Physiological effects of lung-protective ventilation in patients with lung fibrosis and usual interstitial pneumonia pattern versus primary ARDS: a matched-control study.

BACKGROUND: Although patients with interstitial pneumonia pattern (ILD-UIP) and acute exacerbation (AE) leading to severe acute respiratory failure may require invasive mechanical ventilation (MV), physiological data on lung mechanics during MV are lacking. We aimed at describing the physiological effect of lung-protective ventilation in patients with AE-ILD-UIP compared with primary ARDS. METHODS: Partitioned lung and chest wall mechanics were assessed in a series of AE-ILD-UIP patients matched 1:1 with primary ARDS as controls (based on BMI and PaO2/FiO2 ratio). Three PEEP levels (zero = ZEEP, 4-8 cmH2O = PEEPLOW, and titrated to achieve positive end-expiratory transpulmonary pressure PL,EE = PEEPTITRATED) were used for measurements. RESULTS: Ten AE-ILD-UIP patients and 10 matched ARDS were included. In AE-ILD-UIP median PL,EE at ZEEP was - 4.3 [- 7.6- - 2.3] cmH2O and lung elastance (EL) 44 [40-51] cmH2O/L. At PEEPLOW, PL,EE remained negative and EL did not change (p = 0.995) versus ZEEP. At PEEPTITRATED, PL,EE increased to 0.8 [0.3-1.5] cmH2O and EL to 49 [43-59] (p = 0.004 and p < 0.001 compared to ZEEP and PEEPLOW, respectively). ΔPL decreased at PEEPLOW (p = 0.018) and increased at PEEPTITRATED (p = 0.003). In matched ARDS control PEEP titration to obtain a positive PL,EE did not result in significant changes in EL and ΔPL. CONCLUSIONS: In mechanically ventilated AE-ILD-UIP patients, differently than in patients with primary ARDS, PEEP titrated to obtain a positive PL,EE significantly worsened lung mechanics.

Molecular Biology and Therapeutic Targets of Primitive Tracheal Tumors: Focus on Tumors Derived by Salivary Glands and Squamous Cell Carcinoma.

Primary tracheal tumors are rare, constituting approximately 0.1-0.4% of malignant diseases. Squamous cell carcinoma (SCC) and adenoid cystic carcinoma (ACC) account for about two-thirds of these tumors. Despite most primary tracheal cancers being eligible for surgery and/or radiotherapy, unresectable, recurrent and metastatic tumors may require systemic treatments. Unfortunately, the poor response to available chemotherapy as well as the lack of other real therapeutic alternatives affects the quality of life and outcome of patients suffering from more advanced disease. In this condition, target therapy against driver mutations could constitute an alternative to chemotherapy, and may help in disease control. The past two decades have seen extraordinary progress in developing novel target treatment options, shifting the treatment paradigm for several cancers such as lung cancer. The improvement of knowledge regarding the genetic and biological alterations, of major primary tracheal tumors, has opened up new treatment perspectives, suggesting the possible role of biological targeted therapies for the treatment of these rare tumors. The purpose of this review is to outline the state of knowledge regarding the molecular biology, and the preliminary data on target treatments of the main primary tracheal tumors, focusing on salivary-gland-derived cancers and squamous cell carcinoma.

Nasal pressure swings as the measure of inspiratory effort in spontaneously breathing patients with de novo acute respiratory failure.

BACKGROUND: Excessive inspiratory effort could translate into self-inflicted lung injury, thus worsening clinical outcomes of spontaneously breathing patients with acute respiratory failure (ARF). Although esophageal manometry is a reliable method to estimate the magnitude of inspiratory effort, procedural issues significantly limit its use in daily clinical practice. The aim of this study is to describe the correlation between esophageal pressure swings (ΔPes) and nasal (ΔPnos) as a potential measure of inspiratory effort in spontaneously breathing patients with de novo ARF. METHODS: From January 1, 2021, to September 1, 2021, 61 consecutive patients with ARF (83.6% related to COVID-19) admitted to the Respiratory Intensive Care Unit (RICU) of the University Hospital of Modena (Italy) and candidate to escalation of non-invasive respiratory support (NRS) were enrolled. Clinical features and tidal changes in esophageal and nasal pressure were recorded on admission and 24 h after starting NRS. Correlation between ΔPes and ΔPnos served as primary outcome. The effect of ΔPnos measurements on respiratory rate and ΔPes was also assessed. RESULTS: ΔPes and ΔPnos were strongly correlated at admission (R2 = 0.88, p < 0.001) and 24 h apart (R2 = 0.94, p < 0.001). The nasal plug insertion and the mouth closure required for ΔPnos measurement did not result in significant change of respiratory rate and ΔPes. The correlation between measures at 24 h remained significant even after splitting the study population according to the type of NRS (high-flow nasal cannulas [R2 = 0.79, p < 0.001] or non-invasive ventilation [R2 = 0.95, p < 0.001]). CONCLUSIONS: In a cohort of patients with ARF, nasal pressure swings did not alter respiratory mechanics in the short term and were highly correlated with esophageal pressure swings during spontaneous tidal breathing. ΔPnos might warrant further investigation as a measure of inspiratory effort in patients with ARF. TRIAL REGISTRATION: NCT03826797 . Registered October 2016.

Molecular Mechanisms and Physiological Changes behind Benign Tracheal and Subglottic Stenosis in Adults.

Laryngotracheal stenosis (LTS) is a complex and heterogeneous disease whose pathogenesis remains unclear. LTS is considered to be the result of aberrant wound-healing process that leads to fibrotic scarring, originating from different aetiology. Although iatrogenic aetiology is the main cause of subglottic or tracheal stenosis, also autoimmune and infectious diseases may be involved in causing LTS. Furthermore, fibrotic obstruction in the anatomic region under the glottis can also be diagnosed without apparent aetiology after a comprehensive workup; in this case, the pathological process is called idiopathic subglottic stenosis (iSGS). So far, the laryngotracheal scar resulting from airway injury due to different diseases was considered as inert tissue requiring surgical removal to restore airway patency. However, this assumption has recently been revised by regarding the tracheal scarring process as a fibroinflammatory event due to immunological alteration, similar to other fibrotic diseases. Recent acquisitions suggest that different factors, such as growth factors, cytokines, altered fibroblast function and genetic susceptibility, can all interact in a complex way leading to aberrant and fibrotic wound healing after an insult that acts as a trigger. However, also physiological derangement due to LTS could play a role in promoting dysregulated response to laryngo-tracheal mucosal injury, through biomechanical stress and mechanotransduction activation. The aim of this narrative review is to present the state-of-the-art knowledge regarding molecular mechanisms, as well as mechanical and physio-pathological features behind LTS.

Early Inspiratory Effort Assessment by Esophageal Manometry Predicts Noninvasive Ventilation Outcome in De Novo Respiratory Failure. A Pilot Study.

Rationale: The role of inspiratory effort still has to be determined as a potential predictor of noninvasive mechanical ventilation (NIV) failure in acute hypoxic de novo respiratory failure.Objectives: To explore the hypothesis that inspiratory effort might be a major determinant of NIV failure in these patients.Methods: Thirty consecutive patients with acute hypoxic de novo respiratory failure admitted to a single center and candidates for a 24-hour NIV trial were enrolled. Clinical features, tidal change in esophageal pressure (ΔPes), tidal change in dynamic transpulmonary pressure (ΔPl), expiratory Vt, and respiratory rate were recorded on admission and 2-4 to 12-24 hours after NIV start and were tested for correlation with outcomes.Measurements and Main Results: ΔPes and ΔPes/ΔPl ratio were significantly lower 2 hours after NIV start in patients who successfully completed the NIV trial (n = 18) compared with those who needed endotracheal intubation (n = 12) (median [interquartile range], 11 [8-15] cm H2O vs. 31.5 [30-36] cm H2O; P < 0.0001), whereas other variables differed later. ΔPes was not related to other predictors of NIV failure at baseline. NIV-induced reduction in ΔPes of 10 cm H2O or more after 2 hours of treatment was strongly associated with avoidance of intubation and represented the most accurate predictor of treatment success (odds ratio, 15; 95% confidence interval, 2.8-110; P = 0.001 and area under the curve, 0.97; 95% confidence interval, 0.91-1; P < 0.0001).Conclusions: The magnitude of inspiratory effort relief as assessed by ΔPes variation within the first 2 hours of NIV was an early and accurate predictor of NIV outcome at 24 hours.Clinical trial registered with www.clinicaltrials.gov (NCT03826797).

Fibrotic Idiopathic Interstitial Lung Disease: The Molecular and Cellular Key Players.

Interstitial lung diseases (ILDs) that are known as diffuse parenchymal lung diseases (DPLDs) lead to the damage of alveolar epithelium and lung parenchyma, culminating in inflammation and widespread fibrosis. ILDs that account for more than 200 different pathologies can be divided into two groups: ILDs that have a known cause and those where the cause is unknown, classified as idiopathic interstitial pneumonia (IIP). IIPs include idiopathic pulmonary fibrosis (IPF), non-specific interstitial pneumonia (NSIP), cryptogenic organizing pneumonia (COP) known also as bronchiolitis obliterans organizing pneumonia (BOOP), acute interstitial pneumonia (AIP), desquamative interstitial pneumonia (DIP), respiratory bronchiolitis-associated interstitial lung disease (RB-ILD), and lymphocytic interstitial pneumonia (LIP). In this review, our aim is to describe the pathogenic mechanisms that lead to the onset and progression of the different IIPs, starting from IPF as the most studied, in order to find both the common and standalone molecular and cellular key players among them. Finally, a deeper molecular and cellular characterization of different interstitial lung diseases without a known cause would contribute to giving a more accurate diagnosis to the patients, which would translate to a more effective treatment decision.

Pulmonary Stretch and Lung Mechanotransduction: Implications for Progression in the Fibrotic Lung.

Lung fibrosis results from the synergic interplay between regenerative deficits of the alveolar epithelium and dysregulated mechanisms of repair in response to alveolar and vascular damage, which is followed by progressive fibroblast and myofibroblast proliferation and excessive deposition of the extracellular matrix. The increased parenchymal stiffness of fibrotic lungs significantly affects respiratory mechanics, making the lung more fragile and prone to non-physiological stress during spontaneous breathing and mechanical ventilation. Given their parenchymal inhomogeneity, fibrotic lungs may display an anisotropic response to mechanical stresses with different regional deformations (micro-strain). This behavior is not described by the standard stress-strain curve but follows the mechano-elastic models of "squishy balls", where the elastic limit can be reached due to the excessive deformation of parenchymal areas with normal elasticity that are surrounded by inelastic fibrous tissue or collapsed induration areas, which tend to protrude outside the fibrous ring. Increasing evidence has shown that non-physiological mechanical forces applied to fibrotic lungs with associated abnormal mechanotransduction could favor the progression of pulmonary fibrosis. With this review, we aim to summarize the state of the art on the relation between mechanical forces acting on the lung and biological response in pulmonary fibrosis, with a focus on the progression of damage in the fibrotic lung during spontaneous breathing and assisted ventilatory support.

Molecular Mechanisms and Cellular Contribution from Lung Fibrosis to Lung Cancer Development.

Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive, fibrosing interstitial lung disease (ILD) of unknown aetiology, with a median survival of 2-4 years from the time of diagnosis. Although IPF has unknown aetiology by definition, there have been identified several risks factors increasing the probability of the onset and progression of the disease in IPF patients such as cigarette smoking and environmental risk factors associated with domestic and occupational exposure. Among them, cigarette smoking together with concomitant emphysema might predispose IPF patients to lung cancer (LC), mostly to non-small cell lung cancer (NSCLC), increasing the risk of lung cancer development. To this purpose, IPF and LC share several cellular and molecular processes driving the progression of both pathologies such as fibroblast transition proliferation and activation, endoplasmic reticulum stress, oxidative stress, and many genetic and epigenetic markers that predispose IPF patients to LC development. Nintedanib, a tyrosine-kinase inhibitor, was firstly developed as an anticancer drug and then recognized as an anti-fibrotic agent based on the common target molecular pathway. In this review our aim is to describe the updated studies on common cellular and molecular mechanisms between IPF and lung cancer, knowledge of which might help to find novel therapeutic targets for this disease combination.

Feasibility and clinical impact of out-of-ICU noninvasive respiratory support in patients with COVID-19-related pneumonia.

INTRODUCTION: The severe acute respiratory syndrome-coronavirus 2 outbreak spread rapidly in Italy and the lack of intensive care unit (ICU) beds soon became evident, forcing the application of noninvasive respiratory support (NRS) outside the ICU, raising concerns over staff contamination. We aimed to analyse the safety of the hospital staff and the feasibility and outcomes of NRS applied to patients outside the ICU. METHODS: In this observational study, data from 670 consecutive patients with confirmed coronavirus disease 2019 referred to pulmonology units in nine hospitals between March 1 and May 10, 2020 were analysed. Data collected included medication, mode and usage of NRS (i.e. high-flow nasal cannula (HFNC), continuous positive airway pressure (CPAP), noninvasive ventilation (NIV)), length of stay in hospital, endotracheal intubation (ETI) and deaths. RESULTS: 42 (11.1%) healthcare workers tested positive for infection, but only three of them required hospitalisation. Data are reported for all patients (69.3% male), whose mean±sd age was 68±13 years. The arterial oxygen tension/inspiratory oxygen fraction ratio at baseline was 152±79, and the majority (49.3%) of patients were treated with CPAP. The overall unadjusted 30-day mortality rate was 26.9%, with 16%, 30% and 30% for HFNC, CPAP and NIV, respectively, while the total ETI rate was 27%, with 29%, 25% and 28%, respectively; the relative probability of death was not related to the NRS used after adjustment for confounders. ETI and length of stay were not different among the groups. Mortality rate increased with age and comorbidity class progression. CONCLUSIONS: The application of NRS outside the ICU is feasible and associated with favourable outcomes. Nonetheless, it was associated with a risk of staff contamination.

Serial ultrasound assessment of diaphragmatic function and clinical outcome in patients with amyotrophic lateral sclerosis.

BACKGROUND: Diaphragmatic assessment by ultrasound (US) is a non-invasive and useful method in the clinical management of patients with Amyotrophic Lateral Sclerosis (ALS). The aim of our observational study was to evaluate the impact of serial assessment of the diaphragmatic function by US on long-term outcomes in a series of patients suffering from ALS and to correlate US indices of diaphragmatic function and respiratory function tests with these outcomes. METHODS: A cohort of 39 consecutive patients has been followed up to 24 months. Both lung volume (forced vital capacity, FVC) and diaphragmatic pressure generating capacity (by sniff inspiratory nasal pressure (SNIP) and by both US thickening fraction, ΔTdi, and the ratio of the thickening fraction between tidal volume and maximal lung capacity, ΔTmax) were recorded at baseline and every 3 months. Parameters were then correlated with outcomes (nocturnal hypoventilation, daily hypercapnia, start of ventilatory support (NIV), and death at 1 year) over time. RESULTS: The occurrence of ΔTmax > 0.75 increased the risk to start NIV (HR = 5.6, p = 0.001) and to die (HR = 3.7, p = 0.0001) compared with patients maintaining lower values. Moreover, compared with the occurrence of FVC < 50% of predicted, ΔTmax > 0.75 appeared slightly better correlated with NIV commencement within 6 months. CONCLUSIONS: Serial diaphragmatic assessment by ultrasound is a useful and accurate method to predict the initiation of NIV earlier in patients with ALS.

Ultrasound-assessed diaphragmatic impairment is a predictor of outcomes in patients with acute exacerbation of chronic obstructive pulmonary disease undergoing noninvasive ventilation.

BACKGROUND: Ultrasound (US) evaluation of diaphragmatic dysfunction (DD) has proved to be a reliable technique in critical care. In this single-center prospective study, we investigated the impact of US-assessed DD on noninvasive ventilation (NIV) failure in patients with acute exacerbations of chronic obstructive pulmonary disease (AECOPD) and its correlation with the transdiaphragmatic pressure assessed using the invasive sniff maneuver (Pdi sniff). METHODS: A population of 75 consecutive patients with AECOPD with hypercapnic acidosis admitted to our respiratory intensive care unit (RICU) were enrolled. Change in diaphragm thickness (ΔTdi) < 20% during tidal volume was the predefined cutoff for identifying DD+/- status. Correlations between ΔTdi < 20% NIV failure and other clinical outcomes were investigated. Correlation between ΔTdi and Pdi sniff values was analyzed in a subset of ten patients. RESULTS: DD+ patients had a higher risk for NIV failure than DD- patients (risk ratio, 4.4; p <  0.001), and this finding was significantly associated with higher RICU, in-hospital, and 90-day mortality rates; longer mechanical ventilation duration; higher tracheostomy rate; and longer RICU stay. Huge increases in NIV failure (HR, 6.2; p < 0.0001) and 90-day mortality (HR, 4.7; p = 0.008) in DD+ patients were found by Kaplan-Meier analysis. ΔTdi highly correlated with Pdi sniff (Pearson's r = 0.81; p = 0.004). ΔTdi < 20% showed better accuracy in predicting NIV failure than baseline pH value and early change in both arterial blood pH and partial pressure of carbon dioxide following NIV start (AUCs 0.84 to DTdi < 20%, 0.51 to pH value at baseline, 0.56 to early change in arterial blood pH following NIV start, and 0.54 to early change in partical pressure of carbon dioxide following NIV start, respectively; p < 0.0001). CONCLUSIONS: Early and noninvasive US assessment of DD during severe AECOPD is reliable and accurate in identifying patients at major risk for NIV failure and worse prognosis.

Integrated endoscopic treatment of primitive unresectable tracheal tumor: the INTACT retrospective cohort study.

Background: Primitive tracheal tumors represent a rare entity whose management, when unresectable, remains challenging. Primary aim of this study was to explore the survival and the factors influencing prognosis of patients with unresectable primitive tracheal tumor undergoing multimodal treatment integrating interventional bronchoscopy and radiotherapy. Methods: This retrospective cohort study was conducted at the University Hospital of Modena (Italy) over a 12-year period (January 2010 to January 2022) analyzing patients with unresectable primary tracheal tumor receiving interventional bronchoscopy treatment followed by radiotherapy. Survival analysis was conducted for the whole population and according to histology, development of metastasis, stent placement and the onset of disease relapse. The raw and independent association between potential risk factor and 5-year mortality and the reported complications were investigated. Results: A total of 12 patients were included. Five-year survival rate was 42% with a median survival time of 26.7 (interquartile range, 4.1-82) months. Survivors showed a higher prevalence of cystic-adenoid histology (80% vs. 14%), while patients who were dead at 5 years were those with a more advanced T (prevalence of T2: 71% vs. 0%) and a lower response to first line treatment (57% vs. 0%). Treatment complications accounted for stent dislocation (33%) and the onset of granuloma (18%), while no major side effects were reported. The presence of cystic-adenoid histology resulted in significantly improved 5-year survival rate (80% vs. 14%). The onset of distal metastasis, the occurrence of disease relapse and the placement of tracheal stent did not result significantly associated with lower survival. Among analysed variables, only the presence of cystic-adenoid histology resulted independently associated with survival (odds ratio =0.1, P=0.04). Conclusions: Multimodal treatment including interventional bronchoscopy and associated radiotherapy for unresectable primary tracheal tumors seems not burdened by significant complications and may provide benefits in terms of survival for those patients with cystic-adenoid histology.

Effect of high flow nasal oxygen on inspiratory effort of patients with acute hypoxic respiratory failure and do not intubate orders.

High flow nasal oxygen (HFNO) is recommended as a first-line respiratory support during acute hypoxic respiratory failure (AHRF) and represents a proportionate treatment option for patients with do not intubate (DNI) orders. The aim of the study is to assess the effect of HFNO on inspiratory effort as assessed by esophageal manometry in a population of DNI patients suffering from AHRF. Patients with AHRF and DNI orders admitted to Respiratory intermediate Care Unit between January 1st, 2018 and May 31st, 2023 to receive HFNO and subjected to esophageal manometry were enrolled. Esophageal pressure swing (ΔPes), clinical variables before and after 2 h of HFNO and clinical outcome (including HFNO failure) were collected and compared as appropriate. The change in physiological and clinical parameters according to the intensity of baseline breathing effort was assessed and the correlation between baseline ΔPes values and the relative change in breathing effort and clinical variables after 2 h of HFNO was explored. Eighty-two consecutive patients were enrolled according to sample size calculation. Two hours after HFNO start, patients presented significant improvement in ΔPes (12 VS 16 cmH2O, p < 0.0001), respiratory rate (RR) (22 VS 28 bpm, p < 0.0001), PaO2/FiO2 (133 VS 126 mmHg, p < 0.0001), Heart rate, Acidosis, Consciousness, Oxygenation and respiratory rate (HACOR) score, (4 VS 6, p < 0.0001), Respiratory rate Oxygenation (ROX) index (8.5 VS 6.1, p < 0.0001) and BORG (1 VS 4, p < 000.1). Patients with baseline ΔPes below 20 cmH2O where those who improved all the explored variables, while patients with baseline ΔPes above 30 cmH2O did not report significant changes in physiological or clinical features. A significant correlation was found between baseline ΔPes values and after 2 h of HFNO (R2 = 0.9, p < 0.0001). ΔPes change 2 h after HFNO significantly correlated with change in BORG (p < 0.0001), ROX index (p < 0.0001), HACOR score (p < 0.001) and RR (p < 0.001). In DNI patients with AHRF, HFNO was effective in reducing breathing effort and improving respiratory and clinical variables only for those patients with not excessive inspiratory effort.

Stress-strain curve and elastic behavior of the fibrotic lung with usual interstitial pneumonia pattern during protective mechanical ventilation.

Patients with acute exacerbation of lung fibrosis with usual interstitial pneumonia (EUIP) pattern are at increased risk for ventilator-induced lung injury (VILI) and mortality when exposed to mechanical ventilation (MV). Yet, lack of a mechanical model describing UIP-lung deformation during MV represents a research gap. Aim of this study was to develop a constitutive mathematical model for UIP-lung deformation during lung protective MV based on the stress-strain behavior and the specific elastance of patients with EUIP as compared to that of acute respiratory distress syndrome (ARDS) and healthy lung. Partitioned lung and chest wall mechanics were assessed for patients with EUIP and primary ARDS (1:1 matched based on body mass index and PaO2/FiO2 ratio) during a PEEP trial performed within 24 h from intubation. Patient's stress-strain curve and the lung specific elastance were computed and compared with those of healthy lungs, derived from literature. Respiratory mechanics were used to fit a novel mathematical model of the lung describing mechanical-inflation-induced lung parenchyma deformation, differentiating the contributions of elastin and collagen, the main components of lung extracellular matrix. Five patients with EUIP and 5 matched with primary ARDS were included and analyzed. Global strain was not different at low PEEP between the groups. Overall specific elastance was significantly higher in EUIP as compared to ARDS (28.9 [22.8-33.2] cmH2O versus 11.4 [10.3-14.6] cmH2O, respectively). Compared to ARDS and healthy lung, the stress/strain curve of EUIP showed a steeper increase, crossing the VILI threshold stress risk for strain values greater than 0.55. The contribution of elastin was prevalent at lower strains, while the contribution of collagen was prevalent at large strains. The stress/strain curve for collagen showed an upward shift passing from ARDS and healthy lungs to EUIP lungs. During MV, patients with EUIP showed different respiratory mechanics, stress-strain curve and specific elastance as compared to ARDS patients and healthy subjects and may experience VILI even when protective MV is applied. According to our mathematical model of lung deformation during mechanical inflation, the elastic response of UIP-lung is peculiar and different from ARDS. Our data suggest that patients with EUIP experience VILI with ventilatory setting that are lung-protective for patients with ARDS.

Decreased expression of autophagic beclin 1 protein in idiopathic pulmonary fibrosis fibroblasts.

Autophagy is the main cellular pathway for degradation of long-lived proteins and organelles and regulates cell fate in response to stress. Beclin 1 is a key regulator of this process. In some settings autophagy and apoptosis seem to be interconnected. Recent reports indicate that fibroblasts in idiopathic pulmonary fibrosis (IPF) acquire resistance to apoptosis. Here, we examined the expression of beclin 1, and of the anti apoptotic protein Bcl-2 in human IPF fibroblasts using immunohistochemistry and molecular biology in bioptic sections, in primary cultures of fibroblasts taken from patients with IPF and in fibroblast cell lines. Expression of beclin 1 in fibroblasts from IPF was down-regulated in comparison with fibroblasts from normal lungs while the anti-apoptotic protein Bcl-2 expression was over-expressed. Treatment of fibroblast cell cultures with cisplatin induced a significant increase in beclin 1 and caspase 3 protein levels but a reduction in Bcl-2 expression. These observations were confirmed by the analysis of acid compartments and transmission electron microscopy. Our results demonstrate a modified expression of the apoptotic beclin 1 Bcl-2 proteins in human IPF fibroblasts suggesting the existence of an autophagy/apoptosis system dysfunction.

Proteomic profiling of formalin-fixed paraffine-embedded tissue reveals key proteins related to lung dysfunction in idiopathic pulmonary fibrosis.

Introduction: Idiopathic pulmonary fibrosis (IPF) severely affects the lung leading to aberrant deposition of extracellular matrix and parenchymal stiffness with progressive functional derangement. The limited availability of fresh tissues represents one of the major limitations to study the molecular profiling of IPF lung tissue. The primary aim of this study was to explore the proteomic profiling yield of archived formalin-fixed paraffin-embedded (FFPE) specimens of IPF lung tissues. Methods: We further determined the protein expression according to respiratory functional decline at the time of biopsy. The total proteins isolated from 11 FFPE samples of IPF patients compared to 3 FFPE samples from a non-fibrotic lung defined as controls, were subjected to label-free quantitative proteomic analysis by liquid chromatography-mass spectrometry (LC-MS/MS) and resulted in the detection of about 400 proteins. Results: After the pairwise comparison between controls and IPF, functional enrichment analysis identified differentially expressed proteins that were involved in extracellular matrix signaling pathways, focal adhesion and transforming growth factor ß (TGF-ß) signaling pathways strongly associated with IPF onset and progression. Five proteins were significantly over- expressed in the lung of IPF patients with either advanced disease stage (Stage II) or impaired pulmonary function (FVC<75, DLCO<55) compared to controls; these were lymphocyte cytosolic protein 1 (LCP1), peroxiredoxin-2 (PRDX2), transgelin 2 (TAGLN2), lumican (LUM) and mimecan (OGN) that might play a key role in the fibrogenic processes. Discussion: Our work showed that the analysis of FFPE samples was able to identify key proteins that might be crucial for the IPF pathogenesis. These proteins are correlated with lung carcinogenesis or involved in the immune landscape of lung cancer, thus making possible common mechanisms between lung carcinogenesis and fibrosis progression, two pathological conditions at risk for each other in the real life.