Therapeutic bronchoscopy for malignant central airway obstructions caused by non-bronchogenic cancers: Results from the EpiGETIF registry.

BACKGROUND AND OBJECTIVE: Little is known about malignant central airway obstruction (MCAO) complicating the metastatic spread of non-bronchogenic solid cancers (NBC) and their bronchoscopic management. This study aimed to describe the epidemiology of this population and determine prognostic factors before therapeutic bronchoscopy (TB). METHODS: In this multicenter study using the EpiGETIF registry, we analysed patients treated with TB for MCAO caused by NBC between January 2019 and December 2022. RESULTS: From a database of 2389 patients, 436 patients (18%) with MCAO and NBC were identified. After excluding patients with direct local invasion, 214 patients (8.9%) were analysed. The main primaries involved were kidney (17.8%), colon (16.4%), sarcoma (15.4%), thyroid (8.9%) and head and neck (7.9%) cancers. Most patients (63.8%) had already received one or more lines of systemic treatment. Obstructions were purely intrinsic in 58.2%, extrinsic in 11.1% and mixed in 30.8%. Mechanical debulking was used in 73.4% of cases, combined with thermal techniques in 25.6% of cases. Airway stenting was required in 38.4% of patients. Median survival after TB was 11.2 months, influenced by histology (p = 0.002), performance status (p = 0.019), initial hypoxia (HR 1.45 [1.01-2.18]), prior oncologic treatment received (HR 1.82 [1.28-2.56], p < 0.001) and assessment of success at the end of the procedure (HR 0.66 [0.44-0.99], p < 0.001). Complications rate was 8.8%, mostly mild, with no procedure-related mortality. CONCLUSION: TB for MCAO caused by a NBC metastasis provides rapid improvement of symptoms and prolonged survival. Patients should be promptly referred by medical oncologists for bronchoscopic management based on the prognostic factors identified.

Therapeutic bronchoscopy for malignant central airway obstruction: Introduction to the EpiGETIF registry.

BACKGROUND AND OBJECTIVE: EpiGETIF is a web-based, multicentre clinical database created in 2019 aiming for prospective collection of data regarding therapeutic rigid bronchoscopy (TB) for malignant central airway obstruction (MCAO). METHODS: Patients were enrolled into the registry from January 2019 to November 2022. Data were prospectively entered through a web-interface, using standardized definitions for each item. The objective of this first extraction of data was to describe the population and the techniques used among the included centres to target, facilitate and encourage further studies in TB. RESULTS: Overall, 2118 patients from 36 centres were included. Patients were on average 63.7 years old, mostly male and smokers. Most patients had a WHO score ≤2 (70.2%) and 39.6% required preoperative oxygen support, including mechanical ventilation in 6.7%. 62.4% had an already known histologic diagnosis but only 46.3% had received any oncologic treatment. Most tumours were bronchogenic (60.6%), causing mainly intrinsic or mixed obstruction (43.3% and 41.5%, respectively). Mechanical debulking was the most frequent technique (67.3%), while laser (9.8%) and cryo-recanalization (2.7%) use depended on local expertise. Stenting was required in 54.7%, silicone being the main type of stent used (55.3%). 96.3% of procedure results were considered at least partially successful, resulting in a mean 4.1 points decrease on the Borg scale of dyspnoea. Complications were noted in 10.9%. CONCLUSION: This study exposes a high volume of TB that could represent a good source of future studies given the dismal amount of data about the effects of TB in certain populations and situations.

Endobronchial valves: 1st Multicenter retrospective study on the 2-step approach.

BACKGROUND: Although the endobronchial valves (EBV) were successfully developed as treatment for severe emphysema, its main complication, pneumothorax, remained an important concern. OBJECTIVE: To assess whether the placement of Zephyr© endobronchial valves throughout 2 procedures instead of 1 minor the frequency of pneumothorax without lowering the benefits of such treatment. METHODS: This retrospective study was conducted in 15 pulmonology department in France. All the patients met the inclusion criteria of the recommendation set by the expert panel on the Endoscopic Lung Volume Reduction (ELVR) updated in 2019. As recommended, all the scan were analyzed with the StratX© (PulmonX Corporation, Redwood city, CA) protocol, and completed by a Chartis© (PulmonX Corporation, Redwood city, CA) in case of questionable fissure. During the first procedure, all but the most proximal sub-segment of the targeted lobe were occluded. One month after, EBV were placed in the bronchus of the last subsegment. All patients were evaluated before and 3 months after the second procedure. RESULTS: Between March 2019 and December 2020, 96 patients received EBV treatment. 12 patients (12.5%) presented a pneumothorax (3 after the 1st step and 9 after the 2nd procedure). Beside pneumothorax, the main adverse event was exacerbation (10.4%) and pneumonia (4.1%). No death were reported. Significant improvement were found for FEV1 (14.6 ± 25.3%), RV (- 0.69 ± 2.1 L), 6MWT (34.8 ± 45.9 m), BODE Score (-1.41 ± 1.41pts), and mMRC scale (-0.85 ± 0.7pts). These results are compared not only to the results previously published using the usual approach but also to our previous publication evaluating the 2-step approach. Some patients presented authentic segmental atelectasis despite infralobar treatment. CONCLUSION: Placing EBV during 2 procedures instead of one led to a significant decrease of post treatment pneumothoraces without increasing the rate of other complications. It does not seem to alter the benefits of such therapy for severe emphysema. These results must be confirmed by launching a multicenter, prospective, randomized, controlled study to compare the frequency of pneumothorax and the efficacy of this new approach with the usual one-time procedure.

Incidence and risk factors of anastomotic complications after lung transplantation.

BACKGROUND: Anastomotic complications are common after lung transplantation (1.4-33% of cases) and still associated with a high morbi-mortality. METHODS: The current study is a monocenter retrospective analysis of symptomatic anastomotic complications (SAC) occurring after lung transplantation between 2010 and 2016, using the macroscopic, diameter, and suture (M-D-S) classification from consensus of French experts in bronchoscopy. The objectives were to determine incidence from surgery, risk factors, and impact of survival of SAC. We defined SAC as M-D-S abnormalities (stenosis ⩾ 50% or dehiscence) requiring bronchoscopic or surgical interventions. RESULTS: A total of 121 patients were included. SAC occurred in 26.5% of patients (n = 32), divided in symptomatic stenosis for 23.7% (n = 29), and symptomatic dehiscence in 2.5% (n = 3). In multivariate analysis, donor bacterial lung infection [HR 2.08 (1.04-4.17), p = 0.04] and age above 50 years [HR 3.26 (1.04-10.26), p = 0.04] were associated with SAC occurrence. Cystic fibrosis etiology was associated with better survival on Kaplan-Meier curve (p < 0.001). SAC [HR 2.15 (1.07-4.32), p = 0.03] was independently associated with worst survival. The 29 symptomatic patients because of stenosis required endoscopic procedure, of whom 16 patients needed bronchial stent placement. Four patients underwent surgery: three patients because of dehiscence and one because of severe bilateral stenosis (re-transplantation). DISCUSSION: SAC occurred in 26.5% of patients. Donor lung infection was the only alterable identified factors. The increase rate of SAC in older patients above 50 years of age encourages in regular endoscopic monitoring.

Immune alveolitis in interstitial lung disease: an attractive cytological profile in immunocompromised patients.

BACKGROUND: Bronchoalveolar lavage (BAL) is a major diagnostic tool in interstitial lung disease (ILD). Its use remains largely quantitative, usually focused on cell differential ratio. However, cellular morphological features provide additional valuable information. The significance of the "immune alveolitis" cytological profile, characterized by lymphocytic alveolitis with activated lymphocytes and macrophages in epithelioid transformation or foamy macrophages desquamating in cohesive clusters with lymphocytes, remains unknown in ILD. Our objective was to describe patients' characteristics and diagnoses associated with an immune alveolitis profile in undiagnosed ILD. METHODS: We performed a monocentric retrospective observational study. Eligible patients were adults undergoing diagnostic exploration for ILD and whose BAL fluid displayed an immune alveolitis profile. For each patient, we collected clinical, radiological and biological findings as well as the final etiology of ILD. RESULTS: Between January 2012 and December 2018, 249 patients were included. Mean age was 57 ± 16 years, 140 patients (56%) were men, and 65% of patients were immunocompromised. The main etiological diagnosis was Pneumocystis pneumonia (PCP) (24%), followed by drug-induced lung disease (DILD) (20%), viral pneumonia (14%) and hypersensitivity pneumonitis (HP) (10%). All PCP were diagnosed in immunocompromised patients while HP was found in only 8% of this subgroup. DILD and viral pneumonia were also commonly diagnosed in immunocompromised patients (94% and 80%, respectively). CONCLUSION: Our study highlights the additional value of BAL qualitative description in ILD. We suggest incorporating the immune alveolitis profile for the diagnosis and management of ILD, especially in immunocompromised patients, since it guides towards specific diagnoses.

Involvement of the M-CSF/IL-34/CSF-1R pathway in malignant pleural mesothelioma.

BACKGROUND: Malignant pleural mesothelioma (MPM) is a rare and aggressive cancer related to asbestos exposure. The tumor microenvironment content, particularly the presence of macrophages, was described as crucial for the development of the disease. This work aimed at studying the involvement of the M-CSF (CSF-1)/IL-34/CSF-1R pathway in the formation of macrophages in MPM, using samples from patients. METHODS: Pleural effusions (PEs), frozen tumors, primary MPM cells and MPM cell lines used in this study belong to biocollections associated with clinical databases. Cytokine expressions were studied using real-time PCR and ELISA. The Cancer Genome Atlas database was used to confirm our results on an independent cohort. An original three-dimensional (3D) coculture model including MPM cells, monocytes from healthy donors and a tumor antigen-specific cytotoxic CD8 T cell clone was used. RESULTS: We observed that high interleukin (IL)-34 levels in PE were significantly associated with a shorter survival of patients. In tumors, expression of CSF1 was correlated with 'M2-like macrophages' markers, whereas this was not the case with IL34 expression, suggesting two distinct modes of action of these cytokines. Expression of IL34 was higher in MPM cells compared with primary mesothelial cells. Particularly, high expression of IL34 was observed in MPM cells with an alteration of CDKN2A. Finally, using 3D coculture model, we demonstrated the direct involvement of MPM cells in the formation of immunosuppressive macrophages, through activation of the colony stimulating factor-1 receptor (CSF1-R) pathway, causing the inhibition of cytotoxicity of tumor antigen-specific CD8+ T cells. CONCLUSIONS: The M-CSF/IL-34/CSF-1R pathway seems strongly implicated in MPM and could constitute a therapeutic target to act on immunosuppression and to support immunotherapeutic strategies.

Impact of Silicone Stent Placement in Symptomatic Airway Obstruction due to Non-Small Cell Lung Cancer - A French Multicenter Randomized Controlled Study: The SPOC Trial.

BACKGROUND: Therapeutic bronchoscopy (TB) is an accepted strategy for the symptomatic management of central airway malignant obstruction. Stent insertion is recommended in case of extrinsic compression, but its value in preventing airway re-obstruction after endobronchial treatment without extrinsic compression is unknown. OBJECTIVE: Silicone stent Placement in symptomatic airway Obstruction due to non-small cell lung Cancer (SPOC) is the first randomized controlled trial investigating the potential benefit of silicone stent insertion after successful TB in symptomatic malignant airway obstruction without extrinsic compression. METHOD: We planned an inclusion of 170 patients in each group (stent or no stent) over a period of 3 years with 1-year follow-up. The 1-year survival rate without symptomatic local recurrence was the main endpoint. Recurrence rate, survival, quality of life, and stent tolerance were secondary endpoints. During 1-year follow-up, clinical events were monitored by flexible bronchoscopies and were evaluated by an independent expert committee. RESULTS: Seventy-eight patients (mean age 65 years) were randomized into 2 arms: stents (n = 40) or no stents (n = 38) after IB. Consequently, our main endpoint could not be statistically answered. Improvement of dyspnea symptoms is noticeable in each group but lasts longer in the stent group. Stents do not change the survival curve but reduce unattended bronchoscopies. In the no stent group, 19 new TB were performed with 16 stents inserted contrasting with 10 rigid bronchoscopies and 3 stents placed in the stent group. In a subgroup analysis according to the oncologic management protocol following TB (first-line treatment and other lines or palliation), the beneficial effect of stenting on obstruction recurrence was highly significant (p < 0.002), but was not observed in the naïve group, free from first-line chemotherapy. CONCLUSION: Silicone stent placement maintains the benefit of TB after 1 year on dyspnea score, obstruction's recurrence, and the need for new TB. Stenting does not affect the quality of life and is suggested for patients after failure of first-line chemotherapy. It is not suggested in patients without previous oncologic treatment.

Frequent Homozygous Deletions of Type I Interferon Genes in Pleural Mesothelioma Confer Sensitivity to Oncolytic Measles Virus.

INTRODUCTION: Oncolytic immunotherapy is based on the use of nonpathogenic replicative oncolytic viruses that infect and kill tumor cells exclusively. Recently, we found that the spontaneous oncolytic activity of the Schwarz strain of measles virus (MV) against human malignant pleural mesothelioma (MPM) depends on defects in the antiviral type I interferon (IFN-I) response in tumor cells. METHODS: In this study, we studied three independent human MPM bio-collections to identify the defects in the IFN-I responses in tumor cells. RESULTS: We show that the most frequent defect is the homozygous deletions (HDs) of all the 14 IFN-I genes (IFN-α and IFN-ß) that we found in more than half of MV-sensitive MPM cell lines. These HDs occur together with the HDs of the tumor suppressor gene CDKN2A also located in the 9p21.3 chromosome region. Therefore, the IFN-I-/- MPM cell lines develop a partial and weak IFN-I response when they are exposed to the virus compared with that of normal cells and MV-resistant MPM cell lines. This response consists of the expression of a restricted number of IFN-stimulated genes that do not depend on the presence of IFN-I. In addition, the IFN-I-/- MPM cell lines infected by MV also develop a pro-inflammatory response associated with stress of the endoplasmic reticulum. CONCLUSION: Our study emphasizes the link between HDs of IFN-I encoding genes and the CDKN2A gene in MPM and sensitivity to MV oncolytic immunotherapy.

Brain-derived neurotrophic factor, a new soluble biomarker for malignant pleural mesothelioma involved in angiogenesis.

Malignant pleural mesothelioma (MPM) is a rare and aggressive cancer related to asbestos exposure. The discovery of soluble biomarkers with diagnostic/prognostic and/or therapeutic properties would improve therapeutic care of MPM patients. Currently, soluble biomarkers described present weaknesses preventing their use in clinic. This study aimed at evaluating brain-derived neurotrophic factor (BDNF), we previously identified using transcriptomic approach, in MPM. We observed that high BDNF expression, at the mRNA level in tumors or at the protein level in pleural effusions (PE), was a specific hallmark of MPM samples. This protein presented significant but limited diagnostic properties (area under the curve (AUC) = 0.6972, p < 0.0001). Interestingly, high BDNF gene expression and PE concentration were predictive of shorter MPM patient survival (13.0 vs 8.3 months, p < 0.0001, in PE). Finally, BDNF did not affect MPM cell oncogenic properties but was implicated in PE-induced angiogenesis. In conclusion, BDNF appears to be a new interesting biomarker for MPM and could also be a new therapeutic target regarding its implication in angiogenesis.

Pleural Effusions from Patients with Mesothelioma Induce Recruitment of Monocytes and Their Differentiation into M2 Macrophages.

INTRODUCTION: Mesothelioma is a rare and aggressive cancer related to asbestos exposure. We recently showed that pleural effusions (PEs) from patients with mesothelioma contain high levels of the C-C motif chemokine ligand 2 (CCL2) inflammatory chemokine. In the present work, we studied the effect of CCL2 contained in mesothelioma samples, particularly on monocyte recruitment. Then, we studied the fate of these monocytes in malignant pleural mesothelioma (MPM) PEs and their impact on tumor cells' properties. METHODS: The implication of CCL2 in monocyte recruitment was evaluated using transmigration assays and a CCL2 blocking antibody. The phenotype of macrophages was determined by flow cytometry and enzyme-linked immunosorbent assay. Immunohistochemical analysis was used to support the results. Cocultures of macrophages with mesothelioma cells were performed to study cancer cell proliferation and resistance to treatment. RESULTS: We showed that CCL2 is a major factor of monocyte recruitment induced by MPM samples. Macrophages obtained in MPM samples were M2 macrophages (high CD14, high CD163, and interleukin-10 secretion after activation). The colony-stimulating factor 1 receptor/macrophage colony-stimulating factor (M-CSF) pathway is implicated in M2 polarization, and high levels of M-CSF were measured in MPM samples compared with benign PE (4.17 ± 2.75 ng/mL and 1.94 ± 1.47 ng/mL, respectively). Immunohistochemical analysis confirmed the presence of M2 macrophages in pleural and peritoneal mesothelioma. Finally, we showed that M2 macrophages increased mesothelioma cell proliferation and resistance to treatment. CONCLUSIONS: These results demonstrate the implication of CCL2 in MPM pathogenesis and designate M-CSF as a new potential biomarker of MPM. This study also identifies CCL2 and colony-stimulating factor 1 receptor/M-CSF as interesting new targets to modulate pro-tumorigenic properties of the tumor microenvironment.

Respiratory Conditions Associated with Tracheobronchomegaly (Mounier-Kuhn Syndrome): A Study of Seventeen Cases.

BACKGROUND: Mounier-Kuhn syndrome (MKS) is a rare disorder characterized by enlargement of the trachea and main bronchi and associated with recurrent respiratory tract infections. OBJECTIVE: This multicenter, retrospective study was carried out to describe respiratory conditions associated with tracheobronchomegaly. METHODS: Nine institutions involved in the 'Groupe d'Endoscopie de Langue Française' (GELF) participated in this study. A standard form was used to record patient characteristics, treatments and follow-up from medical charts. RESULTS: Seventeen patients, 53% male, aged 58 ± 18 years at diagnosis were included. Recurrent infections revealed MKS in 88% of cases. Main comorbid conditions were diffuse bronchiectasis in 88% of patients and tracheobronchomalacia in 67% of cases. The exacerbation rate was 1.5 exacerbations/patient/year. The main non-respiratory morbid condition was gastroesophageal reflux disease in 29% of cases. Interventional bronchoscopy was performed in seven patients (41%), consisting of laser (n = 2) and tracheal stenting (n = 5). Complications related to stents were observed in 80% of cases with a mean stent duration of 8 months. Four deaths, including three due to respiratory causes, occurred during follow-up. CONCLUSIONS: This is the largest series of MKS reported in the literature, showing that bronchiectasis and tracheobronchomalacia are the main associated morbid conditions that constitute a challenge for treatment.

Sensitivity of human pleural mesothelioma to oncolytic measles virus depends on defects of the type I interferon response.

Attenuated measles virus (MV) is currently being evaluated as an oncolytic virus in clinical trials and could represent a new therapeutic approach for malignant pleural mesothelioma (MPM). Herein, we screened the sensitivity to MV infection and replication of twenty-two human MPM cell lines and some healthy primary cells. We show that MV replicates in fifteen of the twenty-two MPM cell lines. Despite overexpression of CD46 by a majority of MPM cell lines compared to healthy cells, we found that the sensitivity to MV replication did not correlate with this overexpression. We then evaluated the antiviral type I interferon (IFN) responses of MPM cell lines and healthy cells. We found that healthy cells and the seven insensitive MPM cell lines developed a type I IFN response in presence of the virus, thereby inhibiting replication. In contrast, eleven of the fifteen sensitive MPM cell lines were unable to develop a complete type I IFN response in presence of MV. Finally, we show that addition of type I IFN onto MV sensitive tumor cell lines inhibits replication. These results demonstrate that defects in type I IFN response are frequent in MPM and that MV takes advantage of these defects to exert oncolytic activity.

No impact of passive smoke on the somatic profile of lung cancers in never-smokers.

EGFR and HER2 mutations and ALK rearrangement are known to be related to lung cancer in never-smokers, while KRAS, BRAF and PIK3CA mutations are typically observed among smokers. There is still debate surrounding whether never-smokers exposed to passive smoke exhibit a "smoker-like" somatic profile compared with unexposed never-smokers. Passive smoke exposure was assessed in the French BioCAST/IFCT-1002 never-smoker lung cancer cohort and routine molecular profiles analyses were compiled. Of the 384 patients recruited into BioCAST, 319 were tested for at least one biomarker and provided data relating to passive smoking. Overall, 219 (66%) reported having been exposed to passive smoking. No significant difference was observed between mutation frequency and passive smoke exposure (EGFR mutation: 46% in never exposed versus 41% in ever exposed; KRAS: 7% versus 7%; ALK: 13% versus 11%; HER2: 4% versus 5%; BRAF: 6% versus 5%; PIK3CA: 4% versus 2%). We observed a nonsignificant trend for a negative association between EGFR mutation and cumulative duration of passive smoke exposure. No association was found for other biomarkers. There is no clear association between passive smoke exposure and somatic profile in lifelong, never-smoker lung cancer.

Oncolytic virotherapy for human malignant mesothelioma: recent advances.

Cancer virotherapy is an attractive alternative to conventional treatments because it offers a wide range of antitumor effects due to 1) the diversity of the oncolytic viruses that are now available and 2) their multifaceted activities against both tumor cells and tumor vessels, in addition to their ability to induce antitumor immune responses. In this review, we summarize preclinical and clinical data regarding the targeting of malignant mesothelioma (MM) by oncolytic viruses. We also discuss the potential of other oncolytic viruses that have already shown antitumor effects against several malignancies in advanced clinical trials but are yet to be tested against MM cells. Finally, we review how the activation of the immune system and combinations with other types of anticancer treatments could support the development of oncolytic virotherapy for the treatment of MM.

Cisplatin in combination with Phenethyl Isothiocyanate (PEITC), a potential new therapeutic strategy for malignant pleural mesothelioma.

Malignant pleural mesothelioma (MPM) is a very aggressive form of cancer with a poor diagnosis and prognosis. The first line treatment for MPM is a combination of cisplatin and Pemetrexed, which displayed limited efficacy and severe side effects. The naturally occurring compound phenethyl isothiocyanate (PEITC) previously showed interesting anti-tumor properties on several cancer cell lines. We thus aim at evaluating PEITC used alone or in combination with cisplatin in order to improve MPM treatment. Nine MPM cell lines and primary mesothelial cells (PMC), co-cultured or not with M2 macrophages present in MPM microenvironment, were used to assess PEITC and cisplatin anti-tumor properties. Compounds were used alone or in combination. Both PEITC and cisplatin were cytotoxic on MPM cells in a dose dependent manner. We herein showed that PEITC-induced cytotoxicity was due to the generation of reactive oxygen species. Moreover, we showed that cisplatin-PEITC combination allowed the potentialization of both compounds' cytotoxic effects and prevented the emergence of resistant MPM cells. Interestingly, PMC were not sensitive to the combination. Finally, we showed that M2 macrophages did not alter the anti-tumor properties of the combination. Cisplatin-PEITC combination thus represents a promising strategy to induce a selective toxicity towards malignant cells.

A new endoscopic standardized grading system for macroscopic central airway complications following lung transplantation: the MDS classification.

OBJECTIVES: After lung transplant, between 9 and 13% of bronchial anastomoses develop complications severe enough to warrant therapeutic intervention. These complications include stenosis, dehiscence, granulation tissue, bronchomalacia and fistula. Most of these have already been included in a classification or another, but none of these have been universally accepted. Moreover, no grading system has integrated all of these complications. The Groupe Transplantation (GT) (Transplant Group), from the Société de Pneumologie de Langue Française (SPLF) [French Language Pulmonology Society], maintains a prospective national registry of lung transplants performed in France. The GT has mandated the Groupe d'Endoscopie de Langue Française (GELF), also from the SPLF, to develop an endoscopic classification, in order to describe the macroscopic aspect of the bronchial anastomoses, and downhill airways, using a standardized and exhaustive grading system. METHODS: An endoscopic classification that would take into account the three major aspects of the description of bronchial anastomoses was elaborated. The first parameter is the macroscopic aspect (M), the second, the diameter (D) of the anastomosis and the third, the sutures (S) of the anastomosis. This classification was then submitted to expert bronchoscopists from nine centres, responsible for lung transplants in France, for their opinion, using a five-item questionnaire, according to the Delphi methodology. RESULTS: After the first round of consultation, all experts (100%) agreed on Questions 1 and 4. Answers were positive for Questions 2 (59%), 3 (56.25%) and 5 (70%). A modified classification, incorporating propositions from the first round, was then submitted. This second round allowed a consensus to be reached between all experts: the MDS classification. Each parameter (M, D and S) can be classified from 0 to 3. For M and D, it is possible to determine the extent of abnormalities downhill from the anastomosis into four subgroups (a, b, c or d). For S, the localization of abnormalities can be divided between two subgroups (e and f). CONCLUSION: The MDS classification, established by a consensus of French experts in bronchoscopy, could represent a standardized, universally acceptable system to describe central airway complications after lung transplant.

CCL2, galectin-3, and SMRP combination improves the diagnosis of mesothelioma in pleural effusions.

INTRODUCTION: Malignant pleural mesothelioma (MPM) is a highly aggressive tumor with poor prognosis. One major challenge for this disease is the development of new, early, and highly reliable diagnostic markers. The aim of this study was to compare the diagnostic value of the chemokine chemokine (C-C motif) ligand 2 (CCL2), galectin-3, and the secretory leukocyte peptidase inhibitor (SLPI) with soluble mesothelin-related peptides (SMRP), and to evaluate the diagnostic performance of marker combinations. METHODS: The levels of the different markers were measured by enzyme-linked immunosorbent assay in pleural fluids from patients with MPM (n = 61), adenocarcinomas (ADCA, n = 25), or with benign pleural effusions (BPE, n = 15). RESULTS: SMRP, SLPI, and CCL2 concentrations were significantly higher in pleural effusions from mesothelioma patients. Conversely, galectin-3 levels seemed to be elevated in patients with pulmonary ADCA. Receiver operating characteristic curve analysis revealed that SMRP (area under the curve [AUC] = 0.9059), CCL2 (AUC = 0.7912), galectin-3 (AUC = 0.7584), and SLPI (AUC = 0.7219) were potentially interesting biomarkers for the differentiation of MPM patients from those with BPE or ADCA. Of interest, we showed that the combination of SMRP/CCL2/galectin-3 greatly improved MPM diagnosis (AUC = 0.9680), when compared with SMRP alone. CONCLUSION: The combination of SMRP/CCL2/galectin-3 seems to represent a promising panel of biomarkers for the reliable diagnosis of MPM in pleural fluids.

Identification of novel markers for the diagnosis of malignant pleural mesothelioma.

The diagnosis of malignant pleural mesothelioma is difficult, with the most common differential diagnoses being benign pleural diseases and metastatic adenocarcinomas (ADCA). To identify novel markers that would be able to improve diagnostic accuracy, we performed a genome-wide gene expression analysis on tumor cell lines established from pleural effusions (malignant pleural mesothelioma and lung ADCA). This analysis led to the identification of genes encoding novel and pertinent cellular and soluble markers, for which the expression was validated by real-time RT-PCR. Immunohistochemical staining of tumor biopsy specimens with anti-type III collagen antibodies showed positive labeling for mesothelioma cells but not for ADCA cells. Using enzyme-linked immunosorbent assay, we showed that the C-C motif chemokine 2 (CCL2) concentration was significantly higher in pleural effusions from patients with mesothelioma (n = 61) than in subjects with ADCA (n = 25) or with benign pleural effusions (n = 15): median (interquartile range) = 2.99 ng/ml (1.76 to 6.01) vs 0.99 ng/ml (0.51 to 1.83) and 1.47 ng/ml (0.80 to 1.56), respectively, P < 0.0001. Conversely, the galectin-3 concentration was lower in mesothelioma: 11.50 ng/ml (6.73 to 23.53) vs 24.74 ng/ml (20.42 to 70.35) and 17.64 ng/ml (14.81 to 24.68), respectively, P < 0.0001. The areas under the curve for CCL2 were 0.8030 and 0.7716 for the differentiation of mesothelioma from ADCA or benign pleural effusions, respectively. Similarly, the areas under the curve obtained for galectin-3 were 0.7980 and 0.6923, respectively. In conclusion, type III collagen, CCL2, and galectin-3 are promising new diagnostic markers for mesothelioma.

Aberrant splicing and protease involvement in mesothelin release from epithelioid mesothelioma cells.

Elevated amounts of soluble mesothelin-related proteins (SMRP) have already been reported in sera and pleural effusions from mesothelioma patients, providing a useful diagnostic marker for malignant pleural mesothelioma (MPM). However, the origin of SMRP is not yet understood. Production of SMRP could be related to abnormal splicing events leading to synthesis of a secreted protein (release) or to an enzymatic cleavage from membrane-bound mesothelin (ectodomain shedding). To test these hypotheses, we used a panel of mesothelioma cells established in culture from pleural effusions of MPM patients. Our in vitro results confirmed specific mesothelin expression and SMRP production in supernatants from epithelioid MPM cell lines, thus providing a relevant cellular model to study soluble mesothelin production mechanisms. The expression of mesothelin-encoding RNA variants was screened by reverse transcription-polymerase chain reaction experiments. Protease involvement in mesothelin cleavage from the cellular surface was investigated by treatment of MPM cells with GM6001, a broad-spectrum MMP- and ADAM-family inhibitor. GM6001 treatment significantly impaired SMRP production by MPM cell lines, in favor of an enzymatic-mediated shedding process. In addition, a splice variant transcript of mesothelin (variant 3) was detected in these MPM cell lines, in accordance with the release of a secreted part of the protein. Our results indicate that both mechanisms could be implicated in soluble mesothelin production by epithelioid mesothelioma cells.