Leflunomide as part of the treatment for multidrug-resistant cytomegalovirus disease after lung transplantation: case report and review of the literature.

Treatment of cytomegalovirus (CMV) disease in transplant patients is challenging and, with antiviral resistance to first-line drugs, it remains uncertain which treatment algorithm to follow. Some data suggest that leflunomide, a pyrimidine synthesis inhibitor, can be used to treat resistant CMV infections. We report a 57-year-old CMV immunoglobulin-G (IgG)-seronegative woman, who received a bilateral lung transplant (LuTx) from a CMV IgG-positive donor with CMV primary disease. The CMV strain was genotypically resistant to ganciclovir, foscarnet, and cidofovir. After starting leflunomide as add-on therapy to a multidrug anti-CMV regimen, viral load declined substantially in 2 months without adverse events. This experience is discussed against the background of existing literature on the use of leflunomide as an anti-CMV agent in LuTx recipients.

Recombinant human serum amyloid P in healthy volunteers and patients with pulmonary fibrosis.

PRM-151, recombinant human Pentraxin-2 (PTX-2) also referred to as serum amyloid P (SAP), is under development for treatment of fibrosis. A First-in-Human (FIH) trial was performed to assess the safety, tolerability, and pharmacokinetics of single ascending intravenous doses of PRM-151 administered to healthy subjects, using a randomized, blinded, placebo controlled study design. Each cohort included three healthy subjects (PRM-151:placebo; 2:1). SAP levels were assessed using a validated ELISA method, non-discriminating between endogenous and exogenous SAP. At a dose level of 10 mg/kg, at which a physiologic plasma level of SAP was reached, two additional healthy volunteers and three pulmonary fibrosis (PF) patients were enrolled enabling comparison of the pharmacokinetic SAP profile between healthy volunteers and PF patients. In addition, the percentage of fibrocytes (CD45+/Procollagen-1+ cells) in whole blood samples was assessed to demonstrate biological activity of PRM-151 in the target population. PRM-151 administration was generally well tolerated. In two pulmonary fibrosis patients non-specific, transient skin reactions (urticaria and erythema) were observed. PRM-151 administration resulted in a 6-to 13-fold increase in mean baseline plasma SAP levels at dose levels of 5, 10, and 20 mg/kg. The estimated t1/2 of PRM-151 in healthy volunteers was 30 h. Pharmacokinetic profiles were comparable between healthy volunteers and PF patients. PRM-151 administration resulted in a 30-50% decrease in fibrocyte numbers 24 h post-dose. This suggests that administration of PRM-151 may be associated with a reduction of fibrocytes in PF patients, a population for which current pharmacotherapeutic options are limited. The pharmacological action of PRM-151 should be confirmed in future research.

Topical treatment targeting sphingosine-1-phosphate and sphingosine lyase abrogates experimental allergic rhinitis in a murine model.

BACKGROUND: Sphingosine-1-phosphate (S1P) plays a crucial role in homeostasis of the immune system by regulating lymphocyte recirculation and inflammatory cell recruitment. The levels of S1P are tightly controlled through regulated production and controlled breakdown by sphingosine-lyase (SL). The S1P analogue FTY720 has been developed as an immunosuppressant in transplantation and tested as a treatment for various inflammatory diseases. FTY720 exploits S1P biology by acting as a S1P1 and S1P 3 agonist and by inhibiting S1P breakdown by SL. OBJECTIVE: Here, we investigate interfering S1P in allergic rhinitis (AR) and its way of action. METHODS: Allergic rhinitis was induced by sensitizing mice to ovalbumin (OVA) and challenging the nose with OVA allergen. At the time of allergen challenge, mice received topical intranasal treatment with FTY720. To address the relative contribution of SL inhibition in mediating its effects, some mice were treated with the SL inhibitor 2-acetyl-4-tetrahydroxybutyl (THI). RESULTS: FTY720 treatment resulted in significantly fewer eosinophils, mast cells and dendritic cells in the nasal mucosa of AR animals, compared with diluent treatment. Levels of IL-4, IL-5, IL-10 and IL-13 produced by lymph node cells fell significantly in FTY720-treated animals. Moreover, FTY720 proved potent enough to suppress inflammation in a model of persistent AR. In vitro and in vivo experiments indicate that FTY720 impaired Th2 differentiation and proliferation important in driving eosinophilia and induced apoptosis in mast cells. CONCLUSION: Our results indicate that interfering with S1P metabolism is a powerful and feasible strategy to develop new topical agents that suppress AR.

Ursodeoxycholic acid suppresses eosinophilic airway inflammation by inhibiting the function of dendritic cells through the nuclear farnesoid X receptor.

BACKGROUND: Ursodeoxycholic acid (UDCA) is the only known beneficial bile acid with immunomodulatory properties. Ursodeoxycholic acid prevents eosinophilic degranulation and reduces eosinophil counts in primary biliary cirrhosis. It is unknown whether UDCA would also modulate eosinophilic inflammation outside the gastrointestinal (GI) tract, such as eosinophilic airway inflammation seen in asthma. The working mechanism for its immunomodulatory effect is unknown. METHODS: The immunosuppressive features of UDCA were studied in vivo, in mice, in an ovalbumin (OVA)-driven eosinophilic airway inflammation model. To study the mechanism of action of UDCA, we analyzed the effect of UDCA on eosinophils, T cells, and dendritic cell (DCs). DC function was studied in greater detail, focussing on migration and T-cell stimulatory strength in vivo and interaction with T cells in vitro as measured by time-lapse image analysis. Finally, we studied the capacity of UDCA to influence DC/T cell interaction. RESULTS: Ursodeoxycholic acid treatment of OVA-sensitized mice prior to OVA aerosol challenge significantly reduced eosinophilic airway inflammation compared with control animals. DCs expressed the farnesoid X receptor for UDCA. Ursodeoxycholic acid strongly promoted interleukin (IL)-12 production and enhanced the migration in DCs. The time of interaction between DCs and T cells was sharply reduced in vitro by UDCA treatment of the DCs resulting in a remarkable T-cell cytokine production. Ursodeoxycholic acid-treated DCs have less capacity than saline-treated DCs to induce eosinophilic inflammation in vivo in Balb/c mice. CONCLUSION: Ursodeoxycholic acid has the potency to suppress eosinophilic inflammation outside the GI tract. This potential comprises to alter critical function of DCs, in essence, the effect of UDCA on DCs through the modulation of the DC/T cell interaction.

New roads open up for implementing immunotherapy in mesothelioma.

Treatment options for malignant mesothelioma are limited, and the results with conventional therapies have been rather disappointing to this date. Chemotherapy is the only evidence-based treatment for mesothelioma patients in good clinical condition, with an increase in median survival of only 2 months. Therefore, there is urgent need for a different approach to battle this malignancy. As chronic inflammation precedes mesothelioma, the immune system plays a key role in the initiation of this type of tumour. Also, many immunological cell types can be found within the tumour at different stages of the disease. However, mesothelioma cells can evade the surveillance capacity of the immune system. They build a protective tumour microenvironment to harness themselves against the immune system's attacks, in which they even abuse immune cells to act against the antitumour immune response. In our opinion, modulating the immune system simultaneously with the targeting of mesothelioma tumour cells might prove to be a superior treatment. However, this strategy is challenging since the tumour microenvironment possesses numerous forms of defence strategies. In this paper, we will discuss the interplay between immunological cells that can either inhibit or stimulate tumour growth and the challenges associated with immunotherapy. We will provide possible strategies and discuss opportunities to overcome these problems.

Optical detection of preneoplastic lesions of the central airways.

Current routine diagnosis of premalignant lesions of the central airways is hampered due to a limited sensitivity (white light bronchoscopy) and resolution (computer tomography (CT), positron emission tomography (PET)) of currently used techniques. To improve the detection of these subtle mucosal abnormalities, novel optical imaging bronchoscopic techniques have been developed over the past decade. In this review we highlight the technological developments in the field of endoscopic imaging, and describe their advantages and disadvantages in clinical use.

SUVmax during 18FDG-PET scanning in small cell lung cancer: similar information as in non-small cell lung cancer?

In patients with non-small cell lung carcinoma (NSCLC) fluorine-18 fluorodeoxyglucose positron emission tomography (18FDG-PET)-scanning is shown to be of prognostic value. Small cell lung cancer (SCLC) is an aggressive tumor with poor prognosis. Limited results on the prognostic and predictive value of the maximum standard uptake values (SUVmax) obtained during 18FDG-PET scanning in SCLC are available. An observational study in 75 chemonaive patients diagnosed with SCLC who underwent a 18FDG-PET scan was performed. SUVmax values of the primary tumor were related to the overall survival (OS) and the progression free survival (PFS). Significant lower SUVmax values of the primary tumor were observed in patients with stage I-III disease compared to stage IV disease. SUVmax did not discriminate for either OS or PFS in the whole group of patients. In patients with stage IV disease and treatment with chemotherapy, OS and PFS were significantly higher in patients with a high SUVmax. (p-value 0.005 and 0.002 respectively) compared to patients with a low SUVmax value. In patients with SCLC metabolic activity determined using 18FDG-PET (SUVmax) differed between stage I-III and stage IV diseases. Compared to NSCLC, the relationship between SUVmax) and prognosis seems more complex.

Zoledronic acid impairs myeloid differentiation to tumour-associated macrophages in mesothelioma.

BACKGROUND: Suppressive immune cells present in tumour microenvironments are known to augment tumour growth and hamper efficacy of antitumour therapies. The amino-bisphosphonate Zoledronic acid (ZA) is considered as an antitumour agent, as recent studies showed that ZA prolongs disease-free survival in cancer patients. The exact mechanism is a topic of debate; it has been suggested that ZA targets tumour-associated macrophages (TAMs). METHODS: We investigate the role of ZA on the myeloid differentiation to TAMs in murine mesothelioma in vivo and in vitro. Mice were intraperitoneally inoculated with a lethal dose of mesothelioma tumour cells and treated with ZA to determine the effects on myeloid differentiation and survival. RESULTS: We show that ZA impaired myeloid differentiation. Inhibition of myeloid differentiation led to a reduction in TAMs, but the number of immature myeloid cells with myeloid-derived suppressor cell (MDSC) characteristics was increased. In addition, ZA affects the phenotype of macrophages leading to reduced level of TAM-associated cytokines in the tumour microenvironment. No improvement of survival was observed. CONCLUSION: We conclude that ZA leads to a reduction in macrophages and impairs polarisation towards an M2 phenotype, but this was associated with an increase in the number of immature myeloid cells, which might diminish the effects of ZA on survival.

A randomized phase II study comparing two schedules of the 21-day regimen of gemcitabine and carboplatin in advanced non-small cell lung cancer.

PURPOSE: Carboplatin area under the curve (AUC) 5 ml/min on day 1 with gemcitabine 1,250 mg/m(2) on day 1 and day 8 is a widely used regimen in advanced non-small cell lung cancer. Grade 3-4 thrombocytopenia and neutropenia are frequent. The aim of this study is to investigate whether toxicity of gemcitabine/carboplatin could be reduced by administering carboplatin on day 8 instead of day 1 without a decrease in response rate (RR). METHODS: Patients received gemcitabine 1,250 mg/m(2) on days 1 and 8, carboplatin AUC 5 on day 1 (arm A) or day 8 (arm B). Drugs were administered over a 21-day cycle. Toxicity and RR were evaluated weekly and every second cycle, respectively. RESULTS: 71 patients were enrolled into the study. We found 79% (95% CI 61-91%) grade 3-4 toxicity (neutropenia and thrombocytopenia) in arm A and 50% (95% CI 32-68%) in arm B; 66% grade 3-4 thrombocytopenia in arm A and 26% in arm B. We observed 30% grade 4 hematological toxicity in arm A and 3% in arm B. In arm A an overall RR of 20% (95% CI 7.7-38.6%) was seen, and 18.2% (95% CI 7-35.5%) in arm B. CONCLUSIONS: Although the study was prematurely closed, the current data are of interest. The schedule with carboplatin on day 8 is associated with substantially lower grade 3-4 neutropenia and thrombocytopenia with comparable dose intensity and RR.

United airways: circulating Th2 effector cells in an allergic rhinitis model are responsible for promoting lower airways inflammation.

BACKGROUND: Allergic rhinitis (AR) and asthma often coexist and are referred to as 'united airways' disease. However, the molecular and cellular pathways that are crucially involved in the interaction between upper and lower airways remain to be identified. OBJECTIVE: We sought to assess whether and how AR exacerbates lower airway inflammation upon allergen challenge in mice. METHODS: We previously developed an intranasal ovalbumin (OVA)-driven AR model, characterized by nasal eosinophilic inflammation, enhanced serum levels of OVA-specific IgE and Th2 cytokine production in cervical lymph nodes. In OVA-sensitized mice with or without AR, a lower airway challenge was given, and after 24 h, lower airway inflammation was analysed. RESULTS: We found that AR mice were more susceptible to eosinophilic inflammation following a lower airway OVA challenge than OVA-sensitized controls. AR mice manifested increased numbers of eosinophils in bronchoalveolar lavage fluid and increased inter-cellular adhesion molecule-1 (ICAM-1) expression on lung endothelium, when compared with OVA-sensitized controls. Depletion of T cells in OVA-challenged AR mice completely abrogated all hallmarks of lower airway inflammation, including enhanced IL-5 and tissue eosinophilia. Conversely, adoptive transfer of Th2 effector cells in naïve animals induced lower airway eosinophilic inflammation after challenge with OVA. Blocking T cell recirculation during AR development by the spingosine-1 analogue FTY720 also prevented lower airway inflammation including ICAM-1 expression in AR mice upon a single lower airway challenge. CONCLUSION: Our mouse model of 'united airways' disease supports epidemiological and clinical data that AR has a significant impact on lower airway inflammation. Circulating Th2 effector cells are responsible for lung priming in AR mice, most likely through up-regulation of ICAM-1.

Non-Cross Resistant Sequential Single Agent Chemotherapy in First-Line Advanced Non-Small Cell Lung Cancer Patients: Results of a Phase II Study.

Background. sequential chemotherapy can maintain dose intensity and preclude cumulative toxicity by increasing drug diversity. Purpose. to investigate the toxicity and efficacy of the sequential regimen of gemcitabine followed by paclitaxel in first line advanced stage non-small cell lung cancer (NSCLC) patients with good performance status (PS). Patients and methods. gemcitabine 1250 mg/m(2) was administered on day 1 and 8 of course 1 and 2; Paclitaxel 150 mg/m(2) on day 1 and 8 of course 3 and 4. Primary endpoint was response rate (RR), secondary endpoints toxicity and time to progression (TTP). Results. Of the 21 patients (median age 56, range 38-80 years; 62% males, 38% females) 10% (2/21) had stage IIIB, 90% (19/21) stage IV, 15% PS 0, 85% PS 1. 20% of patients had a partial response, 30% stable disease, 50% progressive disease. Median TTP was 12 weeks (range 6-52 weeks), median overall survival (OS) 8 months (range 1-27 months), 1-year survival was 33%. One patient had grade 3 hematological toxicity, 2 patients a grade 3 peripheral neuropathy. Conclusions. sequential administration of gemcitabine followed by paclitaxel in first line treatment of advanced NSCLC had a favourable toxicity profile, a median TTP and OS comparable with other sequential trials and might, therefore, be a treatment option for NSCLC patients with high ERCC1 expression.

A novel method for isolating dendritic cells from human bronchoalveolar lavage fluid.

BACKGROUND: Dendritic cells (DCs) play a pivotal role in linking the innate and adaptive immune response and have been implicated in a variety of pulmonary diseases. Currently, studies on the role of DCs are limited by difficulties in isolating DCs from the lung. Surgical lung specimens are not readily available and purification of DCs from digested lung tissue is likely to induce phenotypical and functional changes. DCs obtained from the alveolar spaces are thought to represent the local microenvironment and can be obtained using minimally invasive techniques. We developed a novel method of isolating DCs from bronchoalveolar lavage (BAL) fluid. METHODS: After removal of macrophages, the remaining BAL cells were stained with a lineage mix (CD3-, CD14-, CD16-, CD19-, CD56-FITC), CD11c and HLA-DR and sorted with a FACS ARIA. DAPI was used as a dead-live marker. mDCs were low autofluorescent, lineage mix negative, CD11c+ and HLA-DR+ cells. pDCs were CD11c(-) but CD123+. Morphological assessment of sorted mDCs and pDCs was performed. Sorted mDCs were tested in a mixed leukocyte reaction (MLR) with naive CD4+ T cells and evaluated for T cell differentiation and cytokine production. With confocal microscopy DC-T cell interaction was assessed. RESULTS: Using our sorting strategy, mDCs and pDCs, with a high purity upon FACS analysis of the sorted fraction, were obtained. These cells showed the morphological characteristics of DCs. Most importantly, mDCs were able to induce T cell proliferation and differentiation in a MLR, and interact with T cells as assessed by confocal microscopy. These results indicate the presence of functional DCs. Freezing and thawing of the BAL cells did not affect phenotype or T cell stimulatory capacity of the isolated DCs. CONCLUSION: Using a novel sorting strategy, functional mDCs can be isolated from BAL fluid, enabling a detailed study in pulmonary disease.

Blockade of CCR4 in a humanized model of asthma reveals a critical role for DC-derived CCL17 and CCL22 in attracting Th2 cells and inducing airway inflammation.

BACKGROUND: As Th2 type lymphocytes orchestrate the cardinal features of allergic asthma, inhibiting their recruitment to the lungs could be of therapeutic benefit. Although human Th2 cells express the CCR4 chemokine receptor and increased production of CCR4 ligands has been found in asthmatic airways, studies in animals have reached contradictory conclusions on whether blocking this pathway would be beneficial. OBJECTIVE: As a lack of efficacy might be due to differences between mouse and man, we readdressed this question using a humanized severe combined immunodeficiency model of asthma. METHODS: Mice received peripheral blood mononuclear cells from house dust mite (HDM) allergic asthmatic patients and then underwent bronchial challenge with HDM. RESULTS: This resulted in marked allergic inflammation and bronchial hyper-reactivity. Administration of CCR4 blocking antibody abolished the airway eosinophilia, goblet cell hyperplasia, IgE synthesis and bronchial hyper-reactivity. In this chimeric system, human CD11c+ dendritic cells (DCs) were the predominant source of CCR4 ligands, suggesting that DC-derived chemokines attract Th2 cells. In separate experiments using human DCs, in vitro exposure to HDM of DCs from HDM allergic patients but not healthy controls caused CCL17 and CCL22 release that resulted in chemoattraction of polarized human Th2 cells in a CCR4-dependent way. CONCLUSIONS: Taken together, our data provide proof of concept that CCR4 blockade inhibits the salient features of asthma and justify further clinical development of CCR4 antagonists for this disease.

Pre-operative pulmonary evaluation of lung cancer patients: a review of the literature.

Complete anatomical resection of the primary tumour is still the standard of care in patients with early stage lung cancer. Because these patients are usually smokers who also suffer from chronic obstructive pulmonary disease, regional differences in pulmonary function due to lung tissue destruction exist. The purpose of the present article is to evaluate the currently available guidelines and to discuss novel methods for the pre-operative functional and anatomical pulmonary evaluation in lung cancer patients. Despite the fact that knowledge on the pre-operative evaluation of the pulmonary function has substantially increased during the past decade, the majority of the studies are small, underpowered and, with exception of a proposed algorithm, not prospectively validated in independent cohorts. The future harmonisation of guidelines is required and novel imaging techniques should be incorporated in the pre-operative evaluation in chronic obstructive pulmonary disease patients with borderline pulmonary function.

Cholera toxin B suppresses allergic inflammation through induction of secretory IgA.

In healthy individuals, humoral immune responses to allergens consist of serum IgA and IgG4, whereas cellular immune responses are controlled by regulatory T (Treg) cells. In search of new compounds that might prevent the onset of allergies by stimulating this type of immune response, we have focused on the mucosal adjuvant, cholera toxin B (CTB), as it induces the formation of Treg cells and production of IgA. Here, we have found that CTB suppresses the potential of dendritic cells to prime for Th2 responses to inhaled allergen. When we administered CTB to the airways of naïve and allergic mice, it strongly suppressed the salient features of asthma, such as airway eosinophilia, Th2 cytokine synthesis, and bronchial hyperreactivity. This beneficial effect was only transferable to other mice by transfer of B but not of T lymphocytes. CTB caused a transforming growth factor-beta-dependent rise in antigen-specific IgA in the airway luminal secretions, which was necessary for its preventive and curative effect, as all effects of CTB were abrogated in mice lacking the luminal IgA transporting polymeric Ig receptor. Not only do these findings show a novel therapeutic avenue for allergy, they also help to explain the complex relationship between IgA levels and risk of developing allergy in humans.

The effects of guideline implementation for proton pump inhibitor prescription on two pulmonary medicine wards.

BACKGROUND: It has been demonstrated that 40% of patients admitted to pulmonary medicine wards use proton pump inhibitors (PPIs) without a registered indication. AIM: To assess whether implementation of a guideline for proton pump inhibitor (PPI) prescription on pulmonary medicine wards could lead to a decrease in use and improved appropriateness of prescription. METHODS: This prospective study comprised two periods, i.e. the situation before and after guideline implementation. In each period, 300 consecutive patients were included. We registered patient characteristics, medications and occurrence of upper gastrointestinal-related disorders. RESULTS: After implementation, fewer patients were started on PPIs [21% vs. 13%; odds ratio (OR): 0.56; 95% confidence interval (CI): 0.33-0.97] and more users discontinued their use; however, the latter was not significant (3% vs. 6%; OR for continuation: 0.56; 95% CI: 0.14-2.23). Multivariable logistic regression analysis confirmed that PPI use during hospitalization decreased after implementation (adjusted pooled OR: 0.54; 95% CI: 0.32-0.90). Implementation did not result in a change in reported reasons for PPI prescription. There was no significant difference in the occurrence of upper GI-related disorders in the first 3 months after discharge. CONCLUSIONS: Guideline implementation for PPI prescription on two pulmonary medicine wards resulted in a reduction in the number of patients starting PPIs during hospitalization, but appropriateness of prescribing PPIs was not affected. Further studies are needed to determine how appropriateness of PPI prescription on pulmonary medicine wards can be further improved.

Altered expression of epithelial junctional proteins in atopic asthma: possible role in inflammation.

Epithelial cells form a tight barrier against environmental stimuli via tight junctions (TJs) and adherence junctions (AJs). Defects in TJ and AJ proteins may cause changes in epithelial morphology and integrity and potentially lead to faster trafficking of inflammatory cells through the epithelium. Bronchial epithelial fragility has been reported in asthmatic patients, but little is known about the expression of TJ and AJ proteins in asthma. We studied epithelial expression of zonula occludens-1 (ZO-1) and AJ proteins E-cadherin, alpha-catenin, and beta-catenin in bronchial biopsies from nonatopic nonasthmatic (healthy) subjects (n = 14), and stable atopic asthmatic subjects (n = 22) at baseline conditions. Immunostaining for these proteins was semi-quantified for separate cellular compartments. E-cadherin, alpha-catenin and beta-catenin were present in the cellular membrane and less in the cytoplasm. Only beta-catenin was present in the nucleus in agreement with its potential function as transcription factor. ZO-1 was present in the apicolateral membrane of superficial cells. alpha-Catenin expression was significantly lower in subjects with asthma than without and correlated inversely with numbers of eosinophils within the epithelium. ZO-1 and E-cadherin expression were significantly lower in asthmatic than in nonasthmatic subjects. Expression of beta-catenin was not different. Our results suggest that the lower epithelial alpha-catenin, E-cadherin and (or) ZO-1 expression in patients with atopic asthma contributes to a defective airway epithelial barrier and a higher influx of eosinophils in the epithelium.

HIF1a expression in bronchial biopsies correlates with tumor microvascular saturation determined using optical spectroscopy.

Tumor hypoxia is generally considered to be related to aggressive behaviour of a tumor. As in lung cancer direct determination of oxygenation is difficult, hypoxia-related proteins have been studied. A number of studies on these proteins show different results and the usefulness of these protein expressions remains questionable. In this article, we relate one of these hypoxia-related proteins (hypoxia-inducible factor, HIF1a) to a direct in vivo spectroscopic measurement of tumor blood saturation performed during bronchoscopy. Seventeen samples from malignancies and non-malignant tissues were studied. Microvascular saturation levels in the no malignancy group equalled 87+/-11.5% (range 71-100%) and in the malignant group 43+/-21% (range 6-63%). This difference was statistically significant (p<0.0002). There was a significant difference in the spectroscopically determined saturations between the biopsies with negative expression of HIF1a and the biopsies with positive expression of HIF1a (p<0.005). From these data, it can be concluded that HIF1a expression is related to a low microvascular blood saturation as determined in vivo by optical spectroscopy. This study may lead to a better acceptance of the usage of different techniques to establish hypoxia in order to study the effect of hypoxia on therapeutic interventions and prognosis of lung cancer.

The high post-test probability of a cytological examination renders further investigations to establish a diagnosis of epithelial malignant pleural mesothelioma redundant.

The aim of the study was to establish in a prospective and blinded manner the diagnostic yield of morphology, immunocytochemistry (ICH) and electron microscopy (EM) in the cytological analysis of malignant pleural mesothelioma (MPM). Pleural fluid from consecutive patients, 14 with a histologically proven MPM, 12 with a malignant pleuritis due to adenocarcinoma (AC), and 13 with a reactive pleural effusion (RM), was separately analyzed. Smears were incubated with monoclonal antibodies (Tag72, Ber-Ep4, anti-CEA, EMA). These were considered suggestive for MPM when only EMA stained positive, for AC when three out of four markers stained positive, and for RM when no marker stained positive. The post-test probability of the morphological, ICH, and EM analysis were 92, 100, 92% or MPM, 91, 100, 86% for AC, and 88, 88, 90% for RM, respectively. We concluded that the high post-test probability of a combined morphological and ICH diagnosis of MPM warrants to cease further diagnostic procedures in these patients. Electron microscopy did not add to accuracy of diagnosis.

Mesothelioma environment comprises cytokines and T-regulatory cells that suppress immune responses.

Malignant mesothelioma is a cancer with dismal prognosis. The objective of the present study was to address the role of the immune system, tumour micro-environment and potential immunosuppression in mesothelioma. Expression profiles of 80 cytokines were determined in the supernatant of mesothelioma cell lines and the original patient's pleural effusion. Influx of immune effector cells was detected by immunohistochemistry. Angiogenin, vascular endothelial growth factor, transforming growth factor-beta, epithelial neutrophil-activating protein-78 and several other proteins involved in immune suppression, angiogenesis and plasma extravasation could be detected in both supernatant and pleural effusion. Surrounding stroma and/or infiltrating cells were the most likely source of hepatocyte growth factor, macrophage inflammatory protein (MIP)-1delta, MIP-3alpha, neutrophil-activating peptide-2, and pulmonary and activation-regulated chemokine that can cause leukocyte infiltration and activation. There was a massive influx of CD4+ and CD8+ T-lymphocytes and macrophages, but not of dendritic cells, in human mesothelioma biopsies. It was further demonstrated that human mesothelioma tissue contained significant amounts of Foxp3+CD4+CD25+ regulatory T-cells. When these CD25+ regulatory T-cells were depleted in an in vivo mouse model, survival increased. Mesothelioma is infiltrated by immune effector cells but also contains cytokines and regulatory T-cells that suppress an efficient immune response. Immunotherapy of mesothelioma might be more effective when combined with drugs that eliminate or control regulatory T-cells.