Overnight desaturation in interstitial lung diseases: links to pulmonary vasculopathy and mortality.

Background: Overnight desaturation predicts poor prognosis across interstitial lung diseases (ILDs). The aim of the present study was to investigate whether nocturnal desaturation is associated with pulmonary vasculopathy and mortality. Methods: A retrospective single centre study of 397 new ILD patients was carried out including patients with idiopathic pulmonary fibrosis (IPF) (n=107) and patients with non-IPF fibrotic ILD (n=290). This is the largest study to date of the effect of significant nocturnal desaturation (SND) (≥10% of total sleep time with oxygen saturation ≤90% measured by pulse oximetry). Results: The prevalence of SND was 28/107 (26.2%) in IPF and 80/290 (27.6%) in non-IPF ILD. The prevalence of SND was higher in non-IPF ILDs than in IPF (p=0.025) in multivariate analysis. SND was associated with noninvasive markers of pulmonary hypertension (PH): tricuspid regurgitation velocity (TRV) (p<0.0001), brain natriuretic peptide (p<0.007), carbon monoxide transfer coefficient (p<0.0001), A-a gradient (p<0.0001), desaturation >4% in 6-min walking test (p<0.03) and pulmonary artery diameter (p<0.005). SND was independently associated with high echocardiographic PH probability in the entire cohort (OR 2.865, 95% CI 1.486-5.522, p<0.002) and in non-IPF fibrotic ILD (OR 3.492, 95% CI 1.597-7.636, p<0.002) in multivariate analysis. In multivariate analysis, SND was associated with mortality in the entire cohort (OR 1.734, 95% CI 1.202-2.499, p=0.003) and in IPF (OR 1.908, 95% CI 1.120-3.251, p=0.017) and non-IPF fibrotic ILD (OR 1.663, 95% CI 1.000-2.819, p=0.041). Separate models with exclusion of each one of the diagnostic subgroups showed that no subgroup was responsible for this finding in non-IPF ILDs. SND was a stronger marker of 5-year mortality than markers of PH. Conclusion: SND was associated with high echocardiographic probability and mortality and was a stronger predictor of mortality in IPF and non-IPF ILDs grouped together to power the study.

An update on current and emerging drug treatments for idiopathic pulmonary fibrosis.

INTRODUCTION: Idiopathic Pulmonary Fibrosis (IPF) is a progressive and devastating lung disease, characterized by progressive lung scarring. AREAS COVERED: Prior to antifibrotic therapy (pirfenidone and nintedanib), there was no validated pharmaceutical therapy for IPF. Both antifibrotics can slow disease progression; however, IPF remains a detrimental disease with poor prognosis and treatment survival rates of less than 7 years from diagnosis. Despite their effect the disease remains non-reversible and progressing whilst their side effect profile is often challenging. Treatment of comorbidities is also crucial. In this review, we discuss the current pharmacological management as well as management of comorbidities and symptoms. We also reviewed clinicaltrials.gov and summarized all the mid- to late-stage clinical trials (phase II and III) registered in IPF over the last 7 years and discuss the most promising drugs in clinical development. EXPERT OPINION: Future for IPF management will need to focus on current unresolved issues. First a primary pathogenetic pathway has not been clearly identified. Future management may involve a combination of the brushstroke approach with antifibrotics with targeted treatments for specific pathways in patient subsets following an 'oncological' approach. Another unmet need is the management of exacerbations, which are deadly in most cases, as well as either treating or preventing lung cancer.

Genotype-Phenotype Relationships in Inheritable Idiopathic Pulmonary Fibrosis: A Greek National Cohort Study.

BACKGROUND: Monogenic and polygenic inheritances are evidenced for idiopathic pulmonary fibrosis (IPF). Pathogenic variations in surfactant protein-related genes, telomere-related genes (TRGs), and a single-nucleotide polymorphism in the promoter of MUC5B gene encoding mucin 5B (rs35705950 T risk allele) are reported. This French-Greek collaborative study, Gen-Phen-Re-GreekS in inheritable IPF (iIPF), aimed to investigate genetic components and patients' characteristics in the Greek national IPF cohort with suspected heritability. PATIENTS AND METHODS: 150 patients with familial PF, personal-family extrapulmonary disease suggesting short telomere syndrome, and/or young age IPF were analyzed. RESULTS: MUC5B rs35705950 T risk allele was detected in 103 patients (90 heterozygous, 13 homozygous, allelic frequency of 39%), monoallelic TRG pathogenic variations in 19 patients (8 TERT, 5 TERC, 2 RTEL1, 2 PARN, 1 NOP10, and 1 NHP2), and biallelic ABCA3 pathogenic variations in 3. Overlapping MUC5B rs35705950 T risk allele and TRG pathogenic variations were shown in 11 patients (5 TERT, 3 TERC, 1 PARN, 1 NOP10, and 1 NHP2), MUC5B rs35705950 T risk allele, and biallelic ABCA3 pathogenic variations in 2. In 38 patients, neither MUC5B rs35705950 T risk allele nor TRG pathogenic variations were detectable. Kaplan-Meier curves showed differences in time-to-death (p = 0.025) where patients with MUC5B rs35705950 T risk allele alone or in combination with TRG pathogenic variations presented better prognosis. CONCLUSION: The Gen-Phen-Re-GreekS in iIPF identified multiple and overlapping genetic components including the rarest, underlying disease's genetic "richesse," complexity and heterogeneity. Time-to-death differences may relate to diverse IPF pathogenetic mechanisms implicating "personalized" medical care driven by genotypes in the near future.

Collagen 1a1 Expression by Airway Macrophages Increases In Fibrotic ILDs and Is Associated With FVC Decline and Increased Mortality.

Within the Interstitial Lung Diseases (ILD), patients with idiopathic pulmonary fibrosis (IPF) and a subset of those with non-IPF fibrotic ILD have a distinct clinical phenotype of progression despite management. This group of patients has been collectively termed the progressive fibrotic phenotype (PFP). Their early recognition may facilitate access to antifibrotic therapies to prevent or slow progression. Macrophages/monocytes within the lung orchestrate the progression and maintenance of fibrosis. A novel role for monocyte-derived macrophages during tissue damage and wound healing is the expression of collagens. We examined Collagen 1a1 expression in airway macrophages from ILD patients at diagnosis. COL1A1 mRNA levels from BAL cells were elevated in IPF and Non-IPF patients. The presence of a UIP pattern and a subsequent progressive phenotype were significantly associated with the higher BAL COL1A1 levels. In Non-IPF patients, higher COL1A1 levels were associated with a more than twofold increase in mortality. The intracellular localisation of COL1A1 in airway macrophages was demonstrated by confocal microscopy in CD45 and CD163 co-staining assays. Additionally, airway macrophages co-expressed COL1A1 with the profibrotic SPP1 gene product osteopontin. The levels of SPP1 mRNA and OPN in the BAL were significantly higher in IPF and Non-IPF patients relative to healthy. Our results suggest that profibrotic airway macrophages are increased in the BAL of patients with IPF and other ILDs and co-express COL1A1 and OPN. Importantly, COL1A1 expression by pro-fibrotic airway macrophages could be a marker of disease progression and poor survival in ILDs.

Real-life Cretan asthma registry focused on severe asthma: On behalf of 'The Cretan registry of the use of Biologics in Severe Asthma'.

Asthma diagnosis and management remains a challenging task for the medical community. The aim of the present study was to present the functional and inflammatory profiles of patients with difficult-to-treat asthma in a real-life clinical setting referred to the specialized asthma clinic at the University Hospital of Heraklion. The registry included a cohort of 267 patients who were referred to the severe asthma clinic. Patients were assessed with emphasis on the history of allergies, nasal polyposis or other comorbidities. Blood testing for eosinophils counts and total and specific IgE, and pulmonary function tests were performed at baseline. The median age of patients with asthma was 55 years old, 68.5% were women and 58.3% were never smokers. The vast majority presented with late onset asthma (75.7%), whereas eight (3%) patients were on oral corticosteroids. The median number of exacerbations during the last 12 months was 1 (0-3). Furthermore, 50.7% of patients had a positive serum allergy test, the median eosinophil count was 300 (188-508.5) cells/µl of blood and median total IgE level was 117.5 (29.4-360.5) IU/ml. Patients were retrospectively grouped in the following categories: Group 1, mild-moderate asthma; group 2, patients prescribed a step 4 or 5 asthma therapy according to Global Initiative for Asthma; and group 3, patients on biologic agents. Group 1 had significantly higher FEV1% than groups 2 and 3 (93.4 vs. 79.9 and 79.4%, respectively; P<0.001). Finally, the median Asthma Control Questionnaire 7 (ACQ7) score was 1.14, with patients from groups 2 and 3 presenting higher ACQ7 scores compared with group 1 patients as expected (1.1 and 2.1 vs. 0.7, respectively; P<0.001). To the best of our knowledge, this was the first real-life asthma study in Crete that demonstrated that severe asthmatics predominantly have late-onset asthma with airflow obstruction and uncontrolled symptoms.

MUC5B promoter variant rs35705950 and rheumatoid arthritis associated interstitial lung disease survival and progression.

BACKGROUND: The major risk factor for idiopathic pulmonary fibrosis (IPF), MUC5B rs35705950, was found to be associated with rheumatoid arthritis-associated interstitial lung disease (RA-ILD). Whilst the MUC5B rs35705950 T risk allele has been associated with better survival in IPF, its impact on RA-ILD prognosis remains to be determined. Our objective was to explore the influence of MUC5B rs35705950 on survival and progression in RA-ILD. METHODS: Through an international retrospective observational study, patients with RA-ILD were genotyped for the MUC5B rs35705950 variant and consecutive pulmonary function tests (PFTs) findings were collected. Longitudinal data up to a 10-year follow-up were considered and analyzed using mixed regression models. Proportional hazards and joint proportional hazards models were used to analyze the association of baseline and longitudinal variables with lung transplant-free survival. Significant progression of RA-ILD was defined as at least an absolute or relative 10% decline of forced vital capacity at 2 years from baseline. RESULTS: Out of 321 registered patients, 261 were included in the study: 139 women (53.3%), median age at RA-ILD diagnosis 65 years (interquartile range [IQR] 57 to 71), 151 ever smokers (59.2%). Median follow-up was 3.5 years (IQR 1.3 to 6.6). Mortality rate was 32% (95%CI 19 to 42) at 10 years. The MUC5B rs35705950 variant did not impact lung transplant-free survival (HR for the T risk allele carriers=1.26; 95%CI 0.61 to 2.62; P=0.53). Decline in pulmonary function at 2 years was not influenced by MUC5B rs35705950 (OR=0.95; 95%CI 0.44 to 2.05; P=0.89), irrespective of the HRCT pattern. CONCLUSION: In this study, the MUC5B rs35705950 promoter variant did not influence transplant- free survival or decline in pulmonary function in patients with RA-ILD.

Enhanced IL-1ß Release Following NLRP3 and AIM2 Inflammasome Stimulation Is Linked to mtROS in Airway Macrophages in Pulmonary Fibrosis.

Fibrotic Interstitial lung diseases (ILDs) are complex disorders of variable clinical behaviour. The majority of them cause significant morbidity, whilst Idiopathic Pulmonary Fibrosis (IPF) is recognised as the most relentless. NLRP3, AIM2, and NLRC4 inflammasomes are multiprotein complexes driving IL-1ß release; a proinflammatory and profibrotic cytokine. Several pathogenetic factors associated with IPF are identified as inflammasome activators, including increases in mtROS and bacterial burden. Mitochondrial oxidation and alterations in bacterial burden in IPF and other ILDs may lead to augmented inflammasome activity in airway macrophages (AMs). IPF (n=14), non-IPF-ILDs (n=12) patients and healthy subjects (n=12) were prospectively recruited and AMs were isolated from bronchoalveolar lavage. IL-1ß release resulting from NLRP3, AIM2 and NLRC4 inflammasomes stimulation in AMs were determined and baseline levels of mitochondrial ROS and microbial burden were also measured. Our results showed that NLRP3 was more inducible in IPF and other ILDs compared to controls. Additionally, following AIM2 activation IL-1ß release was significantly higher in IPF compared to controls, whereas similar trends were observed in Non-IPF-ILDs. NLRC4 activation was similar across groups. mtROS was significantly associated with heightened NLRP3 and AIM2 activation, and mitochondrial antioxidant treatment limited inflammasome activation. Importantly, microbial burden was linked to baseline IL-1ß release and AIM2 and IL-18 relative expression independently of mtROS. In conclusion, the above findings suggested a link between the overactivation of NLRP3 and AIM2 inflammasomes, driven by mitochondrial oxidation, in the pathogenesis of lung fibrosis while changes in the microbiota may prime the inflammasome in the lungs.

Pharmacological management of Idiopathic Pulmonary Fibrosis: current and emerging options.

INTRODUCTION: Idiopathic Pulmonary Fibrosis is a chronic, progressive lung disease characterized by worsening lung scarring and the radiological/histological pattern of usual interstitial pneumonia. Substantial progress has been made in the clinical management of IPF in the last decade. The two novel antifibrotics, Nintedanib and Pirfenidone have changed the landscape of IPF, by hindering disease progression; however, the drugs have significant discontinuation rates, due to adverse events and do not offer a definitive cure, as such IPF remains a deleterious disease with poor survival. AREAS COVERED: In this review, the authors focus on the current and emerging pharmacological options in the treatment of IPF. They include a summary of the current approach including treatment of comorbidities and then discuss promising drugs in the drug pipeline. EXPERT OPINION: IPF remains a disease with detrimental outcomes. The plethora of emerging pharmacological treatments brings hope for the future. The current pharmacological 'one fits all' approach has been proven effective in slowing disease progression. The future lies in an oncological approach with combination of therapies. We expect to see a change in clinical trial endpoints and a more inclusive approach for the diagnosis of IPF. ABBREVIATION LIST: AE: Acute ExacerbationA-SMA: a smooth muscle actinATX: AutotaxinCOPD: Combined Obstructive Pulmonary DiseaseCPFE: Combined Pulmonary Fibrosis and EmphysemaGER: Gastro-esophageal refluxFVC: forced vital capacityECMO: extracorporeal membrane oxygenationILD: Interstitial Lung DiseaseIPF: Idiopathic Pulmonary FibrosisNAC: N-acetylcysteineLPA: Lysophosphatidic acidPH: Pulmonary RehabilitationPR: Pulmonary rehabilitationRCTs: randomized placebo-controlled trialsUIP: usual interstitial pneumonia.

[Comment] Treatment strategies to fight the new coronavirus SARS-CoV-2: A challenge for a Rubik's Cube solver.

SARS-coronavirus-2 (SARS-CoV-2), the etiologic agent of the new lung disease COVID-19 is closely related to SARS-CoV, and together with MERS-CoV are three new human coronaviruses that emerged in the last 20 years. The COVID-19 outbreak is a rapidly evolving situation with higher transmissibility and infectivity compared with SARS and MERS. Clinical presentations range from asymptomatic or mild symptoms to severe illness. The prevalent cause of mortality is pneumonia that progresses to ARDS. The ongoing pandemic has already resulted in more than 135,000 deaths and an unprecedented burden on national health systems worldwide. Pending the availability of a vaccine, there is a critical need to identify effective treatments and a number of clinical trials have been implemented worldwide. Trials are based on repurposed drugs that are already approved for other infections, have acceptable safety profiles or have performed well in animal studies against the other two deadly coronaviruses. Supportive care remains the mainstay of therapy at present, as it is still unclear how well these data can be extrapolated to SARS-CoV-2. Most of those emerging re-introduced drugs are administered to patients in the context of clinical trials. In this review, we summarize the strategies currently employed in the treatment of COVID-19.

Efficacy and safety of nintedanib in a Greek multicentre idiopathic pulmonary fibrosis registry: a retrospective, observational, cohort study.

Nintedanib is a tyrosine kinase inhibitor approved for the treatment of idiopathic pulmonary fibrosis (IPF). In a retrospective, real-world study across seven Greek hospitals, we evaluated the effectiveness and safety of nintedanib in routine clinical practice. Patients diagnosed with IPF, as per guideline criteria or multidisciplinary diagnosis, received nintedanib between January 2013 and January 2018. We evaluated 244 patients: mean±sd age 71.8±7.5 years, 79.1% male, 45.1% current smokers and 33.1% ex-smokers at treatment initiation. At baseline, predicted forced vital capacity (FVC) was 73.3±20.7% and predicted diffusing capacity of the lungs for carbon monoxide (D LCO) was 42.6±16.7%. On average, patients spent 23.6±15.0 months on nintedanib. At 3 years, 78 patients had died, equating to a 3-year survival rate of 59.4% (unaffected by treatment discontinuation or dose reduction). FVC% pred and D LCO% pred were largely stable at 3 years, with no significant difference from baseline (FVC 73.3±20.7% pred versus 78±20.1% pred, p=0.074; D LCO 42.6±16.7% pred versus 40.4±18.1% pred, p=0.334). Of the 244 patients, 55.7% reported an adverse event. Gastrointestinal events were the most common (173 (77.2%) out of 224 total events) and 45.0% of patients experienced diarrhoea. Only 32 (13.1%) patients had to permanently discontinue nintedanib due to an adverse event. This real-world study shows a 3-year survival rate of 59.4% and a low discontinuation rate due to adverse events. Our experience is consistent with previous findings in clinical trials of nintedanib in IPF.

Lung cancer in patients with Idiopathic Pulmonary Fibrosis. A retrospective multicenter study in Greece.

BACKGROUND: Abundant evidence supports an association between Idiopathic Pulmonary Fibrosis (IPF) and lung cancer development. Data on diagnosis and management of patients with IPF and lung cancer are still scarce. PATIENTS AND METHODS: This was a retrospective multicenter study, enrolling 1016 patients with IPF from eight different centers between 2011 and 2018 in Greece. Our aim was to estimate prevalence of lung cancer in patients with IPF in Greece. RESULTS: We identified 102 cases of patients with IPF and lung cancer (prevalence = 10.03% n = 102/1016, mean age±SD = 71.8 ± 6.9, 96 males, mean FVC±SD = 72.7 ± 19.7, mean DLCO±SD = 44.5 ± 16.3). We identified 85 cases (83.3%) of non-small cell lung cancer (35 squamous, 28 adenocarcinoma), and 15 cases (14.7%) of small cell lung cancer. Primary lesion was localized in lower lobes in 57.1% of cases. Lung cancer was diagnosed post IPF diagnosis (mean latency time + SD = 33.2 + 36.1 months) in 57.6% of patients and synchronously in 36.5% of patients. Chemotherapy was applied in 26.7% of cases, while 34.7% of patients underwent surgery. Median survival of patients with IPF and lung cancer was 27.4 months (95% CI: 20.6 to 36.8). CONCLUSIONS: IPF is a risk factor for lung cancer development. In line with current literature, squamous cell carcinoma is the most common histologic subtype in patients with IPF. Large randomized controlled studies on the management of patients with IPF and lung cancer are sorely needed.

Accumulation of damaged mitochondria in alveolar macrophages with reduced OXPHOS related gene expression in IPF.

BACKGROUND: Impaired mitochondria homeostasis and function are established hallmarks of aging and increasing evidence suggests a link with lung fibrosis. Mitochondria homeostasis may be also affected in alveolar macrophages (AMs) in idiopathic pulmonary fibrosis (IPF). In this study, we used bronchoalveolar lavage (BAL), a tool for both clinical and research purposes, and a rich source of AMs. METHODS: BAL samples were examined from 52 patients with IPF and 19 healthy individuals. Measurements of mitochondria reactive oxygen species (mtROS), mitochondria morphology and related gene expression were performed. Additionally, autophagy and mitophagy levels were analysed. RESULTS: Mitochondria in AMs from IPF patients had prominent morphological defects and impaired transcription paralleled to a significant reduction of mitochondria homeostasis regulators PINK1, PARK2 and NRF1. mtROS, was significantly higher in IPF and associated with reduced expression of mitochondria-encoded oxidative phosphorylation (OXPHOS) genes. Age and decline in lung function correlated with higher mtROS levels. Augmentation of damaged, oxidised mitochondria in IPF AMs however was not coupled to increased macroautophagy and mitophagy, central processes in the maintenance of healthy mitochondria levels. CONCLUSION: Our results suggest a perturbation of mitochondria homeostasis in alveolar macrophages in IPF.

Substernal goiter: Treatment and challenges. Twenty-two years of experience in diagnosis and management of substernal goiters.

OBJECTIVE: Descending goiter has been a focus of controversy in thyroid surgery until nowadays. This study aims to investigate the diagnosis and treatment options of thyroid goiters extending into the mediastinum and the thoracic cavity. METHODS AND MATERIALS: A retrospective study was conducted assessing all cases of substernal goiter managed in a tertiary care referral center within 22 years. Demographics, clinical, operative, anatomical, and pathological data of the patients were recorded and analyzed. RESULTS: Among 3.028 total thyroidectomies, 212 procedures for substernal goiters were studied. All cases underwent total thyroidectomy. The surgical approach was cervical in all but two cases. A very low rate of complications and zero mortality were noted. Incidence of malignancy on permanent histology was 16%. CONCLUSION: Descending goiter constitutes a major indication for thyroid surgery. The overwhelming majority of descending goiters may be managed surgically through a neck incision. In experienced hands good results with low morbidity should be expected. Such cases should be considered as challenging, however, and therefore management in a referral center may be necessary in order to ensure optimal results.

Assembly 12: interstitial lung diseases.

Meet @ERStalk Assembly 12: interstitial lung diseases http://ow.ly/Bp0730m9zX4.

Pirfenidone improves survival in IPF: results from a real-life study.

BACKGROUND: Pirfenidone is an antifibrotic compound approved for the treatment of idiopathic pulmonary fibrosis (IPF). We present our real-world experience in terms of Pirfenidone's effect on mortality and adverse events profile outside the restrictions of a clinical trial. METHODS: This is a retrospective observational intention to treat study of 82 consecutive IPF patients (UHH cohort). RESULTS: We observed a high 3-years survival rate of 73% without excluding patients who discontinued treatment for different reasons. The survival was compared to the survival of an IPF cohort from a tertiary referral center (RBH cohort). After exclusion of severe cases (DLco< 30%), in unadjusted analysis, the survival in the UHH cohort was better than in the RBH cohort (HR:0.32, 95% CI: 0.19-0.53, p < 0.0001). After adjustment for age, gender and FVC, the survival remained higher in the UHH cohort (HR:0.28, 95% CI: 0.16-0.48, p < 0.0001). We observed a similar safety profile compared to previously published data and a lower rate of drug discontinuation due to photosensitivity reactions. CONCLUSION: Pirfenidone provides a survival benefit in a real-life IPF cohort compared to previously used medications. Counselling patients and proactively managing possible adverse effects can reduce the necessity to discontinue pirfenidone.

NLRP3/Caspase-1 inflammasome activation is decreased in alveolar macrophages in patients with lung cancer.

Lung cancer (LC) remains the leading cause of cancer-related mortality. The interaction of cancer cells with their microenvironment, results in tumor escape or elimination. Alveolar macrophages (AMs) play a significant role in lung immunoregulation, however their role in LC has been outshined by the study of tumor associated macrophages. Inflammasomes are key components of innate immune responses and can exert either tumor-suppressive or oncogenic functions, while their role in lung cancer is largely unknown. We thus investigated the NLRP3 pathway in Bronchoalveolar Lavage derived alveolar macrophages and peripheral blood leukocytes from patients with primary lung cancer and healthy individuals. IL-1ß and IL-18 secretion was significantly higher in unstimulated peripheral blood leukocytes from LC patients, while IL-1ß secretion could be further increased upon NLRP3 stimulation. In contrast, in LC AMs, we observed a different profile of IL-1ß secretion, characterized mainly by the impairment of IL-1ß production in NLRP3 stimulated cells. AMs also exhibited an impaired TLR4/LPS pathway as shown by the reduced induction of IL-6 and TNF-α. Our results support the hypothesis of tumour induced immunosuppression in the lung microenvironment and may provide novel targets for cancer immunotherapy.

Investigation of key autophagy-and mitophagy-related proteins and gene expression in BALF cells from patients with IPF and RA-ILD.

Idiopathic pulmonary fibrosis (IPF) is a chronic and irreversible interstitial lung disease with a poor prognosis and limited therapeutic options. Over the past decade, research efforts have focused on the pathogenetic mechanisms involved in this enigmatic lung disease. Rheumatoid arthritis (RA) is a chronic inflammatory autoimmune disease often complicated by the development of interstitial lung disease (ILD), leading to high mortality and morbidity. Autophagy is a process regulating the turnover of subcellular components and organelles, and represents a major cellular homeostatic mechanism. Recent evidence suggests a role of autophagy and mitochondrial dysfunction in the development of IPF, focusing on lung fibroblasts and epithelial cells. The aim of this study was to examine the mRNA levels of molecules involved inthe autophagy pathway in bronchoalveolar lavage fluid (BALF)­derived cellsfrom patients with IPF in comparison topatients with RA demonstrating lung involvement (ILD) by RT-qPCR. The significant upregulation of BECLIN1 was observed in patients with RA-ILD compared with those with IPF. Other genes involved in the autophagy pathway were also examined, such as Unc-51 like autophagy activating kinase 1 (ULK1), BCL2 interacting protein 3 (BNIP3) and p62. No differences in the mRNA expression levels of these genes were observed. As regards the selective degradation of mitochondria and mitophagy, similar PTEN-induced putative kinase 1 (PINK1) and PARKIN; E3 ubiquitin ligase (PRKN) expression, as well as PINK1 protein levels, were observed. On the whole, the findings of this study demonstrate an increased expression of BECLIN1 in BALF cells from patients with RA-ILD compared with those from patients with IPF, while similar levels in other key molecules implicating in the autophagy pathway were observed in patients with IPF and RA-ILD.

miR-185 and miR-29a are similarly expressed in the bronchoalveolar lavage cells in IPF and lung cancer but common targets DNMT1 and COL1A1 show disease specific patterns.

Idiopathic pulmonary fibrosis (IPF) and lung cancer (LC) constitute two progressively devastating lung diseases with common risk factors including aging and smoking. There is an increasing interest in the investigation of common pathogenic mechanisms between IPF and LC with therapeutic implications. Several oncomirs, microRNAs associated with malignancy, are also linked with IPF. miR­29a and miR­185 downregulation is probably involved both in carcinogenesis and fibrogenesis. We have previously observed miR­29a and miR­185 downregulation in IPF cells from bronchoalveolar lavage (BAL) and in this study we investigated their expression in LC BAL cells. Common targets of miR­29a and miR­185 such as DNA methyltransferase (DNMT)1, DNMT3b, COL1A1, AKT1 and AKT2 were measured. Potential correlations with pulmonary function tests, smoking status and endobronchial findings were investigated. Similar levels of miR­29a and miR­185 were detected in IPF and LC while their common targets AKT1 and DNMT3b were not found to differ, suggesting potential pathogenetic similarities at the level of key epigenetic regulators. By conrast, COL1A1 mRNA levels were increased in IPF suggesting a disease­specific mRNA signature. Notably, DNMT1 was downregulated in the LC group and its expression was further reduced in the presence of increasing malignant burden as it was implied by the endobronchial findings.

Upregulation of citrullination pathway: From Autoimmune to Idiopathic Lung Fibrosis.

BACKGROUND: Increased protein citrullination and peptidylarginine deiminases (PADIs), which catalyze the citrullination process, are central in Rheumatoid arthritis pathogenesis and probably involved in the initial steps towards autoimmunity. Approximately, 10% of RA patients develop clinically significantly ILD. A possible shared role of protein citrullination in rheumatoid arthritis associated interstitial lung disease (RA-ILD), and idiopathic pulmonary fibrosis (IPF) pathogenesis remains unclear. METHODS: We evaluated PADI2 and PADI4 mRNA expression in bronchoalveolar lavage fluid (BALF) cells of 59 patients with IPF, 27 patients RA-ILD and 10 healthy controls. PADI 2 and 4 expression was analyzed by western blot and immunohistochemistry. Citrullinated protein levels were also quantified. RESULTS: PADI4 mRNA and protein levels were higher in RA-ILD and IPF than controls. Furthermore, PADI4 mRNA levels showed an increase among smokers in RA-ILD. PADI4 expression was detected in granulocytes and macrophages in all groups, with the strongest cytoplasmic expression observed in granulocytes in RA-ILD and IPF. PADI2 mRNA and immunostaining of BAL cells, were similar in all groups among smokers. Overall, stronger staining was observed in current smokers. Citrullinated peptides were significantly increased in IPF compared to RA-ILD and controls. In RA-ILD, protein citrullination strongly correlated with PADI4 expression and anti-citrullinated protein antibodies (ACPAs). CONCLUSIONS: These results suggest that the citrullination pathway is upregulated in IPF and in RA-ILD.