Analysis of Pain Management after Anatomic VATS Resection in Austrian Thoracic Surgery Units.

BACKGROUND: Postoperative pain influences rehabilitation, postoperative complications and quality of life. Despite its impact, there are no uniform treatment guidelines. Different centers seem to use various strategies. This study aims to analyze pain management regimens used after anatomic VATS resections in Austrian thoracic surgery units, with a special interest in opioid usage and strategies to avoid opioids. METHODS: A questionnaire was designed to assess the use of regional anesthesia, postoperative pain medication and characteristics of individual pain management regimens. The questionnaire was sent to all thoracic surgery units in Austria, with nine out of twelve departments returning them. RESULTS: All departments use regional anesthesia during the procedure. Four out of nine centers use epidural analgesia or an intercostal catheter for postoperative regional anesthesia in at least 50% of patients. Two departments follow an opioid restrictive regimen, five depend on the visual analogue scale (VAS) and two administer opioids on a fixed schedule. Three out of nine departments use NSAIDs on a fixed schedule. The most used medication is metamizole (eight out of nine centers; six on a fixed schedule, two depending on VAS) followed by piritramide (six out of nine centers; none as a fixed prescription). CONCLUSIONS: This study reflects the heterogeneity in postoperative pain treatment after VATS anatomic lung resections. All departments use some form of regional anesthesia in the perioperative period; prolonged regional anesthesia is not utilized uniformly to reduce opioid consumption, as suggested in enhanced recovery after surgery programs. More evidence is needed to optimize and standardize postoperative pain treatment.

Validation of Inflammatory Prognostic Biomarkers in Pleural Mesothelioma.

Evoked from asbestos-induced inflammation, pleural mesothelioma represents a fatal diagnosis. Therapy ranges from nihilism to aggressive multimodality regimens. However, it is still unclear who ultimately benefits from which treatment. We aimed to re-challenge inflammatory-related biomarkers' prognostic value in times of modern immune-oncology and lung-sparing surgery. The biomarkers (leukocytes, hemoglobin, platelets, neutrophils, lymphocytes, monocytes, neutrophil-lymphocyte ratio (NLR), lymphocyte-monocyte ratio (LMR), platelet-lymphocyte ratio (PLR), C-reactive protein (CRP)) and clinical characteristics (age, sex, histology, therapy) of 98 PM patients were correlated to overall survival (OS). The median OS was 19.4 months. Significant OS advantages (Log-Rank) were observed in multimodal treatment vs. others (26.1 vs. 7.2 months, p < 0.001), surgery (pleurectomy/decortication) vs. no surgery (25.5 vs. 3.8 months, p < 0.001), a high hemoglobin level (cut-off 12 g/dL, 15 vs. 24.2 months, p = 0.021), a low platelet count (cut-off 280 G/L, 26.1 vs. 11.7 months, p < 0.001), and a low PLR (cut-off 194.5, 25.5 vs. 12.3 months, p = 0.023). Histology (epithelioid vs. non-epithelioid, p = 0.002), surgery (p = 0.004), CRP (cut-off 1 mg/dL, p = 0.039), and platelets (p = 0.025) were identified as independent prognostic variables for this cohort in multivariate analysis (Cox regression, covariates: age, sex, histology, stage, CRP, platelets). Our data verified the previously shown prognostic role of systemic inflammatory parameters in patients treated with lung-sparing surgery within multimodality therapy.

Trabectedin Is Active against Two Novel, Patient-Derived Solitary Fibrous Pleural Tumor Cell Lines and Synergizes with Ponatinib.

Solitary fibrous tumor of the pleura (SFT) is a rare disease. Besides surgery combined with radiotherapy in nondisseminated stages, curative options are currently absent. Out of fourteen primo-cell cultures, established from surgical SFT specimens, two showed stable in vitro growth. Both cell models harbored the characteristic NAB2-STAT6 fusion and were further investigated by different preclinical methods assessing cell viability, clone formation, and protein regulation upon single-drug treatment or in response to selected treatment combinations. Both fusion-positive cell models showed-in line with the clinical experience and the literature-a low to moderate response to most of the tested cytotoxic and targeted agents. However, the multi-tyrosine kinase inhibitors ponatinib and dasatinib, as well as the anti-sarcoma compound trabectedin, revealed promising activity against SFT growth. Furthermore, both cell models spontaneously presented strong FGFR downstream signaling targetable by ponatinib. Most interestingly, the combination of either ponatinib or dasatinib with trabectedin showed synergistic effects. In conclusion, this study identified novel trabectedin-based treatment combinations with clinically approved tyrosine kinase inhibitors, using two newly established NAB2-STAT6 fusion-positive cell models. These findings can be the basis for anti-SFT drug repurposing approaches in this rare and therapy-refractory disease.

Lymph but Not Blood Vessel Invasion Is Independent Prognostic in Lung Cancer Patients Treated by VATS-Lobectomy and Might Represent a Future Upstaging Factor for Early Stages.

Lung cancer is the most frequent cause of cancer-related death worldwide. The patient's outcome depends on tumor size, lymph node involvement and metastatic spread at the time of diagnosis. The prognostic value of lymph and blood vessel invasion, however, is still insufficiently investigated. We retrospectively examined the invasion of lymph vessels and blood vessels separately as two possible prognostic factors in 160 patients who underwent a video-assisted thoracoscopic lobectomy for non-small-cell lung cancer at our institution between 2014 and 2019. Lymph vessel invasion was significantly associated with the UICC stage, lymph node involvement, tumor dedifferentiation, blood vessel invasion and recurrence. Blood vessel invasion tended to be negative prognostic, but missed the level of significance (p = 0.108). Lymph vessel invasion, on the other hand, proved to be a prognostic factor for both histological subtypes, adenocarcinoma (p < 0.001) as well as squamous cell carcinoma (p = 0.018). After multivariate analysis apart from the UICC stage, only lymph vessel invasion remained independently prognostic (p = 0.018). Remarkably, we found analogue survival curve progressions of patients with stage I, with lymph vessel invasion, compared to stage II non-small-cell lung cancer. After further validation in prospective studies, lymph vessel invasion might be considered as an upstaging factor in resectable lung cancer. Especially in the early-stage of the disease, it might represent an additional risk factor to consider adjuvant therapy after surgical resection.

Transbronchial lung cryobiopsy: prospective safety evaluation and 90-day mortality after a standardized examination protocol.

BACKGROUND: Transbronchial lung cryobiopsy (TBLC) is a new method of bronchoscopic tissue sampling in patients with unclear diffuse parenchymal lung disease (DPLD). While not the gold standard, TBLC has a good diagnostic correlation with surgical lung biopsy, and retrospective analyses of peri-interventional complications and mortality are promising. However, prospective reports on 90-day mortality are lacking. OBJECTIVES: This study addresses morbidity and 30- and 90-day mortality in TBLC after a standardized protocol. METHODS: In this prospective study, 75 patients with DPLD requiring tissue sampling were included. A standardized protocol (including prophylactic use of an endobronchial balloon, postinterventional observation, and minimum sampling requirements) was used in all patients. Adverse events (pneumothorax, bronchial bleeding, premature discontinuation, prolonged monitoring at ICU, and fatal outcome) and 30- and 90-day mortality rates were recorded. RESULTS: A total of 308 cryobiopsies were performed in 75 patients. Peri- and postinterventional pneumothorax were observed in 20% (9.3% mild and 10.7% moderate with the necessity of chest drainage), and bronchial bleeding was found in 29.3% (22.7% moderate and 6.7% severe). Total lung capacity below normal value was associated with the risk of pneumothorax (p = 0.009), and diffusion limitation for carbon monoxide below normal value was associated with the risk of bronchial bleeding (p = 0.044). No fatal events were observed within 30 days, and the 90-day mortality rate was 1.3%, but not related to the procedure itself. CONCLUSION: As it gradually becomes the invasive procedure of choice in unclear DPLD, TBLC is a safe procedure with a low 30- and 90-day mortality.Trial registration ID: DRKS00026746 (German Clinical Trial Register).

Apelin-17 to diagnose idiopathic pulmonary arterial hypertension: A biomarker study.

Background: NT-proBNP and GDF-15 are established blood-derived biomarkers for risk assessment in pulmonary hypertension (PH), despite limited sensitivity and specificity. Apelin has a crucial function in endothelial homeostasis, thus it might represent a new biomarker for PH. However, there are numerous circulating apelin isoforms, and their potential role in this setting is unknown. This study evaluated different apelin isoforms in PH patients and prospectively evaluated the role of apelin-17 in comparison with NT-proBNP and GDF-15 as diagnostic marker in idiopathic pulmonary arterial hypertension (IPAH). Methods: Based on our pilot study, we performed a power calculation for apelin-13, apelin-17, apelin-36, as predictor of IPAH vs healthy controls. Apelin-17 provided the best discriminatory power, and accordingly, we enrolled n = 31 patients with IPAH and n = 31 matched healthy controls in a prospective study. NT-proBNP and GDF-15 was determined in all patients. ROC curve analysis was performed to assess the diagnostic value of the markers and their combinations. Results: Apelin-17, NT-proBNP, and GDF-15 were significantly elevated in IPAH patients as compared to controls (p < .001). Apelin-17 detected IPAH with a sensitivity of 68% and a specificity of 93% at a cut-off value of >1,480 pg/ml (AUC 0.86, 95%CI:0.76-0.95) as compared to GDF-15 (sensitivity 86%; specificity 72%, AUC 0.81 (95%CI:0.7-0.92)) and NT-proBNP (sensitivity 86%; specificity 72% (AUC 0.85, 95%CI:0.75-0.95)). Combinations of these markers could be used to increase either specificity or sensitivity. Conclusion: Apelin-17 appears to be suitable blood derived diagnostic marker for idiopathic pulmonary arterial hypertension.

Biomarkers for Malignant Pleural Mesothelioma-A Novel View on Inflammation.

Malignant pleural mesothelioma (MPM) is an aggressive disease with limited treatment response and devastating prognosis. Exposure to asbestos and chronic inflammation are acknowledged as main risk factors. Since immune therapy evolved as a promising novel treatment modality, we want to reevaluate and summarize the role of the inflammatory system in MPM. This review focuses on local tumor associated inflammation on the one hand and systemic inflammatory markers, and their impact on MPM outcome, on the other hand. Identification of new biomarkers helps to select optimal patient tailored therapy, avoid ineffective treatment with its related side effects and consequently improves patient's outcome in this rare disease. Additionally, a better understanding of the tumor promoting and tumor suppressing inflammatory processes, influencing MPM pathogenesis and progression, might also reveal possible new targets for MPM treatment. After reviewing the currently available literature and according to our own research, it is concluded that the suppression of the specific immune system and the activation of its innate counterpart are crucial drivers of MPM aggressiveness translating to poor patient outcome.

Evolution of outcome and complications in TAVR: a meta-analysis of observational and randomized studies.

Aim of the present analysis was to collect and pool all available data currently in the literature regarding outcomes and complications of all approved TAVR prosthesis and to assess the transition from first to next generation TAVR devices by directly comparing both in regard of procedure related complications. Transcatheter aortic valve replacement is a well established treatment modality in patients with severe aortic stenosis deemed to be inoperable or at unacceptable risk for open heart surgery. First generation prostheses were associated with a high rate of peri-procedural complications like paravalvular regurgitation, valve malpositioning, vascular complications and conduction disorders. Refinement of the available devices incorporate features to address the limitations of the first-generation devices. A PRISMA checklist-guided systematic review and meta-analysis of prospective observational studies, national and device specific registries or randomized clinical trials was conducted. Studies were identified by searching PUBMED, SCOPUS, Cochrane Central Register of Controlled Trials and LILACs from January 2000 to October 2017. We extracted and pooled data on both mortality and complications from 273 studies for twelve different valves prostheses in a total of 68,193 patients. In second generation prostheses as compared to first generation devices, we observed a significant decrease in mortality (1.47 ± 1.73% vs. 5.41 ± 4.35%; p < 0.001), paravalvular regurgitation (1.75 ± 2.43vs. 12.39 ± 9.38, p < 0.001) and MACE. TAVR with contemporary next generation devices has led to an impressive improvement in TAVR safety driven by refined case selection, improved procedural techniques and increased site experience.

Tumour cell PD-L1 expression is prognostic in patients with malignant pleural effusion: the impact of C-reactive protein and immune-checkpoint inhibition.

Malignant pleural effusion (MPE) confers dismal prognosis and has limited treatment options. While immune-checkpoint inhibition (ICI) proved clinical efficacy in a variety of malignancies, data on the prognostic role of PD-L1 in MPE is scarce. We retrospectively studied PD-L1 tumour proportion score and Ki-67 index in pleural biopsies or cytologies from 123 patients (69 lung cancer, 25 mesothelioma, and 29 extrathoracic primary malignancies). Additionally, the impact of C-reactive protein (CRP) and platelet count was also analysed. Median overall survival (OS) after MPE diagnosis was 9 months. Patients with PD-L1 positive tumours (≥1%) had significantly shorter OS than patients with negative PD-L1 status (p = 0.031). CRP and Ki-67 index were also prognostic and remained independent prognosticators after multivariate analysis. Interestingly, Ki-67 index and CRP influenced the prognostic power of PD-L1. Finally, patients receiving ICI tended to have a longer median OS and CRP - but not PD-L1 - was a significant prognosticator in this subgroup. In summary, histological and circulating biomarkers should also be taken into account as potential biomarkers in ICI therapy and they may have an impact on the prognostic power of PD-L1. Our findings might help personalizing immune-checkpoint inhibition for patients with MPE and warrant further prospective validation.

A novel mutation of the folliculin gene causing Birt-Hogg-Dubé syndrome as rare cause for secondary pneumothorax.

The Birt-Hogg-Dubé syndrome is an orphan genetic disease characterized by the development of renal neoplasms, fibrofolliculomas, pulmonary cysts and spontaneous pneumothoraces. Here, we report on the case of a 21-year-old man presenting with a primary event of a persistent spontaneous pneumothorax. Computed tomography images and a positive family history for pneumothoraces led to the suspicion of Birt-Hogg-Dubé syndrome. Genetic testing then confirmed the suspected clinical diagnosis, however with a mutation that has not yet been reported.

IL-1 receptor blockade skews inflammation towards Th2 in a mouse model of systemic sclerosis.

The interleukin (IL)-1 family of cytokines is strongly associated with systemic sclerosis (SSc) and pulmonary involvement, but the molecular mechanisms are poorly understood. The aim of this study was to assess the role of IL-1α and IL-1ß in pulmonary vascular and interstitial remodelling in a mouse model of SSc.IL-1α and IL-1ß were localised in lungs of SSc patients and in the fos-related antigen-2 (Fra-2) transgenic (TG) mouse model of SSc. Lung function, haemodynamic parameters and pulmonary inflammation were measured in Fra-2 TG mice with or without 8 weeks of treatment with the IL-1 receptor antagonist anakinra (25 mg·kg-1·day-1). Direct effects of IL-1 on pulmonary arterial smooth muscle cells (PASMCs) and parenchymal fibroblasts were investigated in vitroFra-2 TG mice exhibited increased collagen deposition in the lung, restrictive lung function and enhanced muscularisation of the vasculature with concomitant pulmonary hypertension reminiscent of the changes in SSc patients. Immunoreactivity of IL-1α and IL-1ß was increased in Fra-2 TG mice and in patients with SSc. IL-1 stimulation reduced collagen expression in PASMCs and parenchymal fibroblasts via distinct signalling pathways. Blocking IL-1 signalling in Fra-2 TG worsened pulmonary fibrosis and restriction, enhanced T-helper cell type 2 (Th2) inflammation, and increased the number of pro-fibrotic, alternatively activated macrophages.Our data suggest that blocking IL-1 signalling as currently investigated in several clinical studies might aggravate pulmonary fibrosis in specific patient subsets due to Th2 skewing of immune responses and formation of alternatively activated pro-fibrogenic macrophages.

Targeting TMEM16A to reverse vasoconstriction and remodelling in idiopathic pulmonary arterial hypertension.

Our systematic analysis of anion channels and transporters in idiopathic pulmonary arterial hypertension (IPAH) showed marked upregulation of the Cl- channel TMEM16A gene. We hypothesised that TMEM16A overexpression might represent a novel vicious circle in the molecular pathways causing pulmonary arterial hypertension (PAH).We investigated healthy donor lungs (n=40) and recipient lungs with IPAH (n=38) for the expression of anion channel and transporter genes in small pulmonary arteries and pulmonary artery smooth muscle cells (PASMCs).In IPAH, TMEM16A was strongly upregulated and patch-clamp recordings confirmed an increased Cl- current in PASMCs (n=9-10). These cells were depolarised and could be repolarised by TMEM16A inhibitors or knock-down experiments (n=6-10). Inhibition/knock-down of TMEM16A reduced the proliferation of IPAH-PASMCs (n=6). Conversely, overexpression of TMEM16A in healthy donor PASMCs produced an IPAH-like phenotype. Chronic application of benzbromarone in two independent animal models significantly decreased right ventricular pressure and reversed remodelling of established pulmonary hypertension.Our findings suggest that increased TMEM16A expression and activity comprise an important pathologic mechanism underlying the vasoconstriction and remodelling of pulmonary arteries in PAH. Inhibition of TMEM16A represents a novel therapeutic approach to reverse remodelling in PAH.

Disconnect between Fibrotic Response and Right Ventricular Dysfunction.

Rationale: Remodeling and fibrosis of the right ventricle (RV) may cause RV dysfunction and poor survival in patients with pulmonary hypertension. Objectives: To investigate the consequences of RV fibrosis modulation and the accompanying cellular changes on RV function. Methods: Expression of fibrotic markers was assessed in the RV of patients with pulmonary hypertension, the murine pulmonary artery banding, and rat monocrotaline and Sugen5416/hypoxia models. Invasive hemodynamic and echocardiographic assessment was performed on galectin-3 knockout or inhibitor-treated mice. Measurements and Main Results: Established fibrosis was characterized by marked expression of galectin-3 and an enhanced number of proliferating RV fibroblasts. Galectin-3 genetic and pharmacologic inhibition or antifibrotic treatment with pirfenidone significantly diminished RV fibrosis progression in the pulmonary artery banding model, without improving RV functional parameters. RV fibrotic regions were populated with mesenchymal cells coexpressing vimentin and PDGFRα (platelet-derived growth factor receptor-α), but generally lacked αSMA (α-smooth muscle actin) positivity. Serum levels of galectin-3 were increased in patients with idiopathic pulmonary arterial hypertension but did not correlate with cardiac function. No changes of galectin-3 expression were observed in the lungs. Conclusions: We identified extrapulmonary galectin-3 as an important mediator that drives RV fibrosis in pulmonary hypertension through the expansion of PDGFRα/vimentin-expressing cardiac fibroblasts. However, interventions effectively targeting fibrosis lack significant beneficial effects on RV function.

Prognostic and diagnostic impact of fibrinogen, neutrophil-to-lymphocyte ratio, and platelet-to-lymphocyte ratio on thymic epithelial tumors outcome.

BACKGROUND: Peripheral blood-derived inflammation-based markers, such as Neutrophil-to-Lymphocyte Ratio (NLR), Platelet-to-Lymphocyte Ratio (PLR), and Fibrinogen have been identified as prognostic markers in various solid malignancies. Here we aimed to investigate the prognostic and diagnostic impact of NLR, PLR, and Fibrinogen in patients with thymic epithelial tumors (TETs). RESULTS: Pretreatment Fibrinogen serum concentrations, NLRs and PLRs were highest in patients with TCs and advanced tumor stages. High pretreatment Fibrinogen serum concentration (≥452.5 mg/dL) was significantly associated with worse cause specific survival (CSS; p = 0.001) and freedom from recurrence (FFR; p = 0.043), high NLR (≥4.0) with worse FFR (p = 0.008), and high PLR (≥136.5) with worse CSS (p = 0.032). Longitudinal analysis revealed that compared to patients without tumor recurrence, patients with tumor recurrence had significantly higher NLR (11.8 ± 4.0 vs. 4.70 ± 0.5; p = 0.001) and PLR (410.8 ± 149.1 vs. 228.3 ± 23.7; p = 0.031). CONCLUSION: Overall, Fibrinogen serum concentrations, NLRs, and PLRs were associated with higher tumor stage, more aggressive tumor behavior, recurrence, and worse outcome. Prospective multicenter studies of the diagnostic and prognostic potential of Fibrinogen, NLR, and PLR are warranted. METHODS: This retrospective analysis included 122 patients with TETs who underwent surgical resection between 1999-2015. Fibrinogen serum concentrations, NLRs, and PLRs were measured in patients preoperatively, postoperatively, and later during follow-up. These markers were analyzed for association with several clinical variables, including tumor stage, tumor subtype, FFR, and CSS and to evaluate their prognostic and diagnostic impact for detecting tumor recurrence.

Chylothorax in a 32-Year-Old Patient With Lymphangioleiomyomatosis After Bilateral Lung Transplant.

We report the case of a 32-year-old woman with persistent chylothorax after double-lung transplant for lymphangioleiomyomatosis. Dietary restrictions failed to decrease chylous effusions, making surgical revision necessary. The choice of an abdominal approach and postoperative treatment with somatostatin proved successful. The patient showed no recurrence of chylothorax at her 2-year follow up.

Treprostinil inhibits proliferation and extracellular matrix deposition by fibroblasts through cAMP activation.

Idiopathic pulmonary fibrosis (IPF) is characterized by peripheral lung fibrosis and increased interstitial extracellular matrix (ECM) deposition. In IPF, tumor growth factor (TGF)-ß1 which is the major stimulus of ECM deposition, and platelet derived growth factor (PDGF)-BB is a potent stimulus of fibrosis. Thus, the effect of Treprostinil on TGF-ß1 and PDGF-induced fibroblast proliferation and ECM deposition was investigated. Human peripheral lung fibroblasts of seven IPF patients and five lung donors were stimulated by PDGF, or TGF-ß1, or the combination. Cells were pre-incubated (30 min) with either Treprostinil, forskolin, di-deoxyadenosine (DDA), or vehicle. Treprostinil time dependently activated cAMP thereby preventing PDGF-BB induced proliferation and TGF-ß1 secretion. Cell counts indicated proliferation; α-smooth muscle actin (α-SMA) indicted differentiation, and collagen type-1 or fibronectin deposition remodeling. Myo-fibroblast indicating α-SMA expression was significantly reduced and its formation was altered by Treprostinil. Collagen type-I and fibronectin deposition were also reduced by Treprostinil. The effect of Treprostinil on collagen type-I deposition was cAMP sensitive as it was counteracted by DDA, while the effect on fibronectin was not cAMP mediated. Treprostinil antagonized the pro-fibrotic effects of both PDGF-BB and TGF-ß1 in primary human lung fibroblasts. The data presented propose a therapeutic relevant anti-fibrotic effect of Treprostinil in IPF.

Resident cell lineages are preserved in pulmonary vascular remodeling.

Pulmonary vascular remodeling is the main pathological hallmark of pulmonary hypertension disease. We undertook a comprehensive and multilevel approach to investigate the origin of smooth muscle actin-expressing cells in remodeled vessels. Transgenic mice that allow for specific, inducible, and permanent labeling of endothelial (Cdh5-tdTomato), smooth muscle (Acta2-, Myh11-tdTomato), pericyte (Cspg4-tdTomato), and fibroblast (Pdgfra-tdTomato) lineages were used to delineate the cellular origins of pulmonary vascular remodeling. Mapping the fate of major lung resident cell types revealed smooth muscle cells (SMCs) as the predominant source of cells that populate remodeled pulmonary vessels in chronic hypoxia and allergen-induced murine models. Combining in vivo cell type-specific, time-controlled labeling of proliferating cells with a pulmonary artery phenotypic explant assay, we identified proliferation of SMCs as an underlying remodeling pathomechanism. Multicolor immunofluorescence analysis showed a preserved pattern of cell type marker localization in murine and human pulmonary arteries, in both donors and idiopathic pulmonary arterial hypertension (IPAH) patients. Whilst neural glial antigen 2 (chondroitin sulfate proteoglycan 4) labeled mostly vascular supportive cells with partial overlap with SMC markers, PDGFRα-expressing cells were observed in the perivascular compartment. The luminal vessel side was lined by a single cell layer expressing endothelial markers followed by an adjacent and distinct layer defined by SMC marker expression and pronounced thickening in remodeled vessels. Quantitative flow cytometric analysis of single cell digests of diverse pulmonary artery layers showed the preserved separation into two discrete cell populations expressing either endothelial cell (EC) or SMC markers in human remodeled vessels. Additionally, we found no evidence of overlap between EC and SMC ultrastructural characteristics using electron microscopy in either donor or IPAH arteries. Lineage-specific marker expression profiles are retained during pulmonary vascular remodeling without any indication of cell type conversion. The expansion of resident SMCs is the major underlying and evolutionarily conserved paradigm of pulmonary vascular disease pathogenesis. © 2018 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of Pathological Society of Great Britain and Ireland.

The inflammatory cell landscape in the lungs of patients with idiopathic pulmonary arterial hypertension.

Increasing evidence points towards an inflammatory component underlying pulmonary hypertension. However, the conclusive characterisation of multiple inflammatory cell populations in the lung is challenging due to the complexity of marker specificity and tissue inaccessibility. We used an unbiased computational flow cytometry approach to delineate the inflammatory landscape of idiopathic pulmonary arterial hypertension (IPAH) and healthy donor lungs.Donor and IPAH samples were discriminated clearly using principal component analysis to reduce the multidimensional data obtained from single-cell flow cytometry analysis. In IPAH lungs, the predominant CD45+ cell type switched from neutrophils to CD3+ T-cells, with increases in CD4+, CD8+ and γδT-cell subsets. Additionally, diversely activated classical myeloid-derived dendritic cells (CD14-HLA-DR+CD11c+CD1a+/-) and nonclassical plasmacytoid dendritic cells (pDCs; CD14-CD11c-CD123+HLA-DR+), together with mast cells and basophils, were more abundant in IPAH samples. We describe, for the first time, the presence and regulation of two cell types in IPAH, γδT-cells and pDCs, which link innate and adaptive immunity.With our high-throughput flow cytometry with multidimensional dataset analysis, we have revealed the interactive interplay between multiple inflammatory cells is a crucial part of their integrative network. The identification of γδT-cells and pDCs in this disease potentially provides a missing link between IPAH, autoimmunity and inflammation.

Loss of SMAD3 Promotes Vascular Remodeling in Pulmonary Arterial Hypertension via MRTF Disinhibition.

RATIONALE: Vascular remodeling in pulmonary arterial hypertension (PAH) results from smooth muscle cell hypertrophy and proliferation of vascular cells. Loss of BMPR-II (bone morphogenetic protein receptor 2) signaling and increased signaling via TGF-ß (transforming growth factor ß) and its downstream mediators SMAD (small body size [a C. elegans protein] mothers against decapentaplegic [a Drosophila protein family])-2/3 has been proposed to drive lung vascular remodeling; yet, proteomic analyses indicate a loss of SMAD3 in PAH. OBJECTIVES: We proposed that SMAD3 may be dysregulated in PAH and that loss of SMAD3 may present a pathophysiological master switch by disinhibiting its interaction partner, MRTF (myocardin-related transcription factor), which drives muscle protein expression. METHODS: SMAD3 levels were measured in lungs from PAH patients, rats treated either with Sugen/hypoxia or monocrotaline (MCT), and in mice carrying a BMPR2 mutation. In vitro, effects of SMAD3 or BMPR2 silencing or SMAD3 overexpression on cell proliferation or smooth muscle hypertrophy were assessed. In vivo, the therapeutic and prophylactic potential of CCG1423, an inhibitor of MRTF, was investigated in Sugen/hypoxia rats. MEASUREMENTS AND MAIN RESULTS: SMAD3 was downregulated in lungs of patients with PAH and in pulmonary arteries of three independent PAH animal models. TGF-ß treatment replicated the loss of SMAD3 in human pulmonary artery smooth muscle cells (huPASMCs) and human pulmonary artery endothelial cells. SMAD3 silencing increased proliferation and migration in huPASMCs and human pulmonary artery endothelial cells. Coimmunoprecipitation revealed reduced interaction of MRTF with SMAD3 in TGF-ß-treated huPASMCs and pulmonary arteries of PAH animal models. In huPASMCs, loss of SMAD3 or BMPR-II increased smooth muscle actin expression, which was attenuated by MRTF inhibition. Conversely, SMAD3 overexpression prevented TGF-ß-induced activation of an MRTF reporter and reduced actin stress fibers in BMPR2-silenced huPASMCs. MRTF inhibition attenuated PAH and lung vascular remodeling in Sugen/hypoxia rats. CONCLUSIONS: Loss of SMAD3 presents a novel pathomechanism in PAH that promotes vascular cell proliferation and-via MRTF disinhibition-hypertrophy of huPASMCs, thereby reconciling the parallel induction of a synthetic and contractile huPASMC phenotype.

Circulating complement component 4d (C4d) correlates with tumor volume, chemotherapeutic response and survival in patients with malignant pleural mesothelioma.

Only limited information is available on the role of complement activation in malignant pleural mesothelioma (MPM). Thus, we investigated the circulating and tissue levels of the complement component 4d (C4d) in MPM. Plasma samples from 55 MPM patients, 21 healthy volunteers (HV) and 14 patients with non-malignant pleural diseases (NMPD) were measured by ELISA for C4d levels. Tissue specimens from 32 patients were analyzed by C4d immunohistochemistry. Tumor volumetry was measured in 20 patients. We found no C4d labeling on tumor cells, but on ectopic lymphoid structures within the tumor stroma. Plasma C4d levels did not significantly differ between MPM, HV or NMPD. Late-stage MPM patients had higher plasma C4d levels compared to early-stage (p = 0.079). High circulating C4d was associated with a higher tumor volume (p = 0.047). Plasma C4d levels following induction chemotherapy were significantly higher in patients with stable/progressive disease compared to those with partial/major response (p = 0.005). Strikingly, patients with low C4d levels at diagnosis had a significantly better overall survival, confirmed in a multivariate cox regression model (hazard ratio 0.263, p = 0.01). Our findings suggest that circulating plasma C4d is a promising new prognostic biomarker in patients with MPM and, moreover, helps to select patients for surgery following induction chemotherapy.