Diagnostic value of interferon-gamma in tuberculous pleurisy: a metaanalysis.
ABSTRACT Conventional tests are not always helpful in making a diagnosis of tuberculous pleurisy. Many studies have investigated the usefulness of interferon (IFN)-gamma measurements in pleural fluid for the early diagnosis of tuberculous pleurisy. We conducted a metaanalysis to determine the accuracy of IFN-gamma measurements in the diagnosis of tuberculous pleurisy.
After a systematic review of English-language studies, sensitivity, specificity, and other measures of accuracy of IFN-gamma concentrations in the diagnosis of pleural effusion were pooled using random-effects models. Summary receiver operating characteristic curves were used to summarize overall test performance.
Twenty-two studies met our inclusion criteria. The summary estimates for IFN-gamma in the diagnosis of tuberculous pleurisy in the studies included were as follows: sensitivity, 0.89 (95% confidence interval [CI], 0.87 to 0.91); specificity, 0.97 (95% CI, 0.96 to 0.98); positive likelihood ratio, 23.45 (95% CI, 17.31 to 31.78); negative likelihood ratio, 0.11 (95% CI, 0.07 to 0.16); and diagnostic odds ratio, 272.7 (95% CI, 147.5 to 504.2).
IFN-gamma determination is a sensitive and specific test for the diagnosis of tuberculous pleurisy. The measurement of IFN-gamma levels in pleural effusions is thus likely to be a useful tool for diagnosing tuberculous pleurisy. The results of IFN-gamma assays should be interpreted in parallel with clinical findings and the results of conventional tests.
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ABSTRACT: The objective of the present study was to investigate the presence of interleukin (IL)-27 in pleural effusions and to evaluate the diagnostic significance of pleural IL-27. The concentrations of IL-27 were determined in pleural fluids and sera from 68 patients with tuberculous pleural effusion, 63 malignant pleural effusion, 22 infectious pleural effusion, and 21 transudative pleural effusion. Flow cytometry was used to identify which pleural cell types expressed IL-27. It was found that the concentrations of pleural IL-27 in tuberculous group were significantly higher than those in malignant, infectious, and transudative groups, respectively. Pleural CD4(+) T cells, CD8(+) T cells, NK cells, NKT cells, B cells, monocytes, macrophages, and mesothelial cells might be the cell sources for IL-27. IL-27 levels could be used for diagnostic purpose for tuberculous pleural effusion, with the cut off value of 1,007 ng/L, IL-27 had a sensitivity of 92.7% and specificity of 99.1% for differential diagnosing tuberculous pleural effusion from non-tuberculous pleural effusions. Therefore, compared to non-tuberculous pleural effusions, IL-27 appeared to be increased in tuberculous pleural effusion. IL-27 in pleural fluid is a sensitive and specific biomarker for the differential diagnosing tuberculous pleural effusion from pleural effusions with the other causes.PLoS ONE 01/2012; 7(7):e40450. · 4.09 Impact Factor
Article: Clinical diagnostic utility of IP-10 and LAM antigen levels for the diagnosis of tuberculous pleural effusions in a high burden setting.[show abstract] [hide abstract]
ABSTRACT: Current tools for the diagnosis of tuberculosis pleural effusions are sub-optimal. Data about the value of new diagnostic technologies are limited, particularly, in high burden settings. Preliminary case control studies have identified IFN-gamma-inducible-10 kDa protein (IP-10) as a promising diagnostic marker; however, its diagnostic utility in a day-to-day clinical setting is unclear. Detection of LAM antigen has not previously been evaluated in pleural fluid. We investigated the comparative diagnostic utility of established (adenosine deaminase [ADA]), more recent (standardized nucleic-acid-amplification-test [NAAT]) and newer technologies (a standardized LAM mycobacterial antigen-detection assay and IP-10 levels) for the evaluation of pleural effusions in 78 consecutively recruited South African tuberculosis suspects. All consenting participants underwent pleural biopsy unless contra-indicated or refused. The reference standard comprised culture positivity for M. tuberculosis or histology suggestive of tuberculosis. Of 74 evaluable subjects 48, 7 and 19 had definite, probable and non-TB, respectively. IP-10 levels were significantly higher in TB vs non-TB participants (p<0.0001). The respective outcomes [sensitivity, specificity, PPV, NPV %] for the different diagnostic modalities were: ADA at the 30 IU/L cut-point [96; 69; 90; 85], NAAT [6; 93; 67; 28], IP-10 at the 28,170 pg/ml ROC-derived cut-point [80; 82; 91; 64], and IP-10 at the 4035 pg/ml cut-point [100; 53; 83; 100]. Thus IP-10, using the ROC-derived cut-point, missed approximately 20% of TB cases and mis-diagnosed approximately 20% of non-TB cases. By contrast, when a lower cut-point was used a negative test excluded TB. The NAAT had a poor sensitivity but high specificity. LAM antigen-detection was not diagnostically useful. Although IP-10, like ADA, has sub-optimal specificity, it may be a clinically useful rule-out test for tuberculous pleural effusions. Larger multi-centric studies are now required to confirm our findings.PLoS ONE 01/2009; 4(3):e4689. · 4.09 Impact Factor
Article: Diagnostic accuracy of adenosine deaminase and lymphocyte proportion in pleural fluid for tuberculous pleurisy in different prevalence scenarios.[show abstract] [hide abstract]
ABSTRACT: Tuberculous pleural effusion (TPE) is a paucibacillary manifestation of tuberculosis, so isolation of Mycobacterium tuberculosis is difficult, biomarkers being an alternative for diagnosis. Adenosine deaminase (ADA) is the most cost-effective pleural fluid marker and is routinely used in high prevalence settings, whereas its value is questioned in areas with low prevalence. The lymphocyte proportion (LP) is known to increase the specificity of ADA for this diagnosis. We analyse the diagnostic usefulness of ADA alone and the combination of ADA ≥ 40 U/l (ADA(40)) and LP ≥ 50% (LP(50)) in three different prevalence scenarios over 11 years in our area. Biochemistry, cytology and microbiology studies from 472 consecutive pleural fluid samples were retrospectively analyzed. ADA and differential cell count were determined in all samples. We established three different prevalence periods, based on percentage of pleural effusion cases diagnosed as tuberculosis: 1998-2000 (31.3%), 2001-2004 (11.8%), and 2005-2008 (7.4%). ROC curves, dispersion diagrams and pre/post-test probability graphs were produced. TPE accounted for 73 episodes (mean prevalence: 15.5%). The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) for ADA(40) were 89%, 92.7%, 69.2% and 97.9%, respectively. For ADA(40)+LP(50) the specificity and PPV increased (98.3% and 90%) with hardly any decrease in the sensitivity or NPV (86.3% and 97.5%). No relevant differences were observed between the three study periods. ADA remains useful for the diagnosis of TPE even in low-to-intermediate prevalence scenarios when combined with the lymphocyte proportion.PLoS ONE 01/2012; 7(6):e38729. · 4.09 Impact Factor