Pleural tuberculosis in the United States: incidence and drug resistance

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.

Recruitment of IL-27-Producing CD4(+) T Cells and Effect of IL-27 on Pleural Mesothelial Cells in Tuberculous Pleurisy

BACKGROUND

The numbers of IL-27-producing CD4(+) T cells and the concentration of soluble IL-27 have been found to be increased in tuberculous pleural effusion (TPE). The objective of the present study was to explore the mechanism by which IL-27(+)CD4(+) T cells are recruited into the pleural space, and to explore the impact of IL-27 on pleural mesothelial cells (PMCs).

METHODS

The expression profiles of chemokine receptor (CCR) were determined by flow cytometry. The chemoattractant activity of chemokines CCL20 and CCL22 for IL-27(+)CD4(+) T cells in vitro was observed. Effects of IL-27 on wound healing, proliferation and apoptosis of PMCs were also investigated.

RESULTS

IL-27(+)CD4(+) T cells in TPE expressed high level of CCR6, medium level of CCR4, and low levels of CCR2, CCR3, CCR5, CCR7, CCR10, and CXCR3. Recruitment of IL-27(+)CD4(+) T cells into TPE could be induced by pleural CCL20 and CCL22. By activating STAT3 signaling, IL-27 significantly improved wound healing and promoted proliferation of PMCs, and completely prevented apoptosis of PMCs induced by IFN-γ.

CONCLUSIONS

After being recruited into pleural space by CCL20 or/and CCL22, these pleural IL-27-producing CD4(+) T cells may play important roles in tuberculosis immunity by affecting PMC functions.

High IL-35 pleural expression in patients with tuberculous pleural effusion

Background

IL-35 is a novel anti-inflammatory and immunosuppressive cytokine primarily produced by Treg cells, and is involved in inflammatory diseases and autoimmune diseases. However, its roles in tuberculous pleural effusion (TPE) remain unknown. We aimed to investigate the potential involvement of IL-35 in TPE.

Material/Methods

Thirty TPE patients and 20 lung cancer patients with malignant pleural effusion (MPE) were recruited. Samples of pleural effusion (100 mL) were collected after traditional pleurocentesis. Blood was sampled from TPE patients. Mononuclear cells were isolated by Ficoll-Hypaque gradient. Proportions of Th1, Th17, and IL-35-producing cells were analyzed by flow cytometry. IL-35 was assessed by real-time RT-PCR, ELISA, and immunofluorescence. An ELISPOT assay was used to assess the effect of IL-35 on pleural effusion mononuclear cells (PEMCs).

Results

Proportions of IL-35-producing cells were higher in TPE compared with MPE (49.4±6.0 vs. 15.8±5.4%, P<0.001) and blood from TPE patients (49.4±6.0% vs. 16.6±3.1, P<0.001). IL-35, IL-17 and IFN-γ were elevated in TPE compared with MPE (all P<0.01). ELISPOT assay showed that IL-35 reduced the proportion of IFN-γ-producing CD4⁺ T cells in TPE. IL-35 mRNA expression was higher in TPE compared with MPE (P<0.001). Immunofluorescence showed that IL-35-positive cells were present in pleural tissues from TPE patients.

Conclusions

Results suggest that there is an imbalance in IL-35 metabolism in TPE. However, further studies are required to assess the exact relationship with the immune system response to tuberculosis. IL-35 might play a role in TPE and might be targeted as a treatment for TPE.

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.

Large pleural nodules secondary to Mycobacterium tuberculosis

Mycobacterium tuberculosis disease is a common disease worldwide. Pleural visualization, however, is usually not required as the diagnosis can typically be made by less invasive methods. Thoracoscopic visualization typically reveals pleural erythema and studding with numerous small pleural tubercules and adhesions. We present images from a patient with less commonly seen large pleural nodules and plaques resulting from tuberculous pleuritis.

Medical Thoracoscopy vs Closed Pleural Biopsy in Pleural Effusions: A Randomized Controlled Study

BACKGROUND

Pleural effusion is a common diagnostic dilemma for the pulmonologist. A histological diagnosis would many a time steer the way to an accurate diagnosis of the aetiologies of pleural effusions. This study has compared two methods for obtaining histological specimens in cases of undiagnosed pleural effusions.

AIM

To compare the efficacy of closed pleural biopsy with Abrahm's needle and medical thoracoscopic biopsy in the diagnosis of undiagnosed exudative pleural effusions at a tertiary care setting.

STUDY DESIGN

Randomized controlled study.

STUDY PERIOD

November 2008-October 2010.

METHODOLOGY

All patients who were admitted with pleural effusions underwent a clinical workup for pleural effusions. Light's criterion was used to differentiate between exudative and transudative pleural effusions. Those patients with exudative pleural effusions, who did not have a specific diagnosis, were included in the study. Fifty eight patients were included in the study and they were randomized into 2 Groups of 29 patients each. One group was subjected to medical thoracoscopic pleural biopsy and the other to closed pleural biopsy with Abrahm's needle. Demographic, clinical and biochemical characteristics, diagnostic yields and the complications among the two groups were compared.

RESULT

Medical thoracoscopy has a diagnostic yield of 86.2% with complication rate of 10.3% compared to 62.1% and 17.2% respectively in closed pleural biopsy group.

CONCLUSION

Medical thoracoscopic pleural biopsy had a better diagnostic yield with a lower complication rate as compared to closed pleural biopsy with Abrahm's needle.

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.

Tuberculous pleural effusion

Tuberculous pleural effusion (TBPE) is the most common form of extrapulmonary tuberculosis (TB) in Spain, and is one of the most frequent causes of pleural effusion. Although the incidence has steadily declined (4.8 cases/100,000population in 2009), the percentage of TBPE remains steady with respect to the total number of TB cases (14.3%-19.3%). Almost two thirds are men, more than 60% are aged between 15-44years, and it is more common in patients with human immunodeficiency virus. The pathogenesis is usually a delayed hypersensitivity reaction. Symptoms vary depending on the population (more acute in young people and more prolonged in the elderly). The effusion is almost invariably a unilateral exudate (according to Light's criteria), more often on the right side, and the tuberculin test is negative in one third of cases. There are limitations in making a definitive diagnosis, so various pleural fluid biomarkers have been used for this. The combination of adenosine deaminase and lymphocyte percentage may be useful in this respect. Treatment is the same as for any TB. The addition of corticosteroids is not advisable, and chest drainage could help to improve symptoms more rapidly in large effusions.

Different subsets of macrophages in patients with new onset tuberculous pleural effusion

OBJECTIVE

Macrophages are the infiltrate components of tuberculous pleural effusion (TPE). This study is aimed at examining the role of different subsets of macrophages in pleural fluid (PF) and peripheral blood (PB) from patients with new onset TPE.

METHODS

The numbers of PB and PF CD163(+), CD206(+) and CD115(+) macrophages in 25 patients with new onset TPE and 17 healthy controls (HC) were determined by flow cytometry. The concentrations of serum and PF cytokines were determined by cytometric bead array (CBA) and enzyme-linked immunosorbentassay (ELISA). The potential association between the numbers of different subsets of macrophages and the values of clinical measures in TPE patients were analyzed.

RESULTS

The numbers of PB CD14(+)CD163(-) M1-like and CD14(+)CD163(-) interleukin (IL)-12(+) M1 macrophages were significantly higher than that in the HC, but lower than PF, and the numbers of PF CD14(+)CD163(+), CD14(+)CD163(+)CD206(+), CD14(+)CD163(+)CDll5(+) M2-like, and CD14(+)CD163(+)IL-10(+) M2 macrophages were less than PB in the TPE patients. The levels of serum IL-1, IL-6, IL-8, IL-12, tumor growth factor (TGF)-β1, and tumor necrosis factor (TNF)-α in the TPE patients were significantly higher than that in the HC, but lower than that in the PF. The levels of PF IL-10 were significantly higher than that in the PB of patients and HC. In addition, the levels of serum IL-12 and TNF-α were correlated positively with the values of erythrocyte sedimentation rate (ESR) and the numbers of ESAT-6- and culture filtrate protein 10 (CFP-10)-specific IFN-γ-secreting T cells, and the levels of PF TNF-α were correlated positively with the levels of PF adenosine deaminase (ADA) and lactate dehydrogenase (LDH) in those patients.

CONCLUSION

Our data indicate that Mycobacterium tuberculosis (M. tb) infection induces M1 predominant pro-inflammatory responses, contributing to the development of TPE in humans.

Role of blind closed pleural biopsy in the managment of pleural exudates

INTRODUCTION

The performance of blind closed pleural biopsy (BCPB) in the study of pleural exudates is controversial.

OBJECTIVE

To assess the diagnostic yield of BCPB in clinical practice and its role in the study of pleural exudates.

METHODS

Data were retrospectively collected on all patients who underwent BCPB performed between January 1999 and December 2011.

RESULTS

A total of 658 BCPBs were performed on 575 patients. Pleural tissue was obtained in 590 (89.7%) of the biopsies. A malignant pleural effusion was found in 35% of patients. The cytology and the BCPB were positive in 69.2% and 59.2% of the patients, respectively. Of the patients with negative cytology, 21 had a positive BCPB (diagnostic improvement, 15%), which would have avoided one pleuroscopy for every seven BCPBs that were performed. Of the 113 patients with a tuberculous effusion, granulomas were observed in 87 and the Lowenstein culture was positive in an additional 17 (sensitivity 92%). The overall sensitivity was 33.9%, with a specificity and positive predictive value of 100%, and a negative predictive value of 71%. Complications were recorded in 14.4% of patients (pneumothorax 9.4%; chest pain 5.6%; vasovagal reaction, 4.1%; biopsy of another organ 0.5%).

CONCLUSIONS

BCPB still has a significant role in the study of a pleural exudate. If an image-guided technique is unavailable, it seems reasonable to perform BCPB before resorting to a pleuroscopy. These results support BCPB as a relatively safe technique.

Diagnostic value of interleukin 21 and carcinoembryonic antigen levels in malignant pleural effusions

The aim of this study was to evaluate the diagnostic value of interleukin 21 (IL-21) and carcinoembryonic antigen (CEA) in tuberculous pleural effusions (TPEs) and malignant pleural effusions (MPEs). Pleural effusion samples from 103 patients were classified on the basis of diagnosis as TPE (n=51) and MPE (n=52). The concentration of IL-21 was determined by ELISA. Lactate dehydrogenase (LDH), adenosine dehydrogenase (ADA) and CEA levels were also determined in all patients. A significant difference was observed in the levels of ADA and CEA (P<0.01), but not in the levels of LDH (P>0.05) between TPE and MPE. The concentration of IL-21 in MPE was significantly higher compared to TPE (P<0.01). With a threshold value of 4.32 pg/ml, IL-21 had a sensitivity of 76.9% (40/52) and a specificity of 80.4% (41/51). Combined detection of IL-21 and CEA had a sensitivity of 69.2% (36/52) and a specificity of 92.2% (47/51). These two markers can contribute to the differential diagnosis of MPEs.

Induction of CCL8/MCP-2 by mycobacteria through the activation of TLR2/PI3K/Akt signaling pathway

Pleural tuberculosis (TB), together with lymphatic TB, constitutes more than half of all extrapulmonary cases. Pleural effusions (PEs) in TB are representative of lymphocytic PEs which are dominated by T cells. However, the mechanism underlying T lymphocytes homing and accumulation in PEs is still incompletely understood. Here we performed a comparative analysis of cytokine abundance in PEs from TB patients and non-TB patients by protein array analysis and observed that MCP-2/CCL8 is highly expressed in the TB-PEs as compared to peripheral blood. Meanwhile, we observed that CCR5, the primary receptor used by MCP-2/CCL8, is mostly expressed on pleural CD4⁺ T lymphocytes. Furthermore, we found that infection with either Mycobacterium bovis Bacillus Calmette-Guérin (BCG) or Mycobacterium tuberculosis H37Rv induced production of MCP-2/CCL8 at both transcriptional and protein level in Raw264.7 and THP-1 macrophage cells, mouse peritoneal macrophages as well as human PBMC monocyte-derived macrophages (MDMs). The induction of MCP-2/CCL8 by mycobacteria is dependent on the activation of TLR2/PI3K/Akt and p38 signaling pathway. We conclude that accumulation of MCP-2/CCL8 in TB-PEs may function as a biomarker for TB diagnosis.

Extensive fibrosis caused by Pleural Tuberculosis: a lesson from a case without post-exposure-prophylaxis

We report the case of a 9-year-old boy with extensive pleural fibrosis and contraction of the affected hemithorax secondary to pleural tuberculosis (TB), who was successfully treated with a 6 months course of the standard WHO regimen. Although well described for the adult population, this complication is rare among children and to our knowledge, no such case has been described since the widespread introduction of antitubercular therapy in the 1950s. This case underscores the importance of appropriate follow-up and administration of chemoprophylaxis after TB exposure.

Association between elevated pleural interleukin-33 levels and tuberculous pleurisy

Background

Interferon-γ (IFN-γ) plays a crucial role in Mycobacterium tuberculosis induced pleural responses. Interleukin (IL)-33 up-regulates the production of IFN-γ. We aimed to identify whether an association between pleural IL-33 levels and tuberculous pleurisy exists and determine its diagnostic value.

Methods

Pleural IL-33, ST2 (a receptor of IL-33), adenosine deaminase (ADA), and IFN-γ, as well as serum IL-33 and ST2 were measured in 220 patients with pleural effusions (PEs). Patients with malignant (MPEs), parapneumonic (PPEs), tuberculous (TPEs), and cardiogenic (CPEs) pleural effusions were included.

Results

Pleural and serum IL-33 levels were highest or tended to be higher in patients with TPEs than in those with other types of PEs. The median pleural fluid-to-serum IL-33 ratio was higher in TPE cases (≥ 0.91) than in other PE cases (≤ 0.56). Pleural IL-33 levels correlated with those of pleural ADA and IFN-γ. However, the diagnostic accuracies of pleural IL-33 (0.74) and pleural fluid-to-serum IL-33 ratio (0.75) were lower than that of ADA (0.95) or IFN-γ (0.97). Pleural ST2 levels in patients with MPEs were higher than in patients with TPEs. Serum ST2 levels did not differ among the groups.

Conclusions

We identified an association between elevated pleural IL-33 levels and tuberculous pleurisy. However, we recommend conventional pleural markers (ADA or IFN-γ) as diagnostic markers of TPE.

Recent epidemiological trends in tuberculous pleural effusion in Galicia, Spain

OBJECTIVE

Knowledge on the distribution and determinants of tuberculous pleural effusions (TBPE) is incomplete. We aimed to describe the epidemiological trends and individual characteristics of TBPE in Galicia, Spain, over a 10-year period (2000-2009).

DESIGN

A retrospective, observational study based on epidemiological data obtained from the Galician Tuberculosis Register.

RESULTS

There were 1835 cases of TBPE (16.3% of the total 11,241 TB cases reported). The number and incidence of TBPE decreased significantly during the study period, from (262 and 9.6/100,000 inhabitants in 2000, to 133 and 4.8 in 2009, respectively; P<.001 for both). The mean annual decrease in TBPE incidence was 6.9%, and 50% overall. TBPE mainly affected males (63.5%), precisely 61.2% young males between 15 and 44 years. Twenty-five percent had lung involvement (chest X-ray), and 41.7% had a positive sputum culture. A significant increase (P<.001) was observed during the study in the percentage of patients who had more TB risk factors.

CONCLUSIONS

The incidence of TBPE decreased significantly during the study period, with no changes in epidemiological characteristics, and with trends similar to the total number of TB cases. The introduction of the Galician Prevention and Control Plan (GPCP) for tuberculosis appears to be effective for better control of TB.

Pleural tuberculosis: is radiological evidence of pulmonary-associated disease related to the exacerbation of the inflammatory response?

OBJECTIVE

Pleural tuberculosis is the most frequently occurring form of extra pulmonary disease in adults. In up to 40% of cases, the lung parenchyma is concomitantly involved, which can have an epidemiological impact. This study aims to evaluate the pleural and systemic inflammatory response of patients with pleural or pleuropulmonary tuberculosis.

METHODS

A prospective study of 39 patients with confirmed pleural tuberculosis. After thoracentesis, a high resolution chest tomography was performed to evaluate the pulmonary involvement. Of the 39 patients, 20 exhibited only pleural effusion, and high resolution chest tomography revealed active associated-pulmonary disease in 19 patients. The total protein, lactic dehydrogenase, adenosine deaminase, vascular endothelial growth factor, interleukin-8, tumor necrosis factor-α, and transforming growth factor-β(1) levels were quantified in the patient serum and pleural fluid.

RESULTS

All of the effusions were exudates with high levels of adenosine deaminase. The levels of vascular endothelial growth factor and transforming growth factor-β(1) were increased in the blood and pleural fluid of all of the patients with pleural tuberculosis, with no differences between the two forms of tuberculosis. The tumor necrosis factor-α levels were significantly higher in the pleural fluid of the patients with the pleuropulmonary form of tuberculosis. The interleukin-8 levels were high in the pleural fluid of all of the patients, without any differences between the forms of tuberculosis.

CONCLUSION

Tumor necrosis factor-α was the single cytokine that significantly increased in the pleural fluid of the patients with pulmonary involvement. However, an overlap in the results does not permit us to suggest that cytokine is a biological marker of concomitant parenchymal involvement. Although high resolution chest tomography can be useful in identifying these patients, the investigation of fast acid bacilli and cultures for M. tuberculosis in the sputum is recommended for all patients who are diagnosed with pleural tuberculosis.

Amplified Mycobacterium tuberculosis direct test for diagnosing tuberculous pleurisy--a diagnostic accuracy study

BACKGROUND

The study was designed to investigate the clinical usefulness of Amplified Mycobacterium Tuberculosis Direct (AMTD) tests for diagnosing TB pleurisy.

METHODS

One hundred and fifty-two patients for whom the exclusion of tuberculous pleural effusion was necessary were retrospectively analyzed.

RESULTS

The sensitivity of AMTD in diagnosing pleural TB was 36.4% (20 of 55). Combining sputum and pleural effusion AFB smear, pleural biopsy, and AMTD test of pleural effusion increased sensitivity to 82.5% (33/40). There were significantly higher percentages of neutrophils in the pleural effusion in the positive than in the negative AMTD group (38.0 ± 6.7% vs. 11.1 ± 3.7%, p<0.001). Patients with symptom duration <18 days prior to pleural effusion studies had more positive AMTD tests than those with symptom >18 days (70% vs. 31.4%; OR 5.09; 95% CI 1.54-16.79; p = 0.011).

CONCLUSIONS

Combining AMTD tests with conventional diagnostic methods offer good sensitivity for pleural TB diagnosis. Patients in the early course of the disease are better candidates for AMTD tests.

Diagnostic accuracy of adenosine deaminase and lymphocyte proportion in pleural fluid for tuberculous pleurisy in different prevalence scenarios

Background

Tuberculous pleural effusion (TPE) is a paucibacillary manifestation of tuberculosis, so isolation of Mycobacterium tuberculosis is difficult, biomarkers being an alternative for diagnosis. Adenosine deaminase (ADA) is the most cost-effective pleural fluid marker and is routinely used in high prevalence settings, whereas its value is questioned in areas with low prevalence. The lymphocyte proportion (LP) is known to increase the specificity of ADA for this diagnosis. We analyse the diagnostic usefulness of ADA alone and the combination of ADA ≥40 U/l (ADA₄₀) and LP≥50% (LP₅₀) in three different prevalence scenarios over 11 years in our area.

Materials and Methods

Biochemistry, cytology and microbiology studies from 472 consecutive pleural fluid samples were retrospectively analyzed. ADA and differential cell count were determined in all samples. We established three different prevalence periods, based on percentage of pleural effusion cases diagnosed as tuberculosis: 1998–2000 (31.3%), 2001–2004 (11.8%), and 2005–2008 (7.4%). ROC curves, dispersion diagrams and pre/post-test probability graphs were produced. TPE accounted for 73 episodes (mean prevalence: 15.5%). The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) for ADA₄₀ were 89%, 92.7%, 69.2% and 97.9%, respectively. For ADA₄₀+LP₅₀ the specificity and PPV increased (98.3% and 90%) with hardly any decrease in the sensitivity or NPV (86.3% and 97.5%). No relevant differences were observed between the three study periods.

Conclusions/Significance

ADA remains useful for the diagnosis of TPE even in low-to-intermediate prevalence scenarios when combined with the lymphocyte proportion.

When pleural potassium exceeds 5.0 mEq/L, high pleural adenosine deaminase levels do not necessarily indicate tuberculous pleuritis

BACKGROUND AND OBJECTIVE

The aim of this study was to determine whether high levels of pleural adenosine deaminase (pADA) are predictive for tuberculosis when pleural effusions do not satisfy the criteria for lymphocytic effusions or show neutrophil predominance.

METHODS

This was a retrospective observational study of 147 consecutive patients with exudative pleural effusions that were diagnosed by analysis of fluid samples during a 3-year period from 1 April 2007 to 31 March 2010. Multiple linear correlation tests were used to assess clinical variables as possible predictors of high pADA levels.

RESULTS

High pleural LDH (pLDH) and pleural potassium (pK) levels were associated with high pADA levels (P < 0.0001). Although there was a linear correlation between pLDH and pADA levels in patients with parapneumonic effusions (PPE) (n = 75), tubercular effusions (n = 21), malignant effusions (n = 41) and miscellaneous effusions (n = 10), a significant linear correlation between pK and pADA levels was observed only in patients with PPE (ρ = 0.525, P < 0.0001). When the cut-off value for pK was set at 5.0 mEq/L, pADA levels were >50 IU/L and pK levels were >5.0 mEq/L in only one patient (5%) in the tuberculosis group (n = 21) and 15 patients (12%, all with PPE) in the non-tuberculosis group (n = 126).

CONCLUSIONS

When pK levels exceed 5.0 mEq/L, high pADA levels do not necessarily indicate the presence of tuberculous pleuritis.

Immune response to Mycobacterium tuberculosis infection in the parietal pleura of patients with tuberculous pleurisy

The T lymphocyte-mediated immune response to Mycobacterium tuberculosis infection in the parietal pleura of patients with tuberculous pleurisy is unknown. The aim of this study was to investigate the immune response in the parietal pleura of tuberculous pleurisy compared with nonspecific pleuritis. We have measured the numbers of inflammatory cells particularly T-cell subsets (Th1/Th2/Th17/Treg cells) in biopsies of parietal pleura obtained from 14 subjects with proven tuberculous pleurisy compared with a control group of 12 subjects with nonspecific pleuritis. The number of CD3+, CD4+ and CCR4+ cells and the expression of RORC2 mRNA were significantly increased in the tuberculous pleurisy patients compared with the nonspecific pleuritis subjects. The number of toluidine blue+ cells, tryptase+ cells and GATA-3+ cells was significantly decreased in the parietal pleura of patients with tuberculous pleurisy compared with the control group of nonspecific pleuritis subjects. Logistic regression with receiver operator characteristic (ROC) analysis for the three single markers was performed and showed a better performance for GATA-3 with a sensitivity of 75%, a specificity of 100% and an AUC of 0.88. There was no significant difference between the two groups of subjects in the number of CD8, CD68, neutrophil elastase, interferon (IFN)-γ, STAT4, T-bet, CCR5, CXCR3, CRTH2, STAT6 and FOXP3 positive cells. Elevated CD3, CD4, CCR4 and Th17 cells and decreased mast cells and GATA-3+ cells in the parietal pleura distinguish patients with untreated tuberculous pleurisy from those with nonspecific pleuritis.

Risk factors for development of paradoxical response during anti-tuberculosis treatment in HIV-negative patients with pleural tuberculosis

Paradoxical response (PR) is the unusual expansion or new formation of a tuberculous lesion during anti-tuberculosis (TB) treatment. Pleural TB is the second most common form of extrapulmonary TB and has clinical importance because it occurs in a restricted space. Limited information is available for PR in HIV-negative patients with pleural TB. The aim of this study was to evaluate the clinical characteristics and risk factors of PR in HIV-negative patients with pleural TB. Patients diagnosed with pleural TB between 2003 and 2008 at Chung-Ang University Hospital and Yong-San Hospital, Seoul, South Korea were included. We evaluated the incidence and treatment outcome of PR in pleural TB, and compared baseline clinical characteristics and laboratory findings between TB patients with PR and those without PR. PR was present in 32 (23%) of 139 patients after mean 51.1 days following initiation of treatment. Out of 32 patients, 18 patients needed additional treatment for symptom control. PR patients had a high incidence of adverse drug reaction such as drug skin reaction or liver function abnormality (P < 0.05). The risk factors for PR are younger age, high serum albumin level, low proportion of lymphocyte, and high proportion of PMN in pleural fluid (P < 0.05). PR is not an uncommon problem in HIV-negative pleural TB and half of these patients need additional treatment. Therefore, physicians must pay more attention for PR during the management of pleural TB in the expected patients to develop PR.

Current concepts in the management of tuberculosis

Tuberculosis (TB) poses a serious threat to public health throughout the world but disproportionately afflicts low-income nations. Persons in close contact with a patient with active pulmonary TB and those from endemic regions of the world are at highest risk of primary infection, whereas patients with compromised immune systems are at highest risk of reactivation of latent TB infection (LTBI). Tuberculosis can affect any organ system. Clinical manifestations vary accordingly but often include fever, night sweats, and weight loss. Positive results on either a tuberculin skin test or an interferon-γ release assay in the absence of active TB establish a diagnosis of LTBI. A combination of epidemiological, clinical, radiographic, microbiological, and histopathologic features is used to establish the diagnosis of active TB. Patients with suspected active pulmonary TB should submit 3 sputum specimens for acid-fast bacilli smears and culture, with nucleic acid amplification testing performed on at least 1 specimen. For patients with LTBI, treatment with isoniazid for 9 months is preferred. Patients with active TB should be treated with multiple agents to achieve bacterial clearance, to reduce the risk of transmission, and to prevent the emergence of drug resistance. Directly observed therapy is recommended for the treatment of active TB. Health care professionals should collaborate, when possible, with local and state public health departments to care for patients with TB. Patients with drug-resistant TB or coinfection with human immunodeficiency virus should be treated in collaboration with TB specialists. Public health measures to prevent the spread of TB include appropriate respiratory isolation of patients with active pulmonary TB, contact investigation, and reduction of the LTBI burden.

Increased frequencies of T helper type 17 cells in tuberculous pleural effusion

Th17 cells have emerged as an important mediator in inflammatory and autoimmune diseases. Recent studies suggest a potential impact of Th17 cells on tuberculosis (TB) infection. This study was designed to investigate the possible involvement of Th17 cells in tuberculous pleural effusion. Compared with healthy volunteers, patients with TB had a higher proportion of Th17 cells in peripheral blood mononuclear cells (PBMCs). Moreover, the percentage of Th17 cells in pleural effusions of TB patients was obviously higher than that in PBMC from TB patients or healthy controls. Furthermore, the mRNA and protein expression levels of IL-17 and IL-6 were significantly increased in the patients with tuberculous pleural effusion, while expression level of TGF-β was decreased in the pleural effusion. Correlation analysis showed a significant correlation between IFN-γ concentrations and the frequencies of Th17 cells in tuberculous pleural effusion. These results indicate that Th17 cells may contribute to the immunopathogenesis of tuberculous pleural effusion.

Assessment of the N-PCR assay in diagnosis of pleural tuberculosis: detection of M. tuberculosis in pleural fluid and sputum collected in tandem

BACKGROUND

The nonspecific clinical presentation and paucibacillary nature of tuberculous pleuritis remains a challenge for diagnosis. Diagnosis of tuberculous pleural effusion depends on the demonstration of the presence of tubercle bacilli in the sputum, pleural fluid, or pleural biopsy specimen, or demonstration of granuloma in pleura by histological examination. We examined the clinical utility of the diagnosis of pleural tuberculosis using the in house N-PCR assay, AFB smear microscopy and culture. Besides pleural fluid the inclusion of sputum in the efficacy of diagnosis of pleural tuberculosis was scrutinized.

METHODOLOGY/PRINCIPAL FINDINGS

Pleural fluid and sputum samples of 58 tuberculous and 42 non-tuberculous pleural effusion patients were processed for AFB smear microscopy, culture and the N-PCR assay. Mycobacteria were detected exclusively in tuberculous pleural effusion samples. None of the non-tuberculous pleural effusion samples were positive for mycobacteria. Comparative analysis showed that the N-PCR assay had the highest sensitivity. Inclusion of sputum along with pleural fluid increased N-PCR sensitivity from 51.7 to 70.6% (p<0.0001).This improved sensitivity was reflected in AFB smear microscopy and isolation by culture. The sensitivity enhanced on inclusion of sputum from 3.4 (p = 0.50) to 10.3% (p = 0.038) for AFB smear microscopy and for isolation of mycobacteria from 10.3(p = 0.03) to 22.4% (p = 0.0005). Thirteen isolates were obtained from 58 pleural tuberculosis patients. Eleven mycobacterial isolates were identified as M. tuberculosis and two as M. fortuitum and M. chelonae. Complete concordance was seen between the biochemical identification of isolates and the N-PCR identification of mycobacterial species prior to isolation.

CONCLUSIONS/SIGNIFICANCE

To the best of our knowledge this is the first PCR based report on utility of sputum for diagnosis of pleural tuberculosis. The present study demonstrates that a combination of pleural fluid with sputum sample and N-PCR improved the diagnosis of pleural tuberculosis.

Pleural fluid characteristics of tuberculous pleural effusions

Mycobacterium tuberculosis (TB) infection of the pleural space is an important cause of pleural effusion in areas of high TB prevalence. Microbiological analyses of pleural fluid in the acute setting may be negative. Consequently, investigations may proceed to more invasive techniques, such as pleural biopsy or thoracoscopy. Ongoing research has led to implementing a number of additional fluid analyses that may lead to a diagnosis without a need for further invasive procedures. In this review, we discuss the characteristics of tuberculous pleural fluid that may assist in this important diagnosis, and we highlight the benefits of specific biomarker analyses. English-language publications from a MEDLINE search and references from relevant articles from January 1, 1990 to September 1, 2009 were reviewed. The key words searched included tuberculosis, pleural fluid, effusion, diagnosis, adenosine deaminase, and interferon.

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.

Childhood pleural tuberculosis: a review of 45 cases

BACKGROUND

Pleural tuberculosis (TB) can be seen in isolation or complicate untreated pulmonary disease in children. It is infrequently suspected in low incidence countries, leading to delays in diagnosis and treatment.

METHODS

This was a retrospective descriptive case series of children<or=18 years old with pleural TB seen in a referral clinic in Houston, Texas from 1984 to 2008. Medical record data, radiographs, and health department records were reviewed. Epidemiologic, clinical, radiographic, and microbiologic findings are described.

RESULTS

Forty-five children (mean age 10.9 years) were diagnosed with TB. Contacts with cases of infectious tuberculosis were identified for 20 children (44%). Positive tuberculin skin tests were seen in 89%. Seventy-three percent of children had concomitant pulmonary parenchymal disease or intrathoracic lymphadenopathy. Cultures were attempted in 40 of 45 children (89%). No patient had acid-fast bacillus smear-positive pleural fluid, but pleural fluid cultures were positive in 56%. Cultures from other respiratory sources were positive in 48% of patients. Although all patients had symptomatic resolution and radiographic improvement, chest radiographs were improved but abnormal in 62% of patients at the end of therapy. No child developed relapse or recrudescence after therapy was discontinued.

CONCLUSIONS

Pleural TB was usually associated with a positive tuberculin skin test, and lung parenchymal infiltrates were seen commonly. All children had symptomatic resolution and radiographic improvement, and 6-month courses of therapy resulted in disease resolution for children with isolated pleural or pleural and pulmonary parenchymal disease.

Tuberculous pleural effusion

Tuberculous pleural effusion is one of the most common forms of extrapulmonary tuberculosis (TB). The immediate cause of the effusion is a delayed hypersensitivity response to mycobacterial antigens in the pleural space. For this reason microbiological analyses are often negative and limited by the lengthy delay in obtaining results. In areas with high TB prevalence, pleural fluid adenosine deaminase (ADA) levels greater than 40 U/l argue strongly for TB; in contrast, low levels of pleural ADA have high negative predictive value in low-prevalence countries. The specificity of this enzyme increases if only lymphocytic exudates are considered. The shortcoming of the ADA test is its inability to provide culture and drug sensitivity information, which is paramount in countries with a high degree of resistance to anti-TB drugs. Sputum induction (in addition to pleural fluid) for acid-fast bacilli and culture is a recommended procedure in all patients with TB pleurisy. The microscopic-observation drug-susceptibility assay performed on pleural fluid or pleural tissue increases by two to three times the detection of TB over conventional cultures, and it allows for the identification of multidrug-resistant TB. A reasonable management strategy for pleural TB would be to initiate a four-drug regimen and perform a therapeutic thoracentesis in patients with large, symptomatic effusions.

Aspectos epidemiológicos da tuberculose pleural no estado de São Paulo (1998-2005)

OBJETIVO: Analisar as características epidemiológicas e tendências quanto à incidência de TB pleural. MÉTODOS: Estudo descritivo, retrospectivo dos casos de TB reportados entre 1998 e 2005 e coletados do banco de dados do Sistema de Notificação de Tuberculose (Epi-TB) da Secretaria de Saúde do Estado de São Paulo. RESULTADOS: Foram notificados 144.347 casos novos de TB durante o período estudado. A forma pulmonar foi predominante (118.575 casos; 82,2%). Das formas extrapulmonares (25.773 casos; 17,8%), a pleural foi a mais referida (12.545 casos; 48,7%). A incidência (por 100.000 habitantes) de todas as formas diminuiu, (49,7 em 1998 e 44,6 em 2005; R² = 0,898; p < 0,001), enquanto a incidência de TB pleural permaneceu estável (4,1 em 1998 e 3,8 em 2005; R² = 0,433; p = 0,076). A maior incidência de TB pleural ocorreu em pacientes do sexo masculino (2:1) entre 30 e 59 anos de idade. Dos 12.545 pacientes com TB pleural, 4.018 (32,0%) apresentaram comorbidades: alcoolismo (9,5%); HIV (8,0%); diabetes (3,3%); e doença mental (1,2%). O diagnóstico referido fundamentou-se em métodos bacteriológicos (14,2%) e histológicos (30,2%), assim como outros não especificados (55,6%). CONCLUSÕES: No estado de São Paulo, a TB pleural foi a forma extrapulmonar predominante, apresentando incidência estável no período entre 1998 e 2005, apesar da tendência de diminuição das formas pulmonares. A histologia e a bacteriologia definiram o diagnóstico em 44,4% dos casos.

Diagnosis and management of pleural effusions: a practical approach

Pleural effusion is defined as an abnormal amount of pleural fluid accumulation in the pleural space and is the result of an imbalance between excessive pleural fluid formation and pleural fluid absorption. Although the list of causes of pleural effusions is extensive, the great majority of the cases are caused by pneumonia, congestive heart failure, and malignancy. In this article, we provide an overview of the most common causes of pleural effusions likely to be encountered by the general practitioner, and a practical approach to the diagnosis and management of this common condition.