T Lymphocyte Maturation Profile in the EBUS-TBNA Lymph Node Depending on the DLCO Parameter in Patients with Pulmonary Sarcoidosis.

Sarcoidosis (SA) is a systemic granulomatous disorder of unknown etiology with lung and mediastinal lymph nodes (LNs) as the main location. T lymphocytes play important role in the formation of granulomas in SA, but still little is known about the role of maturation profile in the development of inflammatory changes. The aim of this study was to determine the CD4+ and CD8+ T cells maturation profile in LNs and in peripheral blood (PB) and its relation to disease severity expressed by diffusing capacity of the lung for carbon monoxide (DLCO). 29 patients with newly pulmonary SA were studied. Flow cytometry was used for cells evaluation in EBUS-TBNA samples. We observed lower median proportion of T lymphocytes, CD4+ T and CD8+ T cells in patients with DLCO< 80% than in patients with normal diffusion (DLCO > 80%). Patients with DLCO < 80% had lower median proportion of effector and higher median proportion of central memory CD4+ and CD8+ T cells than patients with DLCO > 80%. We reported for the first time that LNs CD4+ and CD8+ T cells maturation differs depending on the DLCO value in sarcoidosis. Lymphocytes profiles in LNs may reflect the immune status of patients with SA and can be analysed by flow cytometry of EBUS-TBNA samples.

Hypoxia Promotes a Mixed Inflammatory-Fibrotic Macrophages Phenotype in Active Sarcoidosis.

Background: Macrophages are pivotal cells in sarcoidosis. Monocytes-derived (MD) macrophages have recently been demonstrated to play a major role especially in pulmonary sarcoidosis. From inflammatory tissues to granulomas, they may be exposed to low oxygen tension environments. As hypoxia impact on sarcoidosis immune cells has never been addressed, we designed the present study to investigate MD-macrophages from sarcoidosis patients in this context. We hypothesized that hypoxia may induce functional changes on MD-macrophages which could have a potential impact on the course of sarcoidosis. Methods: We studied MD-macrophages, from high active sarcoidosis (AS) (n=26), low active or inactive sarcoidosis (IS) (n=24) and healthy controls (n=34) exposed 24 hours to normoxia (21% O2) or hypoxia (1.5% O2). Different macrophage functions were explored: hypoxia-inducible factor-1α (HIF-1α) and nuclear factor-kappa B (NF-κB) activation, cytokines secretion, phagocytosis, CD80/CD86/HLA-DR expression, profibrotic response. Results: We observed that hypoxia, with a significantly more pronounced effect in AS compared with controls and IS, increased the HIF-1α trans-activity, promoted a proinflammatory response (TNFα, IL1ß) without activating NF-κB pathway and a profibrotic response (TGFß1, PDGF-BB) with PAI-1 secretion associated with human lung fibroblast migration inhibition. These results were confirmed by immunodetection of HIF-1α and PAI-1 in granulomas observed in pulmonary biopsies from patients with sarcoidosis. Hypoxia also decreased the expression of CD80/CD86 and HLA-DR on MD-macrophages in the three groups while it did not impair phagocytosis and the expression of CD36 expression on cells in AS and IS at variance with controls. Conclusions: Hypoxia had a significant impact on MD-macrophages from sarcoidosis patients, with the strongest effect seen in patients with high active disease. Therefore, hypoxia could play a significant role in sarcoidosis pathogenesis by increasing the macrophage proinflammatory response, maintaining phagocytosis and reducing antigen presentation, leading to a deficient T cell response. In addition, hypoxia could favor fibrosis by promoting profibrotic cytokines response and by sequestering fibroblasts in the vicinity of granulomas.

Myeloid ABCG1 Deficiency Enhances Apoptosis and Initiates Efferocytosis in Bronchoalveolar Lavage Cells of Murine Multi-Walled Carbon Nanotube-Induced Granuloma Model.

The use of carbon nanotubes has increased in the past few decades. Carbon nanotubes are implicated in the pathogenesis of pulmonary sarcoidosis, a chronic granulomatous inflammatory condition. We developed a murine model of chronic granulomatous inflammation using multiwall carbon nanotubes (MWCNT) to investigate mechanisms of granuloma formation. Using this model, we demonstrated that myeloid deficiency of ATP-binding cassette (ABC) cholesterol transporter (ABCG1) promotes granuloma formation and fibrosis with MWCNT instillation; however, the mechanism remains unclear. Our previous studies showed that MWCNT induced apoptosis in bronchoalveolar lavage (BAL) cells of wild-type (C57BL/6) mice. Given that continual apoptosis causes persistent severe lung inflammation, we hypothesized that ABCG1 deficiency would increase MWCNT-induced apoptosis thereby promoting granulomatous inflammation and fibrosis. To test our hypothesis, we utilized myeloid-specific ABCG1 knockout (ABCG1 KO) mice. Our results demonstrate that MWCNT instillation enhances pulmonary fibrosis in ABCG1 KO mice compared to wild-type controls. Enhanced fibrosis is indicated by increased trichrome staining and transforming growth factor-beta (TGF-ß) expression in lungs, together with an increased expression of TGF-ß related signaling molecules, interleukin-13 (IL-13) and Smad-3. MWCNT induced more apoptosis in BAL cells of ABCG1 KO mice. Initiation of apoptosis is most likely mediated by the extrinsic pathway since caspase 8 activity and Fas expression are significantly higher in MWCNT instilled ABCG1 KO mice compared to the wild type. In addition, TUNEL staining shows that ABCG1 KO mice instilled with MWCNT have a higher percentage of TUNEL positive BAL cells and more efferocytosis than the WT control. Furthermore, BAL cells of ABCG1 KO mice instilled with MWCNT exhibit an increase in efferocytosis markers, milk fat globule-EGF factor 8 (MFG-E8) and integrin ß3. Therefore, our observations suggest that ABCG1 deficiency promotes pulmonary fibrosis by MWCNT, and this effect may be due to an increase in apoptosis and efferocytosis in BAL cells.

Challenges in Cardiac and Pulmonary Sarcoidosis: JACC State-of-the-Art Review.

Sarcoidosis is a complex disease with heterogeneous clinical presentations that can affect virtually any organ. Although the lung is typically the most common organ involved, combined pulmonary and cardiac sarcoidosis (CS) account for most of the morbidity and mortality associated with this disease. Pulmonary sarcoidosis can be asymptomatic or result in impairment in quality of life and end-stage, severe, and/or life-threatening disease. The latter outcome is seen almost exclusively in those with fibrotic pulmonary sarcoidosis, which accounts for 10% to 20% of pulmonary sarcoidosis patients. CS is problematic to diagnose and may cause significant morbidity and death from heart failure or ventricular arrhythmias. The diagnosis of CS usually requires surrogate cardiac imaging biomarkers, as endomyocardial biopsy has relatively low yield, even with directed electrophysiological mapping. Treatment of CS is often multifactorial, involving a combination of antigranulomatous therapy and pharmacotherapy for cardiac arrhythmias and/or heart failure in addition to device placement and cardiac transplantation.

Novel protein pathways in development and progression of pulmonary sarcoidosis.

Pulmonary involvement occurs in up to 95% of sarcoidosis cases. In this pilot study, we examine lung compartment-specific protein expression to identify pathways linked to development and progression of pulmonary sarcoidosis. We characterized bronchoalveolar lavage (BAL) cells and fluid (BALF) proteins in recently diagnosed sarcoidosis cases. We identified 4,306 proteins in BAL cells, of which 272 proteins were differentially expressed in sarcoidosis compared to controls. These proteins map to novel pathways such as integrin-linked kinase and IL-8 signaling and previously implicated pathways in sarcoidosis, including phagosome maturation, clathrin-mediated endocytic signaling and redox balance. In the BALF, the differentially expressed proteins map to several pathways identified in the BAL cells. The differentially expressed BALF proteins also map to aryl hydrocarbon signaling, communication between innate and adaptive immune response, integrin, PTEN and phospholipase C signaling, serotonin and tryptophan metabolism, autophagy, and B cell receptor signaling. Additional pathways that were different between progressive and non-progressive sarcoidosis in the BALF included CD28 signaling and PFKFB4 signaling. Our studies demonstrate the power of contemporary proteomics to reveal novel mechanisms operational in sarcoidosis. Application of our workflows in well-phenotyped large cohorts maybe beneficial to identify biomarkers for diagnosis and prognosis and therapeutically tenable molecular mechanisms.

Application of Proteomics in Sarcoidosis.

Sarcoidosis is a multisystem disease with heterogeneity in manifestations and outcomes. System-level studies leveraging "omics" technologies are expected to define mechanisms contributing to sarcoidosis heterogeneous manifestations and course. With improvements in mass spectrometry (MS) and bioinformatics, it is possible to study protein abundance for a large number of proteins simultaneously. Contemporary fast-scanning MS enables the acquisition of spectral data for deep coverage of the proteins with data-dependent or data-independent acquisition MS modes. Studies leveraging MS-based proteomics in sarcoidosis have characterized BAL fluid (BALF), alveolar macrophages, plasma, and exosomes. These studies identified several differentially expressed proteins, including protocadherin-2 precursor, annexin A2, pulmonary surfactant A2, complement factors C3, vitamin-D-binding protein, cystatin B, and amyloid P, comparing subjects with sarcoidosis with control subjects. Other studies identified ceruloplasmin, complement factors B, C3, and 1, and others with differential abundance in sarcoidosis compared with other interstitial lung diseases. Using quantitative proteomics, most recent studies found differences in PI3K/Akt/mTOR, MAP kinase, pluripotency-associated transcriptional factor, and hypoxia response pathways. Other studies identified increased clathrin-mediated endocytosis and Fcγ receptor-mediated phagocytosis pathways in sarcoidosis alveolar macrophages. Although studies in mixed BAL and blood cells or plasma are limited, some of the changes in lung compartment are detected in the blood cells and plasma. We review proteomics for sarcoidosis with a focus on the existing MS data acquisition strategies, bioinformatics for spectral data analysis to infer protein identity and quantity, unique aspects about biospecimen collection and processing for lung-related proteomics, and proteomics studies conducted to date in sarcoidosis.

T-bet Expression in Peripheral Th17.0 Cells Is Associated With Pulmonary Function Changes in Sarcoidosis.

Background: Interferon-gamma (IFN-γ) is a key mediator of sarcoidosis-related granulomatous inflammation. Previous findings of IFN-γ-producing Th17 cells in bronchoalveolar lavage fluid from sarcoidosis patients invokes the transition of Th17.0 cells to Th17.1 cells in the disease's pathogenesis. Since the T-bet transcription factor is crucial for this transition, the goal of this study was to determine if T-bet expression in Th17.0 cells reflects the extent of granulomatous inflammation in sarcoidosis patients as assessed by clinical outcomes. Methods: Using a case-control study design, we identified two groups of sarcoidosis subjects (total N = 43) with pulmonary function tests (PFTs) that either (1) changed (increased or decreased) longitudinally or (2) were stable. We used flow cytometry to measure the transcription factors T-bet and RORγt in Th1, Th17.0, and Th17.1 cell subsets defined by CCR6, CCR4 and CXCR3 in blood samples. We compared the percentages of T-bet+ cells in RORγt+Th17.0 cells (defined as CCR6+CCR4+CXCR3-) based on subjects' PFT group. We also assessed the relationship between the direction of change in PFTs with the changes in %T-bet+ frequencies using mixed effects modeling. Results: We found that T-bet expression in subjects' RORγt+Th17.0 cells varied based on clinical outcome. The T-bet+ percentage of RORγt+Th17.0 cells was higher in the cases (subject group with PFT changes) as compared to controls (stable group) (27 vs. 16%, p = 0.0040). In comparisons before and after subjects' PFT changes, the T-bet+ frequency of RORγt+Th17.0 cells increased or decreased in the opposite direction of the PFT change. The percentage of these T-bet+ cells was also higher in those with greater numbers of involved organs. Serum levels of interferon-γ-induced chemokines, CXCL9, CXCL10, and CXCL11, and whole blood gene expression of IFN-γ-related genes including GBP1, TAP1, and JAK2 were independently positively associated with the T-bet+ frequencies of RORγt+Th17.0 cells. Conclusions: These data suggest that expression of T-bet in Th17.0 cells could reflect the extent of granulomatous inflammation in sarcoidosis patients because they represent a transition state leading to the Th17.1 cell phenotype. These findings indicate that Th17 plasticity may be part of the disease paradigm.

Current Sarcoidosis Models and the Importance of Focusing on the Granuloma.

The inability to effectively model sarcoidosis in the laboratory or in animals continues to hinder the discovery and translation of new, targeted treatments. The granuloma is the signature pathological hallmark of sarcoidosis, yet there are significant knowledge gaps that exist with regard to how granulomas form. Significant progress toward improved therapeutic and prognostic strategies in sarcoidosis hinges on tractable experimental models that recapitulate the process of granuloma formation in sarcoidosis and allow for mechanistic insights into the molecular events involved. Through its inherent representation of the complex genetics underpinning immune cell dysregulation in sarcoidosis, a recently developed in vitro human granuloma model holds promise in providing detailed mechanistic insight into sarcoidosis-specific disease regulating pathways at play during early stages of granuloma formation. The purpose of this review is to critically evaluate current sarcoidosis models and assess their potential to progress the field toward the goal of improved therapies in this disease. We conclude with the potential integrated use of preclinical models to accelerate progress toward identifying and testing new drugs and drug combinations that can be rapidly brought to clinical trials.

Association of TGF-ß3 and ANXA11 with pulmonary sarcoidosis in Greek population.

BACKGROUND: In sarcoidosis, the direction and intensity of immunological reactions involved in disease pathophysiology is affected by variation in the genes coding for effector and regulatory molecules with immune functions. This study, therefore, investigates polymorphic variants in genes involved in inflammation, immune reactions, and granuloma formation in context of their plausible association with sarcoidosis, with specific focus on Greek population. METHODS: A total of 18 single-nucleotide polymorphisms (SNPs) were genotyped in Greek patients with pulmonary sarcoidosis (n = 103) and in healthy Greek control subjects (n = 100) using multiplexed MassARRAY (MassARRAY ®) iPLEX assay based on MALDI-TOF mass spectrometry. RESULTS: TGF-ß3 rs3917200*G variant was associated with sarcoidosis (OR: 3.04 [95% CI: 1.98-4.69], p = 2.76*10-7). Further, ANXA11 rs1049550*A variant was associated with sarcoidosis (OR: 0.59 [0.39-0.89], p = 0.01). CONCLUSIONS: This first study of genetic variation of immune-related genes in Greek patients with sarcoidosis brings to attention a novel disease 'susceptibility' factor: TGF-ß3 rs3917200*G allele. It also confirms previously reported 'protective' association between sarcoidosis and functional variant ANXA11 rs1049550*A. Further work is required to validate these findings and to expand investigation of their plausible relationship with clinical course of the disease.

TREM-1 and TREM-2 Expression on CD14+ Cells in Bronchoalveolar Lavage Fluid in Pulmonary Sarcoidosis and Hypersensitivity Pneumonitis in the Context of T Cell Immune Response.

BACKGROUND: Sarcoidosis and hypersensitivity pneumonitis (HP) are immunologically mediated processes caused by hypersensitivity reaction accompanied by similar features including lymphocytic alveolitis and granuloma formation. Recent studies describe the role of TREM receptors in T cell activation, differentiation, and granuloma formation. Alveolar macrophages activation via TREM receptors may be the key factor mediating subsequent immune response. The aim of the study was to analyse TREM-1 and TREM-2 expression to identify further molecular mechanisms participating in the immunopathogenesis of sarcoidosis and HP. METHODS: Flow cytometry was performed to analyse TREM-1 and TREM-2 expression on CD14+ cells in bronchoalveolar lavage fluid from patients having sarcoidosis or HP and a control group. RESULTS: The study proved increased TREM-1 expression on alveolar macrophages in pulmonary sarcoidosis and diminished TREM-1 expression in HP-Sarcoidosis: median: 76.7; HP: median: 29.9; control: median: 53.3, (sarcoidosis versus HP: p < 0.001; sarcoidosis versus control: p < 0.05). TREM-2 expression was increased in both, sarcoidosis and HP-sarcoidosis: median: 34.79; HP: median: 36.00; control: median: 12.98, (sarcoidosis versus control: p < 0.05; HP versus control: p < 0.05). Correlation analysis showed negative correlation between TREM-1 and total number of CD8+ cytotoxic T cells. In sarcoidosis TREM-1 expression decreased with changes of HRCT image, decrease in CD4/CD8 ratio and decrease in DLCO. CONCLUSIONS: Differences in TREM receptor expression in sarcoidosis (increase in TREM-1 and TREM-2) and HP (increase in TREM-2) and correlation analysis suggests that activation via TREM may participate in typical immunological characteristics of sarcoidosis and HP.

Randomised, placebo-controlled trial of dexamethasone for quality of life in pulmonary sarcoidosis.

BACKGROUND: Many patients with pulmonary sarcoidosis experience reduced quality of life. Although oral corticosteroids are the most common agents used in sarcoidosis, very little is known on the effects on quality of life. METHODS: In this double-blind, placebo-controlled trial, newly diagnosed patients without an indication for high dose immunosuppressive therapy were randomised to once-daily dexamethasone 1 mg (6.5 mg prednisone equivalent) or placebo for 6 months. The primary study parameter was the subscale physical functioning of the 36-item Short Form health survey (SF-36). Secondary parameters included five other patient reported outcome measures, disease activity markers and plasma cytokine profiles. RESULTS: A total of 16 patients was randomised to dexamethasone (n = 7) and placebo (n = 9). During follow-up no significant difference for physical functioning was measured (p = 0.18). Dexamethasone treated patients showed a decrease in fatigue score (Checklist Individual Strength) from 106 (baseline) to 88 (3 months; p = 0.03); 86 (6 months; p = 0.05); 79 (9 months; p = 0.04); 90 (12 months; p = 0.03). Placebo treated patients showed no change: 96 (baseline) to 105 (3 months; p = 0.16); 91 (6 months; p = 0.48); 92 (9 months; p = 0.61); 95 (12 months; p = 0.90). During treatment with dexamethasone significant improvements in the SF-36 subscales vitality and pain, and a significant reduction in serum angiotensin-converting enzyme, soluble interleukin 2 receptor levels and serum cytokines and chemokines were measured. CONCLUSIONS: Low-dose dexamethasone results in a reduction of the inflammatory profile and has the potential to improve quality of life parameters and fatigue.

Sarcoidosis and the alpha chemokine MIG.

In patients with sarcoidosis, a lot of researches showed increased levels of the Th1 chemokine monokine induced by interferon (IFN)-γ (MIG) and its (C-X-C motif) receptor (CXCR)3 both in biopsy specimens and bronchoalveolar lavage fluid (BALF). In BALF these levels were associated with CD4(+) and total lymphocytes. Positive CXCR3 ligands staining were found in the alveolar macrophages, and in the epithelioid and giant cells in the sarcoid lungs. It can be assumed that in sarcoid lung the accumulation of Th1 lymphocytes is largely related to MIG. Moreover, the potential role of MIG as a biomarker of sarcoidosis and its severity were proven, given its circulating levels that correlated with the clinical course and gravity of the disease.

The Role of Urinary Calcium and Chitotriosidase in a Cohort of Chronic Sarcoidosis Patients.

BACKGROUND: Calcium metabolism alterations are quite common in sarcoidosis and have been correlated with disease activity. OBJECTIVES: The aim of the study was to investigate the clinical significance of calcium metabolism alterations in patients with chronic sarcoidosis. We paid particular attention to associations with specific disease phenotypes and chitotriosidase (CTO) expression. METHODS: 212 chronic sarcoidosis patients (mean age 56.07 ± 12 years; 97 males) were retrospectively recruited. Demographic, clinical, functional, and radiological data, and serum-urinary calcium metabolism were entered into an electronical database for analysis. Levels of CTO and angiotensin-converting enzyme (ACE) were measured and bone mineral density and lung function tests were conducted. RESULTS: Hypercalciuria and hypercalcemia were observed in 18.8 and 1.8% of patients, respectively. Urinary calcium levels correlated with CTO activity (r = 0.33, p = 0.0042). Patients with worsening persistent disease showed the highest levels of urinary calcium. Diffusing capacity of the lung for carbon monoxide (DLCO) percentage correlated inversely with urinary calcium (r = 0.1482; p = 0.0397). CONCLUSIONS: Calcium metabolism alteration, particularly hypercalciuria, was observed in a significant percentage of patients of sarcoidosis. Urinary calcium was correlated with clinical status, DLCO, and serum CTO activity, suggesting its potential role as a biomarker of the activity and severity of sarcoidosis.

Lung CD4+ Vα2.3+ T-cells in sarcoidosis cohorts with Löfgren's syndrome.

BACKGROUND: Sarcoidosis is diagnosed by a combination of typical clinical and radiological findings together with biopsy proof of non-caseating epithelioid cell granulomas in affected tissues and/or the cell distribution in bronchoalveolar lavage fluid (BALF). We aimed at investigating the usefulness of measuring the proportion of T-cell receptor (TCR) CD4+ Vα2.3+ T-cells in BALF as an additive marker to CD4/CD8-ratio to confirm the diagnosis. METHODS: From a register consisting of 749 sarcoidosis patients [Löfgren's syndrome (LS) n = 274, non-LS n = 475] with information on Vα2.3+ T-cells, an expansion of CD4+ Vα2.3+ T-cells (CD4+ Vα2.3+ T cells > 10.5% in BALF) was seen in 268 (36%). Controls were healthy volunteers (n = 69) and patients with other pulmonary conditions (n = 39), investigated because of suspicion of sarcoidosis. RESULTS: A proportion of CD4+ Vα2.3+ T-cells in BALF > 10.5% was highly specific for sarcoidosis, with a specificity of 97% and with a sensitivity of 36% (p < 0.0001). Receiver operating characteristic (ROC) curves show that testing for CD4+ Vα2.3+ T-cells in BALF was a more useable test in individuals with LS [area under the curve (AUC) 0.82, p < 0.0001] compared to the whole patient group (AUC 0.64, p < 0.0001). CONCLUSION: In this study, we show that an increased proportion of CD4+ Vα2.3+ T-cells in BALF is highly specific for sarcoidosis. This suggests that this T-cell subset could be used as an additional tool to the CD4/CD8-ratio to support the sarcoidosis diagnosis, particularly in patients with LS but also in patients with non-LS.

[Is hypoxia a factor in the progression of pulmonary sarcoidosis?] / L'hypoxie est-elle un facteur impactant l'évolution de la sarcoïdose pulmonaire ?

Sarcoidosis is a systemic granulomatous disease that can reduce life expectancy mainly due to pulmonary fibrosis resulting from granulomatous inflammation The lack of vascularization within pulmonary granulomas suggests that macrophages localized in the center of these structures are hypoxic. Hypoxia signaling pathways are known to be pro-inflammatory and pro-fibrotic in various pathological conditions. Recent data suggest an involvement of the transcription factor hypoxia-inducible factor (HIF) in the pathogenesis of sarcoidosis. This could represent a new research approach for the understanding and therapeutic management of sarcoidosis.

18F-FDG PET/CT in Pulmonary Sarcoidosis:Quantifying Inflammation by the TLG index.

Objectives: In sarcoidosis progressive pulmonary disease affects prognosis. Pulmonary disease activity estimated by classic means poorly predicts severity and progressiveness. 18F-fluoro-2-deoxyglucose-positron-emission-tomography computed-tomography (18F-FDG-PET/CT) estimates pulmonary activity by inflammatory-cells metabolism. We aimed to investigate pulmonary sarcoidosis by 18F-FDG-PET/CT and evaluate the role of total-lesion-glycolysis (TLG) value, as an index quantifying the whole burden of lung inflammation.Methods: This is a retrospective study of sequentially gathered data. From a Greek cohort of 195 sarcoidosis-patients, 87 were identified with lung increased 18F-FDG uptake and further studied.Results: Visualizing lung by 18F-FDG-PET/CT identified new imaging patterns and revealed activity in all Scadding stages. Ever-smokers presented significantly higher TLG and lower DLCO compared to never-smokers. However, TLG value did not correlate with functional indices and did not differ between symptomatic and non-symptomatic patients. Among treatment-naïve patients, TLG did not differ significantly in those requiring therapy compared to those remained off.Conclusion: 18F-FDG PET/CT improved imaging and detection of pulmonary involvement and through TLG value revealed the deleterious smoking effect. The fact that TLG neither detected patients with clinical symptoms and functional impairment nor identified those requiring treatment once again confirms that in pulmonary sarcoidosis the link between activity, severity and decision to treat still eludes us.

Elevated level of Galectin-1 in bronchoalveolar lavage of patients with idiopathic pulmonary fibrosis.

RATIONALE: Galectin-1 is a carbohydrate-binding protein involved in apoptosis, cell-proliferation and differentiation, implicated in T-cell homeostasis and survival. The aim of the present study was to determine concentrations of galectin-1 in BAL fluid from patients with IPF and other interstitial lung diseases in order to validate proteomic previous findings. METHODS: 36 IPF patients (16 females, mean age of 64.8 ± 8.9 years), 24 sarcoidosis patients (15 females, mean age of 56.3 ± 13.4), 7 interstitial lung diseases associated to systemic sclerosis (ILD-SSc) patients (5 females, mean age of 55.5 ± 16.4) and six healthy controls (4 females, mean age 47.8 ± 15.2) were included. Galectin-1 concentrations were determined in BAL samples by an ELISA assay. RESULTS: Galectin-1 concentrations were significantly higher in BAL of IPF patients than in sarcoidosis and ILD-SSc patients and healthy controls. In IPF patients, galectin-1 levels showed significant inverse correlations with DLCO%, KCO% and BAL lymphocyte percentages and a positive correlation with BAL macrophage percentages. Former IPF smokers had higher concentrations of this protein compared with non-smoker IPF patients. CONCLUSION: Galectin-1 was confirmed a protein of interest in idiopathic pulmonary fibrosis. Its BAL concentrations were higher in IPF patients than in controls and correlated with disease severity. Galectin-1 was suggested to have a role in the pathogenesis of IPF, principally through the ERK/MAPK pathway and the inhibition of galectin-1 is a potential therapeutic target worthy of research.

Metabolomic and metallomic profile differences between Veterans and Civilians with Pulmonary Sarcoidosis.

Sarcoidosis is a disorder characterized by granulomatous inflammation of unclear etiology. In this study we evaluated whether veterans with sarcoidosis exhibited different plasma metabolomic and metallomic profiles compared with civilians with sarcoidosis. A case control study was performed on veteran and civilian patients with confirmed sarcoidosis. Proton nuclear magnetic resonance spectroscopy (1H NMR), hydrophilic interaction liquid chromatography mass spectrometry (HILIC-MS) and inductively coupled plasma mass spectrometry (ICP-MS) were applied to quantify metabolites and metal elements in plasma samples. Our results revealed that the veterans with sarcoidosis significantly differed from civilians, according to metabolic and metallomics profiles. Moreover, the results showed that veterans with sarcoidosis and veterans with COPD were similar to each other in metabolomics and metallomics profiles. This study suggests the important role of environmental risk factors in the development of different molecular phenotypic responses of sarcoidosis. In addition, this study suggests that sarcoidosis in veterans may be an occupational disease.

IL-17A Can Promote Propionibacterium acnes-Induced Sarcoidosis-Like Granulomatosis in Mice.

The etiology of sarcoidosis is unknown. In this study, Propionibacterium acnes (PA) was used to induce sarcoidosis-like granulomatous inflammation in a mouse model. Wild-Type (WT) C57BL/6 mice were divided into three groups: (1) WT-PA group; (2) WT-PA + Incomplete Freund's Adjuvant (IFA) group; and (3) WT-PBS group. Loose granuloma formation was observed in the lungs on day 56 in the WT-PA and WT-PA + IFA groups. The proportions of peripheral Th17 cells in the WT-PA (p = 0.0004) and WT-PA + IFA groups (p = 0.0005) were significantly higher than that in the WT-PBS group. The proportions of peripheral Treg cells in the WT-PA (p < 0.0001) and WT-PA + IFA groups (p < 0.0001) were lower than that in the WT-PBS group. Then, to explore the mechanism of IL-17, Wild-Type (WT) C57BL/6 mice were divided into three groups: (1) WT-PBS group (2) WT-PA group; (3) WT-PA + mouse IL-17A neutralizing antibody (IL-17Ab) group. IL-17A gene knockout mice (KO) were divided into two groups: (1) KO -PA group; (2) KO-PBS group. The KO-PA and WT-PA + IL-17Ab groups showed reduced inflammation and no loose granuloma formation on day 56. As compared to the WT-PA group, the ratio of peripheral Th17 in the KO-PA (p < 0.0001) and WT-PA + IL-17Ab groups (p < 0.0001) decreased, while the ratio of peripheral Treg in the KO-PA (p < 0.0001) and WT-PA + IL-17Ab (p = 0.0069) groups increased on day 56. Hence, PA can be used to establish a mouse model of sarcoidosis-like granuloma. IL-17A plays an important role in experimental sarcoidosis-like granuloma formation.

Alveolar Macrophage ABCG1 Deficiency Promotes Pulmonary Granulomatous Inflammation.

Pulmonary granuloma formation is a complex and poorly understood response to inhaled pathogens and particulate matter. To explore the mechanisms of pulmonary granuloma formation and maintenance, our laboratory has developed a multiwall carbon nanotube (MWCNT)-induced murine model of chronic granulomatous inflammation. We have demonstrated that the MWCNT model closely mimics pulmonary sarcoidosis pathophysiology, including the deficiency of alveolar macrophage ATP-binding cassette (ABC) lipid transporters ABCA1 and ABCG1. We hypothesized that deficiency of alveolar macrophage ABCA1 and ABCG1 would promote pulmonary granuloma formation and inflammation. To test this hypothesis, the effects of MWCNT instillation were evaluated in ABCA1, ABCG1, and ABCA1/ABCG1 myeloid-specific knockout (KO) mice. Histological examination revealed significantly larger pulmonary granulomas in ABCG1-KO and ABCA1/ABCG1 double-KO animals when compared with wild-type animals. Evaluation of BAL cells indicated increased expression of CCL2 and osteopontin, genes shown to be involved in the formation and maintenance of pulmonary granulomas. Single deficiency of alveolar macrophage ABCA1 did not affect MWCNT-induced granuloma formation or proinflammatory gene expression. These observations indicate that the deficiency of alveolar macrophage ABCG1 promotes pulmonary granulomatous inflammation and that this is augmented by additional deletion of ABCA1.