Catherine Moermans

Local and systemic cellular inflammation and cytokine release in chronic obstructive pulmonary disease

BACKGROUND Chronic obstructive pulmonary disease (COPD) is a chronic airway inflammatory disease caused by repeated exposure to noxious gases or particles. It is now recognized that the disease also features systemic inflammation. The purpose of our study was to compare airway and systemic inflammation in COPD to that seen in healthy subjects and to relate the inflammation with the disease severity. METHODS Ninety-five COPD patients, encompassing the whole severity spectrum of the disease, were recruited from our outpatient clinic and rehabilitation center and compared to 33 healthy subjects. Induced sputum and blood samples were obtained for measurement of inflammatory cell count. Interleukin (IL)-4, IL-6, IL-10, TNF-α and IFN-γ produced by 24h sputum and blood cell cultures were measured. RESULTS Compared to healthy subjects, COPD exhibited a prominent airway neutrophilic inflammation associated with a marked IL-10, IL-6 and TNF-α release deficiency that contrasted with a raised IFN-γ production. Neutrophilic inflammation was also prominent at blood level together with raised production of IFN-γ, IL-10 and TNF-α. Furthermore, sputum neutrophilia correlated with disease severity assessed by GOLD stages. Likewise the extent of TNF-α release from blood cells also positively correlated with the disease severity but negatively with that of sputum cell culture. Blood release of TNF-α and IL-6 negatively correlated with body mass index. Altogether, our results showed a significant relationship between cellular marker in blood and sputum but poor relationship between local and systemic release of cytokines. CONCLUSIONS COPD is characterized by prominent neutrophilic inflammation and raised IFN-γ production at both bronchial and systemic level. Overproduction of TNF-α at systemic level correlates with disease severity and inversely with body mass index.

Blood Biomarkers in Idiopathic Pulmonary Fibrosis.

PurposeIdiopathic pulmonary fibrosis (IPF) is a progressive and lethal lung disease of unknown origin whose incidence has been increasing over the latest decade partly as a consequence of population ageing. New anti-fibrotic therapy including pirfenidone and nintedanib have now proven efficacy in slowing down the disease. Nevertheless, diagnosis and follow-up of IPF remain challenging.MethodsThis review examines the recent literature on potentially useful blood molecular and cellular biomarkers in IPF. Most of the proposed biomarkers belong to chemokines (IL-8, CCL18), proteases (MMP-1 and MMP-7), and growth factors (IGBPs) families. Circulating T cells and fibrocytes have also gained recent interest in that respect. Up to now, though several interesting candidates are profiling there has not been a single biomarker, which proved to be specific of the disease and predictive of the evolution (decline of pulmonary function test values, risk of acute exacerbation or mortality).ConclusionLarge scale multicentric studies are eagerly needed to confirm the utility of these biomarkers.

Impact of Cotransplantation of Mesenchymal Stem Cells on Lung Function After Unrelated Allogeneic Hematopoietic Stem Cell Transplantation Following Non-Myeloablative Conditioning

Background In the context of hematopoietic stem cell transplantation (HSCT), mesenchymal stem cells (MSC) have been used to promote engraftment and prevent graft-versus-host disease. However, in animal models, MSC were shown to cause pulmonary alterations after systemic administration. The impact of MSC infusion on lung function has not been studied in humans. The objective of the study was to investigate the impact of MSC co-infusion on lung function and airway inflammation as well as on the incidence of pulmonary infections and cytomegalovirus (CMV) reactivation after HSCT. Methods We have prospectively followed 30 patients who underwent unrelated HSCT with MSC co-infusion after non-myeloablative conditioning (NMA). Each patient underwent detailed lung function testing (FEV1, FVC, FEV1/FVC, RV, TLC, DLCO, and KCO) and measurement of exhaled nitric oxide before HSCT and 3, 6, and 12 months posttransplant. The incidence of pulmonary infections and CMV reactivation were also monitored. This group was compared with another group of 28 patients who underwent the same type of transplantation but without MSC co-infusion. Results Lung function tests did not show important modifications over time and did not differ between the MSC and control groups. There was a higher 1-year incidence of infection, particularly of fungal infections, in patients having received a MSC co-infusion. There was no difference between groups regarding the 1-year incidence of CMV reactivation. Conclusions MSC co-infusion does not induce pulmonary deterioration 1 year after HSCT with NMA conditioning. MSC appear to be safe for the lung, but close monitoring of pulmonary infections remains essential.

Sputum biomarkers in IPF: Evidence for raised gene expression and protein level of IGFBP-2, IL-8 and MMP-7.

Background Idiopathic pulmonary fibrosis (IPF) is a rare lung disease of unknown origin leading rapidly to death. This paper addresses the issue of whether sputum induction is a suitable tool to study respiratory tract inflammation and potential biomarkers in IPF compared to COPD, a fibrosing airway wall disease. Methods In a cross-sectional analysis, 15 IPF patients, 32 COPD and 30 healthy subjects underwent sputum induction. Total sputum cell counts and the amount of TGF- β, IGF-1, IGF-2, IGFBP-1, IGFBP-2, IGFBP-3, IL-8, IL-13, MMP-7, MMP-9, YKL-40, TNF-α and KL-6 in sputum supernatant were analysed. We also profiled gene expression of cells in the induced sputum for TGF-β, MMP-7, YKL-40, IGFBP-2, IL-6, IL-8 and TNF-α. Results IPF patients, like COPD, had increased sputum absolute number of neutrophils, eosinophils, macrophages and epithelial cells compared to HS. IPF sputum supernatants had increased concentrations of IGFBP-2, IL-8, TGF-β, MMP-7, MMP-9 and KL-6 (p<0.05, p<0.0001, p<0.05, p<0.05, p<0.0001, p<0.05 respectively) when compared to healthy subjects where COPD had higher IL-6 and TNF-α levels than IPF (p<0.05 and p<0.05 respectively) and HS (p<0.0001 and p<0.001 respectively) and higher IL-8 and MMP-9 than HS (p<0.0001 and p<0.001 respectively). Conversely to IL-6 and TNF-α, MMP-7 was increased in IPF compared to COPD (p<0.05). The KL-6 and MMP-7 protein levels in sputum were inversely correlated with total lung capacity (TLC, % of predicted) in IPF patients (r = -0.73 and r = -0.53 respectively). Sputum gene expression analysis identified a significant increase for IGFBP-2, IL-6, IL-8 and MMP-7 in IPF compared to HS (p<0.05, p<0.01, p<0.05 and p<0.0001 respectively) and for IGFBP-2, YKL-40, IL-6, IL-8 and MMP-7 compared to COPD (p<0.01, p<0.01, p<0.05, p<0.01 and p<0.0001 respectively). Furthermore, gene expression of TGF-β was increased in IPF compared to COPD (p<0.001) but not to HS. Conclusion Our data show clear increase in expression and production of IGFBP-2, IL-8 and MMP-7 in sputum from patients with IPF that may contribute to the disease.

Increased of exhaled breath condensate neutrophil chemotaxis in acute exacerbation of COPD

BackgroundNeutrophils have been involved in the pathogenesis of chronic obstructive pulmonary disease (COPD). Underlying mechanisms of neutrophil accumulation in the airways of stable and exacerbated COPD patients are poorly understood. The aim of this study was to assess exhaled breath condensate (EBC) neutrophil chemotactic activity, the level of two chemoattractants for neutrophils (GRO-α and LTB4) during the course of an acute exacerbation of COPD (AECOPD).Methods50 ex smoking COPD patients (33 with acute exacerbation and 17 in stable disease) and 20 matched ex smoking healthy controls were compared. EBC was collected by using a commercially available condenser (EcoScreen®). EBC neutrophil chemotactic activity (NCA) was assessed by using Boyden microchambers. Chemotactic index (CI) was used to evaluate cell migration. LTB4 and GROα levels were measured by a specific enzyme immunoassay in EBC.ResultsStable COPD and outpatients with AECOPD, but not hospitalized with AECOPD, had raised EBC NCA compared to healthy subjects (p < 0.05 and p < 0.01 respectively). In outpatients with AECOPD EBC NCA significantly decreased 6 weeks after the exacerbation. Overall EBC NCA was weakly correlated with sputum neutrophil counts (r = 0.26, p < 0.05).EBC LTB4 levels were increased in all groups of COPD compared to healthy subjects while GRO-α was only raised in patients with AECOPD. Furthermore, EBC LTB4 and GRO-α significantly decreased after recovery of the acute exacerbation. Increasing concentrations (0.1 to 10 μg/mL) of anti- human GRO-α monoclonal antibody had no effect on EBC neutrophil chemotactic activity of 10 exacerbated COPD patients.ConclusionsEBC NCA rose during acute exacerbation of COPD in ambulatory patients and decreased at recovery. While LTB4 seems to play a role both in stable and in exacerbated phase of the disease, the role of GRO-α as a chemotactic factor during AECOPD is not clearly established and needs further investigation.

Raised interferon β, type 3 interferon and interferon stimulated genes - evidence of innate immune activation in neutrophilic asthma.

Interferons play an important role in innate immunity. Previous studies report deficiency in virus induction of interferon (IFN)‐α, IFN‐β and IFN‐λ in bronchial epithelial and bronchial lavage cells in atopic asthmatics. It is now recognized that asthma is a heterogeneous disease comprising different inflammatory phenotypes, some of which may involve innate immune activation in the absence of overt infection.

The Lung Microbiome in Idiopathic Pulmonary Fibrosis: A Promising Approach for Targeted Therapies

This review focuses on the role of the lung microbiome in idiopathic pulmonary fibrosis. Although historically considered sterile, bacterial communities have now been well documented in lungs both in healthy and pathological conditions. Studies in idiopathic pulmonary fibrosis (IPF) suggest that increased bacterial burden and/or abundance of potentially pathogenic bacteria may drive disease progression, acute exacerbations, and mortality. More recent work has highlighted the interaction between the lung microbiome and the innate immune system in IPF, strengthening the argument for the role of both host and environment interaction in disease pathogenesis. Existing published data suggesting that the lung microbiome may represent a therapeutic target, via antibiotic administration, immunization against pathogenic organisms, or treatment directed at gastroesophageal reflux. Taken altogether, published literature suggests that the lung microbiome might serve in the future as a prognostic biomarker, a therapeutic target, and/or provide an explanation for disease pathogenesis in IPF.

Lung function and airway inflammation monitoring after hematopoietic stem cell transplantation

BACKGROUND Induced sputum is a non-invasive method to investigate airway inflammation, which has been used to assess pulmonary inflammatory diseases. However, this procedure has not been studied in the context of hematopoietic stem cell transplantation (HSCT). METHODS We monitored lung function in 182 patients who underwent HSCT and measured airway inflammation by sputum induction in 80 of them. We prospectively measured FEV1, FVC, DLCO, KCO, TLC, RV, exhaled nitric oxide (FeNO) as well as sputum cell counts before and 3, 6, 12, 24 and 36 months after HSCT. RESULTS For the whole cohort there was a progressive decrease in TLC, which was significant after 3 years (p < 0.01). By contrast, there was no change in other lung functions parameters or in FeNO. Baseline sputum analysis revealed increased neutrophil counts in patients {Median (IQR): 63% (38-79)} compared to healthy subjects matched for age {Median (IQR): 49% (17-67), p < 0.001} but there was no significant change in any type of sputum cell counts over the three years. When comparing myeloablative (MA) vs non-myeloablative (NMA) conditioning, falls in FEV1, FVC and DLCO, and rise in RV and sputum neutrophils were more pronounced over the first year of observation in those receiving MA. CONCLUSIONS There was a progressive loss in lung function after HSCT, featuring a restrictive pattern. Myeloablative conditioning was associated with early rise of sputum neutrophils and greater alteration in lung function over the first year.

Increased production of TGF-β1 from sputum cells of COPD: Relationship with airway obstruction

HighlightsAn original model of sputum cell culture maintaining cell interactions was used.Total and active TGF‐&bgr;1 levels were increased in COPD compared to controls.The total TGF‐&bgr;1 release was correlated to the disease severity.There was no link between total TGF‐&bgr;1 level and age, smoking status or emphysema.The total TGF&bgr;‐1 production was inversely correlated to that of TNF‐&agr;. Abstract Chronic obstructive pulmonary disease (COPD) is a chronic airway disease characterized by a profound airway remodelling that leads to airway obstruction. A role for transforming growth factor‐&bgr;1 (TGF‐&bgr;1) has been proposed in airway remodelling of COPD. Regarding the TGF‐&bgr;1 production at local level, the results seemed to be controversial. In this study, an original model of sputum cell culture thought to maintain important cells interactions, was used. We investigated the production of TGF‐&bgr;1 from sputum cell culture in 33 COPD encompassing the whole severity spectrum and compared the results with those found in 39 healthy controls. Sputum was induced by inhalation of saline, the cellular fraction cultured for 24 h and the spontaneous production of total TGF‐&bgr;1 was assessed by ELISA. Using, a TGF‐&bgr;1 reporter cell assay, we also compared the levels of active and total TGF‐&bgr;1 in the sputum cell culture supernatants of COPD and controls. Moreover, as a combination of tumor necrosis factor‐&agr; (TNF‐&agr;) and TGF‐&bgr;1 have been shown to have a cumulative impact on the severity of airflow limitation in COPD, the TNF‐&agr; release was also measured in a representative subgroup of patients. Our results indicated that the use of sputum cell culture was a reliable and reproducible method to assess TGF‐&bgr;1 production at airway level. Sputum cells from COPD produced greater amount of total TGF‐&bgr;1 than those of healthy controls (p < 0.001). This result was confirmed using the cell reporter assay which also showed a higher level of active TGF‐&bgr;1 in the COPD group compared to controls. In addition, total TGF‐&bgr;1 production was increased according to GOLD stage and was inversely related to FEV1/FVC ratio (p < 0.05). By contrast, the production of this growth factor was not correlated with the functional markers of emphysema nor with demographic characteristics such as age, BMI or smoking status. Interestingly, the production of total TGF‐&bgr;1 was inversely related to that of TNF‐&agr; (r = −0.53, p < 0.05) which was decreased in COPD. In summary, COPD patients displayed a raised production of total and active TGF‐&bgr;1 from their airway cells. Total TGF‐&bgr;1 correlates with the severity of airway obstruction without evidence of a link with emphysema.

Disturbed Cytokine Production at the Systemic Level in Difficult-to- Control Atopic Asthma: Evidence for Raised Interleukin-4 and Decreased Interferon-γ Release following Lipopolysaccharide Stimulation

Background: Disturbed cytokine production is thought to govern inflammation in asthma, which, in its turn, may lead to uncontrolled disease. The aim of this study was to assess the relationship between cytokine production from blood leucocytes and the level of asthma control. Methods: We compared the production of interleukin (IL)-4, IL-6, IL-10, interferon (IFN)-γ and tumour necrosis factor-α from peripheral blood leucocytes in non-atopic healthy subjects (n = 22), atopic non-asthmatics (n = 10), well-controlled asthmatics [Juniper asthma control questionnaire (ACQ) score <1.5; n = 20] and patients with uncontrolled asthma despite inhaled or oral corticoids (ACQ score ≧1.5; n = 20). Fifty microlitres of peripheral blood was incubated for 24 h with RPMIc, lipopolysaccharide (LPS; 1 ng/ml) or phytohaemagglutinin (1 µg/ml), and cytokines were measured by immunotrapping (ELISA). Results: Both controlled and uncontrolled asthmatics as well as atopic non-asthmatics spontaneously produced more IL-4 than non-atopic healthy subjects (p < 0.001). IL-4 production induced by LPS was significantly greater (p < 0.05) in both asthma groups compared to atopic non-asthmatics and non-atopic healthy subjects. By contrast, IFN-γ release induced by LPS was lower in uncontrolled asthmatics than in non-atopic healthy subjects (p < 0.05) and controlled asthmatics (p < 0.05). IL-10 release after LPS was greater in uncontrolled asthmatics than in atopic non-asthmatics (p < 0.05). No difference was observed regarding other cytokines. Conclusion: Blood cells from patients with difficult-to-control atopic asthma display highly skewed Th2 cytokine release following LPS stimulation.