The efficiency of a clinical pathway to guide combined applications of interventional pulmonology in undiagnosed pleural effusions

The diagnostic procedure of pleural effusion (PEs) is challenging due to low detection rates and numerous aetiologies. Hence, any attempt to enhance diagnosis is worthwhile. We present a clinical pathway to guide combined application of interventional pulmonology (IP) for tracing causes of undiagnosed PEs. Subjects with undiagnosed PEs were identified in the Hospital Information System of Dalian Municipal Central Hospital from January 1, 2012, to December 31, 2018. Eligible subjects were divided into a group of combined tests and a group of medical thoracoscopy (MT). Optimal and subsequent diagnostic tests were performed depending on the guidance of the clinical pathway by matching profitable chest lesions with the respective adaptation. As the guidance of clinical pathway, common bronchoscopy would be preferentially selected if pulmonary lesions involved or within the central bronchus, EBUS-TBNA was favoured when pulmonary lesions were adjacent to the central bronchus or with the enlarged mediastinal/hilar lymph nodes, guided bronchoscopy would be preferred if pulmonary nodules/masses were larger than 20 mm with discernible bronchus signs, CT-assisted transthoracic core biopsy was preferred if pulmonary nodules were less than 20 mm, image guided cutting needle biopsy was the recommendation if the pleural thickness was larger than 10 mm and pulmonary lesions were miliary. MT was preferred only when undiagnosed PEs was the initial symptom and pulmonary lesions were miliary or absent. A total of 83.57% cases of undiagnosed PEs were eligible for the clinical pathway, and 659 and 216 subjects were included in the combined tests and MT groups, respectively, depending on the optimal recommendation of the clinical pathway. The total diagnostic yields in the combined tests and MT groups were 95.99% and 91.20%, respectively, and the difference in total diagnostic yield was statistically significant (χ² = 7.510, p = 0.006). Overall, clinical pathway guidance of the combined application of IP is useful for tracing the causes of undiagnosed PEs. The diagnostic yield of undiagnosed PEs is significantly increased compared with that of MT alone.

Single-cell immune profiling reveals functional diversity of T cells in tuberculous pleural effusion

Orchestration of an effective T lymphocyte response at infection sites is critical for protection against Mycobacterium tuberculosis (Mtb) infection. However, the local T cell immunity landscape in human tuberculosis is poorly defined. Tuberculous pleural effusion (TPE), caused by Mtb, is characterized by an influx of leukocytes to the pleural space, providing a platform suitable for delineating complex tissue responses to Mtb infection. Using single-cell transcriptomics and T cell receptor sequencing, we analyzed mononuclear cell populations in paired pleural fluid and peripheral blood of TPE patients. While all major cell clusters were present in both tissues, their relative proportions varied significantly by anatomic location. Lineage tracking analysis revealed subsets of CD8 and CD4 T cell populations with distinct effector functions specifically expanded at pleural sites. Granzyme K–expressing CD8 T cells were preferentially enriched and clonally expanded in pleural fluid from TPE, suggesting that they are involved in the pathogenesis of the disease. The findings collectively reveal the landscape of local T cell immunity in tuberculosis.

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.

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.

Role of C-Reactive Protein in Discrimination between Transudative and Exudative Pleural Effusions

Background: There is still no wide agreement regarding the efficacy of the serum levels of C-reactive protein (CRPs), pleural fluid levels of CRP (CRPpf), and their ratio (CRPr) in the discrimination between transudative (Tr) and exudative (Ex) pleural effusions (PEs). Most of the previous studies were conducted on small cohorts, and the role of CRPs in the CRPpf gradient (CRPg) in this discrimination has not been previously reported. The present study aims to assess the diagnostic efficacy of CRPs, CRPpf, CRPg, and CRPr in the discrimination between TrPE and ExPE in a relatively large cohort of patients with PE. Methods: The study population included 492 patients with PE, 210 of them with TrPE and 282 with ExPE. The levels of CRPs and CRPpf were measured, and the CRPg and CRPr were calculated. The values are presented as mean ± SD. Results: The mean levels of CRPs, CRPpf, CRPg, and CRPr of the TrPEs were 11.3 ± 5.7 mg/L, 4.6 ± 2.8 mg/L, 6.7 ± 3.9 mg/L, and 0.40 ± 0.14, respectively, and for the ExPEs, they were 140.5 ± 112.8 mg/L, 52.8 ± 53.2 mg/L, 87.2 ± 72.4 mg/L, and 0.37 ± 0.15, respectively. The levels of CRPs, CRPpf, and CRPg were significantly higher in the ExPEs than in the TrPEs (p < 0.0001). No significant difference was found between the two groups for the levels of CRPr (p = 0.15). The best cut-off value calculated by the receiver operating characteristic (ROC) analysis for discriminating TrPE from ExPE was for CRPs, 20.5 mg/L with area under the curve (AUC) = 97% and p < 0.0001; for CRPpf, 9.9 mg/L with AUC = 95% and p < 0.0001; and for CRPg, 13.6 mg/L with AUC = 96% and p < 0.0001. Conclusion: CRPs, CRPpf, and CRPg are strong markers for discrimination between TrPE and ExPE, while CRPr has no role in this discrimination.

Pleural fluid tumor necrosis factor for diagnosis of pleural tuberculosis: A systematic review and meta-analysis

OBJECTIVE

Tumor necrosis factor (TNF) is an important local host response mediator in tuberculous pleural effusion (TPE) and is proposed as a potential biomarker for diagnosing TPE. We assessed the performance of pleural fluid TNF in the diagnosis of TPE, and evaluated its ability to distinguish TPE from parapneumonic or malignant effusions.

METHODS

We queried the PubMed and Embase databases for studies indexed till August 2020. We included studies that (a) provided data on sensitivity and specificity of pleural fluid TNF for the diagnosis of TPE, or (b) compared pleural fluid TNF levels between TPE and malignant or parapneumonic effusions. We used a hierarchical summary receiver operating characteristic plot to model summary sensitivity and specificity. A random effects model was used to pool standardized mean differences (SMD) across studies comparing TPE and other effusions. We explored heterogeneity using subgroup analysis. We also performed meta-regression to identify factors significantly influencing results.

RESULTS

We retrieved 1090 citations, and included 38 publications, in our review. The summary estimates for sensitivity, specificity, and diagnostic odds ratio were 0.79 (95% CI 0.72-0.84), 0.82 (95% CI 0.76-0.87), and 16.84 (95% CI 9.47-29.95) respectively. Pleural fluid TNF levels were significantly higher in TPE than in malignant effusions (summary SMD 1.50, 95% CI 1.13-1.87), but not parapneumonic effusions (summary SMD 0.61, 95% CI -0.14 to 1.35). None of the prespecified subgroup variables significantly influenced summary estimates.

CONCLUSION

Pleural fluid TNF has poor diagnostic accuracy for diagnosing TPE and imperfectly discriminates TPE from parapneumonic pleural effusions.

Contemporary Approach to the Diagnosis of Malignant Pleural Effusion

Advanced malignancy is a prevalent cause of exudative pleural effusion. The management of malignant pleural effusion (MPE) has been the subject of several recent randomized controlled trials and excellent reviews. Less attention has been focused on another controversial and challenging aspect of MPE: establishing the diagnosis. Before selecting the optimal management strategy, the presence of an MPE must first be correctly identified with an emphasis on minimizing invasiveness and discomfort in a patient with late-stage cancer. The aim of the present review is to summarize the current knowledge about MPE diagnostics and to propose an algorithm for the diagnosis of MPE in established or suspected malignancy.

Adenosine deaminase cutoff value when diagnosing tuberculous pleurisy in patients aged 40 years and older

INTRODUCTION

Tuberculous pleurisy (TBP) is one of the most common manifestations of extra-pulmonary tuberculosis. In patients aged ≥40 years, a closed needle pleural biopsy is recommended with an adenosine deaminase (ADA) level of 40-70 U/L. We aim to investigate whether the cutoff value of ADA and the cancer ratio in patients with TBP aged ≥40 years is different and determine the effects of both compounded biomarkers on diagnosing TBP.

MATERIALS AND METHODS

Between 2009 and 2016, the ADA levels were measured in pleural effusions from patients who were admitted to the Chest disease clinic.

RESULTS

Of the 196 patients included in the study, 104 were aged ≥40 years. A significant relationship was found between the serum LDH/pleural ADA (sLDH/pADA) ratio and ADA levels in patients aged >40 years (OR: 0.935 and OR: 1.085, respectively). The model using an ADA value ≥30 and an sLDH/pADA ratio <16 yielded a sensitivity of 94.25% (95% CI, 87.1-98.10) in all patients and 69.23% (95% CI, 54.9-81.28) in patients aged >40 years.

CONCLUSION

ADA and the sLDH/pADA ratio are simple, cost-efficient, and obtain fast results and, therefore, are the preferred methods in TBP diagnosis. The diagnosis rate in the present study was 91% using ADA levels in combination with the sLDH/pADA ratio, both of which can be obtained only through thoracentesis.

Pleural and serum markers for diagnosis of malignant pleural effusion

BACKGROUND

Differentiation between benign and malignant exudative pleural effusion remains a clinical challenge. Recently, several markers have been reported to increase the diagnostic accuracy of malignant pleural effusion, with controversial results.

METHODS

Patients with exudative pleural effusion were divided into 2 groups: a malignant pleural effusion group (39 patients) diagnosed by malignant cells in pleural fluid cytology or by malignant infiltration of the pleura on pleural biopsy, and a benign pleural effusion group (51 patients) with neither malignant cells in pleural fluid cytology nor malignant infiltration of the pleura on pleural biopsy. Matrix metalloproteinase-9 and tissue inhibitor of metalloproteinase-1 were determined in both serum and pleural fluid samples, using commercially available enzyme-linked immunosorbent assay kits.

RESULTS

The etiology of malignant pleural effusion in the malignant group was breast cancer in 43.6% and bronchogenic carcinoma in 25.6%. There was a statistically significant difference between the 2 groups regarding sex, with more males in the benign group. There was no significant difference between groups regarding age. The median levels of matrix metalloproteinase-9 and tissue inhibitor of metalloproteinase-1 were higher in the malignant group than in the benign group, and the differences were highly significant in both pleural fluid (p < 0.001) and serum (p < 0.001).

CONCLUSION

Matrix metaloproteinase-9 and tissue inhibitor of metalloproteinase-1 in serum and pleural fluid samples might be valuable markers for differentiating benign from malignant pleural effusions.

Development and validation of a novel scoring system developed from a nomogram to identify malignant pleural effusion

BACKGROUND

This study aimed to establish and validate a novel scoring system based on a nomogram for the differential diagnosis of malignant pleural effusion (MPE) and benign pleural effusion (BPE).

METHODS

Patients with PE and confirmed aetiology who underwent diagnostic thoracentesis were included in this study. One retrospective set (N = 1261) was used to develop and internally validate the predictive model. The clinical, radiological and laboratory features were collected and subjected to logistic regression analyses. The primary predictive model was displayed as a nomogram and then modified into a novel scoring system, which was externally validated in an independent set (N = 172).

FINDINGS

The novel scoring system was composed of fever (3 points), erythrocyte sedimentation rate (4 points), effusion adenosine deaminase (7 points), serum carcinoembryonic antigen (CEA) (4 points), effusion CEA (10 points) and effusion/serum CEA (8 points). With a cutoff value of 15 points, the area under the curve, specificity and sensitivity for identifying MPE were 0.913, 89.10%, and 82.63%, respectively, in the training set, 0.922, 93.48%, 81.51%, respectively, in the internal validation set and 0.912, 87.61%, 81.36%, respectively, in the external validation set. Moreover, this scoring system was exclusively applied to distinguish lung cancer with PE from tuberculous pleurisy and showed a favourable diagnostic performance in the training and validation sets.

INTERPRETATION

This novel scoring system was developed from a retrospective study and externally validated in an independent set based on six easily accessible clinical variables, and it exhibited good diagnostic performance for identifying MPE.

FUNDING

NFSC grants (no. 81572942, no. 81800094).

The diagnostic yield of closed needle pleural biopsy in exudative pleural effusion: a retrospective 10-year study

Background

Pleural effusion is a common presentation in clinical practice. About 40% of exudative pleural effusion is unable to be diagnosed through thoracentesis, and closed pleural biopsy (CPB) is needed. This study was designed to investigate the diagnostic yield of CPB in exudative pleural effusion.

Methods

This was a retrospective 10-year study of patients with unexplained exudative pleural effusion who underwent CPB in two centers. Malignant pleural effusion (MPE) was diagnosed when there was histopathological evidence of pleural tissue, pulmonary tissue, or pleural fluid. Tuberculous pleural effusion (TPE) was confirmed when granuloma or coagulative necrosis was observed in pleural tissue, Ziehl-Neelsen acid-fast staining was positive, or adenosine deaminase (ADA) in pleural effusion was higher than 35IU with clinical symptoms of TB orγ-interferon increased with symptoms of TB.

Results

A total of 644 patients were enrolled, of which 479 were specifically diagnosed (217 patients with TPE and 262 patients with MPE). The sensitivity of CPB in the diagnosis of MPE was 51.5%. Among the pathological types of MPE, lung adenocarcinoma accounted for 77.9% (204/262) of cases, making up the largest proportion. The sensitivity of CPB for diagnosing TPE was 68.7%.

Conclusions

CPB has a relatively high sensitivity in the diagnosis of exudative pleural fluid, especially in relation to tuberculous lesions. CPB could provide an alternative technique in clinical practice, especially for basic hospital units without thoracoscopy.

Identification of Pleural Response Patterns: A Cluster Analysis

BACKGROUND

Pleural effusion occurs as a response of the pleura to aggressions. The pleura reacts differently according to the type of injury. However, pleural reactions have not yet been characterized. The objective of this study was to identify homogeneous clusters of patients based on the analytical characteristics of their pleural fluid and identify pleural response patterns.

METHODS

A prospective study was conducted of consecutive patients seen in our unit for pleural effusion. Principal component and cluster analyses were carried out to identify pleural response patterns based on a combination of pleural fluid biomarkers.

RESULTS

A total of 1613 patients were grouped into six clusters, namely: cluster 1 (10.5% of the cohort, primarily composed of patients with malignant pleural effusions); cluster 2 (17.4%, pleural effusions with inflammatory biomarkers); cluster 3 (16.1%, primarily composed of patients with infectious pleural effusions); cluster 4 (2.5%, a subcluster of cluster 3, superinfectious effusions); cluster 5 (23.4%, paucicellular pleural effusions); and cluster 6 (30.1%, miscellaneous). Significant differences were observed across clusters in terms of the analytical characteristics of PF (p<0.001 for all), age (p<0.001), and gender (p=0.016). A direct relationship was found between the type of cluster and the etiology of pleural effusion.

CONCLUSION

Pleural response is heterogeneous. The pleura may respond differently to the same etiology or similarly to different etiologies, which hinders diagnosis of pleural effusion.

Diagnostic value of polymerase chain reaction/acid-fast bacilli in conjunction with computed tomography-guided pleural biopsy in tuberculous pleurisy: A diagnostic accuracy study

Patients with tuberculous pleurisy often remain undiagnosed even after blind thoracentesis and closed pleural biopsy (PB). In this study, we assessed the value of computed tomography (CT)-guided core needle biopsy of pleural lesion and evaluated the diagnostic accuracy of polymerase chain reaction (PCR)/staining for acid-fast bacilli (AFB) in suspicious tuberculous pleurisy undiagnosed in blind thoracentesis.Patients with exudative pleural effusion (PE) without specific etiology after blind thoracentesis and closed PB were enrolled in this study. PB specimens were obtained through CT-guided core needle biopsy of pleural lesion, then underwent PCR, AFB, histopathological examination, and some routine tests. Diagnostic values were evaluated through sensitivity, specificity, negative predictive value, positive predictive value, and accuracy.A total of 261 participants (TB group: 241, non-TB group: 20) were recruited. In this cohort, the sensitivity, specificity, and accuracy were 56.0%, 95.0%, and 59.0%, respectively for PCR, whereas 57.3%, 95.0%, and 60.2%, respectively for AFB. Their parallel test achieved an improved sensitivity (76.8%) and accuracy (77.8%), with a slight decrease in specificity (90.0%). In histopathological examination, granuloma was the most common finding in TB group (88.4%, 213/241), but also observed in non-TB group (10.0%, 2/20). In addition, pleural lymphocyte percentage in TB group was significantly higher than that of non-TB group (92% vs 61%, respectively; P = .003). However, no significant differences were found for other biomarkers.CT-guided core needle PB is essential for patients with exudative PE but undiagnosed after blind thoracentesis. Combining with PCR and AFB, it strongly improves the diagnosis of tuberculous pleurisy.

Potential biomarkers for antidiastole of tuberculous and malignant pleural effusion by proteome analysis

AIM

To investigate novel potential biomarkers for antidiastole of tuberculous pleural effusion (TPE) from malignant pleural effusion (MPE).

MATERIALS & METHODS

iTRAQTM-coupled LC-MS/MS were applied to analyze the proteome of TPE and MPE samples. The candidate proteins were verified by enzyme-linked immunosorbent assay.

RESULTS

A total of 432 differential proteins were identified. Enzyme-linked immunosorbent assay revealed significantly higher levels of fibronectin (FN) and cathepsin G (CTSG) in MPE than in TPE, but lower levels of leukotriene-A4 hydrolase (LTA4H). The receiver operator characteristic values were 0.285 for FN, 0.64 for LTA4H, 0.337 for CTSG and 0.793 for a combination of these candidate markers.

CONCLUSION

FN, LTA4H and CTSG were identified as potential biomarkers to differentiate TPE from MPE and their combination exhibited higher diagnostic capacity.

Polyserositis: a diagnostic challenge

BACKGROUND

Polyserositis (PS) is the inflammation, with effusion, of different serous membranes. It has been associated with different aetiologies, but the aetiology of PS remains unknown in a high percentage of patients.

AIMS

The general objective of this retrospective study was to analyse the aetiology of PS cases seen at Son Llàtzer Hospital in an 11-year period. Other objectives were to determine the epidemiological, clinical and analytical characteristics of these patients.

METHODS

An observational, descriptive and retrospective study to analyse the aetiology of PS cases seen at Son Llàtzer Hospital. The inflammation of two or more serous membranes confirmed by an imaging test was required and at least one of the serous fluid should be an exudate.

RESULTS

A total of 92 patients was included in the study. The most common diagnosis was neoplasm (nearly one-third of cases) followed by infectious and autoimmune diseases. PS aetiology was unknown in more than one-third. Pleura and pericardium were the most common sites of serosal involvement (83%). Antinuclear antibodies' positivity in serum and increased levels of adenosine deaminase in pleural effusion were significantly associated with a final diagnosis of autoimmune disease. Increased pleural lactate dehydrogenase levels were significantly associated with a final diagnosis of neoplasm. In 9 of 14 patients with a previous cancer, PS represented a recurrence of their cancer. Cases of unknown aetiology presented most frequently as pleural and pericardial involvement, and the majority resolved. In very few patients, an infectious aetiology could be proven.

CONCLUSION

PS is a frequent clinical entity that is associated with different diseases and its diagnosis could be challenging, with a high rate of unknown aetiologies.

Application of endoscopic ultrasound-guided-fine needle aspiration combined with cyst fluid analysis for the diagnosis of mediastinal cystic lesions

BACKGROUND

Mediastinal cystic lesions account for approximately 15-20% of all mediastinal masses and are difficult to differentiate because of similar imaging manifestation. The aim of this study was to differentiate mediastinum cystic lesions through endoscopic ultrasound-guided-fine needle aspiration (EUS-FNA) and parameters from cyst-fluid analysis.

METHODS

Over a period of eight years, 37 patients suspected with mediastinal cystic lesions were assessed. Cyst fluid was collected via EUS-FNA and further examined using cytological and biochemical techniques. Definitive diagnosis was established based on cytology, surgical pathology, and/or clinical follow-up.

RESULTS

Based on the final pathological reports or long-term follow-up, 19 patients were diagnosed with benign cysts, 14 with benign or malignant tumors, 2 with tuberculosis, 1 with an abscess, and 1 with a pancreatic pseudocyst. Computed tomography or magnetic resonance imaging mistakenly distinguished eight cases as solid masses (27.03%), but EUS revealed cystic characteristics. Carcinoembryonic antigen and lactate dehydrogenase (LDH) were evaluated from the cyst fluid obtained by EUS-FNA. There was no statistically significant difference in carcinoembryonic antigen values between benign and malignant cysts; however the average LDH value in the malignancy group was significantly higher than in the benign group.

CONCLUSION

EUS-FNA showed great potential for differentiating mediastinal lesions by combining imaging manifestation and cytological examination. The elevated LDH value from cyst fluid chemical analysis could be used as an auxiliary indicator for diagnosing malignancy.

Vascular endothelial growth factor and protein level in pleural effusion for differentiating malignant from benign pleural effusion

Pleural effusion is associated with multiple benign and malignant conditions. Currently no biomarkers differentiate malignant pleural effusion (MPE) and benign pleural effusion (BPE) sensitively and specifically. The present study identified a novel combination of biomarkers in pleural effusion for differentiating MPE from BPE by enrolling 75 patients, 34 with BPE and 41 with MPE. The levels of lactate dehydrogenase, glucose, protein, and total cell, neutrophil, monocyte and lymphocyte counts in the pleural effusion were measured. The concentrations of interleukin (IL)-1β, IL-4, IL-5, IL-6, IL-8, IL-10, IL-12, tumor necrosis factor-α, interferon γ, transforming growth factor-β1, colony stimulating factor 2, monocyte chemoattractant protein-1 and vascular endothelial growth factor (VEGF) were detected using cytometric bead arrays. Protein and VEGF levels differed significantly between patients with BPE and those with MPE. The optimal cutoff value of VEGF and protein was 214 pg/ml and 3.35 g/dl respectively, according to the receiver operating characteristic curve. A combination of VEGF >214 pg/ml and protein >3.35 g/dl in pleural effusion presented a sensitivity of 92.6% and an accuracy of 78.6% for MPE, but was not associated with a decreased survival rate. These results suggested that this novel combination strategy may provide useful biomarkers for predicting MPE and facilitating early diagnosis.

Predicting Malignant and Paramalignant Pleural Effusions by Combining Clinical, Radiological and Pleural Fluid Analytical Parameters

BACKGROUND

The usefulness of clinical, radiological and pleural fluid analytical parameters for diagnosing malignant and paramalignant pleural effusion is not clearly stated. Hence this study aimed to identify possible predictor variables of diagnosing malignancy in pleural effusion of unknown aetiology.

METHODS

Clinical, radiological and pleural fluid analytical parameters were obtained from consecutive patients who had suffered pleural effusion of unknown aetiology. They were classified into three groups according to their final diagnosis: malignant, paramalignant and benign pleural effusion. The CHAID (Chi-square automatic interaction detector) methodology was used to estimate the implication of the clinical, radiological and analytical variables in daily practice through decision trees.

RESULTS

Of 71 patients, malignant (n = 31), paramalignant (n = 15) and benign (n = 25), smoking habit, dyspnoea, weight loss, radiological characteristics (mass, node, adenopathies and pleural thickening) and pleural fluid analytical parameters (pH and glucose) distinguished malignant and paramalignant pleural effusions (all with a p < 0.05). Decision tree 1 classified 77.8% of malignant and paramalignant pleural effusions in step 2. Decision tree 2 classified 83.3% of malignant pleural effusions in step 2, 73.3% of paramalignant pleural effusions and 91.7% of benign ones.

CONCLUSIONS

The data herein suggest that the identified predictor values applied to tree diagrams, which required no extraordinary measures, have a higher rate of correct identification of malignant, paramalignant and benign effusions when compared to techniques available today and proved most useful for usual clinical practice. Future studies are still needed to further improve the classification of patients.

Advances in the diagnosis of tuberculous pleuritis

Pleural tuberculosis (TB) remains difficult to diagnose. In about two-thirds of the cases the diagnosis is reliant upon clinical suspicion along with consistent fluid biochemistries (i.e., lymphocytic predominant exudates) and exclusion of other potential causes for the effusion. Microbiological methods for a confirmatory diagnosis of pleural TB, which include acid-fast smears (Ziehl-Nelseen), cultures on solid media (Lowenstein-Jensen) and polymerase chain reaction tests from either pleural fluid or sputum samples, remain suboptimal since they are positive in only a minority of patients. Liquid media, however, significantly increase sensitivity while shortening culture positivity as compared with solid cultures. A number of pleural fluid biomarkers such as adenosine deaminase (ADA), interferon-Ƴ, interferon-Ƴ-induced protein of 10 KDa (IP-10) and interleukin-27 (IL-27), have shown promise for the rapid diagnosis of TB, but only ADA combines the accuracy and simplicity required to be considered a mainstay investigative tool for clinical decisions, particularly in areas with medium to high TB prevalence. In countries where ADA is not available, pleural biopsies to evaluate for caseating granulomas are a standard diagnostic approach. They are now frequently performed under ultrasound guidance to optimize yield and patient safety.