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.

NLRP3 inflammasome expression in idiopathic pulmonary fibrosis and rheumatoid lung.

In this study we investigated the implication of NLRP3 inflammasomes in the pathogenesis of idiopathic pulmonary fibrosis (IPF) and rheumatoid arthritis-usual interstitial pneumonia (RA-UIP).NLRP3 inflammasome activation at baseline and following stimulation with lipopolysaccharide/ATP was evaluated by measuring interleukin (IL)-1ß and IL-18 levels released in the bronchoalveolar lavage fluid (BALF) fluid and by cultures of BALF cells. IL-1ß and IL-18 levels were significantly elevated in the BALF and BALF macrophage cultures from RA-UIP patients, consistent with pre-existing inflammasome activation in these patients. In contrast, in IPF, BALF levels of IL-1ß were significantly less elevated relative to RA-UIP and IL-18 was lower than controls. Furthermore, upon inflammasome stimulation, IPF BALF macrophage cultures failed to upregulate IL-1ß and partly IL-18 secretion, in contrast to controls, which showed robust IL-1ß and IL-18 upregulation. Interestingly, RA-UIP BALF cell cultures treated with lipopolysaccharide/ATP showed a potent stimulation of IL-18 secretion but not IL-1ß, the latter being already elevated in the unstimulated cultures, while examination of the intracellular IL-1ß levels in RA-UIP BALF cells upon NLRP3 inflammasome stimulation showed a significant upregulation of IL-1ß suggesting the NLRP3 pathway could be further activated.Taken together, our results suggest distinct inflammasome activation profiles between autoimmune and idiopathic lung fibrosis.

Expression analysis of Akt and MAPK signaling pathways in lung tissue of patients with idiopathic pulmonary fibrosis (IPF).

PURPOSE OF THE STUDY: Several studies in patients with lung cancer have shown that epidermal growth factor receptor regulates various tumorigenic processes through the phosphoinositide 3-kinase/Akt/mammalian target of rapamycin and Ras/Raf/Mek/Erk (mitogen-activated protein kinase (MAPK)) signalling pathways. The aim of our study is to evaluate whether these pathways are implicated in the pathogenesis of idiopathic pulmonary fibrosis (IPF) and to seek indirect evidence of a common pathogenetic pathway with lung cancer. m-RNA expression of oncogenes participating in these two signaling pathways, as well as the combined m-RNA expression of the suppressor genes R-kip and p53 in lung tissue of patients with IPF were evaluated. BASIC PROCEDURES: The study population was composed by two distinct groups. Patients with IPF (n = 25) and control subjects who underwent thoracic surgery for reasons other than interstitial lung disease (n = 10). Expression analysis of the aforementioned oncogenes and suppressor genes was performed using real-time reverse transcription polymerase chain reaction. MAIN FINDINGS: We found no difference in the overall m- RNA expression between controls and IPF in both investigated pathways. However, Braf has been overexpressed in IPF samples (P = 0.01) in contrast with K-ras that has been found downregulated (P < 0.001) in comparison with controls. PRINCIPAL CONCLUSIONS: These findings cannot exclude the hypothesis of involvement of Akt and MAPK signalling pathways in pathogenesis of IPF. However, further investigation is needed in order to verify these data.

Somatic DNA alterations in lung epithelial barrier cells in COPD patients.

BACKGROUND: Instability of the Microsatellite DNA Instability (MSI) and Loss of Heterozygosity (LOH) have been previously detected in sputum cells of COPD patients. However, the particular cell subpopulation exhibiting genetic instability in COPD was uncertain. The aim of this study was to determine which cell type expresses Microsatellite DNA Instability in sputum and BALF samples from COPD patients. METHODS: Thirty-five COPD patients and 30 non-COPD smokers were studied. Sputum was induced from 20 COPD patients and 20 non-COPD smokers and BALF was obtained from 15 COPD patients and 10 non-COPD smokers. The sputum cell pellet and BALF samples were processed using immunomagnetic technology to separate antibody-specific cell subpopulations, using CD45+ for leukocytes, Epithelial enrich (MACS) for sputum epithelial cells and HEA-human epithelial antigen-(Dynal) for BAL epithelial cells. Microsatellite DNA amplification was performed using specific primers, namely G29802, D6S2223, D6S344, D6S263, D5S207, D13S71, RH70958, and D17S250. The presence of MSI and/or LOH was analyzed with LI-COR Saga GT Microsatellite Analysis Software. MEASUREMENTS AND MAIN RESULTS: None of the non-COPD smokers exhibited any genetic alteration. MSI and LOH were found in 15 cases (8 MSI and 7 LOH) in sputum and BAL samples. MSI and/or LOH were revealed only in the epithelial barrier cells. LOH was detected in D5S207, D6S344, G29802 and D17S250 microsatellite markers, while MSI in D13S71, D5S207 and D6S344. The entire leukocyte subpopulation exhibited no genetic alteration. CONCLUSIONS: Our results support the hypothesis that chronic inflammation and oxidative burden in COPD can lead to DNA damage of the lung epithelial barrier cells, detected at the Microsatellite DNA level. Further studies are required to investigate the significance of these findings in the pathogenesis of COPD.

Different activity of the biological axis VEGF-Flt-1 (fms-like tyrosine kinase 1) and CXC chemokines between pulmonary sarcoidosis and idiopathic pulmonary fibrosis: a bronchoalveolar lavage study.

BACKGROUND: We have previously shown a different local and systemic angiogenic profile of CXC chemokines in Idiopathic Pulmonary Fibrosis (IPF) patients compared to sarcoidosis. In particular, sarcoidosis showed an angiostatic microenvironment, as compared with the angiogenic cytokine milieu seen in IPF. Purpose of the Study. Our aim was to further investigate the aforementioned finding by measuring the expression of different chemokines in granulomatous and fibrotic diseases. We estimated the levels of vascular endothelial growth factor (VEGF) and its high-affinity receptor, Flt-1 (fms-like tyrosine kinase 1), in bronchoalveolar lavage fluid (BALF) of patients with IPF and pulmonary sarcoidosis. We have also investigated the mRNA expression of angiogenetic chemokines' receptors such as CXCR2 and CXCR3 and the biological axis of stromal derived factor-1 alpha (SDF-1 alpha or CXCL12 alpha/CXCL12 beta) and receptor, CXCR4. METHODS: We studied prospectively three groups of patients: (i) one group of 18 patients with IPF, (ii) one group of 16 patients with sarcoidosis, and (iii) 10 normal subjects. RESULTS: A statistically significant increase has been detected in VEGF mRNA expression in IPF in comparison with pulmonary sarcoidosis (P = .03). In addition, a significant increase has been measured in CXCL12 alpha in sarcoidosis in comparison to IPF (P = .02). Moreover, a statistically significant decrease has been found in Flt-1 protein levels in pulmonary sarcoidosis in comparison with IPF (P = .03). A significant increase in VEGF (P = .03) and CXCR4 (P = .03) mRNA levels has been also detected in sarcoidosis' patients when compared with healthy controls. CONCLUSIONS: Our data suggest that increased expression of Flt-1 and downregulation of CXCL12 alpha in IPF may further support the hypothesis of a different angiogenetic profile between fibrotic and granulomatous diseases. However, further studies are needed in order to better investigate these enigmatic diseases.

Induced sputum in interstitial lung diseases: novel insights in the diagnosis, evaluation and research.

The search for noninvasive procedures of retrieving cells and soluble material from the lung has gained momentum over the past few years. Induced sputum (IS) by inhalation of hypertonic saline solution is a noninvasive technique used to collect cellular and soluble material from lung airways. During the past decade, this method has been widely used to assess airway inflammation in asthma and chronic obstructive disease, since it produces reliable results and compares favorably to other invasive techniques, such as biopsy and bronchoalveolar lavage fluid. However, recent attention has been paid to its efficacy in the evaluation of interstitial lung diseases. Recent research in this area clearly showed that IS analysis could give extensive information regarding the inflammation in pulmonary sarcoidosis, such as the lymphocytic cell count, the CD4+/CD8+ ratio and the Th1 immunologic response. The CD4+/CD8+ ratio recovered from lymphocytes from IS is as useful as the same value retrieved from examination of lymphocytes recovered from bronchoalveolar lavage fluid for clinical use. The above findings suggest that integrating IS procedure in the diagnosis, evaluation, follow-up and research in patients with pulmonary sarcoidosis is necessary. Besides sarcoidosis, the review of the current literature in other interstitial lung diseases showed that IS could provide us with useful information regarding inflammatory molecules, but cannot fully replace more invasive techniques. This review analyzes the applications of IS in the assessment of fibrotic and granulomatous diseases such as sarcoidosis and extrinsic allergic alveolitis, idiopathic pulmonary fibrosis, connective tissue disorders, occupational lung diseases and other systemic diseases.

Molecular pathways and genetic factors in the pathogenesis of laryngopharyngeal reflux.

The prevalence of laryngopharyngeal reflux (LPR) has been constantly rising in the western world and affects today an alarmingly high percentage of the general population. Even though LPR and gastroesophageal reflux disease (GERD) are both the product of gastroesophageal reflux and seem to be sibling disorders, they constitute largely different pathological entities. While GERD has been for a long time identified as a source of esophageal disease, LPR has only recently been associated with head and neck disorders. Despite the high incidence of LPR and its great impact on patients' quality of life, little is known regarding its pathogenesis. On the other hand, studying the molecular and genetic basis of a disease is of fundamental importance in medicine as it offers better insight into the pathogenesis and opens new, disease-specific therapeutic trends. The aim of this study is to enlighten any known or suspected molecular mechanisms that contribute to the pathogenesis of LPR, and to suggest new trends for future research.

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.

Microsatellite DNA instability in nasal cytology of COPD patients.

Genetic alterations in the microsatellite DNA level have been successfully detected in sputum samples of patients with COPD and have been shown to be disease specific. Furthermore, previous studies have shown that inflammation coexists in the nasal mucosa of patients with COPD. The aim of this study was to assess the presence of MSI in nasal cytological samples of patients with COPD comparing the results with sputum samples of the same individuals. Nasal brush samples, sputum samples obtained by induction, and peripheral blood from 20 patients with COPD were analyzed. DNA was extracted and analyzed for MSI using the following microsatellite markers: RH70958, D5S207, D6S344, D6S263, G29802, D13S71, D14S588, D14S292 and D17S250. Microsatellite analysis was also performed in 8 healthy non-smokers. MSI was detected in the sputum samples of 7 patients with COPD (35%). In contrast, no microsatellite DNA instability was noted in the nasal cytological samples of the same COPD patients. In addition, no genetic alteration was detected in the control group. These results suggest that MSI is a specific finding for the target organ of COPD, i.e. the lungs, despite the fact that inflammation coexists in the nasal mucosa of COPD patients. Our study supports the hypothesis that MSI could be an index of the somatic-acquired genetic alterations in the lungs of COPD patients.

Profile of endocrinological derangements affecting PSA values in patients with COPD.

BACKGROUND/AIM: Chronic obstractive pulmonary disease (COPD) in men has been associated with testosterone deficiency, known as the late-onset hypogonadism. Prostate cancer becomes more prevalent when testosterone values decline in males. We sought to determine endocrinological derangements that may affect PSA values in male patients with COPD. MATERIALS AND METHODS: A total of 69 male patients with COPD and 82 healthy volunteers were divided into subgroups according to: their age: (i) ≤60 years and (ii) >60 years; or disease severity: (i) FEV1<50% and (ii) FEV1≥50% predicted. RESULTS: There was a significant reduction in total and free testosterone in patients with COPD. Patients with COPD aged >60 years had significantly lower free PSA compared to the control group. CONCLUSION: Alterations of the male hormonal status in COPD are related with older age (>60 years) and poorer lung function (FEV1<50% predicted). This may have implications for the use of the PSA-based screening tests in the elderly male population with COPD.

A patient presenting with bilateral lung lesions, pleural effusion, and proteinuria.

Diagnosis and management of a systemic vasculitis are among the most demanding challenges in clinical medicine. A patient with a past history of cryptogenic organizing pneumonia presents with new bilateral lung lesions, unilateral pleural effusion, and significant proteinuria. The patient tested p-ANCA and anti-MPO positive but c-ANCA negative. A diagnosis of granulomatosis with polyangiitis GPA was reached after performing both renal and lung biopsies. Step-by-step differential diagnosis and management are discussed.

Investigation of angiogenetic pathways in nasal polyposis.

Tissue angiogenesis is a complex phenomenon that results in the growth of new blood vessels from the microcirculation. This process has been known to play a crucial role in tumor growth as well as several benign diseases. The aim of this study was to assess mRNA expression of various angiogenic factors and chemokines in nasal polyps and compare the results to normal nasal mucosa. mRNA expression was measured using real-time RT-PCR for the following angiogenic factors and chemokines: VEGF, VEGFR-1, Ang-1, Ang-2, Tie-2A, Tie-2B, SDF-1α, SDF-1ß, CXCR4 and YY1. Biopsy specimens from nasal polyps in the polyposis group and middle turbinates in the control group were studied. A total of 18 nasal polyposis patients were studied and compared to 10 control subjects. Results showed VEGF, VEGFR-1, Ang-1, Ang-2, Tie-2A, Tie-2B, SDF-1α and SDF-1ß mRNA expression to be significantly higher in nasal polyposis patients compared to the control group (p<0.05). The findings of this study support the role of angiogenic growth factors in the pathogenesis of nasal polyposis. Further studies are required to confirm these results and evaluate potential clinical implications.

Expression profiles of Toll-like receptors in non-small cell lung cancer and idiopathic pulmonary fibrosis.

Patients with idiopathic pulmonary fibrosis (IPF) have a higher incidence of lung cancer. The role of Toll-like receptors (TLRs), a key component of the innate immunity, in interstitial lung diseases (ILDs) and lung cancer pathogenesis is not clarified. TLR2, TLR3, TLR4, TLR7, TLR8 and TLR9 mRNA expression was quantitatively measured by real-time reverse transcriptase polymerase chain reaction (RT-PCR) in bronchoalveolar lavage fluid (BALF) of 16 IPF patients, 16 non-small cell lung cancer (NSCLC) patients and 9 control subjects. TLR2, TLR3, TLR4 and TLR9 protein expression was assessed on BALF T-lymphocytes using flow cytometry. TLR3 mRNA expression was significantly higher in NSCLC compared to IPF (p=0.023) and controls (p=0.001). TLR7 mRNA expression levels were significantly higher in both NSCLC and IPF groups compared to controls (p=0.029, p=0.009). TLR9 expression at the mRNA level was significantly higher in both NSCLC and IPF groups compared to controls (p=0.01, p=0.001). Finally, TLR2 mRNA expression was significantly higher in IPF patients compared to controls (p=0.042). Flow cytometry revealed decreased TLR3 and TLR9 expression in IPF patients compared to the NSCLC group (p=0.02, p=0.014) and decreased TLR9 expression in IPF compared with the controls (p=0.04). TLR2 protein expression was significantly higher in IPF patients compared to NSCLC (p=0.04). Increased expression of endosomal TLRs in NSCLC patients and elevated expression of TLR2 in pulmonary fibrosis are the main results of this study. These results do not provide support for a common TLR pathway hypothesis between NSCLC and IPF.

Bronchial artery embolization for management of massive cryptogenic hemoptysis: a case series.

INTRODUCTION: Hemoptysis constitutes a common and urgent medical problem. Swift and effective management is of crucial importance, especially in severe, life-threatening cases. In cases of idiopathic hemoptysis, in which no underlying pulmonary pathology can be identified, treatment is challenging. We report our experience with bronchial artery embolization in the treatment of massive idiopathic hemoptysis. CASES PRESENTATION: We report three consecutive cases of acute severe idiopathic hemoptysis. Our patients (two men aged 51 and 56 years and one woman aged 46 years), were of Caucasian ethnicity. We discuss the results and management of the patients, and review the literature. All three patients were treated safely and successfully with transcatheter embolization of the bronchial arteries using tris-acryl gelatin microspheres. Hemoptysis was controlled. All cases were followed up for 12 months, and there was no recurrence of bleeding. CONCLUSION: Bronchial artery embolization is an effective tool for the evaluation and treatment of massive idiopathic hemoptysis.

Smoking and pulmonary fibrosis: novel insights.

The relationship between smoking and pulmonary fibrosis is under debate and intense investigation. The aim of this paper is to review the existing literature and identify further areas of research interest. Recently the negative influence of cigarette smoking on IPF outcome was highlighted, as non-smokers exhibit a better survival than ex-smokers and combined current- and ex-smokers. In patients with non-specific interstitial pneumonia (NSIP), a high prevalence of emphysema was recently demonstrated, providing an indirect support for a smoking pathogenetic hypothesis in NSIP. The coexistence of pulmonary fibrosis and emphysema has been extensively described in a syndrome termed combined pulmonary fibrosis and emphysema (CPFE). Connective tissue disorders (CTDs) are a group of autoimmune diseases which affect the lung, as one of the most common and severe manifestations. However, the relationship between smoking and autoimmune disorders is still conflicting. Rheumatoid arthritis results from the interaction between genetic and environmental factors, while the best established environmental factor is tobacco smoking. Smoking has also a negative impact on the response of the RA patients to treatment. The aforementioned smoking-related implications give rise to further research questions and certainly provide one more important reason for physicians to advocate smoking cessation and smoke-free environment.

Investigation of Toll-like receptors in the pathogenesis of fibrotic and granulomatous disorders: a bronchoalveolar lavage study.

BACKGROUND AND AIM: Toll-like receptors (TLRs), a key component of innate immunity, have recently been implicated in the pathogenesis of interstitial lung diseases (ILDs). As the involvement of TLRs has not yet been fully elucidated, the aim of the current study was to examine the expression of various TLRs in the bronchoalveolar lavage fluid (BALF) of patients with ILDs. PATIENTS AND METHODS: We studied prospectively three groups of patients: (1) one group of 35 patients with fibrotic disorders, 16 with idiopathic pulmonary fibrosis (IPF) and 19 with fibrotic interstitial pneumonias associated with collagen tissue disorders (CTD-IPs); (2) one group of 14 patients with pulmonary sarcoidosis; and (3) 11 normal subjects. We evaluated TLR expression with flow cytometry and mRNA expression with real-time PCR. RESULTS: An overexpression of TLR-3 mRNA was found in fibrotic disorders (CTD-IPs/IPF) in comparison with sarcoidosis (mean ± SD, 1.104 ± 1.087 versus 0.038 ± 0.03; P = 0.04). Additionally, TLR-3 mRNA was increased in CTD-IPs in comparison with IPF (P = 0.001), sarcoidosis (P = 0.002) and controls (P = 0.05). An upregulation in TLR-7 and -9 mRNA expression was detected in IPF (P = 0.05) and sarcoidosis (P = 0.05), respectively, when compared to controls. A higher percentage of TLR-9-expressing cells was found in BALF of CTD-IPs when compared to IPF (mean ± SD, 36.7 ± 7.06 versus 14.85 ± 3.82; P = 0.025). CONCLUSION: We observed distinct profiles of TLR expression in fibrotic and granulomatous disorders. It is likely that they could play a key role in the pathogenesis of these diseases and represent future therapeutic targets.

Microsatellite DNA instability in nasal polyposis.

OBJECTIVE: Genetic alterations, such as microsatellite instability (MSI) and loss of heterozygosity (LOH), have been detected in various inflammatory diseases, providing evidence that acquired somatic mutations might play a role in the aetiopathogenesis of chronic inflammatory conditions. The aim of this study is to assess the presence of MSI and/or LOH in nasal cytology of patients with nasal polyps. STUDY DESIGN: Prospective case-controlled basic science experiment utilizing human blood and human nasal brush samples. METHODS: Nasal brush samples and peripheral blood from 12 patients with nasal polyps were analyzed. DNA was extracted and analyzed for MSI and LOH using the following microsatellite markers: D2S2113, D6S344, D6S1002, D11S1253, D11S480, USAT24G1, and D13S273, harboring potential susceptibility genes for nasal polyposis. Microsatellite DNA analysis was also performed in 7 control subjects. RESULTS: MSI or LOH were revealed in 3 specimens of the nasal polyps group. Among these there were 2 cases of LOH, one for marker D11S1273 and one for D13S273, and one case of MSI in marker USAT24G1. Each one of these alterations was detected in a different patient. None of the control subjects exhibited any genetic alterations in the 7 markers tested. CONCLUSIONS: This is the first time that microsatellite genetic alterations are reported in nasal disease. The presence of such alterations suggests that acquired genomic somatic mutations might play a role in the pathogenesis of nasal polyps.

Assessment for microsatellite DNA instability in nasal cytology samples of patients with allergic rhinitis.

BACKGROUND: Genetic alterations, including microsatellite instability (MSI) and loss of heterozygosity (LOH), have been described in both malignant and benign diseases. Previous studies have successfully detected such alterations in sputum samples of patients with bronchial asthma (BA). The aim of this study was to assess the presence of MSI and/or LOH in nasal cytology samples of patients with allergic rhinitis (AR). METHODS: Nasal brush samples and peripheral blood from 20 patients with AR were analyzed. DNA was extracted and analyzed for MSI and LOH using the following microsatellite markers: D16S289, D4S2394, D4S1651, DXS8039, D3S3606, and D2S2113, harboring potential susceptibility genes for AR and atopy. Microsatellite analysis was performed also in eight control subjects. RESULTS: No MSI and/or LOH were noted in either the AR or the control group. CONCLUSION: Although MSI and LOH are detectable phenomena in sputum samples of patients with BA, this seems not to be the case for nasal cytology samples of patients with AR. Additional studies are needed, using a larger number of polymorphic markers, to assess if such a difference exists among two diseases otherwise very closely related.