Genotyping in the MHC locus: potential for defining predictive markers in sarcoidosis

In sarcoidosis, host genetic factors are discussed as contributing to disease susceptibility and course. Since tumor necrosis factor (TNF)-α is a central mediator of granuloma formation and since elevated TNF-α levels are found during active phases of sarcoidosis, genetic polymorphisms correlating with influences on TNF-α levels are of special interest. The complete sequencing of the MHC region and the increase in the number of identified gene polymorphisms in this locus associated with TNF-α production offer the opportunity of detecting new genes associated with sarcoidosis and perhaps of defining disease-associated haplotypes that bear the potential of serving as predictive markers for this disease

Prevention of M2 polarization and temporal limitation of differentiation in monocytes by extracellular ATP

BACKGROUND Elevated levels of extracellular adenosine triphosphate (ATP) modulate immunologic pathways and are considered to be a danger signal in inflammation, lung fibrosis and cancer. Macrophages can be classified into two main types: M1 macrophages are classically activated, pro-inflammatory macrophages, whereas M2 macrophages are alternatively activated, pro-fibrotic macrophages. In this study, we examined the effect of ATP on differentiation of native human monocytes into these macrophage subtypes. We characterized M1 and M2 like macrophages by their release of Interleukin-1beta (IL-1β) and Chemokine (C-C motif) ligand 18 (CCL18), respectively. RESULTS Monocytes were stimulated with ATP or the P2X7 receptor agonist Benzoylbenzoyl-ATP (Bz-ATP), and the production of various cytokines was analyzed, with a particular focus on CCL18 and IL-1β, along with the expression of different purinergic receptors. Over a 72 h period of cell culture, monocytes spontaneously differentiated to M2 like macrophages, as indicated by an increased release of CCL18. Immediate stimulation of monocytes with ATP resulted in a dose-dependent reduction in CCL18 release, but had no effect on the concentration of IL-1β. In contrast, delayed stimulation with ATP had no effect on either CCL18 or IL-1β release. Similar results were observed in a model of inflammation using lipopolysaccharide-stimulated human monocytes. Stimulation with the P2X7 receptor agonist Bz-ATP mimicked the effect of ATP on M2-macrophage differentiation, indicating that P2X7 is involved in ATP-induced inhibition of CCL18 release. Indeed, P2X7 was downregulated during spontaneous M2 differentiation, which may partially explain the ineffectiveness of late ATP stimulation of monocytes. However, pre-incubation of monocytes with PPADS, Suramin (unselective P2X- and P2Y-receptor blockers) and KN62 (P2X7-antagonist) failed to reverse the reduction of CCL18 by ATP. CONCLUSIONS ATP prevents spontaneous differentiation of monocytes into M2-like macrophages in a dose- and time-dependent manner. These effects were not mediated by P2X and P2Y receptors

Insights from the German Compassionate Use Program of Nintedanib for the Treatment of Idiopathic Pulmonary Fibrosis

Background: Nintedanib is approved for the treatment of idiopathic pulmonary fibrosis(IPF) and has been shown to slow disease progression by reducing annual lung function decline. Objective: To evaluate the results of a large cohort of IPF patients treated with nintedanib within a compassionate use program(CUP) in Germany(9 centers). Methods: Patients ( >= 40 years) were required to have a confirmed diagnosis of IPF, a forced vital capacity(FVC) >= 50% predicted ( pred.) and a carbon monoxide diffusing capacity(DLCO) 30-79% pred. and not to be eligible for pirfenidone treatment. Clinical data, pulmonary function tests and adverse events were recorded up to July 2015. Results: Sixty-two patients (48 male/14 female) with moderate IPF (FVC 64 +/- 17% pred. and DLCO 40 +/- 10% pred.) were treated with nintedanib. 77% of patients switched from pirfenidone (mean treatment duration 14 +/- 2 months) mostly due to disease progression (mean decline in FVC 7.4 +/- 3% pred. in the 6 months prior to nintedanib intake). Initiation of nintedanib treatment occurred 69 +/- 29 months after IPF diagnosis, and mean treatment duration was 8 +/- 4 months. Most patients (63%) stabilized 6 months after treatment start (mean FVC decline 3 +/- 1 vs. -17 +/- 2% in patients with disease progression;p < 0.01). The most common adverse events were diarrhea (63%) and weight loss (50%). Dose reduction occurred in 34% of cases and treatment discontinuation in 10%. Conclusion: Nintedanib treatment was generally well tolerated and was associated with FVC stabilization in the majority of IPF patients in this CUP setting where most patients were not treatment naive. Our data are in agreement with the previously published data. (C) 2016 The Author(s) Published by S. Karger AG, Base

CCL18 as an indicator of pulmonary fibrotic activity in idiopathic interstitial pneumonias and systemic sclerosis

Objective In diffuse parenchymal lung diseases, the evolution of pulmonary fibrosis is often devastating and may result in death. In this study the role of CCL18 as a biomarker of disease activity in idiopathic interstitial pneumonias (IIPs) and systemic sclerosis (SSc) with lung involvement was evaluated. Methods CCL18 was assessed in supernatants of cultured bronchoalveolar lavage (BAL) cells as well as BAL fluid and serum samples from 43 patients with IIPs, 12 patients with SSc, and 23 healthy control subjects. Concentrations of CCL18 were measured by enzyme-linked immunosorbent assay, and expression of CCL18 was assessed by flow cytometry. Results CCL18 concentrations were statistically significantly increased in all patients with fibrotic lung diseases. Spontaneous CCL18 production by BAL cells was negatively correlated with total lung capacity and the diffusion capacity for carbon monoxide, whereas there was a positive correlation of CCL18 concentrations with BAL neutrophil and eosinophil cell counts. Flow cytometry revealed an increase in the percentage of CCL18-positive alveolar macrophages and an increase in the CCL18 fluorescence intensity per cell in patients with fibrotic lung diseases. In a cohort of patients who were followed up for at least 6 months (n = 40), a close negative correlation was observed between changes in the predicted total lung capacity and changes in CCL18 serum concentrations. Conclusion These findings suggest that CCL18 production by BAL cells and serum CCL18 concentrations reflect pulmonary fibrotic activity in patients with IIPs and those with SSc. Monitoring changes in CCL18 production might be an extraordinarily useful tool in clinical practice and in studies aimed at evaluating new approaches for treatment of fibrotic lung diseases.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/56037/1/22559_ftp.pd

Impact of Lung Function Decline on Mortality in Lung Transplant Recipients: Long-Term Results From the L-CsA-i Study for the Prevention of Bronchiolitis Obliterans Syndrome

BackgroundChronic lung allograft dysfunction (CLAD) is defined by a progressive loss of FEV1 and is associated with premature mortality. The aim of this study was to investigate the direct association between FEV1 decline and risk of mortality in patients after lung transplantation (LTx). Methods10-year follow up data from lung transplant recipients participating in randomized placebo-controlled clinical trial investigating the role of liposomal Cyclosporine A for inhalation (L-CsA-i) in the prevention of bronchiolitis obliterans syndrome (NCT01334892) was used. The association between the course of FEV1 over time and the risk of mortality was assessed using joint modeling and Cox regression analysis. ResultsA total of 130 patients were included. Predictors of FEV1 decline were a higher absolute FEV1 at baseline and male sex. The joint model analysis indicated a significant association of change of FEV1 and risk of mortality (p < 0.001), with a predicted 3.4% increase in mortality risk for each 1% decline in FEV1. Significant predictors of a progressive phenotype were single LTx and treatment with placebo (as opposed to L-CsA-i). At the end of follow-up, 82 patients (63.1%) were still alive. Cox regression analyses for mortality identified only single LTx as a predictor of higher risk. ConclusionBased on our observation of a close association between FEV1 and mortality over a period of 10 years we suggest FEV1 as a valid predictor of mortality and a suitable surrogate endpoint in the investigation of early interventions

Sex differences in the genetics of sarcoidosis across European and African ancestry populations

BackgroundSex differences in the susceptibility of sarcoidosis are unknown. The study aims to identify sex-dependent genetic variations in two clinical sarcoidosis phenotypes: Löfgren’s syndrome (LS) and non-Löfgren’s syndrome (non-LS).MethodsA meta-analysis of genome-wide association studies was conducted on Europeans and African Americans, totaling 10,103 individuals from three population-based cohorts, Sweden (n = 3,843), Germany (n = 3,342), and the United States (n = 2,918), followed by an SNP lookup in the UK Biobank (UKB, n = 387,945). A genome-wide association study based on Immunochip data consisting of 141,000 single nucleotide polymorphisms (SNPs) was conducted in the sex groups. The association test was based on logistic regression using the additive model in LS and non-LS sex groups independently. Additionally, gene-based analysis, gene expression, expression quantitative trait loci (eQTL) mapping, and pathway analysis were performed to discover functionally relevant mechanisms related to sarcoidosis and biological sex.ResultsWe identified sex-dependent genetic variations in LS and non-LS sex groups. Genetic findings in LS sex groups were explicitly located in the extended Major Histocompatibility Complex (xMHC). In non-LS, genetic differences in the sex groups were primarily located in the MHC class II subregion and ANXA11. Gene-based analysis and eQTL enrichment revealed distinct sex-specific gene expression patterns in various tissues and immune cell types. In LS sex groups, a pathway map related to antigen presentation machinery by IFN-gamma. In non-LS, pathway maps related to immune response lectin-induced complement pathway in males and related to maturation and migration of dendritic cells in skin sensitization in females were identified.ConclusionOur findings provide new evidence for a sex bias underlying sarcoidosis genetic architecture, particularly in clinical phenotypes LS and non-LS. Biological sex likely plays a role in disease mechanisms in sarcoidosis

Genetic and geographic influence on phenotypic variation in European sarcoidosis patients

IntroductionSarcoidosis is a highly variable disease in terms of organ involvement, type of onset and course. Associations of genetic polymorphisms with sarcoidosis phenotypes have been observed and suggest genetic signatures.MethodsAfter obtaining a positive vote of the competent ethics committee we genotyped 1909 patients of the deeply phenotyped Genetic-Phenotype Relationship in Sarcoidosis (GenPhenReSa) cohort of 31 European centers in 12 countries with 116 potentially disease-relevant single-nucleotide polymorphisms (SNPs). Using a meta-analysis, we investigated the association of relevant phenotypes (acute vs. sub-acute onset, phenotypes of organ involvement, specific organ involvements, and specific symptoms) with genetic markers. Subgroups were built on the basis of geographical, clinical and hospital provision considerations.ResultsIn the meta-analysis of the full cohort, there was no significant genetic association with any considered phenotype after correcting for multiple testing. In the largest sub-cohort (Serbia), we confirmed the known association of acute onset with TNF and reported a new association of acute onset an HLA polymorphism. Multi-locus models with sets of three SNPs in different genes showed strong associations with the acute onset phenotype in Serbia and Lublin (Poland) demonstrating potential region-specific genetic links with clinical features, including recently described phenotypes of organ involvement.DiscussionThe observed associations between genetic variants and sarcoidosis phenotypes in subgroups suggest that gene–environment-interactions may influence the clinical phenotype. In addition, we show that two different sets of genetic variants are permissive for the same phenotype of acute disease only in two geographic subcohorts pointing to interactions of genetic signatures with different local environmental factors. Our results represent an important step towards understanding the genetic architecture of sarcoidosis

Sarcoidosis from bench to bedside: a state-of-the-art series for the clinician

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