Tuberculous pleural effusion

Interpretable noninvasive diagnosis of tuberculous pleural effusion using LGBM and SHAP: development and clinical application of a machine learning model

Background

Tuberculous pleural effusion (TPE) is a prevalent tuberculosis complication, with diagnosis presenting considerable challenges. Timely and precise identification of TPE is vital for effective patient management and prognosis, yet existing diagnostic methods tend to be invasive, lengthy, and often lack sufficient accuracy. This study seeks to design and validate an interpretable machine learning model based on routine laboratory data to enable noninvasive and rapid TPE diagnosis.

Methods

A multicenter prospective study was conducted across China between January 2021 and September 2024, enrolling 963 patients. The derivation cohort, comprising 763 patients, was employed for model training and internal validation, while 200 patients formed the external validation cohort. The model was built upon 18 routine laboratory parameters, including pleural fluid and serum biomarkers, with multiple machine learning (ML) algorithms evaluated. Light gradient boosting machine (LGBM) emerged as the top-performing model. Shapley Additive exPlanations (SHAP) analysis assessed feature importance and interpretability. Model performance was evaluated via area under the curve (AUC) and accuracy metrics.

Results

Of the 10 ML models compared, LGBM demonstrated superior performance. Feature importance analysis identified 11 key variables, leading to constructing a highly interpretable LGBM model. The model achieved an AUC of 0.9454 in internal validation and 0.9262 in external validation, showcasing strong robustness and generalizability. SHAP analysis enhanced interpretability by highlighting each feature's contribution to prediction outcomes. This model has since been integrated into clinical practice for noninvasive, rapid TPE diagnosis. During external validation, the model achieved a sensitivity of 0.8600, specificity of 0.9056, positive predictive value of 0.8698, and negative predictive value of 0.8686, underscoring its accuracy across diverse patient cohorts.

Interpretation

This interpretable machine learning model offers a noninvasive, accurate solution for early TPE diagnosis, significantly reducing reliance on invasive procedures. The integration of SHAP ensures the model's clinical interpretability, mitigating concerns surrounding the "black-box" nature of many machine learning approaches.

Conclusions

This interpretable LGBM-based model provides a reliable, noninvasive tool for TPE diagnosis. It supports clinical decision-making with real-time risk assessment and promises broader applicability through future integration into clinical information systems.

Study on the Association Network of Tuberculosis Lesions in Adult Extrapulmonary Tuberculosis in China: A Large-Scale Multicenter Observational Study

Background: Extrapulmonary tuberculosis (EPTB) is a significant health problem which can lead to severe morbidity and mortality. In clinical practice, EPTB can have a variety of nonspecific clinical manifestations and can be concurrent with other types of EPTB. As information pertaining to concurrent EPTB is scarce, research efforts are needed to find concurrent EPTB types and to explore the association networks and rules of concurrent EPTB. Materials and Methods: An observational multicenter study was carried out at 21 hospitals from 15 provinces in China from Jan 1, 2011, to Dec 31, 2017. All the adult EPTB inpatients (≥ 15 years) were included. Multivariable logistic regression analysis was used to examine the associations of gender and age group for concurrent EPTB. The association network and rules for concurrent EPTB were analyzed by the Apriori algorithm. Results: A total of 75,993 adult EPTB inpatients (not including EPTB concurrent with PTB) were included. The ratio of male:female was 1.32. The most common types of EPTB lesions were tuberculous pleurisy (46.47%). In the fully adjusted multivariable logistic regression models, it was found that female EPTB patients (aOR = 1.129, 95% CI: 1.081-1.178) were more likely to have concurrent EPTB. As age increased, the risk of concurrent EPTB decreased (aOR < 1, p value for trend < 0.001). The association network graph showed that almost all the EPTB diseases may be concurrent with other types of EPTB. Ureteric tuberculosis and sacral tuberculosis diseases existed mainly in concurrence with other types of EPTB (about 80%). Tuberculous pleurisy and tuberculous lymphadenitis of the neck could be concurrent with more than 60 other types of EPTB disease. The most common concurrent EPTB types were tuberculous peritonitis concurrent with tuberculous pleurisy (1.64%). Sacral tuberculosis concurrentwith lumbar vertebra tuberculosis had the highest confidence value (68.56%). The strongest association rule was found for vesical tuberculosis concurrent with ureteric tuberculosis (lift = 166.18) and ureteric tuberculosis concurrent with vesical tuberculosis (lift = 166.18). Conclusion: The present study revealed the occurrence of concurrent EPTB types and analyzed the association network and rules among adult EPTB for the first time in a large sample population. Clinicians should be alert to the incidence of concurrent EPTB and that these patients require administration of customized treatment regimens in order to achieve the best outcomes.

Application of the metagenomic next-generation sequencing technology to identify the causes of pleural effusion

Background

Pleural effusion (PE), frequently encountered in clinical practice, can arise from a variety of underlying conditions. Accurate differential diagnosis of PE is crucial, as treatment and prognosis are heavily dependent on the underlying etiology. However, diagnosing the cause of PE remains challenging, relying on mycobacteriological methods that lack sensitivity and are time-consuming, or on histological examinations that require invasive biopsies. The recent advancements in metagenomic next-generation sequencing (mNGS) have shown promising applications in the diagnosis of infectious diseases. Despite this, there is limited research on the utility of mNGS as a comprehensive diagnostic tool for simultaneously identifying the causes of PE, particularly in cases of tuberculosis or malignancy.

Methods

This study aimed to assess the efficacy of mNGS in detecting tuberculous pleural effusion (TPE) and malignant pleural effusion (MPE). A total of 35 patients with PE were included, and their PE samples were analyzed using mNGS.

Results

Among the participants, 8 were ultimately diagnosed with TPE, and 10 were diagnosed with MPE, with lung adenocarcinoma being the most prevalent pathological type (50%, 5/10), according to established diagnostic criteria. Additionally, 7 patients were diagnosed with non-infectious PE. However, mNGS identified only 2 cases of TPE and 8 cases of MPE. The sensitivity of mNGS for detecting Mycobacterium tuberculosis was 25% (2/8), while the specificity was 100%. For tumor detection, mNGS demonstrated a sensitivity of 80%, a specificity of 92.6%, and an AUC of 0.882.

Conclusion

mNGS is effective in distinguishing MPE from non-MPE, but is not suitable for diagnosing TPE.

Biological and cytological-morphological assessment of tuberculous pleural effusions

AIM

Tuberculosis (TB) came back in the top of causes for infectious disease-related deaths and its pleural involvement is still in the top two extrapulmonary sites. The authors continued their studies on TB pleural effusions (Pl-Effs) with the assessment of biological and cytological variable of pleural fluid (PF), introducing in the investigation algorithm and testing a new tool, the computer-assisted evaluation of cell populations on PF smears.

PATIENTS, MATERIALS AND METHODS

A series of 85 patients with TB pleurisy (PLTB) were selected from a larger group of 322 patients with different types of Pl-Effs. The algorithm of investigation included. clinical variables, biological assays of PF, gross aspects including imagistic variables and PF cytology on May-Grünwald-Giemsa (MGG)-stained smears. All the data obtained were entered into and processed using Microsoft Excel module of the 2019 Microsoft Office Professional software along with the 2014 XLSTAT add-in program for MS Excel. The PF cellularity was assessed qualitatively by a cytologist and quantitatively with in-house software. Continuous variables were compared using Pearson's correlation test, while categorical variables were compared using χ² (chi-squared) test.

RESULTS

Our analysis showed that patients were usually males, aged between 25 and 44 years with Pl-Eff discovered at clinical imagistic examination, almost always one-sided and free in the pleural cavity. Its extension was either moderate or reduced. The PF had a serous citrine appearance in most of the cases, and biological characteristics pleaded for an exudate [high levels of proteins and lactate dehydrogenase (LDH)], with elevated adenosine deaminase (ADA) values and rich in lymphocytes (Ly). The attempt to identify the pathogen in PF was not of much help. Apart from Ly, neutrophils [polymorphonuclear neutrophils (PMNs)] were a rare presence and their amount had only a trend of direct correlation with Ly. The same situation was encountered in the case of mesothelial cells (MCs). The comparison between the qualitative and the quantitative, computer-assisted evaluations of cytological smears showed that the results of the two methods overlapped in less than one third of the cases, although the sensitivity and specificity values as well as the two calculated predictive values of the qualitative method were encouraging.

CONCLUSIONS

The assessment of biological variables and cell populations of the PF are basic tools in the diagnosis of pleural TB. The assessment of PF cell population could be improved by the use of computer-assisted quantitative analysis of the PF smears, which is simple to design, easy to introduce and handle and reliable.

Evaluation of droplet digital polymerase chain reaction by detecting cell-free deoxyribonucleic acid in pleural effusion for the diagnosis of tuberculous pleurisy: a multicentre cohort study

OBJECTIVES

Tuberculous pleurisy is one of the most common types of extra-pulmonary tuberculosis, but the sensitivity of conventional mycobacterial culture (Culture) or Xpert MTB/RIF assay (Xpert) is not satisfying. This multicentre cohort study evaluated the accuracy of a new cell-free DNA droplet digital PCR assay (cf-ddPCR) for diagnosing tuberculous pleurisy.

METHODS

Patients with suspected tuberculosis (≥5 years of age) with pleural effusion were consecutively recruited from nine research sites across six provinces in China between September 2020 to May 2022. Culture, Xpert, Xpert MTB/RIF Ultra assay (Ultra), real-time PCR, and cf-ddPCR were performed simultaneously for all specimens.

RESULTS

A total of 321 participants were enrolled, and data from 281 (87.5%) participants were available, including 105 definite tuberculous pleurisy, 113 possible tuberculous pleurisy and 63 non-tuberculous pleurisy according to the composite reference standard. The sensitivity of cf-ddPCR was 90.5% (95/105, 95% CI, 82.8-95.1%) in the definite tuberculous pleurisy group, which was significantly higher than those of Culture (57.1%, 60/105, 95% CI, 47.1-66.6%, p < 0.001), Xpert (46.7%, 49/105, 95% CI, 37.0-56.6%, p < 0.001), Ultra (69.5%, 73/105, 95% CI, 59.7-77.9%, p < 0.001) and real-time PCR (75.2%, 79/105, 95% CI, 65.7-82.9%, p < 0.001). In possible tuberculous pleurisy, whose results of Culture and Xpert were both negative, the sensitivity of cf-ddPCR was 61.1% (69/113, 95% CI, 51.4-70.0%), which was still significantly higher than that of Ultra (27.4%, 31/113, 95% CI, 19.7-36.8%, p < 0.001) and real-time PCR (38.9%, 44/113, 95% CI, 30.0-48.6%, p < 0.001).

DISCUSSION

The performance of cf-ddPCR is superior to Culture, Xpert, Ultra, and real-time PCR, indicating that improved diagnostic accuracy can be anticipated by incorporating this new assay.

The evolving landscape of IL-10, IL-22 and IL-26 in pleurisy especially in tuberculous pleurisy

Pleurisy can be categorized as primary or secondary, arising from immunological, tumorous, or microbial conditions. It often results in lung structure damage and the development of various respiratory issues. Among the different types, tuberculous pleurisy has emerged as a prominent focus for both clinical and scientific investigations. The IL-10 family, known for its anti-inflammatory properties in the human immune system, is increasingly being studied for its involvement in the pathogenesis of pleurisy. This review aims to present a detailed overview of the intricate role of IL-10 family members (specifically IL-10, IL-22, and IL-26) in human and animal pleuritic diseases or relevant animal models. These insights could serve as valuable guidance and references for further studies on pleurisy and potential therapeutic strategies.

Diagnostic role of internal mammary lymph node involvement in tuberculous pleurisy: a multicenter study

BACKGROUND AND OBJECTIVES

Diagnosis of tuberculous pleurisy (TP) may be challenging and it often requires pleural biopsy. A tool able to increase pre-test probability of TP may be helpful to guide diagnostic work-up and enlargement of internal mammary lymph node (IMLN) has been suggested to play a potential role. The aim of the present investigation was to assess role of IMLN involvement in TP in a multi-centric case-control study, by comparing its prevalence and test performance to those observed in patients with infectious, non-tuberculous pleurisy (NTIP), and in controls free from respiratory diseases (CP).

METHODS

A total of 419 patients, from 14 Pulmonology Units across Italy were enrolled (127 patients affected by TP, 163 affected by NTIP and 129 CP). Prevalence, accuracy and predictive values of ipsilateral IMLN involvement between cases and control groups were assessed, as well as concordance between chest computed tomography (CT scan) and thoracic ultrasound (TUS) measurements.

RESULTS

The prevalence of ipsilateral IMLN involvement in TP was significantly higher than that observed in NTIP and CP groups (respectively 77.2%, 39.3% and 14.7%). Results on test performance, stratified by age, revealed a high positive predictive value in patients aged ≤50 years, while a high negative predictive value in patients aged >50 years. The comparison between CT scan and ultrasound showed moderate agreement (Kappa=0.502).

CONCLUSIONS

Evaluation of IMLN involvement plays a relevant role in assessing the pre-test probability of TP. Considering the increasing global prevalence of mycobacterial infections, a tool able to guide diagnostic work-up of suspected TP is crucial, especially where local sources are limited.

Diagnostic accuracy and cellular origin of pleural fluid CXCR3 ligands for tuberculous pleural effusion

BACKGROUND

Pleural biomarkers represent potential diagnostic tools for tuberculous pleural effusion (TPE) due to their advantages of low cost, short turnaround time, and less invasiveness. This study evaluated the diagnostic accuracy of two CXCR3 ligands, C-X-C motif chemokine ligand 9 (CXCL9) and CXCL11, for TPE. In addition, we investigated the cellular origins and biological roles of CXCL9 and CXCL11 in the development of TPE.

METHODS

This double-blind study prospectively enrolled patients with undiagnosed pleural effusion from two centers (Hohhot and Changshu) in China. Pleural fluid on admission was obtained and levels of CXCL9 and CXCL11 were measured by an enzyme-linked immunosorbent assay (ELISA). The receiver operating characteristic (ROC) curve and the decision curve analysis (DCA) were used to evaluate their diagnostic accuracy and net benefit, respectively. THP-1 cell-derived macrophages were treated with Bacillus Calmette-Guérin (BCG), and quantitative real-time PCR (qRT-PCR) and ELISA were used to determine the mRNA and protein levels of CXCL9 and CXCL11. The chemoattractant activities of CXCL9 and CXCL11 for T helper (Th) cells were analyzed by a transwell assay.

RESULTS

One hundred and fifty-three (20 TPEs and 133 non-TPEs) patients were enrolled in the Hohhot Center, and 58 (13 TPEs and 45 non-TPEs) were enrolled in the Changshu Center. In both centers, we observed increased CXCL9 and CXCL11 in TPE patients. The areas under the ROC curves (AUCs) of pleural CXCL9 and CXCL11 in the Hohhot Center were 0.70 (95 % CI: 0.55-0.85) and 0.68 (95 % CI: 0.52-0.84), respectively. In the Changshu Center, the AUCs of CXCL9 and CXCL11 were 0.96 (95 % CI: 0.92-1.00) and 0.97 (95 % CI: 0.94-1.00), respectively. The AUCs of CXCL9 and CXCL11 decreased with the advancement of age. The decision curves of CXCL9 and CXCL11 showed net benefits in both centers. CXCL9 and CXCL11 were upregulated in BCG-treated macrophages. Pleural fluid from TPE and conditioned medium from BCG-treated macrophages were chemotactic for Th cells. Anti-CXCL9 or CXCL11 neutralizing antibodies could partly block the chemotactic activity.

CONCLUSIONS

Pleural CXCL9 and CXCL11 are potential diagnostic markers for TPE, but their diagnostic accuracy is compromised in elderly patients. CXCL9 and CXCL11 can promote the migration of peripheral Th cells, thus representing a therapeutic target for the treatment of TPE.

The regulation and potential role of interleukin-32 in tuberculous pleural effusion

The possible protective effect of interleukin-32 (IL-32) in Mycobacterium tuberculosis (Mtb) infection has been indicated. However, few studies have been focused on IL-32 in tuberculosis patients. Additionally, the regulation of IL-32 production has rarely been reported. In the present study, the production, regulation, and role of IL-32 in tuberculous pleurisy (TBP) were investigated. We found that the content of IL-32 in tuberculous pleural effusion (TPE) was higher than the level in the malignant pleural effusion and transudative pleural effusion. The level of IL-32 mRNA in pleural fluid mononuclear cells (PFMCs) was higher than that in peripheral blood mononuclear cells (PBMCs) of patients with TBP, and this difference was mainly reflected in the splice variants of IL-32α, IL-32β, and IL-32γ. Compared with the PBMCs, PFMCs featured higher IL-32β/IL-32γ and IL-32α/IL-32γ ratios. In addition, lipopolysaccharide (LPS), Bacillus Calmette-Guérin (BCG), and H37Ra stimulation could induce IL-32 production in the PFMCs. IL-32 production was positively correlated with the TNF-α, IFN-γ, and IL-1Ra levels in TPE, whereas IFN-γ, but not TNF-α or IL-1Ra, could induce the production of IL-32 in PFMCs. Furthermore, IL-32γ could induce the TNF-α production in PFMCs. Monocytes and macrophages were the main sources of IL-32 in PFMCs. Nevertheless, direct cell-cell contact between lymphocytes and monocytes/macrophages plays an important role in enhancing IL-32 production by monocyte/macrophage cells. Finally, compared with the non-tuberculous pleural effusion, the purified CD4+ and CD8+ T cells in TPE expressed higher levels of intracellular IL-32. Our results suggested that, as a potential biomarker, IL-32 may play an essential role in the protection against Mtb infection in patients with TBP. However, further studies need to be carried out to clarify the functions and mechanisms of the IFN-γ/IL-32/TNF-α axis in patients with TBP.

The tuberculous pleural effusion

Pleural tuberculosis (TB) is a common entity with similar epidemiological characteristics to pulmonary TB. It represents a spectrum of disease that can variably self-resolve or progress to TB empyema with severe sequelae such as chronic fibrothorax or empyema necessitans. Coexistence of and progression to pulmonary TB is high. Diagnosis is challenging, as pleural TB is paucibacillary in most cases, but every effort should be made to obtain microbiological diagnosis, especially where drug resistance is suspected. Much attention has been focussed on adjunctive investigations to support diagnosis, but clinicians must be aware that apparent diagnostic accuracy is affected both by the underlying TB prevalence in the population, and by the diagnostic standard against which the specified investigation is being evaluated. Pharmacological treatment of pleural TB is similar to that of pulmonary TB, but penetration of the pleural space may be suboptimal in complicated effusions. Evidence for routine drainage is limited, but evacuation of the pleural space is indicated in complicated disease.

Educational aims

To demonstrate that pleural TB incorporates a wide spectrum of disease, ranging from self-resolving lymphocytic effusions to severe TB empyema with serious sequelae.To emphasise the high coexistence of pulmonary TB with pleural TB, and the importance of obtaining sputum for culture (induced if necessary) in all cases.To explore the significant diagnostic challenges posed by pleural TB, and consequently the frequent lack of information about drug sensitivity prior to initiating treatment.To highlight the influence of underlying TB prevalence in the population on the diagnostic accuracy of adjunctive investigations for the diagnosis of pleural TB.To discuss concerns around penetration of anti-TB medications into the pleural space and how this can influence decisions around treatment duration in practice.

Diagnostic accuracy and microbial profiles of tuberculous pleurisy: a comparative study of metagenomic next generation sequencing and GeneXpert Mycobacterium tuberculosis

Introduction

There is a clinical challenge in diagnosing tuberculous pleurisy accurately and promptly, highlighting the urgent need for a rapid and sensitive diagnostic method. This study aimed to evaluate the diagnostic accuracy of metagenomic next-generation sequencing (mNGS) and GeneXpert Mycobacterium tuberculosis (MTB) for identifying tuberculous pleurisy and analyzing the microbial profiles of both tuberculous and non-tuberculous pleural effusions.

Methods

The study enrolled 31 patients with suspected tuberculous pleurisy, of which 15 were confirmed to have tuberculous pleurisy and subsequently allocated to the tuberculous pleurisy group (TP group), while the remaining 16 individuals were assigned to the non-tuberculous pleurisy group (NTP group). mNGS and GeneXpert MTB were performed on pleural effusion samples, and the diagnostic accuracy of both tests was compared. We employed established formulas to compute crucial indicators, including sensitivity, specificity, missed diagnosis rate, misdiagnosed rate, positive predictive value (PPV), and negative predictive value (NPV).

Results

The results showed that both tests had high specificity (100%) and positive predictive value (100%) for detecting tuberculous pleurisy, along with comparable sensitivity (46.67% for mNGS and 40.0% for GeneXpert MTB). Further analysis of the combined efficacy of mNGS and GeneXpert MTB showed that the combined test had a sensitivity of 66.67% and a specificity of 100%. mNGS analysis revealed that MTB was detected in 7 out of 15 patients with tuberculous pleural effusions, while non-tuberculous pleural effusions were associated with a diverse range of microbial genera and species. The most frequently detected genera at the microbial genus level in the NTP group were Microbacterium spp. (6/16), Prevotella spp. (5/16), and Campylobacter spp. (5/16).

Discussion

These findings suggest that mNGS and GeneXpert MTB are useful diagnostic tools for identifying patients with tuberculous pleurisy, and mNGS can provide valuable insights into the microbial profiles of both tuberculous and non-tuberculous pleural effusions.

Transforming growth factor-β and matrix metalloproteinases as potential biomarkers of fibrotic lesions induced by tuberculosis: a systematic review and meta-analysis

OBJECTIVES

Very few studies and limited information are available regarding the mechanism of fibrosis in tuberculosis (TB). This study aimed to identify, describe and synthesise potential biomarkers of the development of tissue fibrosis induced by TB through a systematic method and meta-analysis.

METHODS

A literature search was performed using keywords according to the topic from electronic databases (ScienceDirect and PubMed) and other methods (websites, organisations and citations). Studies that matched predetermined eligibility criteria were included. The quality assessment tool used was the Quality Assessment of Diagnostic Accuracy Score 2, and the data obtained were processed using Review Manager V.5.3.

RESULTS

Of the 305 studies, 7 met the eligibility criteria with a total sample of 365. The results of the meta-analysis showed that the post-TB group of patients with pulmonary parenchymal fibrosis had a higher transforming growth factor (TGF)-β level (6.09) than the control group (1.82), with a 4.27 (95% CI: 0.92 to 7.61) mean difference. Moreover, patients with residual pleural thickening post-TB had a higher mean of TGF-β (0.61) than the control group (0.56), with a 0.05 (95% CI: 0.04 to 0.06) mean difference. Besides TGF-β, our qualitative synthesis also found that matrix metalloproteinase-1 might have a role in forming and developing pulmonary tissue fibrosis, thus, could be used as a predictor marker in the formation of fibrotic lesions in patients with TB. In addition, several other biomarkers were assessed in the included studies, such as tumour necrosis factor-α, interleukin (IL)-4, IL-8, IL-10, plasminogen activator inhibitor-1 and platelet-derived growth factor. However, this study is not intended to examine these biomarkers.

CONCLUSIONS

There were differences in the results of TGF-β levels in patients with fibrotic lesions compared with controls. TGF-β might be a biomarker of fibrotic tissue formation or increased pulmonary tissue fibrosis in post-TB patients. However, further studies are needed on a larger scale.

A case of tubercular empyema with pyopneumothorax

Pyopneumothorax is a common complication associated with tuberculosis, especially in patients with lung parenchymal cavitatory lesions. In this publication, we highlight the case of a 43-year-old female patient who presented with chief complaints of dry cough, left-sided chest pain, and dyspnea on exertion. An X-ray of the chest posteroanterior (PA) view, revealed a left-sided moderate pleural effusion with pneumothorax. Immediate intercostal chest drain (ICD) insertion was done and a pleural fluid cytology sample was sent which was suggestive of tubercular empyema and the patient was promptly initiated on anti-tubercular treatment to which she responded well and showed clinical and radiological improvements.

Expert Review on Contemporary Management of Common Benign Pleural Effusions

Heart failure (HF) and cirrhosis are frequently associated with pleural effusions (PEs). Despite their apparently benign nature, both HF-related effusions and hepatic hydrothorax (HH) have poor prognosis because they represent an advanced stage of the disease. Optimization of medical therapy in these two entities involve not only the use of diuretics, but also other pharmacological therapies. For instance, all HF patients with reduced or mildly reduced left ventricular ejection fraction can benefit from angiotensin receptor-neprilysin inhibitors, beta blockers, mineralocorticoid receptor antagonists, and sodium-glucose cotransporter 2 inhibitors. Conversely, it is better for HH patients to avoid nonselective beta blockers. Refractory cardiac- and cirrhosis-related PEs are commonly managed by iterative therapeutic thoracentesis. When repeated aspirations are needed, thereby diminishing quality of life, the insertion of an indwelling pleural catheter (IPC) may be warranted. However, in selected HH patients who are diuretic-resistant or diuretic-intractable, placement of transjugular intrahepatic portosystemic shunts should be considered as a bridge to liver transplantation, whereas in transplant candidates the role of IPC is debatable. Another benign condition, pleural tuberculosis (TB) is a serious health problem in developing countries. Diagnostic certainty is still a concern due to the paucibacillary nature of the infection, although the use of more sensitive nucleic acid amplification tests is becoming more widespread. Its treatment is the same as that of pulmonary TB, but the potential drug interactions between antiretroviral and anti-TB drugs in HIV-coinfected patients as well as the current recommended guidelines for the different types of anti-TB drugs resistance should be followed.

Bacillary Positive Tuberculous Body Fluid Smears: A Perspective on How Fast to Use Acid Fast

Background Tuberculous effusions are common. Classically, they are described as bacteria poor and lymphocyte rich. Our experience, however, has been more varied. We compiled this rare group of bacteria-positive tuberculous fluids to document their cytologic spectrum and to look for possible predictors of bacillary positivity. Methods Fifty-one cases of bacillary positive fluids were identified and their clinicopathological details were noted. Per case, the smear background was assigned as either clear, caseous, suppurative, granular proteinaceous or frankly hemorrhagic. Fine, punched-out vacuoles in the smear background were also noted. The bacillary load in each case was classified from scanty to 3+. Eventually, the clinicopathologic variables were tabulated for frequency and studied for any association with bacillary presence. Results Only 19 of the 51 patients had a history of tuberculosis. Retropositive patients comprised a small proportion (9.8%) and did not always indicate strong (3+) bacillary positivity. The granular proteinaceous background was the most frequent (35%) pattern. Only a suppurative background was associated with strong bacillary positivity. Fine vacuoles were seen almost always with caseous and granular proteinaceous backgrounds but without statistical significance. Conclusion Tuberculous effusions can have diverse smear backgrounds, not necessarily one rich in caseous material. When tuberculosis is known or clinically suspected, non-classical findings such as abundant neutrophils or suppurative background should not dissuade one from requisitioning mycobacterial stains. In fact, acid-fast stains should probably routinely accompany Giemsa slides of clinically idiopathic effusions in endemic areas since it is still the cheapest and fastest method for a conclusive diagnosis.

Application of Adenosine Deaminase and γ-Interferon Release Assay in Pleural Fluid for the Diagnosis of Tuberculous Pleural Effusion in Patients Over 40 Years Old

Background

In patients with tuberculous pleural effusion (TPE) of various ages, the diagnostic accuracy of pleural biomarkers varies, and there are insufficient studies specifically in different age groups. Therefore, we investigated the adenosine deaminase cut-off value and its combination with the gamma interferon release assay for the diagnosis of TPE among patients aged ≥40 years.

Methods

A retrospective analysis of 198 patients who underwent medical thoracoscopy and were admitted to the hospital between 2015 and 2020 with exudative pleural effusion and either fever, night sweats, fatigue, cough, or other clinical manifestations was performed. The medical thoracoscopy, ADA, and T-SPOT results were analysed in the pleural fluid. The patients were divided into groups based on age: 18-39, 40-59, and 60-87.

Results

The best cut-off values of ADA were 29.5, 31.5 and 19.5 U/L, respectively, for the aged 18-39, aged 40-87 and aged 60-87 groups. The accuracy of 31.5 U/L was higher than 40 U/L for aged ≥40 years (86 vs 83%). The ADA diagnostic accuracy was higher than that of people under 40 years (83 vs 77%) when cut-off value of ADA was 40 U/L, but the IGRA accuracy was lower than that of people under 40 (87 vs 91%). The sensitivity of ADA or IGRA detection in patients over 40 years was 99%, and the specificity was 78%. The ADA specificity combined with IGRA for TPE was the highest (100%) in the ≥40 age group, and the sensitivity was 69%.

Conclusion

Our study revealed the best cut-off values of ADA for TBE in different age groups. Combining ADA and IGRA in pleural fluid improves the detection rate of TPE in patients over 40 years of age with exudative pleural effusion. ADA combined with IGRA increases specificity, and ADA or IGRA increases sensitivity substantially.

Pleural tuberculosis: experiences from two centers in Brazil

OBJECTIVE

This study aimed to describe the clinical and laboratory findings of patients diagnosed with pleural tuberculosis at two hospitals in southern Brazil.

METHODS

Patients aged < 18 years were evaluated retrospectively. The patients' medical and epidemiological history, tuberculin skin test results, radiological and pathological findings, and pleural fluid analysis results were retrieved.

RESULTS

Ninety-two patients with pleural tuberculosis were identified. The mean age was 10.9 years old. Twenty-one percent were children aged six years or less. The most common symptoms were fever (88%), cough (72%), and chest pain (70%). Unilateral pleural effusion was observed in 96% of the cases. Lymphocyte predominance was found in 90% of the pleural fluid samples. The adenosine deaminase activity of the pleural fluid was greater than 40 U/L in 85% of patients. A diagnosis of community-acquired pneumonia with antibiotic prescriptions was observed in 76% of the study population.

CONCLUSIONS

Tuberculosis etiology must be considered in unilateral pleural effusion in a child with contact with a case of tuberculosis. Pleural fluid biomarkers contribute to the diagnosis of pleural tuberculosis in children and adolescents.

Interleukin 32 as a Potential Marker for Diagnosis of Tuberculous Pleural Effusion

Accurate differential diagnosis is the key to choosing the correct treatment for pleural effusion. The present study aimed to assess whether interleukin 32 (IL-32) could be a new biomarker of tuberculous pleural effusion (TPE) and to explore the biological role of IL-32 in TPE. IL-32 levels were evaluated in the pleural effusions of 131 patients with undetermined pleural effusion from Wuhan and Beijing cohorts using an enzyme-linked immunosorbent assay method. Macrophages from TPE patients were transfected with IL-32-specific small interfering RNA (siRNA), and adenosine deaminase (ADA) expression was determined by real-time PCR and colorimetric methods. With a cutoff value of 247.9 ng/mL, the area under the curve of the receiver operating characteristic (ROC) curve for IL-32 was 0.933 for TPE, and the sensitivity and specificity were 88.4% and 93.4%, respectively. A multivariate logistic regression model with relatively good diagnostic performance was established. IL-32-specific siRNA downregulated ADA expression in macrophages, and IL-32γ treatment significantly induced ADA expression. Our results indicate that IL-32 in pleural effusion may be a novel biomarker for identifying patients with TPE. In addition, our multivariate model is acceptable to rule in or rule out TPE across diverse prevalence settings. Furthermore, IL-32 may modulate ADA expression in the tuberculosis microenvironment. (This study has been registered at ChiCTR under registration number ChiCTR2100051112 [https://www.chictr.org.cn/index.aspx].) IMPORTANCE Tuberculous pleural effusion (TPE) is a common form of extrapulmonary tuberculosis, with manifestations ranging from benign effusion with spontaneous absorption to effusion with pleural thickening, empyema, and even fibrosis, which can lead to a lasting impairment of lung function. Therefore, it is of great significance to find a rapid method to establish early diagnosis and apply antituberculosis therapy in the early stage. This study indicates that interleukin 32 (IL-32) in pleural effusion is a new high-potency marker to distinguish TPE from pleural effusions with other etiologies. A multivariate model combining age, adenosine deaminase (ADA), lactic dehydrogenase, and IL-32 may reliably rule in TPE in intermediate- or high-prevalence areas. Additionally, we observed that IL-32 might regulate ADA expression in macrophages in the tuberculosis microenvironment. Therefore, this study provides new insights into the role of IL-32 in the tuberculosis microenvironment.

ELISA based assays to measure adenosine deaminases concentration in serum and saliva for the diagnosis of ADA2 deficiency and cancer

Adenosine deaminases (ADAs) are enzymes of purine metabolism converting adenosine to inosine. There are two types of ADAs in humans ADA1 and ADA2. While both ADA1 and ADA2 share the same substrate, they differ in expression, cellular localization, and catalytic properties. The genetic deficiency of ADA1 results in severe combined immunodeficiency (SCID), while lack in ADA2 (DADA2) results in multiple phenotypes ranging from systemic inflammation to vascular pathology. Clinical studies have shown that the levels of ADAs in biological fluids are altered in pathophysiological conditions, suggesting that ADA activity could be a convenient marker for the diagnosis of immune diseases and cancer. Here, we describe sensitive and straightforward ELISA assays to measure ADA1 and ADA2 concentrations in biological fluids. Analysis of the serum and saliva samples from the healthy controls and DADA2 patients revealed that ADA2 enzyme concentration is significantly lower in patients than in healthy controls. In contrast, the concentration of ADA2 increases in the serum of patients with large granular leukocyte leukemia (LGLL) and patients’ saliva with head and neck cancer. Thus, this simple, non-invasive method allows for distinguishing healthy controls from the affected patient. It can be implemented in screening and diagnosis of DADA2 and follow up the treatment of LGLL and several types of head and neck cancer.

Insight into diagnosis of pleural tuberculosis with special focus on nucleic acid amplification tests

INTRODUCTION

Pleural tuberculosis (TB) is the archetype of extrapulmonary TB (EPTB), which mainly affects the pleural space and leads to exudative pleural effusion. Diagnosis of pleural TB is a difficult task predominantly due to atypical clinical presentations and sparse bacillary load in clinical specimens.

AREA COVERED

We reviewed the current literature on the globally existing conventional/latest modalities for diagnosing pleural TB. Bacteriological examination (smear/culture), tuberculin skin testing/interferon-γ release assays, biochemical testing, imaging and histopathological/cytological examination are the main modalities. Moreover, nucleic acid amplification tests (NAATs), i.e. loop-mediated isothermal amplification, PCR/multiplex-PCR, nested-PCR, real-time PCR and GeneXpert® MTB/RIF are being utilized. Currently, GeneXpert Ultra, Truenat MTB^TM, detection of circulating Mycobacterium tuberculosis (Mtb) cell-free DNA by NAATs, aptamer-linked immobilized sorbent assay and immuno-PCR (I-PCR) have also been exploited.

EXPERT OPINION

Routine tests are not adequate for effective pleural TB diagnosis. The latest molecular/immunological tests as discussed above, and the other tools, i.e. real-time I-PCR/nanoparticle-based I-PCR and identification of Mtb biomarkers within urinary/serum extracellular vesicles being utilized for pulmonary TB and other EPTB types may also be exploited to diagnose pleural TB. Reliable diagnosis and early therapy would reduce the serious complications associated with pleural TB, i.e. TB empyema, pleural fibrosis, etc.

Epidemiologic evaluation of pleurisy diagnosed by surgical pleural biopsy using data from a nationwide administrative database

Background

Pleural biopsies for investigating the causes of pleurisy are performed through modalities including needle biopsies, local anesthetic thoracoscopic procedures, and surgery (video‐assisted thoracoscopic surgery and open thoracotomy). To date, there have been no large‐scale nationwide epidemiological studies regarding pleurisy diagnosed via surgical pleural biopsy. This study examined the epidemiology of pleurisy diagnosed via surgical pleural biopsy in a Japanese nationwide administrative database.

Methods

We evaluated Japanese Diagnosis Procedure Combination data of 24 173 patients who underwent video‐assisted thoracoscopic surgery or open thoracotomy and received a diagnosis of pleurisy between April 2014 and March 2020. In addition to pleurisy diagnoses, the patients' clinical information, including age, sex, smoking status (pack‐years), dyspnea grade, length of in‐hospital stay, and comorbidities, were extracted from the dataset.

Results

This study included data from 1699 patients. The most frequent causes of pleurisy were neoplastic diseases (55.9%; malignant mesothelioma 22.5%, lung cancer 15.7%, lymphoma 2.5%), followed by infectious diseases (24.0%; tuberculosis 16.2%, parapneumonic pleural effusion 3.6%, empyema 3.5%, nontuberculous mycobacteriosis 0.5%), collagen vascular diseases (2.8%; rheumatoid arthritis 1.3%, immunoglobulin G4‐related diseases 0.7%, systemic lupus erythematosus 0.3%), and paragonimiasis (0.1%).

Conclusions

Neoplastic diseases, including malignant mesothelioma and lung cancer, were frequently and accurately diagnosed as pleurisy via surgical pleural biopsy. The next leading cause was infectious diseases such as mycobacterial infections. Physicians should consider performing surgical biopsy in light of the knowledge regarding the etiology of pleurisy when a definitive diagnosis cannot be made via needle pleural biopsy.

Mycoplasma pneumoniae Pleural Effusion in Adults

Parapneumonic effusions often complicate Mycoplasma pneumoniae (MP) pneumonia, contrary to the notion that they are a rare feature of MP infection. Increased research and evidence on MP parapneumonic effusions (MPPE) can help elucidate its clinical significance as one of the variable manifestations of MP infection. This article aims to summarize the existing literature about the clinical characteristics of MPPE in adults and discuss its diagnostic implications from the perspective of pleural fluid analysis. Approximately 20–25% of adult patients with MP pneumonia develop MPPE, and its frequency in children and adults seems to be similar. Although the pathogenesis of MPPE remains to be elucidated, MP-induced cell-mediated immune mechanisms might be partially associated with the development of MPPE. MPPE usually shows mononuclear leukocyte predominance with elevated adenosine deaminase (ADA) activity, similar to tuberculous pleural effusion (TPE). The degree of increase in pleural fluid ADA levels and serum inflammatory biomarkers may help differentiate between MPPE and TPE. During the acute phase, a single positive IgM and positive polymerase chain reaction results allow for a precise and reliable MP infection diagnosis. The mainstay of treatment is the selection of adequate anti-mycoplasma antibiotics with or without corticosteroid, based on the local epidemiologic data on macrolide resistance.

Laboratory and radiological discrimination between tuberculous and malignant pleural effusions with high adenosine deaminase levels

BACKGROUND/AIMS

Pleural fluid adenosine deaminase (ADA) levels are useful in discriminating tuberculous pleural effusions (TPEs) from malignant pleural effusions (MPEs). However, some patients with MPE exhibit high-ADA levels, which may mimic TPEs. There is limited data regarding the differential diagnosis between high-ADA MPE and high-ADA TPE. This study aimed to identify the predictors for distinguishing high-ADA MPEs from high-ADA TPEs.

METHODS

Patients with TPE and MPE with pleural fluid ADA levels ≥ 40 IU/L were included in this study. Clinical, laboratory, and radiological data were compared between the two groups. Independent predictors and their diagnostic performance for high-ADA MPEs were evaluated using multivariate logistic regression analysis and receiver operating characteristic curve.

RESULTS

A total of 200 patients (high-ADA MPE, n = 30, and high-ADA TPE, n = 170) were retrospectively included. In the multivariate analysis, pleural fluid ADA, pleural fluid carcinoembryonic antigen (CEA), and pleural nodularity were independent discriminators between high-ADA MPE and high-ADA TPE groups. Using pleural ADA level of 40 to 56 IU/L (3 points), pleural CEA level ≥ 6 ng/mL (6 points), and presence of pleural nodularity (3 points) for predicting high-ADA MPEs, a sum score ≥ 6 points yielded a sensitivity of 90%, specificity of 96%, positive predictive value of 82%, negative predictive value of 98%, and area under the receiver operating characteristic curve of 0.965.

CONCLUSION

A scoring system using three parameters may be helpful in guiding the differential diagnosis between high-ADA MPEs and high-ADA TPEs.

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.

Diagnostic accuracy of adenosine deaminase for pleural tuberculosis in a low prevalence setting: A machine learning approach within a 7-year prospective multi-center study

OBJECTIVE

To analyze the performance of adenosine deaminase in pleural fluid combined with other parameters routinely measured in clinical practice and assisted by machine learning algorithms for the diagnosis of pleural tuberculosis in a low prevalence setting, and secondly, to identify effusions that are non-tuberculous and most likely malignant.

PATIENTS AND METHODS

We prospectively analyzed 230 consecutive patients diagnosed with lymphocytic exudative pleural effusion from March 2013 to June 2020. Diagnosis according to the composite reference standard was achieved in all cases. Pre-test probability of pleural tuberculosis was 3.8% throughout the study period. Parameters included were: levels of adenosine deaminase, pH, glucose, proteins, and lactate dehydrogenase, red and white cell counts and lymphocyte percentage in pleural fluid, as well as age. We tested six different machine learning-based classifiers to categorize the patients. Two different classifications were performed: a) tuberculous/non-tuberculous and b) tuberculous/malignant/other.

RESULTS

Out of a total of 230 patients with pleural effusion included in the study, 124 were diagnosed with malignant effusion and 44 with pleural tuberculosis, while 62 were given other diagnoses. In the tuberculous/non-tuberculous classification, and taking into account the validation predictions, the support vector machine yielded the best result: an AUC of 0.98, accuracy of 97%, sensitivity of 91%, and specificity of 98%, whilst in the tuberculous/malignant/other classification, this type of classifier yielded an overall accuracy of 80%. With this three-class classifier, the same sensitivity and specificity was achieved in the tuberculous/other classification, but it also allowed the correct classification of 90% of malignant cases.

CONCLUSION

The level of adenosine deaminase in pleural fluid together with cell count, other routine biochemical parameters and age, combined with a machine-learning approach, is suitable for the diagnosis of pleural tuberculosis in a low prevalence scenario. Secondly, non-tuberculous effusions that are suspected to be malignant may also be identified with adequate accuracy.

Solitary pleural tuberculoma diagnosed by thoracoscopic surgical resection

Tuberculoma is a manifestation of pleural tuberculosis. Although the clinical manifestation of tuberculoma has been widely reported, the pathogenesis of this condition still remains unclear. An abnormal shadow was detected on the chest radiograph of a 44-year-old man with a history of pulmonary tuberculosis. Computed tomography revealed a well-defined, elliptical 44 mm nodule located in the right posterior thoracic cavity. Thoracoscopic surgery was performed to rule out malignant tumors. Although loose adhesions were observed throughout the thoracic cavity, a nodule was found between the visceral pleura and parietal pleura. En bloc resection was performed, and the patient was pathologically diagnosed with tuberculoma. An acid-fast bacterium culture was negative, and the patient’s recovery was uneventful without chemotherapy. Surgical resection should be considered to rule out malignancy, because tuberculomas are difficult to distinguish from malignant pleural tumors.

Diagnostic accuracy of interleukin-33 for tuberculous pleural effusion: A systematic review and meta-analysis

BACKGROUND

The detection of interleukin 33 (IL-33) in pleural effusion may be more sensitive in diagnosing tuberculous pleural effusion (TPE). The present study aimed to assess the accuracy of pleural IL-33 for the diagnosis of TPE by means of meta-analysis and systematic review of relevant studies.

METHOD

After retrieving the published studies, the sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, diagnostic odds ratio, and a summary receiver operating characteristic curve were assessed to estimate the usefulness of pleural IL-33 in diagnosing TPE using meta-analysis with a random-effects model. We also performed meta-regression and subgroup analysis.

RESULTS

A total of 639 patients from 6 studies were analyzed. The pooled sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, and diagnostic odds ratio were 0.87 (95% confidence interval [CI], 0.82-0.91), 0.76 (95% CI, 0.72-0.80), 6.54 (95% CI, 2.65-16.15), 0.17 (95% CI, 0.10-1.27), and 45.40 (95% CI, 12.83-160.70) respectively. The area under the curve was 0.94. The composition of the included population was the main cause of heterogeneity and subgroup analysis showed that pleural IL-33 had a higher specificity (0.93, 95% CI 0.87-0.96) when used for differential diagnosis between TPE and malignant pleural effusion.

CONCLUSION

The detection of IL-33 alone in pleural effusion seems to not be an efficient diagnostic marker for TPE but may serve as a novel biomarker to differentiate between TPE and malignant pleural effusion.

Factors associated with negative pleural adenosine deaminase results in the diagnosis of childhood pleural tuberculosis

Background

Until now, the influential factors associated with pleural adenosine deaminase (ADA) activity among children remain unclear. This retrospective study was therefore conducted aiming to investigate the factors associated with negative pleural ADA results in the diagnosis of childhood pleural tuberculosis (TB).

Methods

Between January 2006 and December 2019, children patients with definite or possible pleural TB were recruited for potential analysis. Then, patients were stratified into two categories: negative pleural ADA results group (experimental group, ≤40 U/L) and positive pleural ADA results group (control group, > 40 U/L). Univariate and multivariate logistic regression analyses were performed to estimate risk factors for negative pleural ADA results.

Results

A total of 84 patients with pleural TB were recruited and subsequently classified as experimental (n = 17) and control groups (n = 67). Multivariate analysis (Hosmer–Lemeshow goodness-of-fit test: χ² = 1.881, df = 6, P = 0.930) revealed that variables, such as chest pain (age-adjusted OR = 0.0510, 95% CI: 0.004, 0.583), pleural total protein (≤45.3 g/L, age-adjusted OR = 27.7, 95% CI: 2.5, 307.7), pleural lactate dehydrogenase (LDH, ≤505 U/L, age-adjusted OR = 59.9, 95% CI: 4.2, 857.2) and blood urea nitrogen (≤3.2 mmol/L, age-adjusted OR = 32.0, 95% CI: 2.4, 426.9), were associated with negative pleural ADA results when diagnosing childhood pleural TB.

Conclusion

Our findings demonstrated that chest pain, pleural total protein, pleural LDH, and blood urea nitrogen were associated with a negative pleural ADA result for the diagnosis of pleural TB among children. When interpreting pleural ADA levels in children with these characteristics, a careful clinical assessment is required for the pleural TB diagnosis.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-021-06209-1.

GC-MS metabolomics identifies novel biomarkers to distinguish tuberculosis pleural effusion from malignant pleural effusion

Background

Tuberculous pleural effusions (TBPEs) and malignant pleural effusions (MPEs) are two of the most common and severe forms of exudative effusions. Clinical differentiation is challenging; however, metabolomics is a collection of powerful tools currently being used to screen for disease‐specific biomarkers.

Methods

17 TBPE and 17 MPE patients were enrolled according to the inclusion criteria. The normalization gas chromatography‐mass spectrometry (GC‐MS) data were imported into the SIMCA‐P + 14.1 software for multivariate analysis. The principal component analysis (PCA) and orthogonal partial least‐squares discriminant analysis (OPLS‐DA) were used to analyze the data, and the top 50 metabolites of variable importance projection (VIP) were obtained. Metabolites were qualitatively analyzed using the National Institute of Standards and Technology (NIST) databases. Pathway analysis was performed by MetaboAnalyst 4.0. The detection of biochemical indexes such as urea and free fatty acids in these pleural effusions was also verified, and significant differences were found between these two groups.

Results

1319 metabolites were screened by non‐targeted metabonomics of GC‐MS. 9 small molecules (urea, L‐5‐oxoproline, L‐valine, DL‐ornithine, glycine, L‐cystine, citric acid, stearic acid, and oleamide) were found to be significantly different (p < 0.05 for all). In OPLS‐DA, 9 variables were considered significant for biological interpretation (VIP≥1). However, after the ROC curve was performed, it was found that the metabolites with better diagnostic value were stearic acid, L‐cystine, citric acid, free fatty acid, and creatinine (AUC > 0.8), with good sensitivity and specificity.

Conclusion

Stearic acid, L‐cystine, and citric acid may be potential biomarkers, which can be used to distinguish between the TBPE and the MPE.

[Predictive factors and biomarkers of exudative lymphocytic tuberculous pleurisy]

INTRODUCTION

Tuberculosis is the leading cause of exudative lymphocytic pleural effusion.

OBJECTIVE

To determine the predictive factors and assess the diagnostic performance of biomarkers for exudative lymphocytic tuberculous pleural effusion found in our practice.

METHODS

Case-control study from 01 January 2015 to 30 August 2019, including patients admitted to the day-hospital facility for pleural biopsy. Histopathology of pleural biopsy fragments was the gold standard for assessing the diagnostic performance of the biomarkers studied (pleural adenosine deaminase, geneXpert and pleural fluid culture).

RESULTS

One hundred and nine patients were included. The average age was 35.7±18.1 years. In all, 72.5% of them were diagnosed with tuberculosis. After multivariate analysis, only patients aged under 35 years old were found to be at risk for exudative lymphocytic tuberculous pleural effusion (adjusted odds ratio: 9.18 [1.99; 42.28], P=0.004). Histopathology was suggestive of tuberculosis in 84.8% of cases (P<0.0001). The sensitivity of geneXpert was 42.1% and the specificity was 100%, with a mean concordance rate with histopathology (k=0.46). One case of rifampicin-resistant tuberculosis was detected by geneXpert (2.2%). The diagnostic performance of pleural adenosine deaminase varies according to the defined positivity threshold. For values greater than 70UI/L, its sensitivity was 25% and its specificity was 86.7%. The area under the ROC curve of the pleural adenosine deaminase was 0.70.

CONCLUSION

In patients with exudative lymphocytic pleural effusion, young age is a risk factor for pleural tuberculosis. The geneXpert, although not very sensitive, is a moderately efficient and specific test for tuberculosis. Pleural adenosine deaminase is a discriminating and useful biomarker for the diagnosis of tuberculosis.

Performance of Xpert® MTB/RIF in diagnosing tuberculous pleuritis using thoracoscopic pleural biopsy

BACKGROUND

Etiological diagnosis of tuberculous pleuritis is challenging, owing to a paucity of Mycobacterium tuberculosis (MTB) in the affected region. Moreover, currently available methods, such as the detection of acid-fast bacilli and microbiological culture, are not always conducive to timely diagnosis and treatment. In this study, we evaluated the performance of Xpert® MTB/RIF assay (hereinafter referred to as "Xpert") in detecting MTB in difficult-to-diagnose patients using suspensions of pleural biopsy tissue specimens obtained under direct thoracoscopic guidance.

METHODS

One hundred and sixty patients with an unexplained pleural effusion were included from the Shenyang Tenth People's Hospital and Shenyang Chest Hospital, China, between 2017 and 2018. The included patients underwent thoracoscopy under local anesthesia, with an intercostal incision of approximately 1.0 cm for biopsy. The biopsy specimens were used for pathological and etiological examinations. The Xpert test was evaluated for its sensitivity and specificity, as well as positive and negative predictive values (PPV and NPV, respectively), against data obtained using standards: the BACTEC™ MGIT™ 960 liquid culture system and a composite reference standard (CRS).

RESULTS

The sensitivity and specificity of Xpert were 68.8 and 64.6%, respectively, against the MGIT 960 culture data. The PPV and NPV of Xpert were 56.4 and 75.6%, respectively. The sensitivity of Xpert was 69.0% against the CRS data, which was significantly higher than that of MGIT 960 culture (56.6%). The PPV and NPV of Xpert against the CRS data were 100.0 and 57.3%, respectively.

CONCLUSIONS

Xpert is a good rule-in test but has limited value as a rule-out test for the diagnosis of tuberculosis pleuritis.

Pleural Tuberculosis: A Febrile Presentation Without Respiratory Symptoms

Tuberculosis (TB) is one of the largest public health crises globally, with pleural TB comprising a large portion of cases. It has a significantly minimal presence within the United States in comparison to the rest of the world. Awareness of its presence and acumen on diagnostics and treatment are essential. Conventional tests are often time consuming, and do not always yield accurate results. We present the case of a patient presenting with fevers but no cough, who eventually found to have large pleural effusion and concluded to have pleural TB without pulmonary parenchymal involvement. He then showed measurable improvement with empiric treatment.

Metabolic characteristics of large and small extracellular vesicles from pleural effusion reveal biomarker candidates for the diagnosis of tuberculosis and malignancy

Pleural effusion is a common respiratory disease worldwide; however, rapid and accurate diagnoses of tuberculosis pleural effusion (TPE) and malignancy pleural effusion (MPE) remain challenging. Although extracellular vesicles (EVs) have been confirmed as promising sources of disease biomarkers, little is known about the metabolite compositions of its subpopulations and their roles in the diagnosis of pleural effusion. Here, we performed metabolomics and lipidomics analysis to investigate the metabolite characteristics of two EV subpopulations derived from pleural effusion by differential ultracentrifugation, namely large EVs (lEVs, pelleted at 20,000 × g) and small EVs (sEVs, pelleted at 110,000 × g), and assessed their metabolite differences between tuberculosis and malignancy. A total of 579 metabolites, including amino acids, acylcarnitines, organic acids, steroids, amides and various lipid species, were detected. The results showed that the metabolic profiles of lEVs and sEVs overlapped with and difference from each other but significantly differed from those of pleural effusion. Additionally, different type of vesicles and pleural effusion showed unique metabolic enrichments. Furthermore, lEVs displayed more significant and larger metabolic alterations between the tuberculosis and malignancy groups, and their differential metabolites were more closely related to clinical parameters than those of sEV. Finally, a panel of four biomarker candidates, including phenylalanine, leucine, phosphatidylcholine 35:0, and sphingomyelin 44:3, in pleural lEVs was defined based on the comprehensive discovery and validation workflow. This panel showed high performance for distinguishing TPE and MPE, particularly in patients with delayed or missed diagnosis, such as the area under the receiver-operating characteristic curve (AUC) >0.95 in both sets. We conducted comprehensive metabolic profiling analysis of EVs, and further explored the metabolic reprogramming of tuberculosis and malignancy at the level of metabolites in lEVs and sEVs, providing insight into the mechanism of pleural effusion, and identifying novel biomarkers for diagnosing TPE and MPE.

Influence of age on the diagnostic accuracy of soluble biomarkers for tuberculous pleural effusion: a post hoc analysis

BACKGROUND

Accurately diagnosing pleural effusion is a frequent and significant problem in clinical practice. Combining pleural biomarkers with patients' age may be a valuable method for diagnosing TPE. We sought to evaluate the influence of age on diagnostic values of pleural adenosine deaminase (ADA), interferon-gamma (IFN-γ), and interleukin 27 (IL-27) for tuberculous pleural effusion (TPE).

METHODS

Two hundred seventy-four consecutive adult patients with pleural effusion were selected from Beijing and Wuhan between January 1, 2014 and June 30, 2015, and their pleural fluid concentrations of ADA, IFN-γ, and IL-27 were tested. Biomarker performance was analyzed by standard receiver operating characteristic (ROC) curves according to different ages.

RESULTS

Data from the Beijing cohort showed that ADA, IFN-γ, and IL-27 could all accurately diagnose TPE in young patients (≤ 40 years of age). With a cutoff of 21.4 U/L, the area under the curve (AUC), sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of ADA for diagnosing TPE were 1.000 (95% confidence interval: 0.884-1.000), 100.0, 100.0%, 100.0, and 100.0, respectively. In older patients (> 40 years of age), IL-27 and IFN-γ were excellent biomarkers for discriminating TPE versus non-TPE cases. With a cutoff of 591.4 ng/L, the AUC, sensitivity, specificity, PPV, and NPV of IL-27 for diagnosing TPE were 0.976 (95% confidence interval: 0.932-0.995), 96.3, 99.0%, 96.3, and 99.0, respectively. Similar diagnostic accuracy among the three pleural biomarkers was validated in the Wuhan cohort.

CONCLUSIONS

Among young patients, ADA is reliable for diagnosing TPE. Conversely, in older patients, IL-27 and IFN-γ are excellent biomarkers to differentiate TPE versus non-TPE cases.

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.

Retrospective investigation on diagnostic process for benign asbestos pleural effusion (BAPE) using checklist

OBJECTIVES

In Japan, benign asbestos pleural effusion (BAPE) has been eligible for industrial accident compensation since 2003 as an asbestos-related disease despite the lack of good criteria. We compiled a criteria into a checklist of essential items and for excluding other diseases inducing pleural effusion as a diagnosis process.

METHOD

Thoracentesis was performed in order to confirm the presence of pleural effusion at the initial diagnosis, and 105 suspected BAPE patients were retrospectively examined. We complied a checklist comprising the following diagnostic items: (a) occupational asbestos exposure; (b) confirmation of exudate of pleural effusion; (c) exclusion of pleural effusion with malignant tumors based on negative results of CEA and hyaluronic acid, and cytology of pleural effusion; (d) exclusion of rheumatic, bacterial, and tuberculous pleuritis; (d) radiological findings for exclusion of malignancies; and (e) histopathological findings based on thoracoscopy that exclude malignancies (when thoracoscopy was not performed, there was confirmation that no malignancies were present during 3-month follow-up observation). Cases that satisfied all items were defined as BAPE.

RESULTS

Among the 105 suspected cases, there were five cases that had no occupational asbestos exposure; six cases in which transudate of on pleural effusion; one case each of rheumatoid pleuritis and tuberculous pleuritis; and five cases of pleural mesothelioma based on chest radiography and histopathological findings within 3 months after initial diagnosis. Therefore, we excluded 18 cases from the 105 candidates and determined 87 cases of BAPE.

CONCLUSION

We consider that six items described above are suitable for diagnosing BAPE.

The diagnostic effect of sequential detection of ADA screening and T-SPOT assay in pleural effusion patients

Purpose: To evaluate the diagnostic effect of sequential detection of Adenosine deaminase (ADA) screening and T-SPOT assay on tuberculosis (TB) pleurisy in pleural effusion patients. Materials and methods: 248 pleural effusion patients (172 TB and 76 non-TB) were retrospectively analyzed in the study. The concentrations of ADA and lactate dehydrogenase (LDH) were measured in pleural fluids and serum samples of the patients. T-SPOTT assays were performed in pleural fluids. The relationship between ADA, T-SPOT and the occurrence of TB pleurisy was evaluated using logistic regression analysis. Results: The level of pleural ADA and positive rate of T-SPOT were all higher in TB pleurisy group than non-TB pleurisy group (p < .001). The positive rate of T-SPOT detection reached 98.83% in the TB pleurisy group while only 40.7% in non-TB pleurisy group (p < .001). Additionally, 8 patients (4.65%) in the TB pleurisy group showed the level of pleurisy ADA exceeded 40 IU/L while only one patient (1.31%) in the non-TB pleurisy group. Conclusion: The sequential detection of ADA screening and T-SPOT assay was found to be an accurate and rapid method for identifying TB pleurisy from pleural effusion, which would promote effective treatment.

Comparison between the diagnostic accuracy of Xpert MTB/Rif assay and culture for pleural tuberculosis using tissue biopsy

Background

Early diagnosis of pleural tuberculosis is difficult as it is a paucibacillary disease and a combination of tests is required to diagnose it, which have varied diagnostic accuracy and increase the cost. The aim of this study was to evaluate the diagnostic performance of the Xpert MTB/Rif assay on thoracoscopic pleural biopsy specimens.

Methods

A total of 201 patients with exudative pleural effusion and normal lung parenchyma were included in the study. All patients underwent thoracoscopic pleural biopsy under local anaesthesia. Biopsy samples were sent for Xpert MTB/Rif assay and culture, along with histopathology. Chronic granulomatous inflammation on histopathology and response to antituberculous treatment was taken as the reference standard for diagnosis of tuberculous pleurisy.

Results

Of the 198 patients included in the final analysis, 134 had pleural tuberculosis. The sensitivity of the Xpert assay was 52.2% and specificity was 100%, and that of pleural biopsy cultures were 41% and 100% respectively.

Conclusion

The sensitivity and specificity of Xpert MTB/Rif assay scores were high, hence escalating the speed of diagnosis and imparting marked impact on patient outcomes. The Xpert MTB/Rif assay is a potential game changer in diagnosing pleural tuberculosis.

Pleural tissue Xpert MTB/Rif assay has a high diagnostic yield for pleural tuberculosis when good-quality biopsy samples are taken by medical thoracoscopy. It speeds up the diagnosis of pleural TB and has a major impact on patients' outcomes.http://bit.ly/2GtuHJZ

Same-Day Tools, Including Xpert Ultra and IRISA-TB, for Rapid Diagnosis of Pleural Tuberculosis: a Prospective Observational Study

The diagnosis of pleural tuberculosis (TB) is problematic. The comparative performance of newer same-day tools for pleural TB, including Xpert MTB/RIF Ultra (ULTRA), has hitherto not been comprehensively studied. Adenosine deaminase (ADA), IRISA-TB (interferon gamma ultrasensitive rapid immunosuspension assay), Xpert MTB/RIF, and ULTRA performance outcomes were evaluated in pleural fluid samples from 149 patients with suspected pleural TB. The reference standard was culture positivity (fluid, biopsy specimen, or sputum) and/or pleural biopsy histopathology (termed definite TB). Those designated as having non-TB were negative by microbiological testing and were not initiated on anti-TB treatment. To determine the effect of sample concentration, 65 samples underwent pelleting by centrifugation, followed by conventional Xpert MTB/RIF and ULTRA. Of the 149 patients, 49 had definite TB, 16 had probable TB (not definite but treated for TB), and 84 had non-TB. ULTRA sensitivity and specificity (95% confidence intervals [CI]) were similar to those of Xpert MTB/RIF [sensitivity, 37.5% (25.3 to 51.2) versus 28.6% (15.9 to 41.2), respectively; specificity, 98.8% (96.5 to 100) versus 98.8% (96.5 to 100), respectively]. Centrifugation did not significantly improve ULTRA sensitivity (29.5% versus 31.3%, respectively). Adenosine deaminase and IRISA-TB sensitivity were 84.4% (73.9 to 95.0) and 89.8% (81.3 to 98.3), respectively. However, IRISA-TB demonstrated significantly better specificity (96.4% versus 87.5% [P = 0.034]), positive predictive value (93.6% versus 80.9 [P = 0.028]), and positive likelihood ratio (25.1 versus 6.8 [P = 0.032]) than ADA. In summary, Xpert ULTRA has poor sensitivity for the diagnosis of pleural TB. Alternative assays (ADA and IRISA-TB) are significantly more sensitive, with IRISA-TB demonstrating a higher specificity and rule-in value than ADA in this high-TB-burden setting where HIV is endemic.

Pleural tuberculosis

A 35-year-old woman with previously untreated latent tuberculosis was admitted to the hospital for management of a right-sided empyema. After a prolonged hospitalization and several interventions, including chest tubes, bronchoscopy with bronchoalveolar lavage, and a video-assisted thoracoscopic surgery, positive acid-fast bacilli cultures on the initial thoracentesis ultimately led to the diagnosis of pleural tuberculosis. This case highlights the importance of utilizing a combination of diagnostic tests to diagnose pleural tuberculosis, especially in the setting of a negative pleural adenosine deaminase level.

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.

Interpreting pleural fluid results

Interpreting pleural fluid results correctly requires an awareness of the possible aetiologies of a pleural effusion and an understanding of the reliability of the outcome of each investigation. All results must be interpreted within each different clinical context and knowledge of the pitfalls for each test is necessary when the diagnosis is unclear. This review aims to discuss the common aetiologies of a pleural effusion and some of the pitfalls in interpretation that can occur when the diagnosis is unclear.

Inadequate diagnostics: the case to move beyond the bacilli for detection of meningitis due to Mycobacterium tuberculosis

Tuberculosis (TB) meningitis is extremely difficult to diagnose due to its pauci-bacillary disease nature and new techniques are needed. Improved test sensitivity would allow for greater clinician confidence in diagnostic testing and has the potential to improve patient outcomes. Traditional microbiologic and molecular tests for TB meningitis focus on detection of TB bacilli and are inadequate. Smear microscopy is rapid but only ~10-15  % sensitive. Culture has 50-60  % sensitivity but is slow. Xpert MTB/Rif Ultra is a rapid, automated PCR-based assay with ~70  % sensitivity versus clinical case definition. Thus, even the best current testing may miss up to 30  % of cases. Clinicians are often left to treat empirically with prolonged regimens with significant side effects or risk a missed case that would result in death. Rather than relying strictly on microbiologic or molecular testing to diagnose TB meningitis, we propose that testing of CSF for biomarkers of host response may have an adjunctive role to play in improving the diagnosis of TB meningitis.

The role of thoracoscopic biopsies in the diagnosis of pleural tuberculosis

Tuberculosis (TB) is a significant public health problem in many developing countries. In many cases, tuberculosis may present a significant diagnostic challenge. A 32-year-old male Chinese immigrant presented to our institution with a fever and non-productive cough. He was found to have a right pleural effusion, for which a chest drain was inserted. His tuberculin skin test was unreactive (0mm) although he was not immunocompromised (HIV negative). All cultures were negative, and 3 sputum samples and his pleural fluid sample tested negative for acid-fast bacilli. A computed tomography (CT) scan of his chest revealed features suggestive of an early empyema. There was no evidence suggestive of a malignant effusion. In an effort to attain a diagnosis, he underwent a video-assisted thoracoscopy (VATS) procedure with pleural drainage and biopsies. Anti-tuberculosis therapy (ATT) was commenced due to a high level of suspicion after failure of empirical therapy.

Although the Ziehl-Neelsen stain for acid fast bacilli was negative, pleural biopsies demonstrated active chronic granulomatous pleuritis with many Langerhans type giant cells highly suggestive of tuberculosis. He was responsive to treatment and completed 6 months of ATT with complete clinical resolution. In young, immunocompetent patients with an exudative, culture-negative effusion, the diagnosis of pleural tuberculosis must be considered. Pleural biopsy is the gold standard for diagnosing pleural TB but demonstration of acid-fast bacilli or necrotizing granulomas in the specimen are not absolutely necessary to make the diagnosis.