Identification of FGFR4 as a regulator of myofibroblast differentiation in Pulmonary Fibrosis.

Introduction IPF is a devastating lung disease with limited therapeutic options. FGFR4 is a known receptor for several paracrine Fibroblast growth factors (FGFs). FGFR4 is also the main receptor for FGF19, an endocrine FGF that was demonstrated by our group to have anti-fibrotic properties in the lung. We aimed to determine whether FGFR4 could modulate pulmonary fibrogenesis. Methods We assessed FGFR4 mRNA and protein levels in IPF and control lungs. In vitro, we determined the effect of TGF-b, Endothelin-1 and PDGF on FGFR4 expression in human lung fibroblasts. We determined the effect FGFR4 inhibition, using a specific pharmacological inhibitor (FGF401), or genetic deletion in murine embryonic fibroblasts (MEFs) on TGF-b-induced myofibroblastic differentiation. In vivo, we evaluated the development of bleomycin-induced lung fibrosis in Fgfr4-deficient (Fgfr4-/-) mice compared to Wild Type littermates (WT), and after FGF401 treatment in WT mice compared to a control group receiving the solvent only. Results FGFR4 was decreased in IPF lungs as compared to control lungs, at mRNA and protein levels. In vitro, FGFR4 was downregulated after treatment by TGF- ß, Endothelin-1 and PDGF. In vitro, FGFR4 inhibition by FGF401 prevented TGF-b1-induced collagen and ACTA2 increase in lung fibroblasts. Similar results were observed in Fgfr4-/- MEFs. In vivo, FGFR4 genetic deficiency or FGFR4 pharmacological inhibition did not modulate bleomycin-induced pulmonary fibrosis. Conclusion Our data suggest that FGFR4 exerts pro-fibrotic properties by enhancing TGF- ß signaling in vitro. However, the inhibition of FGFR4 is not sufficient to prevent the development of pulmonary fibrosis in vivo.

High risk of lung cancer in surfactant-related gene variant carriers.

BACKGROUND: Several rare surfactant-related gene (SRG) variants associated with interstitial lung disease are suspected to be associated with lung cancer, but data are missing. We aimed to study the epidemiology and phenotype of lung cancer in an international cohort of SRG variant carriers. METHODS: We conducted a cross-sectional study of all adults with SRG variants in the OrphaLung network and compared lung cancer risk with telomere-related gene (TRG) variant carriers. RESULTS: We identified 99 SRG adult variant carriers (SFTPA1 (n=18), SFTPA2 (n=31), SFTPC (n=24), ABCA3 (n=14) and NKX2-1 (n=12)), including 20 (20.2%) with lung cancer (SFTPA1 (n=7), SFTPA2 (n=8), SFTPC (n=3), NKX2-1 (n=2) and ABCA3 (n=0)). Among SRG variant carriers, the odds of lung cancer was associated with age (OR 1.04, 95% CI 1.01-1.08), smoking (OR 20.7, 95% CI 6.60-76.2) and SFTPA1/SFTPA2 variants (OR 3.97, 95% CI 1.39-13.2). Adenocarcinoma was the only histological type reported, with programmed death ligand-1 expression ≥1% in tumour cells in three samples. Cancer staging was localised (I/II) in eight (40%) individuals, locally advanced (III) in two (10%) and metastatic (IV) in 10 (50%). We found no somatic variant eligible for targeted therapy. Seven cancers were surgically removed, 10 received systemic therapy, and three received the best supportive care according to their stage and performance status. The median overall survival was 24 months, with stage I/II cancers showing better survival. We identified 233 TRG variant carriers. The comparative risk (subdistribution hazard ratio) for lung cancer in SRG patients versus TRG patients was 18.1 (95% CI 7.1-44.7). CONCLUSIONS: The high risk of lung cancer among SRG variant carriers suggests specific screening and diagnostic and therapeutic challenges. The benefit of regular computed tomography scan follow-up should be evaluated.

Cystic lung in sarcoidosis: Clinico-radiologic characteristic and evolution.

BACKGROUND AND OBJECTIVE: Sarcoidosis can manifest with atypical findings on chest computed tomography (CT). Cysts are a rare manifestation of lung sarcoidosis. The aim of the study was to describe a series of patients with cystic sarcoidosis and their clinical-radiological characteristics and progression. METHODS: In this retrospective, bicentric study we recruited all patients affected by sarcoidosis with lung cystic lesions at chest CT. We collected clinical characteristics, pulmonary tests and tracked number, distribution and size of the cysts at diagnosis and at the last evaluation. RESULTS: Twelve patients (6 males, median age 53 years) were identified (prevalence: 1.9%; 95% Confidence Interval: 0.8%-2.9%). All patients presented multiple cystic lesions (median number: 14 [range: 2-216]) with a bilateral distribution in 10/12, micronodules and nodules in 11/12 and fibrotic lesions in 4/12. Seven patients had normal lung function test, three had an obstructive syndrome, one had a restrictive syndrome and one had coexistence of both. During follow-up (median: 10 years [range 1-16 years]), an increase of the number of cysts was observed in four patients. At last evaluation, 3/12 patients experienced a decline of forced vital capacity >10% and 3/12 patients a decline of diffusing capacity for carbon monoxide (DLCO) >10%. A lower DLCO at diagnosis, and the presence of nodules or fibrotic lesions on CT were associated with an increase in the number of cysts. CONCLUSION: Cystic lung lesions are rare in patients with sarcoidosis and do not influence long term prognosis.

[Exogenous lipid pneumonia]. / Pneumopathie lipidique exogène.

Exogenous lipid pneumonia is an underdiagnosed pathology due to acute or chronic inhalation of lipid substances (paraffin oil, nasal drops, etc.). The clinical and CT appearance is polymorphic, ranging from fibrosing interstitial lung disease to a pseudo-tumoral nodule. The key to CT diagnosis is fatty hypodensity within condensations. The key to histopathological diagnosis is the presence of macrovacuoles in the macrophages, Oil-red-O+(on fresh/frozen material). The differential diagnosis is represented by endogenous lipid pneumonia, common and associated with bronchial obstruction, with necrotic changes, and specific entities such as alveolar proteinosis, hoarding (Niemann-Pick disease) or cordarone treatment.

FGF19 Is Downregulated in Idiopathic Pulmonary Fibrosis and Inhibits Lung Fibrosis in Mice.

Idiopathic pulmonary fibrosis (IPF) is a devastating lung disease with limited therapeutic possibilities. FGF19 (fibroblast growth factor 19), an endocrine FGF, was recently shown to decrease liver fibrosis. To ask whether FGF19 had antifibrotic properties in the lung and decipher its effects on common features associated with lung fibrogenesis, we assessed, by ELISA, FGF19 concentrations in plasma and BAL fluids obtained from control subjects and patients with IPF. In vivo, using an intravenously administered adeno11-associated virus, we overexpressed FGF19 at the fibrotic phase of two experimental models of murine lung fibrosis and assessed its effect on lung morphology, lung collagen content, fibrosis markers, and profibrotic mediator expression at mRNA and protein levels. In vitro, we investigated whether FGF19 could modulate the TGF-ß-induced differentiation of primary human lung fibroblasts into myofibroblasts and the apoptosis of murine alveolar type II cells. Although FGF19 was not detected in BAL fluid, FGF19 concentration was decreased in the plasma of patients with IPF compared with control subjects. In vivo, the overexpression of FGF19 was associated with a marked decrease of lung fibrosis and fibrosis markers, with a decrease of profibrotic mediator expression and lung collagen content. In vitro, FGF19 decreased alveolar type 2 epithelial cell apoptosis through the decrease of the proapoptotic BIM protein expression and prevented TGF-ß-induced myofibroblast differentiation through the inhibition of JNK phosphorylation. Altogether, these data identify FGF19 as an antifibrotic molecule with potential therapeutic interest in fibrotic lung disorders.

NADPH oxidase DUOX1 sustains TGF-ß1 signalling and promotes lung fibrosis.

Interstitial lung fibroblast activation coupled with extracellular matrix production is a pathological signature of pulmonary fibrosis, and is governed by transforming growth factor (TGF)-ß1/Smad signalling. TGF-ß1 and oxidative stress cooperate to drive fibrosis. Cells can produce reactive oxygen species through activation and/or induction of NADPH oxidases, such as dual oxidase (DUOX1/2). Since DUOX enzymes, as extracellular hydrogen peroxide (H2O2--)-generating systems, are involved in extracellular matrix formation and in wound healing in different experimental models, we hypothesised that DUOX-based NADPH oxidase plays a role in the pathophysiology of pulmonary fibrosis.Our in vivo data (idiopathic pulmonary fibrosis patients and mouse models of lung fibrosis) showed that the NADPH oxidase DUOX1 is induced in response to lung injury. DUOX1-deficient mice (DUOX1+/- and DUOX1-/-) had an attenuated fibrotic phenotype. In addition to being highly expressed at the epithelial surface of airways, DUOX1 appears to be well expressed in the fibroblastic foci of remodelled lungs. By using primary human and mouse lung fibroblasts, we showed that TGF-ß1 upregulates DUOX1 and its maturation factor DUOXA1 and that DUOX1-derived H2O2 promoted the duration of TGF-ß1-activated Smad3 phosphorylation by preventing phospho-Smad3 degradation. Analysis of the mechanism revealed that DUOX1 inhibited the interaction between phospho-Smad3 and the ubiquitin ligase NEDD4L, preventing NEDD4L-mediated ubiquitination of phospho-Smad3 and its targeting for degradation.These findings highlight a role for DUOX1-derived H2O2 in a positive feedback that amplifies the signalling output of the TGF-ß1 pathway and identify DUOX1 as a new therapeutic target in pulmonary fibrosis.

Specific Genomic Alterations in High-Grade Pulmonary Neuroendocrine Tumours with Carcinoid Morphology.

INTRODUCTION: High-grade lung neuroendocrine tumours with carcinoid morphology have been recently reported; they may represent the thoracic counterparts of grade 3 digestive neuroendocrine tumours. We aimed to study their genetic landscape including analysis of tumoral heterogeneity. METHODS: Eleven patients with high-grade (>20% Ki-67 and/or >10 mitoses) lung neuroendocrine tumours with a carcinoid morphology were included. We analysed copy number variations, somatic mutations, and protein expression in 16 tumour samples (2 samples were available for 5 patients allowing us to study spatial and temporal heterogeneity). RESULTS: Genomic patterns were heterogeneous ranging from "quiet" to tetraploid, heavily rearranged genomes. Oncogene mutations were rare and most genetic alterations targeted tumour suppressor genes. Chromosomes 11 (7/11), 3 (6/11), 13 (4/11), and 6-17 (3/11) were the most frequently lost. Altered tumour suppressor genes were common to both carcinoids and neuroendocrine carcinomas, involving different pathways including chromatin remodelling (KMT2A, ARID1A, SETD2, SMARCA2, BAP1, PBRM1, KAT6A), DNA repair (MEN1, POLQ, ATR, MLH1, ATM), cell cycle (RB1, TP53, CDKN2A), cell adhesion (LATS2, CTNNB1, GSK3B) and metabolism (VHL). Comparative spatial/temporal analyses confirmed that these tumours emerged from clones of lower aggressivity but revealed that they were genetically heterogeneous accumulating "neuroendocrine carcinoma-like" genetic alterations through progression such as TP53/RB1 alterations. CONCLUSION: These data confirm the importance of chromatin remodelling genes in pulmonary carcinoids and highlight the potential role of TP53 and RB1 to drive the transformation in more aggressive high-grade tumours.

Functional assessment and phenotypic heterogeneity of SFTPA1 and SFTPA2 mutations in interstitial lung diseases and lung cancer.

INTRODUCTION: Interstitial lung diseases (ILDs) can be caused by mutations in the SFTPA1 and SFTPA2 genes, which encode the surfactant protein (SP) complex SP-A. Only 11 SFTPA1 or SFTPA2 mutations have so far been reported worldwide, of which five have been functionally assessed. In the framework of ILD molecular diagnosis, we identified 14 independent patients with pathogenic SFTPA1 or SFTPA2 mutations. The present study aimed to functionally assess the 11 different mutations identified and to accurately describe the disease phenotype of the patients and their affected relatives. METHODS: The consequences of the 11 SFTPA1 or SFTPA2 mutations were analysed both in vitro, by studying the production and secretion of the corresponding mutated proteins and ex vivo, by analysing SP-A expression in lung tissue samples. The associated disease phenotypes were documented. RESULTS: For the 11 identified mutations, protein production was preserved but secretion was abolished. The expression pattern of lung SP-A available in six patients was altered and the family history reported ILD and/or lung adenocarcinoma in 13 out of 14 families (93%). Among the 28 SFTPA1 or SFTPA2 mutation carriers, the mean age at ILD onset was 45 years (range 0.6-65 years) and 48% underwent lung transplantation (mean age 51 years). Seven carriers were asymptomatic. DISCUSSION: This study, which expands the molecular and clinical spectrum of SP-A disorders, shows that pathogenic SFTPA1 or SFTPA2 mutations share similar consequences for SP-A secretion in cell models and in lung tissue immunostaining, whereas they are associated with a highly variable phenotypic expression of disease, ranging from severe forms requiring lung transplantation to incomplete penetrance.

Interaction between PGI2 and ET-1 pathways in vascular smooth muscle from Group-III pulmonary hypertension patients.

Pulmonary hypertension (PH) is characterized by an elevation of mean pulmonary artery pressure and it is classified into five groups. Among these groups, PH Group-III is defined as PH due to lung disease or hypoxia. Prostacyclin (PGI2) analogues (iloprost, treprostinil) and endothelin-1 (ET-1) receptor antagonists (ERA) (used alone or in combination) are therapies used for treating PH. The mechanisms underlying the positive/negative effects of combination treatment are not well documented, and in this study, we tested the hypothesis that the combination of a PGI2 analogue (iloprost, treprostinil) and an ERA may be more effective than either drug alone to treat vasculopathies observed in PH Group-III patients. Using Western blotting, ETA and ETB receptor expression were determined in human pulmonary artery (HPA) preparations derived from control and PH Group-III patients, and the physiologic impact of altered expression ratios was assessed by measuring ET-1 induced contraction of ex vivo HPA and human pulmonary veins (HPV) in an isolated organ bath system. In addition, the effects of single agent or combination treatments with a PGI2 analogue and an ERA on ET-1 release and HPA smooth muscle cells (hPASMCs) proliferation were determined by ELISA and MTT techniques, respectively. Our results indicate that the increased ETA/ETB receptor expression ratio in HPA derived from PH Group-III patients is primarily governed by a greatly depressed ETB receptor expression. However, contractions induced by ET-1 are not impacted in HPA and HPV derived from PH Group-III patients as compared to controls. Also, we found that the combination of an ETA receptor antagonist (BQ123) with iloprost provides greater inhibition of hPASMCs proliferation (-48±14% control; -32±06% PH) than either agent alone. Of note, while the ETB receptor antagonist (BQ788) increases ET-1 production from PH Group-III patients' preparations (HPA, parenchyma), even under these more proliferative conditions, iloprost and treprostinil are still effective to inhibit hPASMCs proliferation (-22/-24%). Our findings may provide new insights for the treatment of PH Group-III by combining a PGI2 analogue and a selective ETA receptor antagonist.

Regulator of telomere length 1 (RTEL1) mutations are associated with heterogeneous pulmonary and extra-pulmonary phenotypes.

Regulator of telomere length 1 (RTEL1) mutations have been evidenced in 5-9% of familial pulmonary fibrosis; however, the phenotype of patients with interstitial lung disease (ILD) and RTEL1 mutations is poorly understood.Whole exome sequencing was performed in 252 probands with ILD and we included all patients with ILD and RTEL1 mutation. RTEL1 expression was evaluated by immunochemistry in the lungs of controls, as well as in RTEL1 and telomerase reverse transcriptase (TERT) mutation carriers.We identified 35 subjects from 17 families. Median age at diagnosis of ILD was 53.1 years (range 28.0-80.6). The most frequent pulmonary diagnoses were idiopathic pulmonary fibrosis (n=20, 57%), secondary ILD (n=7, 20%) and unclassifiable fibrosis or interstitial pneumonia with autoimmune features (n=7, 20%). The median transplant-free and overall survival periods were 39.2 months and 45.3 months, respectively. Forced vital capacity at diagnosis was the only factor associated with decreased transplant-free survival. Extra-pulmonary manifestations were less frequent as compared to other telomere-related gene mutation carriers. A systematic analysis of the literature identified 110 patients with ILD and RTEL1 mutations (including this series) and confirmed the heterogeneity of the pulmonary phenotype, the prevalence of non-idiopathic diseases and the low prevalence of extra-pulmonary manifestations.Immunohistochemistry showed that RTEL1 was expressed by bronchial and alveolar epithelial cells, as well as by alveolar macrophages and lymphocytes, but not by fibroblasts.

Critical role of neutrophil extracellular traps (NETs) in patients with Behcet's disease.

OBJECTIVES: Behçet's disease (BD) is a chronic systemic vasculitis. Thrombosis is a frequent and life-threatening complication. The pathogenesis of BD is poorly understood and evidence supporting a role for primed neutrophils in BD-associated thrombotic risk is scant. To respond to inflammatory insults, neutrophils release web-like structures, known as neutrophil extracellular traps (NETs), which are prothrombotic. We evaluated the role of NETs and markers of NETs in BD. METHODS: Blood samples were collected from patients with BD, according to the International Study Group Criteria for Behçet's disease, and healthy donors (HD). NET components, including cell-free DNA (CfDNA) and neutrophil enzymes myeloperoxidase (MPO), were assessed in serum or in purified neutrophils from patients with BD and HD. RESULTS: Patients with active BD had elevated serum cfDNA levels and MPO-DNA complexes compared with patients with inactive BD and to HD. In addition, levels of cfDNA and MPO-DNA complexes were significantly higher in patients with BD with vascular involvement compared with those without vascular symptoms. Purified neutrophils from patients with BD exhibited spontaneous NETosis compared with HD. Thrombin generation in BD plasma was significantly increased and positively correlated with the levels of MPO-DNA complexes and cfDNA. Importantly, DNAse treatment significantly decreased thrombin generation in BD plasma but not in HD plasma. In addition, biopsy materials obtained from patients with BD showed NETs production in areas of vasculitic inflammation and thrombosis. CONCLUSIONS: Our data show that NETs and markers of NETS levels are elevated in patients with BD and contribute to the procoagulant state. Targeting NETs may represent a potential therapeutic target for the reduction or prevention of BD-associated thrombotic risk.

C4d detection and histological patterns in the diagnosis of antibody-mediated rejection after lung transplantation: a single-centre study.

AIMS: Antibody-mediated rejection (AMR) is an emerging and challenging issue in transplantation. Endothelial deposition of C4d and microvascular inflammation (MI) are reliable markers of AMR in renal and cardiac transplantation, but remain controversial in the lung. Our aim was to assess C4d immunohistochemistry and histological patterns for the diagnosis of lung AMR. METHODS AND RESULTS: We reviewed 158 transbronchial biopsies (TBBs) (n = 85 clinically indicated, and n = 73 surveillance TBBs) from 48 recipients, blinded to clinical and serological data. C4d was scored as 0, 1+ (<10%), 2+ (10-50%) or 3+ (>50%). TBBs were reassessed for MI and acute lung injury (ALI). Donor-specific antibodies (DSAs), acute clinical graft dysfunction and chronic lung allograft graft dysfunction (CLAD) were recorded. C4d3+, C4d2+, C4d1+ and C4d0 occurred respectively in four (2.5%), six (3.8%), 28 (17.7%) and 120 (75.9%) TBBs. MI and ALI were rare but more frequent in C4d1-3+ TBBs than in the absence of C4d. C4d2+ was frequently observed with concomitant infection. Among the surveillance TBBs, only two (2.7%) showed MI. Neither ALI nor C4d3+ was diagnosed on surveillance TBBs. No significant association was found between histopathological findings and DSAs. All four patients with C4d3+ could retrospectively be diagnosed with AMR and developed CLAD. CONCLUSION: Although rare, diffuse C4d deposition appears to be a strong indication of acute clinical AMR in lung transplant patients, whereas intermediate C4d2+ requires more investigations. In stable patients, histopathology and C4d may lack the sensitivity to diagnose subclinical AMR. This emphasises the need for a multidisciplinary evaluation of each suspected AMR case, and the need for complementary diagnostic tools.

Human airway trypsin-like protease exerts potent, antifibrotic action in pulmonary fibrosis.

Idiopathic pulmonary fibrosis (IPF) is characterized by the deposition of excessive extracellular matrix and the destruction of lung parenchyma, resulting from an aberrant wound-healing response. Although IPF is often associated with an imbalance in protease activity, the mechanisms underlying the sustained repair mechanisms are not fully understood. Here, we addressed the role of the recently identified, membrane-anchored serine protease human airway trypsin-like protease (HAT). In the present study, we show that both HAT expression and activity were up-regulated in human IPF specimens. Next, adenoviral overexpression of HAT before bleomycin challenge attenuated lung injury as well as extracellular matrix deposition in the bleomycin-induced pulmonary fibrosis model. In vitro, HAT prevented specific fibrosis-associated responses in primary human pulmonary fibroblasts and induced the expression of mediators associated with the prostaglandin E2 pathway. Altogether, our findings suggested that HAT could have a protective role in IPF and other fibrotic lung disorders.-Menou, A., Flajolet, P., Duitmen, J., Justet, A., Moog, S., Jaillet, M., Tabèze, L., Solhonne, B., Garnier, M., Mal, H., Mordant, P., Castier, Y., Cazes, A., Sallenave, J.-M., Mailleux, A. A., Crestani, B. Human airway trypsin-like protease exerts potent, antifibrotic action in pulmonary fibrosis.

[Guidelines for the macroscopic management of surgically resected lung carcinoma]. / Recommandations SFP pour la prise en charge macroscopique des pièces de résections de tumeurs pulmonaires.

Gross examination is an essential step for pathological report of a surgical sample. It includes the description of the surgical specimen and their disease(s), the precise and exhaustive sampling of tumoral and adjacent tumoral tissue areas. This examination requires a good knowledge of the updated pTNM classification. Pathologists from the PATTERN group have collaborated with thoracic surgeons, under the auspices of the Sociéte française de pathologie, to propose guidelines for resected specimen management. This approach fits into the context of the elaboration of structured pathological report proposed by the société française de pathologie, which is necessary for a standardized management of patients.

Pseudomonas aeruginosa LasB protease impairs innate immunity in mice and humans by targeting a lung epithelial cystic fibrosis transmembrane regulator-IL-6-antimicrobial-repair pathway.

BACKGROUND: Pseudomonas aeruginosa lung infections are a huge problem in ventilator-associated pneumonia, cystic fibrosis (CF) and in chronic obstructive pulmonary disease (COPD) exacerbations. This bacterium secretes virulence factors that may subvert host innate immunity. OBJECTIVE: We evaluated the effect of P. aeruginosa elastase LasB, an important virulence factor secreted by the type II secretion system, on ion transport, innate immune responses and epithelial repair, both in vitro and in vivo. METHODS: Wild-type (WT) or cystic fibrosis transmembrane conductance regulator (CFTR)-mutated epithelial cells (cell lines and primary cells from patients) were treated with WT or ΔLasB pseudomonas aeruginosa O1 (PAO1) secretomes. The effect of LasB and PAO1 infection was also assessed in vivo in murine models. RESULTS: We showed that LasB was the most abundant protein in WT PAO1 secretomes and that it decreased epithelial CFTR expression and activity. In airway epithelial cell lines and primary bronchial epithelial cells, LasB degraded the immune mediators interleukin (IL)-6 and trappin-2, an important epithelial-derived antimicrobial molecule. We further showed that an IL-6/STAT3 signalling pathway was downregulated by LasB, resulting in inhibition of epithelial cell repair. In mice, intranasally instillated LasB induced significant weight loss, inflammation, injury and death. By contrast, we showed that overexpression of IL-6 and trappin-2 protected mice against WT-PAO1-induced death, by upregulating IL-17/IL-22 antimicrobial and repair pathways. CONCLUSIONS: Our data demonstrate that PAO1 LasB is a major P. aeruginosa secreted factor that modulates ion transport, immune response and tissue repair. Targeting this virulence factor or upregulating protective factors such as IL-6 or antimicrobial molecules such as trappin-2 could be beneficial in P. aeruginosa-infected individuals.

Role of C1q-binding anti-HLA antibodies as a predictor of lung allograft outcome.

Presence of anti-human leukocyte antigen donor-specific antibodies (DSAs) is associated with poor outcome after lung transplantation. Currently, DSAs are detected using the Luminex technique, which may be overly sensitive. The new C1q assay allows for the exclusive detection of complement (C1q)-binding antibodies, involved in antibody-mediated rejection. We investigated whether early detection of complement-binding DSAs is associated with chronic lung allograft dysfunction (CLAD) and survival.From 2009 to 2012, lung transplant recipients from three transplantation centres were screened for the presence of DSA and their complement-binding capacity during the 6-12 months post-transplantation in a stable condition.The analysis included 168 patients. The 3-year rates of freedom from CLAD and graft survival were lower for patients with complement-binding DSAs (33.6% and 53.7%, respectively), as compared with patients with non-complement-binding DSAs (61.9% and 77.4%, respectively) and patients without DSA (70% and 84.9%, respectively) (p<0.001 and p=0.001, respectively). Detection of complement-binding DSA was associated with a risk of graft loss that was nearly tripled after adjustment for clinical, functional, histological and immunological factors (hazard ratio 2.98, 95% CI 1.33-6.66; p=0.008).Assessment of the C1q-binding capacity of DSA appears to be useful in identifying stable lung transplant recipients at high risk of lung allograft loss.

[PD-L1 testing in non-small cell lung carcinoma: Guidelines from the PATTERN group of thoracic pathologists]. / Tests immunohistochimiques PD-L1 dans les cancers du poumon non à petites cellules : recommandations par le groupe PATTERN de pathologistes thoraciques.

Lung cancer is the leading cause of cancer death in France with low response rates to conventional chemotherapy. Nevertheless, new therapies have emerged recently, among which PD1 immune checkpoint inhibitors (ICI), such as nivolumab (OPDIVO®, Bristol-Myers Squibb) and pembrolizumab (KEYTRUDA®, Merck & Co), or PD-L1 ICI, such as atezolizumab (TECENTRIQ®, Genentech), durvalumab (IMFINZI®, Astra-Zeneca), and avelumab (BAVENCIO®, EMD Serono). The prescription of pembrolizumab for advanced stage non-small cell lung carcinoma (NSCLC) patients requires the demonstration of PD-L1 expression by tumor cells by immunohistochemistry (IHC) (minimum of 50% of positive tumor cells is required for first-line setting, and of 1% for second-line and beyond) and PD-L1 assay is now considered as a companion diagnostic tool for this drug. Numerous standardized PD-L1 assays performed on dedicated platforms have been validated in clinical trials, each antibody being associated to one specific PD1 or PD-L1 inhibitor. However, not all pathologists have access to the dedicated platforms and the high cost of these assays is still a limitation to their implementation; in addition, the small size of the NSCLC tumor samples does not allow to perform at the same time multiple assays for multiple drugs. The use of laboratory-developed tests seems feasible but their validation must guarantee the same sensitivities and specificities as standardized tests. In this context, the French group of thoracic pathologists PATTERN has teamed up with thoracic oncologists to provide recommendations on the indication, the critical technical steps and the interpretation of the PD-L1 IHC test to help pathologists to implement quickly and in the best conditions this new theranostic test.

FGF9 prevents pleural fibrosis induced by intrapleural adenovirus injection in mice.

Fibroblast growth factor 9 (FGF9) is necessary for fetal lung development and is expressed by epithelium and mesothelium. We evaluated the role of FGF9 overexpression on adenoviral-induced pleural injury in vivo and determined the biological effects of FGF9 on mesothelial cells in vitro. We assessed the expression of FGF9 and FGF receptors by mesothelial cells in both human and mouse lungs. Intrapleural injection of an adenovirus expressing human FGF9 (AdFGF9) or a control adenovirus (AdCont) was performed. Mice were euthanized at days 3, 5, and 14 Expression of FGF9 and markers of inflammation and myofibroblastic differentiation was studied by qPCR and immunohistochemistry. In vitro, rat mesothelial cells were stimulated with FGF9 (20 ng/ml), and we assessed its effect on proliferation, survival, migration, and differentiation. FGF9 was expressed by mesothelial cells in human idiopathic pulmonary fibrosis. FGF receptors, mainly FGFR3, were expressed by mesothelial cells in vivo in humans and mice. AdCont instillation induced diffuse pleural thickening appearing at day 5, maximal at day 14 The altered pleura cells strongly expressed α-smooth muscle actin and collagen. AdFGF9 injection induced maximal FGF9 expression at day 5 that lasted until day 14 FGF9 overexpression prevented pleural thickening, collagen and fibronectin accumulation, and myofibroblastic differentiation of mesothelial cells. In vitro, FGF9 decreased mesothelial cell migration and inhibited the differentiating effect of transforming growth factor-ß1. We conclude that FGF9 has a potential antifibrotic effect on mesothelial cells.

Morphologic and molecular study of lung cancers associated with idiopathic pulmonary fibrosis and other pulmonary fibroses.

BACKGROUND: Primitive lung cancers developed on lung fibroses are both diagnostic and therapeutic challenges. Their incidence may increase with new more efficient lung fibrosis treatments. Our aim was to describe a cohort of lung cancers associated with idiopathic pulmonary fibrosis (IPF) and other lung fibrotic disorders (non-IPF), and to characterize their molecular alterations using immunohistochemistry and next-generation sequencing (NGS). METHODS: Thirty-one cancer samples were collected from 2001 to 2016 in two French reference centers for pulmonary fibrosis - 18 for IPF group and 13 for non-IPF group. NGS was performed using an ampliseq panel to analyze hotspots and targeted regions in 22 cancer-associated genes. ALK, ROS1 and PD-L1 expressions were assessed by immunohistochemistry. RESULTS: Squamous cell carcinoma was the most frequent histologic subtype in the IPF group (44%), adenocarcinoma was the most frequent subtype in the non-IPF group (62%). Forty-one mutations in 13 genes and one EGFR amplification were identified in 25 samples. Two samples had no mutation in the selected panel. Mutations were identified in TP53 (n = 20), MET (n = 4), BRAF (n = 3), FGFR3, PIK3CA, PTEN, STK11 (n = 2), SMAD4, CTNNB1, DDR2, ERBB4, FBXW7 and KRAS (n = 1) genes. No ALK and ROS1 expressions were identified. PD-L1 was expressed in 10 cases (62%) with only one (6%) case >50%. CONCLUSIONS: This extensive characterization of lung fibrosis-associated cancers evidenced molecular alterations which could represent either potential therapeutic targets either clues to the pathophysiology of these particular tumors. These findings support the relevance of large molecular characterization of every lung fibrosis-associated cancer.

[Efficacy of PD-1/PD-L1 immune checkpoint inhibitors and PD-L1 testing in thoracic cancers]. / Efficacité des inhibiteurs du checkpoint immunitaire PD-1/PD-L1 et testing PD-L1 dans les cancers thoraciques.

Tumoral immune environment is a major component of cancer. Its composition and its organization represent a reproducible characteristic of tumors and a validated prognostic factor. In non-small cell lung cancer (NSCLC), cytotoxic T CD8+ lymphocyte density, associated with a Th1 environment and tertiary lymphoid structures impacts survival. Tumor cell-immune cell interaction is targeted by PD1/PD-L1 inhibitors. In advanced NSCLC, PD1/PD-L1 inhibitors are more effective than second-line chemotherapy. Pembrolizumab outperforms first-line chemotherapy in NSCLC strongly positive for PD-L1. PD1/PD-L1 inhibitors are currently tested in mesothelioma and thymic tumors. PD-L1 expression evaluated with immunochemistry is the most studied predictive biomarker of PD1/PD-L1 inhibitor efficacy. Tumor and immune cell expression of PD-L1 is still difficult to evaluate because of intra-tumoral heterogeneity and expression modulation by the microenvironment. Four commercial diagnostic antibodies are in development, with differences concerning recognized epitopes, methodology of evaluation of PD-L1 expression, positivity threshold, kit and platforms used. Clinical trials in NSCLC have shown that patients with tumors strongly positive for PD-L1 derived the best clinical benefit with PD1/PD-L1 inhibitors whereas clinical benefit is less common in tumors negative for PD-L1. PD-L1 expression is not a perfect biomarker since some PD-L1 negative NSCLC respond to PD1/PD-L1 inhibitors and some PD-L1 positive NSCLC do not. PD-L1 testing is likely to be implemented in daily practice for selection of advanced NSCLC that will be treated with pembrolizumab, underscoring the relevance of ongoing harmonization studies of the use of the different antibodies available for PD-L1 testing.