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

The diagnostic value of T cell spot test and adenosine deaminase in pleural effusion for tuberculous pleurisy: A systematic review and meta-analysis

BACKGROUND

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.

METHODS

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.

RESULTS

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; I² = 92.7%); specificity, 0.79 (95% CI: 0.76-0.82; I² = 93.7%); PLR, 4.49 (95% CI: 2.29-8.80; I² = 94.9%); NLR, 0.15 (95% CI: 0.08-0.30; I² = 94.3%), DOR, 35.72 (95% CI: 11.15-114.47; I² = 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; I² = 98.2%); specificity, 0.90 (95% CI: 0.88-0.92; I² = 69.4%); PLR, 6.12 (95% CI: 4.71-7.96; I² = 11.9%); NLR, 0.33 (95% CI: 0.12-0.89; I² = 99.5%), DOR, 23.18 (95% CI: 12.75-42.14; I² = 66.7%). The AUC for SROC was 0.9208 (95% CI: 0.9029-0.9387).

CONCLUSION

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.

Pleural Tuberculosis

Pleural tuberculosis (TB) is common and often follows a benign course but may result in serious long-term morbidity. Diagnosis is challenging because of the paucibacillary nature of the condition. Advances in Mycobacterium culture media and PCR-based techniques have increased the yield from mycobacteriologic tests. Surrogate biomarkers perform well in diagnostic accuracy studies but must be interpreted in the context of the pretest probability in the individual patient. Confirming the diagnosis often requires biopsy, which may be acquired through thoracoscopy or image-guided closed pleural biopsy. Treatment is standard anti-TB therapy, with optional drainage and intrapleural fibrinolytics or surgery in complicated cases.

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.

Use of T-SPOT.TB for the diagnosis of unconventional pleural tuberculosis is superior to ADA in high prevalence areas: a prospective analysis of 601 cases

BACKGROUND

Tuberculous pleural effusion (TPE) is the most common extrapulmonary manifestation and may have lasting effect on lung function. However conventional diagnostic tests for TPE register multiple limitations. This study estimates diagnostic efficacy of the interferon gamma release assay (IGRA: T-SPOT.TB) in TPE patients of different characteristics.

METHODS

We performed a prospective, single-centre study including all suspected pleural effusion patients consecutively enrolled from June 2015 to October 2018. Through receiver operating characteristic (ROC) curves, technical cut-offs and the utility of T-SPOT on pleural fluid (PF) were determined and analysed. Logistic regression analysis was performed to obtain the independent risk factors for TPE, and evaluated the performance of the T-SPOT assay stratified by risk factors in comparison to ADA.

RESULTS

A total of 601 individuals were consecutively recruited. The maximum spot-forming cells (SFCs) of early secretory antigenic target-6 (ESAT-6) and culture filtrate protein-10 (CFP-10) in the PF T-SPOT assay had the best diagnostic efficiency in our study, which was equal to ADA (0.885 vs 0.887, P = 0.957) and superior to peripheral blood (PB), with a sensitivity of 83.0% and a specificity of 83.1% (The cut-off value was 466 SFCs/10⁶ mononuclear cells). Among the TPE patients with low ADA (< 40 IU/L), the sensitivity and specificity of PF T-SPOT were still 87.9 and 90.5%, respectively. The utility of ADA was negatively related to increasing age, but the PF T-SPOT test had a steady performance at all ages. Age (< 45 yrs.; odds ratio (OR) = 5.61, 95% confidence interval (CI) 3.59-8.78; P < 0.001), gender (male; OR = 2.68, 95% CI 1.75-2.88; P < 0.001) and body mass index (BMI) (< 22; OR = 1.93, 95% CI 1.30-2.88; P = 0.001) were independently associated with the risk of TB by multivariate logistic regression analysis. Notably, when stratified by risk factor, the sensitivity of PF T-SPOT was superior to the sensitivity for ADA (76.5% vs. 23.5%, P = 0.016) and had noninferior specificity (84.4% vs. 96.9%, P = 0.370).

CONCLUSIONS

In conclusion, the PF T-SPOT assay can effectively discriminate TPE patients whose ADA is lower than 40 IU/L and is superior to ADA in unconventional TPE patients (age ≥ 45 yrs., female or BMI ≥ 22). The PF T-SPOT assay is an excellent choice to supplement ADA to diagnose TPE.

The diagnostic utility of pleural markers for tuberculosis pleural effusion

Tuberculosis pleural effusion (TPE) is common in clinical practice, and its diagnosis remains a challenge for clinicians. Ziehl-Neelsen staining, PE Mycobacterium tuberculosis culture, and biopsy are the gold standards for TPE diagnosis; however, they are time-consuming, invasive, observer-dependent, and insensitive. PE markers represent a rapid, low-cost, and non-invasive objective diagnostic tool for TPE. In the past decades, several PE biomarkers have been developed, and their diagnostic accuracy has been evaluated in many studies. Here, we reviewed the literature to summarize the diagnostic accuracy of these biomarkers, especially using the evidence from systematic review and meta-analysis. The current research strongly suggests that adenosine deaminase (ADA), interferon-gamma (IFN-γ), and interleukin 27 (IL-27) have extremely higher diagnostic accuracy for TPE, while the diagnostic accuracy of interferon gamma release assays (IGRAs), tumor necrosis factor-α (TNF-α), and interferon-γ-induced protein 10 kDa (IP-10) is moderate. Although some evidence supports C-X-C motif chemokine ligand 9 (CXCL9), CXCL11, CXCL12, sFas ligand, angiotensin-converting enzyme (ACE), calpain-1, spectrin breakdown products (SBDP), matrix metalloproteinase-1 (MMP-1), soluble CD26 (sCD26), soluble interleukin 2 receptor (sIL-2R) as useful diagnostic markers for TPE, more support is needed to validate their diagnostic accuracy. Finally, nucleic acid amplification tests (NAATs) have extremely high diagnostic specificity, but their sensitivity is low. Taken together, ADA is the preferred marker for TPE because its low cost and suitability for standardization.

Diagnostic value of pleural fluid T-SPOT for tuberculous pleurisy: An updated meta-analysis

BACKGROUND

Diagnosing tuberculous pleurisy (TP) remains a clinical challenge and the best method to diagnose it is controversial. Although several studies have investigated the performance of pleural fluid (PF) T-SPOT for pleural tuberculosis (plTB) diagnosis, the heterogeneity of its accuracy exists. Therefore, we performed an updated meta-analysis of the existing evidence on the utility of PF T-SPOT to diagnose TP.

METHODS

PubMed and EmBase were searched for relevant English articles up to July 29, 2019. Statistical analysis was performed using Stata, Revman, and Meta-Disc. 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 the overall diagnostic performance.

RESULTS

A total of 13 studies (997 patients with TP and 656 patients without TP) were identified and enrolled to meta-analysis, giving the following pooled values for diagnostic accuracy of PF T-SPOT: sensitivity, 0.91 (95% CI, 0.89-0.92, I2 = 80.9%); specificity, 0.88 (95% CI, 0.86-0.91, I2 = 87.3%); PLR, 6.28 (95% CI, 2.88-13.69, I2 = 93.3%); NLR, 0.12 (95% CI, 0.07-0.21, I2 = 84.9%); DOR, 59.74 (95% CI, 24.13-147.93, I2 = 78.3%); and the area under the SROC curve, 0.95 (95% CI, 0.93-0.97).

CONCLUSIONS

Our meta-analysis suggests that PF T-SPOT has important diagnostic value for plTB. However, the standardization of the operating procedure needs to be further promoted, which would make the results more credible.

Tuberculous pleural effusion: diagnosis & management

Background: Tuberculosis (TB) is the world's leading cause of death from infectious disease. The World Health Organization (WHO) recognized 6.3 million new TB cases in 2017, 16% corresponding to extrapulmonary forms; pleural tuberculosis (PT) is the most common extrapulmonary form in adults. PT diagnosis is often challenging because the scarcity of bacilli in pleural fluid (PF), sometimes requiring invasive procedures to obtain pleural tissue for histological, microbiological or molecular examination. In regions of medium and high disease prevalence, adenosine deaminase (ADA), interferon gamma (IFN-γ) and interleukin 27 (IL-27) dosages are useful to establish presumptive diagnosis in patients with compatible clinical/radiological picture who present with lymphocytic pleural effusion. PT treatment is similar to the pulmonary TB treatment regimen recommended by WHO. Area covered: In this update, we present a PT review, including epidemiology, pathogenesis, clinical features, diagnosis, and therapy. Expert opinion: There is no PF test alone accurate for PT diagnosis, despite the evolution in clinical laboratory. ADA, IFN-γ and IL-27 are valuable laboratory biomarkers; however, IFN-γ and IL-27 are quite expensive. Molecular tests present low sensitivity in PF, being useful for diagnostic confirmation. Multidrug therapy remains the PT treatment choice. Advancing research in immunotherapy may bring benefits to PT patients.

Application of Venn's diagram in the diagnosis of pleural tuberculosis using IFN-γ, IP-10 and adenosine deaminase

BACKGROUND

Pleural tuberculosis (PlTB) is the most common extrapulmonary manifestation of this infectious disease which still presents high mortality rates worldwide. Conventional diagnostic tests for PlTB register multiple limitations, including the lack of sensitivity of microbiological methods on pleural specimens and the need of invasive procedures such as pleural biopsy performance. In this scenario, the search for biological markers on pleural fluid (PF) has been the target of several studies as a strategy to overcome the limitations of PlTB diagnosis. This study aims to evaluate the use either isolated or in combination with adenosine deaminase (ADA), interferon-gamma (IFN-γ), interferon-gamma inducible protein of 10-kD (IP-10) levels on PF in order to guide an accurate anti-TB treatment in microbiologically non-confirmed cases.

METHODS AND FINDINGS

Eighty patients presenting pleural effusion under investigation were enrolled in a cross-sectional study conducted at Pedro Ernesto University Hospital, Rio de Janeiro, RJ, Brazil. Peripheral blood (PB) and PF samples collected from all patients were applied to the commercial IFN-γ release assay, QuantiFERON-TB Gold In-Tube, and samples were analyzed for IFN-γ and IP-10 by immunoassays. ADA activity was determined on PF by the colorimetric method. Based on microbiological and histological criteria, patients were categorized as follow: confirmed PlTB (n = 16), non-confirmed PlTB (n = 17) and non-PlTB (n = 47). The Mycobacterium tuberculosis antigen-specific production of IFN-γ and IP-10 on PB or PF did not show significant differences. However, the basal levels of these biomarkers, as well as the ADA activity on PF, were significantly increased in confirmed PlTB in comparison to non-PlTB group. Receiver operating characteristics curves were performed and the best cut-off points of these three biomarkers were estimated. Their either isolated or combined performances (sensitivity [Se], specificity [Sp], positive predictive value [PPV], negative predictive value [NPV] and accuracy [Acc]) were determined and applied to Venn's diagrams among the groups. Based on the confirmed PlTB cases, IFN-γ showed the best performance of them at a cut-off point of 2.33 IU/mL (Se = 93.8% and Sp = 97.9%) followed by ADA at a cut-off of 25.80 IU/L (Se = 100% and Sp = 84.8%) and IP-10 (Cut-point = 4,361.90 pg/mL, Se = 75% and Sp = 82.6%). IFN-γ plus ADA (cut-point: 25.80 IU/L) represent the most accurate biomarker combination (98.4%), showing Se = 93.7%, Sp = 100%, PPV = 100% and NPV = 97.9%. When this analysis was applied in non-confirmed PlTB, 15/17 (88.2%) presented at least two positive biomarkers in combination.

CONCLUSION

IFN-γ, IP-10, and ADA in PlTB effusions are significantly higher than in non-PlTB cases. IFN-γ is an excellent rule-in and rule-out test compared to IP-10 and ADA. The combination of IFN-γ and ADA, in a reviewed cut-off point, showed to be particularly useful to clinicians as their positive results combined prompts immediate treatment for TB while both negative results suggest further investigation.

Accuracy of interleukin-27 assay for the diagnosis of tuberculous pleurisy: A PRISMA-compliant meta-analysis

BACKGROUND

The concentration of interleukin-27 (IL-27) in pleural effusions was found to be increased in tuberculous pleurisy and several studies have investigated the diagnostic value of IL-27 for tuberculous pleural effusions (TPEs), but the results varied a lot. We conducted the present study to comprehensively evaluate the diagnostic value of IL-27 for TPE.

METHODS

Primary diagnostic test studies of IL-27 for TPE was searched and identified from databases. The pooled sensitivity, specificity, positive likelihood ratio, negative likelihood ration, diagnostic odds ratio, and receiver operating characteristic curves (SROCs) were computed or pooled to summarize the overall test performance.

RESULTS

Nine studies with a total number of 1226 patients were identified in our research. The main pooled estimates were as follows: sensitivity 0.92 [95% confidence interval (CI), 0.90-0.95], specificity 0.90 (95% CI, 088-0.92), and area under the SROC 0.97. No evidence of publication bias was detected.

CONCLUSION

Our research suggested the good diagnostic value of IL-27 for TPE and it could be used as a diagnostic biomarker.

Pleural fluid tests to diagnose tuberculous pleuritis

PURPOSE OF REVIEW

This article summarizes current data regarding the accuracy of pleural fluid tests assisting the diagnosis of tuberculous pleuritis (TBP).

RECENT FINDINGS

No pleural fluid test reliably rules-in TBP in settings with low TBP prevalence. Interferon-γ) alone or in combination with adenosine deaminase (ADA) is more reliable than ADA for this purpose in nonlow prevalences. ADA can reliably rule-out TBP in prevalences of less than 40% although in higher prevalences the product of interleukin-27 and ADA is the most accurate rule-out test.

SUMMARY

The definite diagnosis of TBP requires the isolation of Mycobacterium tuberculosis from pleural fluid or biopsies. Because of the low sensitivity of pleural fluid cultures and the invasiveness of pleural biopsy techniques, the concept of a pleural fluid test that accurately establishes or excludes TBP diagnosis has been proposed. Numerous pleural fluid tests have been evaluated for this purpose with ADA being the most widely accepted one. During the last years, it has been demonstrated that the ability of ADA to rule-in or rule-out TBP is affected by the prevalence of TBP in the setting where the test is used. The complementary use of interferon-γ or interleukin-27 increases the ability of ADA to rule-in or rule-out the disease, respectively.

Diagnostic value of interferon-γ-induced protein of 10kDa for tuberculous pleurisy: A meta-analysis

BACKGROUND

The accurate diagnosis of tuberculous pleurisy is still a clinical challenge. Many studies reported that interferon-γ-induced protein of 10kDa (IP-10) plays a role in diagnosing tuberculous pleurisy, but with considerable variance of results. This meta-analysis aimed to evaluate the overall diagnostic accuracy of IP-10 for tuberculous pleurisy.

METHODS

PubMed, EMBASE, and other databases were searched for studies examining accuracy of pleural IP-10 for diagnosing tuberculous pleurisy. Related data were extracted and sensitivity/specificity, positive/negative likelihood ratio (PLR/NLR), and diagnostic odds ratio (DOR) were pooled. Summary receiver operating characteristic curve and area under the curve (AUC) were performed and calculated to summarize the overall test performance.

RESULTS

Fourteen studies involving 1382 subjects met inclusion criteria, including 715 cases of tuberculous pleurisy and 667 controls. Summary estimates of the diagnostic performance of the IP-10 for tuberculous pleurisy were listed as follows: sensitivity, 0.84 (95%CI 0.81 to 0.87); specificity, 0.90 (95% CI 0.88 to 0.92); PLR, 7.96 (95% CI 5.59 to 11.32); NLR, 0.19 (95% CI 0.15 to 0.24); DOR, 49.82 (95% CI 28.08 to 88.38); and AUC 0.94. No publication bias was detected.

CONCLUSION

Pleural IP-10 is a useful diagnostic marker for tuberculous pleurisy. Nevertheless, its result should be interpreted together with the results of conventional test and clinical information of patients.

Tuberculosis in Infants and Children

One million children develop tuberculosis disease each year, and 210,000 die from complications of tuberculosis. Childhood tuberculosis is very different from adult tuberculosis in epidemiology, clinical and radiographic presentation, and treatment. This review highlights the many unique features of childhood tuberculosis, with special emphasis on very young children and adolescents, who are most likely to develop disease after infection has occurred.

Accuracy of the Bronchoalveolar Lavage Enzyme-Linked Immunospot Assay for the Diagnosis of Pulmonary Tuberculosis: A Meta-analysis

Assessing of local immune response may improve the accuracy of pulmonary tuberculosis (PTB) diagnosis. Many studies have investigated diagnosing PTB based on enzyme-linked immunospot (ELISPOT) assay of bronchoalveolar lavage (BAL) fluid, but the results have been inconclusive. We meta-analyzed the available evidences on overall diagnostic performance of ELISPOT assay of BAL fluid for diagnosing PTB.A systematic literature search was performed using PubMed, Embase, Wangfang, Weipu, and CNKI. Data were pooled on sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), and diagnostic odds ratio (DOR). Overall test performance was summarized using summary receiver operating characteristic curves and the area under the curve (AUC). Deeks test was used to test for potential publication bias.Seven publications with 814 subjects met our inclusion criteria and were included in this meta-analysis. The following pooled estimates for diagnostic parameters were obtained: sensitivity, 0.90 (95% CI: 0.85-0.94); specificity, 0.80 (95% CI: 0.77-0.84); PLR, 5.08 (95% CI: 2.70-9.57); NLR, 0.13 (95% CI: 0.06-0.28); DOR, 49.12 (95% CI: 12.97-186.00); and AUC, 0.96. No publication bias was identified.The available evidence suggests that ELISPOT assay of BAL fluid is a useful rapid diagnostic test for PTB. The results of this assay should be interpreted in parallel with clinical findings and the results of conventional tests.