The relationship between pleural fluid findings and the development of pleural thickening in patients with pleural tuberculosis

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.

Trend of the Tuberculous Pleurisy Notification Rate in Eastern China During 2017-2021: Spatiotemporal Analysis

BACKGROUND

Tuberculous pleurisy (TP) presents a serious allergic reaction in the pleura caused by Mycobacterium tuberculosis; however, few studies have described its spatial epidemiological characteristics in eastern China.

OBJECTIVE

This study aimed to determine the epidemiological distribution of TP and predict its further development in Zhejiang Province.

METHODS

Data on all notified cases of TP in Zhejiang Province, China, from 2017 to 2021 were collected from the existing tuberculosis information management system. Analyses, including spatial autocorrelation and spatial-temporal scan analysis, were performed to identify hot spots and clusters, respectively. The prediction of TP prevalence was performed using the seasonal autoregressive integrated moving average (SARIMA), Holt-Winters exponential smoothing, and Prophet models using R (The R Foundation) and Python (Python Software Foundation).

RESULTS

The average notification rate of TP in Zhejiang Province was 7.06 cases per 100,000 population, peaking in the summer. The male-to-female ratio was 2.18:1. In terms of geographical distribution, clusters of cases were observed in the western part of Zhejiang Province, including parts of Hangzhou, Quzhou, Jinhua, Lishui, Wenzhou, and Taizhou city. Spatial-temporal analysis identified 1 most likely cluster and 4 secondary clusters. The Holt-Winters model outperformed the SARIMA and Prophet models in predicting the trend in TP prevalence.

CONCLUSIONS

The western region of Zhejiang Province had the highest risk of TP. Comprehensive interventions, such as chest x-ray screening and symptom screening, should be reinforced to improve early identification. Additionally, a more systematic assessment of the prevalence trend of TP should include more predictors.

Rapid Detection of Mycobacterium tuberculosis in Pleural Fluid Using Resuscitation-Promoting Factor-Based Thin Layer Agar Culture Method

Background

Pleural tuberculous is difficult to diagnose. Culture is still considered the gold standard, especially in resource-limited settings where quick, cheap, and easy techniques are needed. The aim of the study was to evaluate resuscitation-promoting factors (Rpfs)-based thin layer agar (TLA) culture method for quick detection of Mycobacterium tuberculosis in pleural fluid.

Methods

Patients with suspected pleural TB were enrolled prospectively in our hospital, pleural fluid of all patients were collected, stained with Ziehl–Neelsen for acid-fast bacilli (AFB), cultured on Rpfs-TLA, TLA, and Löwenstein–Jensen (LJ) medium, and identified according to recommended procedures.

Results

A total of 137 suspected pleural TB were enrolled and categorized, including 103 pleural TB (49 confirmed and 54 probable pleural TB) and 34 non-TBP patients. The sensitivity of Rpfs-TLA for total pleural TB was 43.7% (34.5∼53.3%), higher than that of TLA 29.1% (21.2∼38.5%) and LJ 26.2% (18.7∼35.5%) (p < 0.01), and all specificity was 100% in the diagnosis of pleural TB. Median time to detection of a positive culture was 11.8 days (95% CI 10.4∼13.4) for Rpfs-TLA, 21.0 days (95% CI 19.1∼22.9) for TLA, and 30.5 days (95% CI 28.5∼32.5) for LJ (p < 0.001).

Conclusion

Rpfs-TLA is an accurate, rapid, cheap, and easy culture method, which makes it promising for use in clinical laboratories.

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.

Macrophage M1/M2 ratio as a predictor of pleural thickening in patients with tuberculous pleurisy

We evaluated the association between macrophage polarization and the development of pleural thickening in patients with tuberculous pleurisy. Patients with tuberculous pleurisy admitted to our hospital between October 2018 and March 2019 were prospectively recruited. Pleural fluid samples were obtained before treatment for detection of adenosine deaminase (ADA) and macrophage phenotype (M1: CD14+ CD86+; M2: CD14+ CD163+). Peripheral blood samples were subjected to interferon gamma release assay (IGRA). All subjects were administered standard anti-tuberculosis regimen (2HREZ/4HR); high-resolution CT was performed to determine pleural thickening (thickness>2mm) after completion of treatment. Pleural effusion in patients with thickened pleura had significantly more M1 but fewer M2 macrophages, and higher ADA level, as compared to those with normal pleura (P<0.05). No significant between-group difference was observed with respect to IGRA. In receiver operating characteristic (ROC) curve analysis, the optimal cut-off level of M1/M2 ratio for predicting pleural thickening was 1.149 (area under the curve: 0.842; sensitivity: 88.6%; specificity: 69.2%; positive predictive value: 86.3%; negative predictive value: 81.7%). M1/M2 ratio in the pleural fluid is a promising marker for predicting the development of pleural thickening in patients with tuberculous pleurisy. Macrophage-mediated immune response may play an important role in the pathogenesis of tuberculous pleurisy.

Study to identify incidence and risk factors associated Residual pleural opacity in tubercular pleural effusion

INTRODUCTION

Residual pleural opacity (RPO) is a common radiographic sequela in patients with tubercular pleural effusion at the end of the treatment. This study was designed to find out the risk factors associated with residual pleural opacity (RPO).

MATERIALS & METHODS

This was a prospective longitudinal study performed to analyse data of 56 patients (46 males & 10 females) who were diagnosed as tubercular pleural effusion and treated for the same between 1st Jan 2019 to 30th March 2020. Chest X-ray posteroanterior & Lateral view was done (performed) at 0 and 6 months of treatment to quantify the amount of pleural effusion and measured the residual pleural opacity at the end of the treatment. RPO included both non resolving pleural effusion as well as residual pleural thickening (RPT). All statistical analysis was done using SPSS version 20.0 (SPSS Inc., Chicago, IL, USA). Multivariate logistic regression was performed to explore the association of risk factors and Residual pleural opacity. The statistical significance level was set at 0.05 (two-tailed).

RESULTS

The incidence of Residual pleural opacity (RPO) at the end of 6 months of antituberculosis treatment was 53.57% (30/56)). The study patients were divided into RPO and non- RPO group. Male gender had significantly higher incidence of RPO (93.3% vs 69.2% P = 0.01)). Patients with RPO group had significantly more cough and weight loss as compared to non RPO group (96.6% vs 65.3% P = 0.002 and 60% vs 23% P = 0.005). The proportion of patients who underwent therapeutic aspiration and gained weight of more than 5kg during treatment (19.5% vs 7.6% P = 0.02 & 46.6% vs 7.6% P = 0.001) was significantly higher in RPO group. A significantly lower protein, glucose and higher LDH level in pleural fluid was observed in the RPO group compared to non-RPO group (P = 0.006, P = 0.01, P = 0.001)). No significant difference was found in the pleural fluid ADA, lymphocyte, neutrophil levels between the two groups (p > 0.05). Logistic regression analysis showed that the male gender, low pleural fluid glucose, presence of cough and weight loss were associated with significantly increased risk of residual pleural opacity and thickening (p < 0.05).

CONCLUSION

Tubercular pleural effusion is associated with residual pleural opacity in more than half of the patients. Male gender and low glucose levels in pleural fluid was associated with increased risk of residual pleural opacity.

Diagnostic performance of nucleic acid tests in tuberculous pleurisy

BACKGROUND

Tuberculous pleurisy (TBP) is the most common form of extrapulmonary tuberculosis (TB). However, rapid diagnostic methods with high accuracy for tuberculous pleurisy are urgently needed. In the present study, we evaluated the diagnostic accuracy of Xpert MTB/RIF, LAMP and SAT-TB assay with pleural fluids from culture-positive TBP patients.

METHODS

We prospectively enrolled 300 patients with exudative pleural effusions used as the samples for Xpert MTB/RIF, LAMP and SAT-TB assay. Of these, 265 including 223 patients diagnosed with TBP and 42 non-TBP patients used as controls were analyzed.

RESULTS

The sensitivities of Xpert MTB/RIF (27.4%), LAMP (26.5%) and SAT-TB assay (32.3%) were significantly higher than that of pleural effusion smear (14.3%, X² = 20.65, P <  0.001), whereas they were much lower than expected for the analysis of pleural effusion samples. Both SAT-TB assay and Xpert MTB/RIF demonstrated high specificities (100%) and PPVs (100%), but the NPVs of all of the tests were < 22%. The area under ROC curve of pleural effusion smear, LAMP, Xpert MTB/RIF and SAT-TB assays was 0.524 (95% CI 0.431-0.617), 0.632 (95% CI 0.553-0.71), 0.637 (95% CI 0.56-0.714) and 0.673 (95% CI 0.6-0.745). SAT-TB assays had the highest AUC.

CONCLUSION

Nucleic acid amplification tests are not the first choice in the diagnosis of tuberculous pleurisy. In this type of test, SAT-TB is recommended because of its low cost, relatively more accurate compared with the other two tests. This prospective study was approved by The Ethics Committee of the Shanghai Pulmonary Hospital (approval number: K19-148).

TRIAL REGISTRATION

ClinicalTrials.gov identifier: ChiCTR1900026234 (Retrospectively registered). The registration date is September 28, 2019.

Tuberculous pleural effusion

Tuberculous effusion is a common disease entity with a spectrum of presentations from a largely benign effusion, which resolves completely, to a complicated effusion with loculations, pleural thickening and even frank empyema, all of which may have a lasting effect on lung function. The pathogenesis is a combination of true pleural infection and an effusive hypersensitivity reaction, compartmentalized within the pleural space. Diagnostic thoracentesis with thorough pleural fluid analysis including biomarkers such as adenosine deaminase and gamma interferon achieves high accuracy in the correct clinical context. Definitive diagnosis may require invasive procedures to demonstrate histological evidence of caseating granulomas or microbiological evidence of the organism on smear or culture. Drug resistance is an emerging problem that requires vigilance and extra effort to acquire a complete drug sensitivity profile for each tuberculous effusion treated. Nucleic acid amplification tests such as Xpert MTB/RIF can be invaluable in this instance; however, the yield is low in pleural fluid. Treatment consists of standard anti-tuberculous therapy or a guideline-based individualized regimen in the case of drug resistance. There is low-quality evidence that suggests possible benefit from corticosteroids; however, they are not currently recommended due to concomitant increased risk of adverse effects. Small studies report some short- and long-term benefit from interventions such as therapeutic thoracentesis, intrapleural fibrinolytics and surgery but many questions remain to be answered.

Pleural tuberculosis: A concise clinical review

Tuberculosis (TB) is the leading infectious cause of death worldwide, and the commonest cause of death in people living with HIV. Globally, pleural TB remains one of the most frequent causes of pleural exudates, particularly in TB-endemic areas and in the HIV positive population. Most TB pleural effusions are exudates with high adenosine deaminase (ADA), lymphocyte-rich, straw-coloured and free flowing, with a low yield on mycobacterial culture. TB pleurisy can also present as loculated neutrophil-predominant effusions which mimic parapneumonic effusions. Rarely, they can present as frank TB empyema, containing an abundance of mycobacteria. Up to 80% of patients have parenchymal involvement on chest imaging. The diagnosis is simple if M. tuberculosis is detected in sputum, pleural fluid or biopsy specimens, and the recent advent of liquid medium culture techniques has increased the microbiological yield dramatically. Where the prevalence of TB is high the presence of a lymphocyte-predominant exudate with a high ADA has a positive predictive value of 98%. In low prevalence areas, the absence of an elevated ADA and lymphocyte predominance makes TB very unlikely, and pleural biopsy should be performed to confirm the diagnosis. Pleural biopsy for liquid culture and susceptibility testing must also be considered where the prevalence of drug resistant TB is high. Treatment regimens are identical to those administered for pulmonary TB. Initial pleural drainage may have a role in symptom relief and in hastening the resolution of the effusion. Surgical intervention may be required in loculated effusions and empyemas.

Calpain and spectrin breakdown products as potential biomarkers in tuberculous pleural effusion

Background

Early diagnosis of tuberculous pleural effusion (TPE) remains difficult. Calpain is a family of calcium-dependent endopeptidase that plays an important role in extracellular matrix (ECM) remodeling and collagen synthesis. The aim of this study was to explore the diagnostic value of pleural fluid angiotensin-converting enzyme (ACE), calpain-1, spectrin breakdown products (SBDP), and matrix metalloproteinase-1 (MMP-1) in TPE and malignant pleural effusion (MPE).

Methods

The study included 47 patients with TPE, 28 patients with MPE, and 10 patients with transudate of non-tuberculous and non-malignant origin as controls. Calpain-1, ACE, SBDP, and MMP-1 levels in pleural fluid were measured by the ELISA method.

Results

ACE, calpain-1, SBDP, and MMP-1 levels were higher in TPE than MPE and transudate (all, P<0.05). On multivariate logistic regression analysis, adenosine deaminase (ADA) ≥40 IU/mL, calpain-1 ≥787 ng/mL, and SBDP ≥2.745 ng/mL were independent factors associated with TPE. The predicted probability of TPE based on these three predictors had an area under the receiver operating characteristic (ROC) curve of 0.985, with 97.9% sensitivity and 86.6% specificity under a cut-off value of 0.326. In patients with TPE, residual pulmonary thickening (RPT) was associated with significantly higher calpain-1, SBDP, and MMP-1 levels (all, P<0.05) versus cases without RPT.

Conclusions

Our results suggest that the overproduction of calpain-1 and SBDP is associated with pleural fibrosis in tuberculous pleurisy. While ADA is a conventional marker for diagnostic TPE, the simultaneous measurement of calpain-1 and SBDP l in pleural fluid may improve the diagnostic efficacy.

Bilateral Tuberculous Pleurisy with Subsequent Upper Lobe Predominant Pulmonary Fibrosis Mimicking Pleuroparenchymal Fibroelastosis

Although the majority of patients with Mycobacterium tuberculosis have pulmonary involvement, some cases have pleural involvement as extra-pulmonary sites of infection. We herein report a case of upper lobe-predominant pulmonary fibrosis that developed in a 47-year-old male with a history of bilateral tuberculous pleurisy. Based on his chest radiological findings, pleuroparenchymal fibroelastosis (PPFE) was most strongly suspected, and a surgical lung biopsy (SLB) was performed to obtain a pathological diagnosis. The SLB specimens showed interstitial pneumonia with pleural involvement without any characteristic findings of PPFE. Careful discretion in obtaining a precise diagnosis of this condition should be practiced in such cases.

A Systematic Review of the Prevalence and Pattern of Imaging Defined Post-TB Lung Disease

Background

Tuberculosis is an important risk factor for chronic respiratory disease in resource poor settings. The persistence of abnormal spirometry and symptoms after treatment are well described, but the structural abnormalities underlying these changes remain poorly defined, limiting our ability to phenotype post-TB lung disease in to meaningful categories for clinical management, prognostication, and ongoing research. The relationship between post-TB lung damage and patient-centred outcomes including functional impairment, respiratory symptoms, and health related quality of life also remains unclear.

Methods

We performed a systematic literature review to determine the prevalence and pattern of imaging-defined lung pathology in adults after medical treatment for pleural, miliary, or pulmonary TB disease. Data were collected on study characteristics, and the modality, timing, and findings of thoracic imaging. The proportion of studies relating imaging findings to spirometry results and patient morbidity was recorded. Study quality was assessed using a modified Newcastle-Ottowa score. (Prospero Registration number CRD42015027958)

Results

We identified 37 eligible studies. The principle features seen on CXR were cavitation (8.3–83.7%), bronchiectasis (4.3–11.2%), and fibrosis (25.0–70.4%), but prevalence was highly variable. CT imaging identified a wider range of residual abnormalities than CXR, including nodules (25.0–55.8%), consolidation (3.7–19.2%), and emphysema (15.0–45.0%). The prevalence of cavitation was generally lower (7.4–34.6%) and bronchiectasis higher (35.0–86.0%) on CT vs. CXR imaging. A paucity of prospective data, and data from HIV-infected adults and sub-Saharan Africa (sSA) was noted. Few studies related structural damage to physiological impairment, respiratory symptoms, or patient morbidity.

Conclusions

Post-TB structural lung pathology is common. Prospective data are required to determine the evolution of this lung damage and its associated morbidity over time. Further data are required from HIV-infected groups and those living in sSA.

[Residual pleural opacity in patients treated for pleural tuberculosis in Yaounde]

INTRODUCTION

The aim of this study was to evaluate the incidence and risk factors of residual pleural opacity (RPO) at the end and after 6 months (M12) of antituberculosis treatment (ATT) in adults with pleural tuberculosis.

METHODS

In this prospective cohort study, all patients admitted for pleural tuberculosis between September 2010 and August 2012 in the pneumology A unit of Yaounde Jamot Hospital were included. Each patient was then followed up for 12 months. RPO was considered significant if it was measured 10mm or more on standard chest X-ray. The logistic regression model was used to investigate the risk factors of significant RPO at the end of antituberculosis treatment.

RESULTS

Of the 193 patients included, median (interquartile range) age of 33 (25-42) years, 115 (59.6%) were men. The incidence (95% CI) of significant RPO was 22.0% (14.9-29.1) and 11.0% (4.9-17.1) at the end of ATT and at M12 respectively. In multivariate analysis, the risk factors of the occurrence of a significant RPO at the end of ATT and at M12 were smoking, associated parenchymal lesions, and hypoglycopleuria.

CONCLUSION

Cumulative incidence of RPO ≥ 10 mm was 22% at the end of ATT and 11% after 12 months from the beginning of treatment. Patients with risk factors of RPO ≥ 10 mm should benefit from greater surveillance and appropriate management.

Tuberculous pleural effusions: advances and controversies

On a global scale, tuberculosis (TB) remains one of the most frequent causes of pleural effusions. Our understanding of the pathogenesis of the disease has evolved and what was once thought to be an effusion as a result of a pure delayed hypersensitivity reaction is now believed to be the consequence of direct infection of the pleural space with a cascade of events including an immunological response. Pulmonary involvement is more common than previously believed and induced sputum, which is grossly underutilised, can be diagnostic in approximately 50%. The gold standard for the diagnosis of tuberculous pleuritis remains the detection of Mycobacterium tuberculosis in pleural fluid, or pleural biopsy specimens, either by microscopy and/or culture, or the histological demonstration of caseating granulomas in the pleura along with acid fast bacilli (AFB). In high burden settings, however, the diagnosis is frequently inferred in patients who present with a lymphocytic predominant exudate and a high adenosine deaminase (ADA) level, which is a valuable adjunct in the diagnostic evaluation. ADA is generally readily accessible, and together with lymphocyte predominance justifies treatment initiation in patients with a high pre-test probability. Still, false-negative and false-positive results remain an issue. When adding closed pleural biopsy to ADA and lymphocyte count, diagnostic accuracy approaches that of thoracoscopy. The role of other biomarkers is less well described. Early pleural drainage may have a role in selected cases, but more research is required to validate its use and to define the subpopulation that may benefit from such interventions.

Tuberculous Pleural Effusion

When a patient presents with new pleural effusion, the diagnosis of tuberculous (TB) pleuritis should be considered. The patient is at risk for developing pulmonary or extrapulmonary TB if the diagnosis is not made. Between 3% and 25% of patients with TB will have TB pleuritis. The incidence of TB pleuritis is higher in patients who are human immunodeficiency virus (HIV)-positive. Pleural fluid is an exudate that usually has a predominance of lymphocytes. The easiest way to diagnose TB pleuritis in a patient with lymphocytic pleural effusion is to demonstrate a pleural fluid adenosine deaminase level above 40 IU/L. The treatment for TB pleuritis is the same as that for pulmonary TB. Tuberculous empyema is a rare occurrence, and the treatment is difficult.

Tuberculous pleurisy: an update

Tuberculous pleurisy is the most common form of extrapulmonary tuberculosis in Korea. Tuberculous pleurisy presents a diagnostic and therapeutic problem due to the limitations of traditional diagnostic tools. There have been many clinical research works during the past decade. Recent studies have provided new insight into the tuberculous pleurisy, which have a large impact on clinical practice. This review is a general overview of tuberculous pleurisy with a focus on recent findings on the diagnosis and management.

Hypoventilation syndromes

The hypoventilation syndromes represent a variety of disorders that affect central ventilatory control, respiratory mechanics, or both. Obesity hypoventilation syndrome is a clinically important disorder with serious cardiovascular and metabolic consequences if unrecognized. Hypoventilation in asthma and COPD is caused by mechanical challenges imparted by airflow obstruction and increase in dead space. In neuromuscular disease, respiratory muscle weakness results in hypoventilation. Decreases in thoracic volume and limited expansion of the chest highlight the restrictive ventilatory impairments seen in hypoventilation associated with chest wall disorders. Despite the mechanism, effective hypoventilation treatment targets the underlying disease and use of noninvasive ventilation.

[Management of pleural disease]

In view of the presentations in the First National Forum of Trainee Pneumologists, the present article focuses on infectious pleural effusions and on the study of possible markers of malignant disease in asbestos-exposed individuals. The yield of the distinct techniques for the diagnosis of tuberculous pleural effusion is assessed, with emphasis on analysis of sputum and pleural samples (fluid and tissue) for Mycobacteriumtuberculosis. The utility of adenosine deaminase (ADA) (in the absence of empyema, ADA > 70 U/l is diagnostic of tuberculous pleurisy, while values of less than 40 U/l exclude this diagnosis) and interferon gamma in pleural fluid (cut off: 3.7 Ul/ml) is also discussed. The management of complicated parapneumonic pleural effusions is stratified in four categories, depending on the anatomical and morphological (size and eventual presence of loculations), bacteriological (positivity or negativity of pleural fluid culture) and biochemical (pH/glucose) characteristics of the effusion. Finally, recently developed markers for the evaluation and follow-up of asbestos-exposed individuals are described, with special emphasis on serum determination of mesothelin levels, which seem highly promising as a marker of the development of mesothelioma in these cases. A multicenter study currently being performed in Spain found that soluble mesothelin-related protein (SMRP) levels higher than 0.55 nmol/L showed a sensitivity and specificity of 72% for the diagnosis of epithelial malignant mesothelioma.

Update on tuberculous pleural effusion

The possibility of tuberculous pleuritis should be considered in every patient with an undiagnosed pleural effusion, for if this diagnosis is not made the patient will recover only to have a high likelihood of subsequently developing pulmonary or extrapulmonary tuberculosis Between 3% and 25% of patients with tuberculosis will have tuberculous pleuritis. The incidence of pleural tuberculosis is higher in patients who are HIV positive. Tuberculous pleuritis usually presents as an acute illness with fever, cough and pleuritic chest pain. The pleural fluid is an exudate that usually has predominantly lymphocytes. Pleural fluid cultures are positive for Mycobacterium tuberculosis in less than 40% and smears are virtually always negative. The easiest way to establish the diagnosis of tuberculous pleuritis in a patient with a lymphocytic pleural effusion is to generally demonstrate a pleural fluid adenosine deaminase level above 40 U/L. Lymphocytic exudates not due to tuberculosis almost always have adenosine deaminase levels below 40 U/L. Elevated pleural fluid levels of gamma-interferon also are virtually diagnostic of tuberculous pleuritis in patients with lymphocytic exudates. In questionable cases the diagnosis can be established by demonstrating granulomas or organisms on tissue specimens obtained via needle biopsy of the pleura or thoracoscopy. The chemotherapy for tuberculous pleuritis is the same as that for pulmonary tuberculosis.

Factors influencing residual pleural opacity in tuberculous pleural effusion

Tuberculous pleural effusion (TPE) leads to residual pleural opacity (RPO) in a significant proportion of cases. The aim of this study was to investigate which TPE patients would have RPO following the treatment. This study was performed prospectively for a total of 60 TPE patients, who underwent pleural fluid analysis on the initial visit and chest radiographs and computed tomography (CT) scans before and after the administration of antituberculous medication. At the end of antituberculous medication, the incidence of RPO was 68.3% (41/60) on CT with a range of 2-50 mm. Compared with the non-RPO group, the RPO group had a longer symptom duration and lower pleural fluid glucose level. On initial CT, loculation, extrapleural fat proliferation, increased attenuation of extrapleural fat, and pleura-adjacent atelectasis were more frequent, and parietal pleura was thicker in the RPO group compared with the non-RPO group. By multivariate analysis, extrapleural fat proliferation, loculated effusion, and symptom duration were found to be predictors of RPO in TPE. In conclusion, RPO in TPE may be predicted by the clinico-radiologic parameters related to the chronicity of the effusion, such as symptom duration and extrapleural fat proliferation and loculated effusion on CT.

The use of adjunctive corticosteroids in the treatment of pericardial, pleural and meningeal tuberculosis: do they improve outcome?

Tuberculosis remains a major cause of mortality and morbidity on a global scale. Effective anti-tuberculous chemotherapy has improved outcomes for individuals suffering from tuberculosis, although the disease often results in significant and permanent damage to organs. The use of adjunctive corticosteroid treatment has been studied with a view to demonstrating a reduction in inflammatory events that may improve outcomes for both mortality and morbidity. Cochrane reviews have summarized the evidence for adjunctive corticosteroids in the treatment of tuberculous pericarditis, meningitis and pleural effusion. These reviews have shown improved mortality for pericarditis and meningitis, but inconclusive effects for pericardial constriction and ongoing neurological disability. Rapid improvements in clinical parameters for pleural effusion were not supported by any lasting improved outcomes for these patients.

Transforming growth factor beta-1 as a predictor of fibrosis in tuberculous pleurisy

BACKGROUND AND OBJECTIVE

To clarify the influence of transforming growth factor beta-1 (TGF-beta(1)) in the development of pleural thickening in tuberculosis (TB), the levels of TGF-beta(1) in pleural fluid and in serum of patients with pleural TB and transudative effusions were determined.

METHODS

TGF-beta(1) was quantified in 58 pleural fluid and serum samples of patients with TB (n = 50) or transudative effusions (n = 8). Pleural thickening evaluated by high-resolution CT was scored as 0 (<3 mm); 1 (>or=3 and <10 mm) or 2 (>or=10 mm).

RESULTS

The highest pleural fluid TGF-beta(1) levels before treatment for TB were observed in patients with a pleural thickness score of 2. Of the 14 patients with score 1, five regressed to 0, five progressed to 2, and four maintained 1. All 17 patients with score 2 maintained this evaluation. Patients who presented score 1 and progressed to 2 had higher TGF-beta(1) levels than those who maintained the same score or regressed (score 1 or 0). Patients with score 2 (before or after treatment) had higher TGF-beta(1) levels than those with score 0 or 1.

CONCLUSION

Pleural fluid and serum TGF-beta(1) levels were higher in patients with TB, with a correlation between pleural fluid TGF-beta(1) levels before treatment and the degree of pleural thickening. This finding suggests that TGF-beta(1) might be considered as a predictor of pleural thickening in pleural tuberculosis.

Clinical utility of polymerase chain reaction for diagnosis of smear-negative pleural tuberculosis

BACKGROUND

Polymerase chain reaction (PCR) is a molecular biology technique which can detect Mycobacterium tuberculosis (TB) genome in pleural fluid; however, the results are variable.

METHODS

Two hundred and twelve pleural fluid specimens suspected to be possibly associated with tuberculosis with negative acid-fast smears were sent to our laboratory to test for the presence of M. tuberculosis DNA using nested PCR, the target for the amplification being a segment of IS6110 in the genome of M. tuberculosis. The final diagnosis of TB pleurisy was based on combining clinical judgment with radiologic findings, microbiologic tests, and the histopathologic findings. Forty-nine patients were excluded due to incomplete or inconsistent clinical information.

RESULTS

Of 163 patients enrolled, PCR was positive in 23 (43.4%) of 53 patients with TB pleurisy and 5 (4.5%) of 110 patients with non-TB pleurisy, with a sensitivity and specificity of 43.4% and 95.5%, respectively. Positive culture of pleural fluid was found in 15 (28.3%) of the TB pleurisy group and none in the non-TB group. Fifteen (55.6%) of 27 with pleural biopsy demonstrated chronic granulomatous inflammation with or without caseous necrosis. Of these 27 patients, PCR was positive in 12 (44.4%). A higher proportion (70.4%) of patients with TB pleurisy was diagnosed when PCR was combined with biopsy results.

CONCLUSION

These data indicate that PCR alone has limited value in diagnosis of TB pleurisy with negative smear. However, when used in combination with pleural biopsy, it can be used to increase early detection of TB pleurisy in such patients.

Pleural fibrosis

Pleural fibrosis can result from a variety of inflammatory processes. The response of the pleural mesothelial cell to injury and the ability to maintain its integrity are crucial in determining whether normal healing or pleural fibrosis occurs. The pleural mesothelial cell, various cytokines, and disordered fibrin turnover are involved in the pathogenesis of pleural fibrosis. The roles of these mediators in producing pleural fibrosis are examined. This article reviews the most common clinical conditions associated with the development of pleural fibrosis. Fibrothorax and trapped lung are two unique and uncommon consequences of pleural fibrosis. The management of pleural fibrosis, including fibrothorax and trapped lung, is discussed.

Percentage reduction of pleural effusion as a simple predictor of pleural scarring in tuberculous pleuritis

OBJECTIVE

The aim of the present study was to evaluate the utility of serum and pleural fluid biomarkers for predicting residual pleural scarring (RPS) in tuberculous pleuritis.

METHODOLOGY

A retrospective study of patients with pleural tuberculosis was performed. Demographic data, clinical parameters, haematological indices, serum and pleural fluid biochemistry and pleural effusion area were assessed for correlation with the extent of RPS.

RESULTS

RPS was found in 41.4% of the 70 cases evaluated, with significant pleural scarring being present in 7.1%. It was more common in males (odds ratio 5.55). Among the variables studied, only the percentage reduction of the effusion after 2 weeks of treatment was found to independently predict the extent of RPS (r=-0.502, P<0.001).

CONCLUSION

RPS was more common in males and the percentage reduction in pleural effusion on CXR after 2 weeks of treatment was found to be a useful predictor of RPS.

Resolution of Residual Pleural Disease According to Time Course in Tuberculous Pleurisy During and After the Termination of Antituberculosis Medication

STUDY OBJECTIVES

To assess the resolution of pleural disease in patients with tuberculous pleurisy (TP) during and after antituberculosis medication.

DESIGN

An observational, prospective, longitudinal study.

SETTING

University-affiliated general hospital in Seoul, Korea.

PATIENTS AND METHODS

Chest radiographs of 85 adult TP patients were followed up prospectively from diagnosis to 24 months after the start of medication. The extent of pleural disease, synonymous with the radiographic term, pleural opacity (PO), was evaluated at regular intervals according to a size scale. Additionally, following completion of 6 months of therapy, residual PO (RPO) was determined by either measurement of the widest width of the opacity, if loculated, or at the superior level of the hemidiaphragm.

RESULTS

Seventy-seven patients had a PO graded > or = 2 at the initial presentation. At 6, 9, and 24 months, the number of patients with these grades declined. At these time periods, there were 14, 8, and 7 patients, respectively, remaining with this classification. RPO > 10 mm at 24 months was considered indicative of significant residual pleural disease. During the period after 6 months of antituberculosis medication, the number of patients with RPO > or = 10 mm declined from 43 patients at 6 months to 21 patients at 24 months. The presence of loculation on an initial chest decubitus view was associated with significant RPO at 24 months (p = 0.009).

CONCLUSION

In TP patients, improvement of RPO often occurred even after completion of 6 months of antituberculosis medication up to 24 months. A loculated PO at initial presentation, but not initial PO size, was a predictor of significant RPO at 24 months.

[Prognostic factors of clinical outcome of the tuberculous pleural effusion]

BACKGROUND AND OBJECTIVE

To date, no studies have been reported analyzing the prognosis factors related to severe clinical complications in tuberculous pleural effusion (TPE). We studied clinical, biochemical, radiological, and microbiological factors that could help establish the clinical outcome of TPE.

PATIENTS AND METHOD

Retrospective study of > or = 15 years old patients diagnosed of TPE along 9 years. Patients were classified in two groups: a group without complications (NCG), and a group with complications (CG) on the basis of residual pleural thickening (RPT) > or = 10 mm, need of surgery or death.

RESULTS

Sixty six patients were included, mean age 35.3 years, 53% male, 47 in the NCG group and 19 in the CG (1 died, 4 needed surgery, 14 had RPT). The evolution of clinical symptoms was 20.7 days in the NCG and 45.6 in the CG. 94.7% of the CG patients had loculations (23.4% in the NCG). We observed significant differences in the pH (7.34 vs 7.11), glucose (78 vs 30 mg/dl) and lactic dehydrogenase (925 vs 3,235 U/l).

CONCLUSIONS

Severe TPE has similar characteristics to complicated parapneumonic pleural effusion. Loculations, pH < 7.25 and glucose < 50 mg/dl were indicative of a poorly outcome in our study.

Causes and management of pleural fibrosis

The development of pleural fibrosis follows severe pleural space inflammation which is typically associated with an exudative pleural effusion. The response of the mesothelial cell to injury and its ability, along with the basement membrane, to maintain its integrity, is vital in determining whether there is normal healing or pleural fibrosis. The formation of a fibrinous intrapleural matrix is critical to the development of pleural fibrosis. This matrix is the result of disordered fibrin turnover, whereby fibrin formation is up-regulated and fibrin dissolution is down-regulated. Cytokines, such as TGF-beta and TNF-alpha, facilitate the fibrin matrix formation. A complete understanding of the pathogenesis of pleural fibrosis and why abnormal pleural space remodeling occurs in some and not in others, remains unknown. Clinically significant pleural fibrosis requires involvement of the visceral pleura. Isolated parietal pleural fibrosis, as with asbestos pleural plaques, does not cause restriction or respiratory impairment. The causes of visceral pleural fibrosis include asbestos-associated diffuse pleural thickening, coronary bypass graft surgery, pleural infection (including tuberculous pleurisy), drug-induced pleuritis, rheumatoid pleurisy, uraemic pleurisy, and haemothorax. Systemic and intrapleural corticosteroids administered during the initial presentation of rheumatoid pleurisy in small series may decrease the incidence of pleural fibrosis. Several randomised control trials using corticosteroids in tuberculous pleurisy have not shown efficacy in reducing residual pleural fibrosis. Decortication is effective in treating symptomatic patients regardless of the cause of pleural fibrosis as long as chronicity has been documented and significant underlying parenchymal disease has been excluded.

The management of pleural space infections

Pleural infection is responsible for significant morbidity and mortality worldwide, and its clinical management is challenging. The diagnosis of empyema and tuberculous pleurisy may be difficult, and these conditions may be confused with other causes of exudative pleural effusions. Complicated parapneumonic effusion or empyema may present with 'atypical' clinical features; delays in diagnosis are common and may contribute to the high mortality of these infections. Pleural aspiration is the key diagnostic step; pleural fluid that is purulent or that has a pH < 7.2, or organisms on Gram stain or culture, is an indication for formal intercostal drainage. In order to achieve a definitive diagnosis of tuberculous pleurisy, Mycobacterium tuberculosis must be isolated in the culture of pleural fluid, pleural tissue or sputum; demonstration of granulomas in pleural tissue is also suggestive of tuberculosis. The use of pleural fluid biochemical markers, such as adenosine deaminase, in the diagnosis of tuberculous pleurisy varies among clinicians; the diagnostic value of such markers is affected by the background prevalence of tuberculosis and the likelihood of an alternative diagnosis. Uncertainties also remain regarding the treatment of pleural infection. Treatment of complicated parapneumonic effusion and empyema involves prolonged courses of antibiotics and attention to the patient's nutritional state. The role of intrapleural fibrinolytics and the optimal timing of surgical intervention are unknown. The lack of clear predictors of clinical outcome in empyema contributes to the difficulty in treating this condition. The pharmacological treatment of tuberculous pleurisy is the same as for pulmonary tuberculosis; the precise role of steroids in the treatment of tuberculous pleurisy remains uncertain.

Comparison of Six Biological Markers for the Diagnosis of Tuberculous Pleuritis

STUDY OBJECTIVE

We sought a marker to differentiate tuberculous pleural effusions from nontuberculous pleural effusions, which otherwise can be difficult.

PATIENTS

We studied 55 patients with pleural effusions, 20 (36%) with tuberculous pleuritis and 35 (64%) with a nontuberculous etiology.

MEASUREMENTS AND RESULTS

Pleural fluid levels of adenosine deaminase, interferon (INF)-gamma, interleukin (IL)-12p40, IL-18, immunosuppressive acidic protein, and soluble IL-2 receptors were measured and were subjected to receiver operating characteristic analysis. INF-gamma had the greatest sensitivity and specificity for tuberculous pleuritis among the six biological markers studied.

CONCLUSION

The determination of INF-gamma levels in pleural fluid is the most informative in the diagnosis of tuberculous effusion.

Transforming growth factor beta-1 level in pleural effusion

OBJECTIVE

Transforming growth factor-beta1 is an important immunomodulator. The diagnostic role of TGF-beta1 has not been systematically investigated in pleural effusion.

METHODOLOGY

A prospective clinical study of 45 patients (23 men, 22 women; mean age 49 +/- 21 years) with pleural effusion was performed. Of these patients, 19 had malignant pleural effusion, 14 had tuberculous pleural effusion, seven had empyema/parapneumonic pleural effusion, and five had transudative pleural effusion due to congestive heart failure. The concentrations of TGF-beta1 were measured by ELISA in all pleural fluid samples and in serum samples only from patients with malignant and tuberculous pleural effusions.

RESULTS

The median TGF-beta1 levels of malignant, tuberculous and empyema/parapneumonic pleural effusions were 7.25 ng/mL, 7.81 ng/mL, and 9.75 ng/mL, respectively. There was no significant difference between them. The median TGF-beta1 level was 5.62 ng/mL in the transudate pleural effusion group and it was significantly lower than that in the empyema/parapneumonic group (P < 0.05). The pleural fluid TGF-beta1 levels did not correlate with cell profiles of the pleural fluid. The median serum TGF-beta1 levels in malignant and tuberculous pleural effusion groups were 7.38 ng/mL and 7.38 ng/mL, respectively. There was no significant difference between the levels of TGF-beta1 in paired samples of serum and pleural fluid.

CONCLUSIONS

This study shows that TGF-beta1 concentrations in exudative pleural effusions are higher than those in transudative effusions secondary to congestive heart failure but TGF-beta1 concentrations do not assist in differentiating exudative effusions.

Functional sequelae of tuberculous pleurisy in patients correctly treated

STUDY OBJECTIVES

To assess the functional sequelae (FS) of patients with tuberculous pleurisy (TP), to analyze the influence of different factors in the occurrence of these FS, and, finally, to evaluate the relationship between the FS and roentgenographic sequelae.

DESIGN

An observational, retrospective study.

SETTING

A community teaching hospital in Alicante, Spain.

PATIENTS AND METHODS

From April 1986 to July 2000, all patients with a firmly established diagnosis of TP, who had been functionally studied at the end of follow-up, were included in the study. A diagnosis of TP was considered to be definitive when the presence of granuloma on a pleural biopsy specimen was demonstrated or when a culture was positive for Mycobacterium tuberculosis in pleural fluid (PF) or tissue. The general characteristics of the study population and PF were compared in patients with or without restrictive FS (ie, FVC or TLC < 80%), looking for risk factors for developing this complication.

RESULTS

Eighty-one of 150 patients who had been treated for TP were eligible for the study. At the end of follow-up, eight patients (10%) had a restrictive FS. These patients had a lower PF lactate dehydrogenase concentration (p < 0.001), a higher PF concentration of cholesterol (p < 0.03) and triglycerides (p < 0.03), and a higher percentage of lymphocytes (p < 0.04). A weak correlation was found between the FVC and the intensity of radiographic pleural thickening (r = - 0.298; p < 0.01).

CONCLUSIONS

The FS in patients with TP is restrictive in type, infrequent, and usually mild. A higher PF lipid content or a more chronic inflammatory pleural reaction at diagnosis appear to be risk factors for developing a FS. The correlation between FS and roentgenographic sequelae is poor.

Diagnostic significance of interferon-gamma in tuberculous pleural effusions

STUDY OBJECTIVES

Tuberculosis (TB), the single most frequent infectious cause of death worldwide, also is a major cause of pleural effusion, which in TB usually has lymphocytic and exudative characteristics. Differential diagnosis between TB and nontuberculous pleural effusion can be sometimes difficult, representing a critically important clinical problem.

METHODS

We studied 46 patients presenting with pleural effusion to the National Sanyo Hospital between April 2000 and January 2001 (34 men and 12 women; mean age, 64 years). Ten patients (22%) had tuberculous pleurisy, 19 patients (41%) had malignant pleuritis, and 17 patients (37%) had pleural effusion due to an etiology other than tuberculosis or cancer. Pleural fluid concentrations of four suggested markers were measured using commercially available kits.

RESULTS

The pleural fluid levels (mean +/- SE) of adenosine deaminase (83.3 +/- 18.2 U/L vs 25.8 +/- 20.4 U/L, p < 0.0001), interferon-gamma (137 +/- 230 IU/mL vs 0.41 +/- 0.05 IU/mL, p < 0.0001), immunosuppressive acidic protein (741 +/- 213 micro g/mL vs 445 +/- 180 micro g/mL, p < 0.001) and soluble interleukin 2 receptor (7,618 +/- 3,662 U/mL vs 2,222 +/- 1,027 U/mL, p < 0.0001) were significantly higher for tuberculous pleuritis than for other causes of effusion. Receiver operating characteristic analysis demonstrated that pleural fluid content INF-gamma was the best indicator of tuberculous pleurisy among four relevant biological markers.

CONCLUSIONS

INF-gamma in pleural fluid is the most sensitive and specific among four biological markers for tuberculous pleuritis. Thus, our results suggest that determination of INF-gamma at the onset of pleural effusion is informative for the diagnosis of tuberculous pleuritis. Further studies including larger numbers of patients are needed to verify this result.

Pigtail drainage in the treatment of tuberculous pleural effusions: a randomised study

BACKGROUND

Tuberculous pleurisy can result in obvious clinical symptoms, pleural fibrosis, and pleural thickening. Some studies of tuberculous pleurisy have suggested that symptomatic improvement and minimisation of sequelae can be achieved by completely draining the effusion during treatment, although the results have not been conclusive.

METHODS

Sixty one patients with tuberculous pleurisy were divided into two groups; 30 patients received pigtail drainage combined with antituberculosis (TB) drug treatment and 31 received only anti-TB drugs. Outcome measurements were assessed for a period of 24 weeks after treatment and included symptom scores and the incidence of residual pleural thickening (RPT).

RESULTS

Although the duration of dyspnoea was significantly shortened by the use of pigtail drainage (median 4 days (IQR 4-5) v 8 days (IQR 7-16), p<0.001), a comparison of combined mean (SD) visual analogue scale (VAS) scores showed no significant difference between the groups after one week of treatment (57.1 (33.2) v 68.5 (44.7) or at any time during the follow up period. The incidence of RPT of more than 10 mm in the group treated with pigtail drainage and anti-TB drugs was 26% compared with 28% in the group receiving drug treatment only. The incidence of RPT levels of more than 2 mm in the two groups was 50% and 51%, respectively. No statistical difference between the two groups in terms of forced vital capacity was found at the end of treatment (median (IQR) 85.5% (69-94) of predicted v 88% (78-96) of predicted).

CONCLUSION

The addition of pigtail drainage to an effective anti-TB regimen is not clinically relevant and does not reduce the level of RPT.

[Pleural thickening and tuberculous effusion: searching for predictive data]

Tuberculosis is a very common disease usualy related to bad social-economic conditions and sometimes with associated pleural effusion. Pleural sequelae are referred by some authors as a consequence that may interfere with lung function provoking respiratory failure in some critical situations. Some experts try to find clinical and biochemical parameters in order to detect possibilities that could predict future pleural thickening and necessity of closer vigilance to avoid lung function disability. This study is based on the post-treatment roentgenological pleural findings and their correlation with the initial pleural fluid biochemical data, the volume of the effusions and time of patients complains.

Closed pleural needle biopsy: predicting diagnostic yield by examining pleural fluid parameters

OBJECTIVE

Pleural fluid parameters that predict a diagnostic closed pleural needle biopsy were investigated.

DESIGN

A retrospective analysis.

SETTING

The Institute of Pulmonology, Hadassah University Hospital.

PATIENTS AND METHODS

Forty-four patients who underwent closed pleural needle biopsies were included in this study. Pleural fluid values of protein, glucose, lactate dehydrogenase (LDH), pH, and white blood cell count with differential cell counts, from patients with diagnostic and non-diagnostic pleural biopsies were compared.

RESULTS

Thirteen patients (29%) had diagnostic biopsies. Malignancy was identified in 10 patients (23%), of whom 70% had adenocarcinoma. Three other patients had non-malignant specific diagnosis. LDH levels in pleural fluid from patients with diagnostic pleural biopsy were higher than in patients with non-diagnostic pleural biopsies (1436 +/- 333 U l(-1) vs. 775 +/- 109 U l(-1); P < 0.05). LDH levels less than 510 U l(-1) were highly predictive of a negative biopsy (negative predictive value of 86.6%). Follow up revealed malignancy including mesothelioma and lymphoma, in 10 of 30 (33%) patients with non-diagnostic biopsies, and one patient died of unrelated cause, while the pleural effusion either resolved, remained stable or an alternative benign process was identified in 19 patients (63%).

CONCLUSIONS

Low levels of LDH (< 510 U l(-1)) were highly predictive of a negative pleural needle biopsy. Thus, LDH may serve as a useful guide in deciding whether to perform closed pleural biopsy or to proceed to thoracoscopically guided biopsy.

Evaluation of polymerase chain reaction, adenosine deaminase, and interferon-gamma in pleural fluid for the differential diagnosis of pleural tuberculosis

STUDY OBJECTIVES

Pleural tuberculosis (TB) is a diagnostic challenge because of its nonspecific clinical presentation and paucibacillary nature. The inefficiency of conventional laboratory methods and the reliance on pleural biopsy have motivated the evaluation of alternative diagnostic strategies. We have evaluated polymerase chain reaction (PCR) directed to the IS6110 sequence of Mycobacterium tuberculosis, the determination of adenosine deaminase (ADA) activity, and measurement of interferon (IFN)-gamma levels in pleural fluid in the diagnosis of pleural TB.

PATIENTS

ADA activity, IFN-gamma levels, and PCR were evaluated in 140 cases of pleural effusion, 42 with confirmed pleural TB, 19 with probable pleural TB, 70 with a nontuberculous etiology, and 9 having an undetermined etiology.

RESULTS

ADA activity, IFN-gamma levels, and PCR were 88%, 85.7%, and 73.8% sensitive, respectively, and 85.7%, 97.1%, and 90% specific, respectively, for pleural TB that had been confirmed by either culture or pleural biopsy specimens. The combination of PCR, IFN-gamma measurement, and ADA activity determination allowed the selective increase of sensitivity and specificity for probable and confirmed cases compared to individual methods. Positive and negative predictive values for these individual or combined methods were maintained over a wide range of prevalence of pleural TB in the patient population presenting with pleural effusions. Fever and younger age were associated with tuberculous pleural effusion (p < 0. 0001), while blood in sputum and older age were associated with malignant etiology (p < 0.008).

CONCLUSIONS

These clinical variables together with the use of ADA activity determination, PCR, and measurement of IFN-gamma levels provide the basis for the rapid and efficient diagnosis of pleural TB in different clinical settings.

[Residual pleural thickening in tuberculous pleuritis. Associated factors]]

BACKGROUND

To study the factors related to the development of residual pleural thickening in pleural tuberculosis.

PATIENTS AND METHODS

We studied 39 patients with tuberculous pleural effusion. A chest X-ray was taken of each patient at the end of treatment. The patients' medical histories, pleural fluid findings and diagnostic chest films were evaluated. Residual pleural thickening was defined as thickening that was visibly greater than 2 mm in the lower side portion of the chest film.

RESULTS

Residual pleural thickening developed in 26% of patients and was found mainly in men (RR = 3.86). In no patients with Löwenstein-Jensen cultures positive for Mycobacterium tuberculosis did pleural complications develop.

CONCLUSION

Residual pleural thickening is a common complication of tuberculous pleural effusion. Residual pleural thickening in tuberculous pleurisy occurs more often in men and older patients, and in cases in which pleural liquid culture is negative for M. tuberculosis.

Proinflammatory cytokines and fibrinolytic enzymes in tuberculous and malignant pleural effusions

OBJECTIVES

To measure tumor necrosis factor-alpha (TNF-alpha) and interleukin-1beta (IL-1beta) in pleural effusions caused by tuberculosis (TB) and malignancy and their relationship with plasminogen activator inhibitor type I (PAI-1) and tissue type plasminogen activator (tPA), and to compare the differences between tuberculous and malignant pleural effusions. In addition, the relationship between the effusion levels of these parameters and the development of residual pleural thickening was evaluated in the patients with tuberculous pleurisy.

DESIGN

Prospective study.

MATERIALS AND METHODS

TNF-alpha, IL-1beta, PAI-1, and tPA were measured simultaneously in blood and pleural fluid using an enzyme-linked immunosorbent assay in 33 patients with tuberculous and in 30 patients with malignant pleural effusions. Residual pleural thickening was measured and defined as a pleural thickness of >/= 10 mm found on chest radiographs at the completion of anti-TB chemotherapy in tuberculous pleurisy patients.

RESULTS

In both groups, the levels of proinflammatory cytokines and fibrinolytic enzymes were significantly higher in pleural fluid than in blood. The levels of TNF-alpha and PAI-1 were significantly higher in tuberculous than in malignant effusions. In contrast, malignant pleural fluid had significantly higher values of tPA than did tuberculous pleural fluid. In tuberculous effusions, the values of PAI-1 and the PAI-1/tPA ratio correlated positively and the levels of tPA correlated negatively with those of TNF-alpha and IL-1beta. In malignant pleural fluid, positive correlations were found between the values of proinflammatory cytokines (TNF-alpha and IL-1beta) and PAI-1. Residual pleural thickening was found in 9 of 33 patients (27. 3%) with tuberculous pleurisy. The pleural fluid values of TNF-alpha, IL-1beta, and PAI-1 were significantly higher and the concentrations of tPA were significantly lower in tuberculous pleurisy patients with residual pleural thickening.

CONCLUSIONS

Compared to malignant pleural effusion, fibrinolytic activity in pleural fluid was reduced in tuberculous effusion. Pleural inflammation caused by TB may enhance the release of proinflammatory cytokines, particularly TNF-alpha, which subsequently may increase PAI-1 and decrease tPA in pleural fluid. The imbalance of PAI-1 and tPA in pleural space may lead to fibrin deposition and pleural thickening.

[Prognostic features of residual pleural thickening in metapneumonic pleural effusion]

Residual pleural thickening (RPT) develops in some patients after metapneumonic pleural effusion (MPE). Our aim was to identify factors that predict the development of RPT by retrospectively analyzing patients with MPE secondary to bacterial pneumonia in our practice from 1992 through April 1997. Patients were assigned to groups based on the presence or not of RPT (> 10 mm) three months or more after diagnosis of MPE. One hundred twenty-eight patients were included in the analysis. Seventy-nine patients (62%) developed RPT and 49 (38%) did not. Patients with RPT had significantly lower glucose levels and pH and higher LDH levels in pleural fluid. A higher percentage of patients with RPT had loculate pleural effusions and empyema, and they more often required insertion of drains. Logistic regression analysis showed that only glucose < 40 mg/dl (OR: 3.4; CI 95%: 2.3 to 4.5; p < 0.05) and the presence of pus collected from the initial thoracocentesis (OR: 3.6; CI 95%: 2.6 to 4.5; p < 0.01) were significantly associated with increased risk of developing residual pachypleuritis in subjects with MPE.