural fluid samples for diagnosing TPE. The quality of the studies included was assessed through the QUADAS-2 tool. The pooled estimates of sensitivity and specificity with 95% confidence intervals (95% CI) were generated using a bivariate random-effects model and examined using forest plots and hierarchical summary receiver operating characteristic (HSROC) curves. Indeterminate IGRA results were included for sensitivity calculations. Heterogeneity was explored through subgroup analysis and meta-regression based on prespecified covariates. We identified 19 studies assessing the T.SPOT.TB and/or QuantiFERON assays. There were 20 and 14 evaluations, respectively, of whole-blood and pleural fluid assays, involving 1,085 and 727 subjects, respectively. There was only one good-quality study, and five studies used nonstandard assay thresholds. The pooled sensitivity and specificity for the blood assays were 0.77 (95% CI, 0.71 to 0.83) and 0.71 (95% CI, 0.65 to 0.76), respectively. The pooled sensitivity and specificity for the pleural fluid assays were 0.72 (95% CI, 0.55 to 0.84) and 0.78 (95% CI, 0.65 to 0.87), respectively. There was considerable heterogeneity; however, multivariate meta-regression did not identify any covariate with significant influence. There was no publication bias for blood assays. We conclude that commercial IGRAs, performed either on whole-blood or pleural fluid samples, have poor diagnostic accuracy in patients suspected to have TPE.