Eosinophilic activation in cystic fibrosis

Wound repair and immune function in the Pseudomonas infected CF lung: before and after highly effective modulator therapy

The leading cause of death for people with cystic fibrosis (pwCF) continues to be due to respiratory-related illnesses. Both wound repair and immune cell responses are dysregulated in the CF airways, creating a cycle of unresolved injury and perpetuating inflammation. PwCF are predisposed to colonization and infections with opportunistic bacteria like Pseudomonas aeruginosa (Pa), the most common adult pathogen in CF. Pa possesses key virulence factors that can exacerbate chronic inflammation and lung injury. With the approval of highly effective modulator therapies like elexacaftor/tezacaftor/ivacaftor (ETI), pwCF eligible for ETI have seen drastic improvements in lung function and clinical outcomes, including an increased life expectancy. While modulator therapies are improving bronchial epithelial cellular processes in wound repair and some areas of immunity, many of these processes do not reach a non-CF baseline state or have not been thoroughly studied. The effect of modulator therapy on Pa may lead to a reduction in infection, but in more longitudinal studies, there is not always eradication of Pa, and colonization and infection frequency can return to pre-modulator levels over time. Finally, in this review we explore the current state of additional treatments for CF lung disease, independent of CFTR genotype, including anti-inflammatories, phage-therapies, and Pa vaccines.

Allergic Bronchopulmonary Aspergillosis (ABPA) in the Era of Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) Modulators

Allergic bronchopulmonary aspergillosis (ABPA) is a hypersensitivity disease caused by Aspergillus fumigatus (Af), prevalent in persons with cystic fibrosis (CF) or asthma. In ABPA, Af proteases drive a T-helper cell-2 (Th2)-mediated allergic immune response leading to inflammation that contributes to permanent lung damage. Corticosteroids and antifungals are the mainstays of therapies for ABPA. However, their long-term use has negative sequelae. The treatment of patients with CF (pwCF) has been revolutionized by the efficacy of cystic fibrosis transmembrane conductance regulator (CFTR) modulator therapy. Pharmacological improvement in CFTR function with highly effective elexacaftor/tezacaftor/ivacaftor (ETI) provides unprecedented improvements in lung function and other clinical outcomes of pwCF. The mechanism behind the improvement in patient outcomes is a continued topic of investigation as our understanding of the role of CFTR function evolves. As ETI therapy gains traction in CF management, understanding its potential impact on ABPA, especially on the allergic immune response pathways and Af infection becomes increasingly crucial for optimizing patient outcomes. This literature review aims to examine the extent of these findings and expand our understanding of the already published research focusing on the intersection between ABPA therapeutic approaches in CF and the rapid impact of the evolving CFTR modulator landscape. While our literature search yielded limited reports specifically focusing on the role of CFTR modulator therapy on CF-ABPA, findings from epidemiologic and retrospective studies suggest the potential for CFTR modulator therapies to positively influence pulmonary outcomes by addressing the underlying pathophysiology of CF-ABPA, especially by decreasing inflammatory response and Af colonization. Thus, this review highlights the promising scope of CFTR modulator therapy in decreasing the overall prevalence and incidence of CF-ABPA.

Pseudomonas aeruginosa in chronic lung disease: untangling the dysregulated host immune response

Pseudomonas aeruginosa is a highly adaptable opportunistic pathogen capable of exploiting barriers and immune defects to cause chronic lung infections in conditions such as cystic fibrosis. In these contexts, host immune responses are ineffective at clearing persistent bacterial infection, instead driving a cycle of inflammatory lung damage. This review outlines key components of the host immune response to chronic P. aeruginosa infection within the lung, beginning with initial pathogen recognition, followed by a robust yet maladaptive innate immune response, and an ineffective adaptive immune response that propagates lung damage while permitting bacterial persistence. Untangling the interplay between host immunity and chronic P. aeruginosa infection will allow for the development and refinement of strategies to modulate immune-associated lung damage and potentiate the immune system to combat chronic infection more effectively.

The impact of CFTR modulator triple therapy on type 2 inflammatory response in patients with cystic fibrosis

BACKGROUND

Treatment of cystic fibrosis (CF) has been revolutionized by the use of cystic fibrosis transmembrane conductance regulator (CFTR) protein modulators such as elexacaftor/tezacaftor/ivacaftor (ETI) triple therapy. Prior studies support a role for type 2 (T2) inflammation in many people with CF (PwCF) and CF-asthma overlap syndrome (CFAOS) is considered a separate clinical entity. It is unknown whether initiation of ETI therapy impacts T2 inflammation in PwCF. We hypothesized that ETI initiation decreases T2 inflammation in PwCF.

METHODS

A single center retrospective chart review was conducted for adult PwCF. As markers of T2 inflammation, absolute eosinophil count (AEC) and total immunoglobulin E (IgE) data were collected longitudinally 12 months prior to ETI therapy initiation and 12 months following therapy initiation. Multivariable analyses adjusted for the age, gender, CFTR mutation, disease severity, inhaled steroid use, and microbiological colonization.

RESULTS

There was a statistically significant reduction (20.10%, p < 0.001) in 12-month mean total IgE following ETI initiation; this change remained statistically significant in the multivariate model. The longitudinal analysis demonstrated no change in AEC following therapy initiation.

CONCLUSION

This study demonstrates that there is a statistically significant percent reduction in mean total IgE but no change in AEC following ETI initiation. ETI may lead to decreased antigen and superantigen load in the airway as a result of improved mucociliary clearance and these changes may drive the decline in total IgE, without influencing the epigenetic drivers of eosinophilic inflammation. Further studies are warranted to determine the underlying mechanism of ETI impact on T2 inflammation and possible role for asthma immunomodulator therapy post ETI initiation in CFAOS.

The Impact of CFTR Modulator Triple Therapy on Type 2 Inflammatory Response in Patients with Cystic Fibrosis

Background Treatment of cystic fibrosis (CF) has been revolutionized by the use of cystic fibrosis transmembrane conductance regulator (CFTR) protein modulators such as elexacaftor/tezacaftor/ivacaftor (ETI) triple therapy. Prior studies support a role for type 2 (T2) inflammation in many people with CF (PwCF) and CF-asthma overlap syndrome (CFAOS) is considered a separate clinical entity. It is unknown whether initiation of ETI therapy impacts T2 inflammation in PwCF. We hypothesized that ETI initiation decreases T2 inflammation in PwCF. Methods A single center retrospective chart review was conducted for adult PwCF. As markers of T2 inflammation, absolute eosinophil count (AEC) and total immunoglobulin E (IgE) data were collected longitudinally 12 months prior to ETI therapy initiation and 12 months following therapy initiation. Multivariable analyses adjusted for the age, gender, CFTR mutation, disease severity, inhaled steroid use, and microbiological colonization. Results There was a statistically significant reduction (20.10%, p < 0.001) in 12-month mean IgE following ETI initiation; this change remained statistically significant in the multivariate model. The longitudinal analysis demonstrated no change in AEC following therapy initiation. Conclusion This study shows reduction in IgE but no change in AEC after ETI therapy initiation. We think that the lack of influence on AEC argues against an impact on previously established T2 inflammation and that the reduction in IgE is likely related to antigen load reduction post ETI. Further studies are warranted to determine the underlying mechanism of ETI impact on T2 inflammation and possible role for asthma immunomodulator therapy post ETI initiation in CFAOS.

Inflammation biomarkers in sputum for clinical trials in cystic fibrosis: current understanding and gaps in knowledge

RATIONALE

Sputum biomarkers hold promise as a direct measure of inflammation within the cystic fibrosis (CF) lung, but variability in study design and sampling methodology have limited their use. A full evaluation of the reliability, validity and clinical relevance of individual biomarkers is required to optimise their use within CF clinical research.

OBJECTIVES

A biomarker Special Interest Working Group was established within the European Cystic Fibrosis Society-Clinical Trials Network Standardisation Committee, to perform a review of the evidence regarding sputum biomarkers in CF.

METHODS

From the 139 included articles, we identified 71 sputum biomarkers to undergo evaluation of their clinimetric properties, responsiveness, discriminant, concurrent and convergent validity.

RESULTS

Current evidence confirms the potential of sputum biomarkers as outcome measures in clinical trials. Inconsistency in responsiveness, concurrent and convergent validity require further research into these markers and processing standardisation before translation into wider use. Of the 71 biomarkers identified, Neutrophil Elastase (NE), IL-8, TNF-α and IL-1β, demonstrated validity and responsiveness to be currently considered for use in clinical trials. Other biomarkers show future promise, including IL-6, calprotectin, HMGB-1 and YKL-40.

CONCLUSION

A concerted international effort across the cystic fibrosis community is needed to promote high quality biomarker trial design, establish large population-based biomarker studies, and work together to create standards for collection, storage and analysis of sputum biomarkers.

Hyperinflammation and airway surface liquid dehydration in cystic fibrosis: purinergic system as therapeutic target

OBJECTIVE AND DESIGN

The exacerbate inflammatory response contributes to the progressive loss of lung function in cystic fibrosis (CF), a genetic disease that affects the osmotic balance of mucus and mucociliary clearance, resulting in a microenvironment that favors infection and inflammation. The purinergic system, an extracellular signaling pathway characterized by nucleotides, enzymes and receptors, may have a protective role in the disease, through its action in airway surface liquid (ASL) and anti-inflammatory response.

MATERIALS AND METHODS

To make up this review, studies covering topics of CF, inflammation, ASL and purinergic system were selected from the main medical databases, such as Pubmed and ScienceDirect.

CONCLUSION

We propose several ways to modulate the purinergic system as a potential therapy for CF, like inhibition of P2X7, activation of P2Y2, A2A and A2B receptors and blocking of adenosine deaminase. Among them, we postulate that the most suitable strategy is to block the action of adenosine deaminase, which culminates in the increase of Ado levels that presents anti-inflammatory actions and improves mucociliary clearance. Furthermore, it is possible to maintain the physiological levels of ATP to control the hydration of ASL. These therapies could correct the main mechanisms that contribute to the progression of CF.

Targeting eosinophils in respiratory diseases: Biological axis, emerging therapeutics and treatment modalities

Eosinophils are bi-lobed, multi-functional innate immune cells with diverse cell surface receptors that regulate local immune and inflammatory responses. Several inflammatory and infectious diseases are triggered with their build up in the blood and tissues. The mobilization of eosinophils into the lungs is regulated by a cascade of processes guided by Th2 cytokine generating T-cells. Recruitment of eosinophils essentially leads to a characteristic immune response followed by airway hyperresponsiveness and remodeling, which are hallmarks of chronic respiratory diseases. By analysing the dynamic interactions of eosinophils with their extracellular environment, which also involve signaling molecules and tissues, various therapies have been invented and developed to target respiratory diseases. Having entered clinical testing, several eosinophil targeting therapeutic agents have shown much promise and have further bridged the gap between theory and practice. Moreover, researchers now have a clearer understanding of the roles and mechanisms of eosinophils. These factors have successfully assisted molecular biologists to block specific pathways in the growth, migration and activation of eosinophils. The primary purpose of this review is to provide an overview of the eosinophil biology with a special emphasis on potential pharmacotherapeutic targets. The review also summarizes promising eosinophil-targeting agents, along with their mechanisms and rationale for use, including those in developmental pipeline, in clinical trials, or approved for other respiratory disorders.

Immunomodulation in Cystic Fibrosis: Why and How?

Cystic fibrosis (CF) lung disease is characterized by unconventional mechanisms of inflammation, implicating a chronic immune response dominated by innate immune cells. Historically, therapeutic development has focused on the mutated cystic fibrosis transmembrane conductance regulator (CFTR), leading to the discovery of small molecules aiming at modulating and potentiating the presence and activity of CFTR at the plasma membrane. However, treatment burden sustained by CF patients, side effects of current medications, and recent advances in other therapeutic areas have highlighted the need to develop novel disease targeting of the inflammatory component driving CF lung damage. Furthermore, current issues with standard treatment emphasize the need for directed lung therapies that could minimize systemic side effects. Here, we summarize current treatment used to target immune cells in the lungs, and highlight potential benefits and caveats of novel therapeutic strategies.

ILC2 Lung-Homing in Cystic Fibrosis Patients: Functional Involvement of CCR6 and Impact on Respiratory Failure

Cystic fibrosis patients suffer from a progressive, often fatal lung disease, which is based on a complex interplay between chronic infections, locally accumulating immune cells and pulmonary tissue remodeling. Although group-2 innate lymphoid cells (ILC2s) act as crucial initiators of lung inflammation, our understanding of their involvement in the pathogenesis of cystic fibrosis remains incomplete. Here we report a marked decrease of circulating CCR6⁺ ILC2s in the blood of cystic fibrosis patients, which significantly correlated with high disease severity and advanced pulmonary failure, strongly implicating increased ILC2 homing from the peripheral blood to the chronically inflamed lung tissue in cystic fibrosis patients. On a functional level, the CCR6 ligand CCL20 was identified as potent promoter of lung-directed ILC2 migration upon inflammatory conditions in vitro and in vivo using a new humanized mouse model with light-sheet fluorescence microscopic visualization of lung-accumulated human ILC2s. In the lung, blood-derived human ILC2s were able to augment local eosinophil and neutrophil accumulation and induced a marked upregulation of pulmonary type-VI collagen expression. Studies in primary human lung fibroblasts additionally revealed ILC2-derived IL-4 and IL-13 as important mediators of this type-VI collagen-inducing effect. Taken together, the here acquired results suggest that pathologically increased CCL20 levels in cystic fibrosis airways induce CCR6-mediated lung homing of circulating human ILC2s. Subsequent ILC2 activation then triggers local production of type-VI collagen and might thereby drive extracellular matrix remodeling potentially influencing pulmonary tissue destruction in cystic fibrosis patients. Thus, modulating the lung homing capacity of circulating ILC2s and their local effector functions opens new therapeutic avenues for cystic fibrosis treatment.

Circulating biomarkers of antioxidant status and oxidative stress in people with cystic fibrosis: A systematic review and meta-analysis

INTRODUCTION

Oxidative stress may play an important role in the pathophysiology of cystic fibrosis (CF). This review aimed to quantify CF-related redox imbalances.

METHODS

Systematic searches of the Medline, CINAHL, CENTRAL and PsycINFO databases were conducted. Mean content of blood biomarkers from people with clinically-stable CF and non-CF controls were used to calculate the standardized mean difference (SMD) and 95% confidence intervals (95% CI).

RESULTS

Forty-nine studies were eligible for this review including a total of 1792 people with CF and 1675 controls. Meta-analysis revealed that protein carbonyls (SMD: 1.13, 95% CI: 0.48 to 1.77), total F2-isoprostane 8-iso-prostaglandin F2α (SMD: 0.64, 95% CI: 0.23 to 1.05) and malondialdehyde (SMD: 1.34, 95% CI: 0.30 to 2.39) were significantly higher, and vitamins A (SMD: -0.66, 95% CI -1.14 to -0.17) and E (SMD: -0.74, 95% CI: -1.28 to -0.20), β-carotene (SMD: -1.80, 95% CI: -2.92 to -0.67), lutein (SMD: -1.52, 95% CI: -1.83 to -1.20) and albumin (SMD: -0.98, 95% CI: -1.68 to -0.27) were significantly lower in the plasma or serum of people with CF versus controls.

CONCLUSIONS

This systematic review and meta-analysis found good evidence for reduced antioxidant capacity and elevated oxidative stress in people with clinically-stable CF.

Blockade of equilibrative nucleoside transporter 1/2 protects against Pseudomonas aeruginosa-induced acute lung injury and NLRP3 inflammasome activation

Pseudomonas aeruginosa infections are increasingly multidrug resistant and cause healthcare-associated pneumonia, a major risk factor for acute lung injury (ALI)/acute respiratory distress syndrome (ARDS). Adenosine is a signaling nucleoside with potential opposing effects; adenosine can either protect against acute lung injury via adenosine receptors or cause lung injury via adenosine receptors or equilibrative nucleoside transporter (ENT)-dependent intracellular adenosine uptake. We hypothesized that blockade of intracellular adenosine uptake by inhibition of ENT1/2 would increase adenosine receptor signaling and protect against P. aeruginosa-induced acute lung injury. We observed that P. aeruginosa (strain: PA103) infection induced acute lung injury in C57BL/6 mice in a dose- and time-dependent manner. Using ENT1/2 pharmacological inhibitor, nitrobenzylthioinosine (NBTI), and ENT1-null mice, we demonstrated that ENT blockade elevated lung adenosine levels and significantly attenuated P. aeruginosa-induced acute lung injury, as assessed by lung wet-to-dry weight ratio, BAL protein levels, BAL inflammatory cell counts, pro-inflammatory cytokines, and pulmonary function (total lung volume, static lung compliance, tissue damping, and tissue elastance). Using both agonists and antagonists directed against adenosine receptors A2AR and A2BR, we further demonstrated that ENT1/2 blockade protected against P. aeruginosa -induced acute lung injury via activation of A2AR and A2BR. Additionally, ENT1/2 chemical inhibition and ENT1 knockout prevented P. aeruginosa-induced lung NLRP3 inflammasome activation. Finally, inhibition of inflammasome prevented P. aeruginosa-induced acute lung injury. Our results suggest that targeting ENT1/2 and NLRP3 inflammasome may be novel strategies for prevention and treatment of P. aeruginosa-induced pneumonia and subsequent ARDS.

An investigation into biomarkers for the diagnosis of ABPA and aspergillus disease in cystic fibrosis

BACKGROUND

Allergic bronchopulmonary aspergillosis (ABPA) is a hypersensitivity lung disease due to Aspergillus fumigatus (Af) which occurs in 10% of patients with cystic fibrosis (CF). ABPA is associated with increased morbidity and accelerated lung function decline; however, existing diagnostic criteria are nonspecific and diagnosis remains challenging. As ABPA is driven by Th2 inflammation, the aim of this study was to evaluate exhaled nitric oxide (FE _NO ), eosinophilic cationic protein (ECP), peripheral eosinophil count, and bronchodilator response (BDR) in patients with CF.

METHODS

A prospective observational cohort study of pediatric CF patients in a tertiary center. Patients had a clinical and serologic ABPA assessment, FE_NO , serum ECP, peripheral eosinophil count, and assessment of BDR. Patients were stratified into three groups; ABPA, Af sensitized (AFS), and non-ABPA non-Af-sensitized (non-AFS).

RESULTS

A total of 62 patients were included in the study: 13% ABPA, 19% AFS, and 68% non-AFS. Mean FE_NO was higher in the ABPA group at 37.8 ppb compared to AFS 15.1 ppb (P = .05) and non-AFS 13.7 ppb (P = .04). Mean peripheral eosinophil count in ABPA group was also higher at 1000 cells/uL, compared to AFS 221 cells/uL (P = .03) and non-AFS 220 cells/uL (P = .03). Mean BDR in ABPA group was 13% compared to 5.5% in non-AFS (P = .01). Serum ECP was higher in patients with ABPA positive compared to the other groups, although this was not statistically significant.

CONCLUSION

In children with cystic fibrosis, FE_NO and peripheral eosinophil counts are elevated in ABPA compared to those that are just sensitized to Aspergillus and may serve as useful diagnostic tests.

Pathogenesis, imaging and clinical characteristics of CF and non-CF bronchiectasis

Bronchiectasis is a common feature of severe inherited and acquired pulmonary disease conditions. Among inherited diseases, cystic fibrosis (CF) is the major disorder associated with bronchiectasis, while acquired conditions frequently featuring bronchiectasis include post-infective bronchiectasis and chronic obstructive pulmonary disease (COPD). Mechanistically, bronchiectasis is driven by a complex interplay of inflammation and infection with neutrophilic inflammation playing a predominant role. The clinical characterization and management of bronchiectasis should involve a precise diagnostic workup, tailored therapeutic strategies and pulmonary imaging that has become an essential tool for the diagnosis and follow-up of bronchiectasis. Prospective future studies are required to optimize the diagnostic and therapeutic management of bronchiectasis, particularly in heterogeneous non-CF bronchiectasis populations.

Biofilm-Induced Type 2 Innate Immunity in a Cystic Fibrosis Model of Pseudomonas aeruginosa

Biofilm-producing strains of Pseudomonas aeruginosa are a major cause of morbidity and mortality in cystic fibrosis (CF) patients. In these patients, increased levels of IL-17 as well as of IL-5 and IL-13 along with arginase (Arg)-positive macrophages have been observed in bronchoalveolar lavage fluid. While IL-17 is a strong proinflammatory cytokine associated with host defense against bacterial and fungal infections and is also elevated in several autoimmune diseases, IL-5/IL-13 and Arg1-positive M2 macrophages are part of the anti-inflammatory type 2 (Th2) immunity. To study whether increased IL-5 and IL-13 levels are related to biofilm formation, which is frequently observed in CF patients colonized by P. aeruginosa, we utilized an agarose bead-embedded P. aeruginosa rat model commonly employed in in vivo biofilm studies. We showed that “sterile” agarose bead instillation in rat notably increased lung transcript levels of IL-5 and IL-13 at two post-instillation study-points, day 1 and day 3. Concurrently, increased infiltration of type 2 innate cells such as eosinophils and Arg1 positive M2 activated macrophages (Arg1+CD68+) was also observed both at day 1 and day 3 while the proportion of M1 activated macrophages (iNOS+CD68+) at these time-points decreased. In contrast, P. aeruginosa-loaded beads caused a drastic elevation of proinflammatory Th1 (IFNγ, TNFα, IL-12a) and antibacterial Th17 (IL-17a, IL-17f, IL-22, IL-23a) cytokines along with a high influx of neutrophils and M1 macrophages, while Th2 cytokines (IL-5 and IL-13) drastically declined at day 1 post-infection. Interestingly, at day 3 post-infection, both Th1 and Th17 cytokines sharply declined and corroborated with decreased M1 and increased M2 macrophages. These data suggest that while IL-17 is linked to episodes of acute exacerbations of infection in CF patients, the increased Th2 cytokines and M2 macrophages observed in these patients are largely due to the biofilm matrix. The data presented here has important implications for clinical management of CF patients.

Modulating Innate and Adaptive Immunity by (R)-Roscovitine: Potential Therapeutic Opportunity in Cystic Fibrosis

(R)-Roscovitine, a pharmacological inhibitor of kinases, is currently in phase II clinical trial as a drug candidate for the treatment of cancers, Cushing's disease and rheumatoid arthritis. We here review the data that support the investigation of (R)-roscovitine as a potential therapeutic agent for the treatment of cystic fibrosis (CF). (R)-Roscovitine displays four independent properties that may favorably combine against CF: (1) it partially protects F508del-CFTR from proteolytic degradation and favors its trafficking to the plasma membrane; (2) by increasing membrane targeting of the TRPC6 ion channel, it rescues acidification in phagolysosomes of CF alveolar macrophages (which show abnormally high pH) and consequently restores their bactericidal activity; (3) its effects on neutrophils (induction of apoptosis), eosinophils (inhibition of degranulation/induction of apoptosis) and lymphocytes (modification of the Th17/Treg balance in favor of the differentiation of anti-inflammatory lymphocytes and reduced production of various interleukins, notably IL-17A) contribute to the resolution of inflammation and restoration of innate immunity, and (4) roscovitine displays analgesic properties in animal pain models. The fact that (R)-roscovitine has undergone extensive preclinical safety/pharmacology studies, and phase I and II clinical trials in cancer patients, encourages its repurposing as a CF drug candidate.

Systematic review of blood biomarkers in cystic fibrosis pulmonary exacerbations

BACKGROUND

Biomarkers reflective of disease activity in cystic fibrosis (CF) have the potential to improve patient care, particularly during CF pulmonary exacerbations (CFPEs). Although blood-based biomarkers have been studied in CFPE for nearly 3 decades, none have been integrated into routine clinical practice. To facilitate progress in this area, we performed a systematic review evaluating blood-based biomarkers during CFPE.

METHODS

MEDLINE, EMBASE, and CENTRAL were searched to identify relevant studies published from January 1995 to August 2012. We included all full-text studies examining systemic (blood-based) biomarkers to aid in the diagnosis of CFPE, predict outcomes of CFPE, and/or monitor the response to CFPE treatment.

RESULTS

Seventy-eight unique blood-based biomarkers have been studied to date, mainly inflammatory cytokines, acute phase reactants, and markers of oxidative stress. C-reactive protein (CRP) consistently correlated with disease activity, with a statistically significant increase from stable to exacerbation state in five of six studies, and changes in response to CFPE treatment, with a statistically significant decrease from the beginning to the end of CFPE treatment in 18 of 20 studies. Other promising biomarkers of CFPE disease activity include neutrophil elastase antiproteinase complex, IL-6, myeloperoxidase (MPO), lactoferrin, and calprotectin.

CONCLUSIONS

Although there are several blood-based biomarkers with evidence for application within the CFPE setting, CRP has been the most widely studied biomarker demonstrating the potential for clinical usefulness. Further validation studies and clinical trials are required to determine whether blood-based biomarkers can be used to ultimately improve health outcomes in the setting of a CFPE.

Soluble inflammation markers in nasal lavage from CF patients and healthy controls

BACKGROUND

CF sinonasal and bronchial mucosa reveal identical ion channel defects. Nasal Lavage (NL) allows non-invasive repeated sampling of airway surface liquid. We compared inflammatory mediators in NL from CF-patients and healthy controls, and in CF in relation to sinonasal pathogen colonization.

METHODS

From 40 CF-patients (mean age 21.8yrs, SD 11.8yrs.) and 52 healthy controls (mean age 31.9yrs., SD 13.7yrs.) NL-fluid (10ml/nostril) concentrations of MPO, IL-8, IL-17A, sICAM-1, IL-1β, IL-6, TNF-α, IL-10 and IL-5 were determined using cytometric bead arrays for flow cytometry.

RESULTS

CF-patients showed significantly higher MPO-concentrations in NL-fluid and higher IL-8-levels (n.s.) than controls. MPO, IL-8, IL-17A, sICAM-1, IL-1β and IL-6 were significantly more often detectable in CF-patients than in controls. CF-patients with S. aureus colonization in both upper and lower airways had significantly elevated MPO and IL-8 levels in NL-fluid compared to S. aureus negatives.

CONCLUSION

NL-fluid differed substantially between CF-patients and healthy controls with most promising results for IL-8 and MPO, a primarily in CF-NL assessed mediator. Further studies are required to assess effects of sample collection and processing on concentrations of inflammatory markers and to evaluate potentials of NL analysis in research and clinical routine.

Myeloperoxidase and eosinophil cationic protein in serum and sputum during antibiotic treatment in cystic fibrosis patients with Pseudomonas aeruginosa infection

I order to study the time-course of myeloperoxidase (MPO) and eosinophil cationic protein (ECP) as parameters for monitoring inflammation in cystic fibrosis (CF), we investigated ten patients during both a 14-day intravenous antibiotic treatment and a corresponding self control. Modified Shwachman-Kulczycki score improved significantly (p < 0.008), C-reactive protein (CRP) levels decreased significantly (p < 0.05) during antibiotic treatment, while in the control phase there were no significant differences. Lung function parameters did not change significantly during antibiotic treatment or control phase. Serum MPO concentration (p < 0.006) and peripheral blood neutrophil granulocyte counts (p < 0.04) decreased significantly during antibiotic treatment, but not during the control phase. Sentm ECP concentration showed a tendency to decrease during antibiotic treatment, but this failed to reach significance. In general, sputum concentrations of MPO and ECP Were 500- to 1000-fold higher than in serum. However, neither MPO nor ECP in sputum showed a significan variation over time during antibiotic treatment or control phase. From our data we conclude that: (1) measurements of MPO, neutrophils and CRP in peripheral blood do correlate with clinical parameters such as the modified Shwachman-Kulczycki score; (2) neutrophils and MPO seem to reflect inflammatory changes induced by antibiotic treatment; (3) eosinophils may play a role in CF by an enhanced ‘releasability’ and (4) Sputum measurements of mediators of inflammation cannot be recommended.

Hypothiocyanous acid: benign or deadly?

Hypothiocyanous acid (HOSCN) is produced in biological systems by the peroxidase-catalyzed reaction of thiocyanate (SCN(-)) with H(2)O(2). This oxidant plays an important role in the human immune system, owing to its potent bacteriostatic properties. Significant amounts of HOSCN are also formed by immune cells under inflammatory conditions, yet the reactivity of this oxidant with host tissue is poorly characterized. Traditionally, HOSCN has been viewed as a mild oxidant, which is innocuous to mammalian cells. Indeed, recent studies show that the presence of SCN(-) in airways has a protective function, by preventing the formation of other, more damaging, inflammatory oxidants. However, there is an increasing body of evidence that challenges this dogma, showing that the selectivity of HOSCN for specific thiol-containing cellular targets results in the initiation of significant cellular damage. This propensity to induce cellular dysfunction is gaining considerable interest, particularly in the cardiovascular field, as smokers have elevated plasma SCN(-), the precursor for HOSCN. This review will outline the beneficial and detrimental aspects of HOSCN formation in biological systems.

Serum myeloperoxidase in cystic fibrosis patients receiving systemic antibiotics

Serial serum myeloperoxidase was determined in 27 cystic fibrosis patients with chronic endobronchial Pseudomonas aeruginosa infection over the course of 1 y. The effect of repeated courses of antibiotic therapy on mean serum myeloperoxidase levels was significant (p = 0.034). Serial serum myeloperoxidase may help to guide therapy for pulmonary exacerbations.

Mammalian heme peroxidases: from molecular mechanisms to health implications

A marked increase in interest has occurred over the last few years in the role that mammalian heme peroxidase enzymes, primarily myeloperoxidase, eosinophil peroxidase, and lactoperoxidase, may play in both disease prevention and human pathologies. This increased interest has been sparked by developments in our understanding of polymorphisms that control the levels of these enzymes, a greater understanding of the basic chemistry and biochemistry of the oxidants formed by these species, the development of specific biomarkers that can be used in vivo to detect damage induced by these oxidants, the detection of active forms of these peroxidases at most, if not all, sites of inflammation, and a correlation between the levels of these enzymes and a number of major human pathologies. This article reviews recent developments in our understanding of the enzymology, chemistry, biochemistry and biologic roles of mammalian peroxidases and the oxidants that they generate, the potential role of these oxidants in human disease, and the use of the levels of these enzymes in disease prognosis.

Pulmonary function is negatively correlated with sputum inflammatory markers and cough clearability in subjects with cystic fibrosis but not those with chronic bronchitis

BACKGROUND

Polymorphonuclear neutrophil (PMN)-dominated inflammation is prominent in the airways of subjects with cystic fibrosis (CF) and chronic bronchitis (CB). Interleukin (IL)-8, myeloperoxidase (MPO), and DNA are markers of neutrophilic inflammation. We hypothesized that sputum MPO, DNA, and IL-8 concentrations would negatively correlate with pulmonary function and sputum transportability.

METHODS

We measured pulmonary function and analyzed sputum IL-8, MPO, and DNA concentrations, as well as the transport properties of sputum samples obtained from 16 subjects with CF and 15 subjects with CB. We also evaluated changes in these measurements in paired sputum samples from these subjects obtained 2 to 12 months apart.

RESULTS

IL-8 and MPO concentrations in the sputum of CF subjects was inversely correlated with FEV(1) percent predicted (IL-8: r = -0.40; p = 0.003; MPO: r = -0.38; p = 0.003) and FVC percent predicted (IL-8: r = -0.4; p = 0.02; MPO: r = -0.4; p = 0.02). IL-8 and DNA concentrations were inversely correlated with sputum cough transportability (CTR) [IL-8: r = -0.4; p = 0.02; DNA: r = -0.36; p = 0.048]. Changes in DNA concentration in sputum samples from CF subjects over time were inversely correlated with changes in FEV(1) percent predicted (r = -0.58; p = 0.02), FVC percent predicted (r = -0.74; p = 0.002), and CTR (r = -0.59; p = 0.02). There was no correlation among pulmonary function, sputum properties, and inflammatory markers in the sputum from subjects with CB.

CONCLUSIONS

The sputum concentrations of IL-8, MPO, and DNA appear to be closely associated with pulmonary function in subjects with CF but not in subjects with CB.

Eosinophil cationic protein in patients with fascioliasis: its probable effects on symptoms and signs

Eosinophilia is 1 of the most common signs of fascioliasis especially during acute stage. In this study, our aim was to determine eosinophil cationic protein (ECP) in the sera of patients with fascioliasis and to investigate the likely relation between ECP and symptoms and signs of fascioliasis. Presence of high liver enzyme levels, eosinophilia, abdominal pain or urticaria was not found to be significantly associated with ECP positivity (p>0.05), but statistical analyses revealed that ECP positivity was significantly related to weight loss status of patients (p<0.005). In conclusion, ECP may be 1 of the likely causes of the symptoms and signs of fascioliasis.

Leukotriene receptor antagonists in children with cystic fibrosis lung disease : anti-inflammatory and clinical effects

Cystic fibrosis (CF) lung disease is characterized by chronic endobronchial infection resulting in progressive pulmonary destruction; this is a major cause of mortality and morbidity. Neutrophils are the primary effector cells responsible for the progressive deterioration of lung function. Peptido-leukotriene B4 antagonists, new anti-inflammatory agents that block the neutrophil-dominated inflammation, could have had the potential for long-term use. A trial on the pharmacokinetics of amelubant administered orally as a single dose of up to 75 mg in pediatric patients with CF and 300 mg in adults, and as a repeated dose of 75 mg and 150 mg, respectively, once daily for 15 days provided evidence that amelubant metabolism in adult and pediatric patients with CF is similar to that in healthy adults. In another study using the same dosage regimen, amelubant appeared to be safe and well tolerated. Safety measures included physical examination, vital signs, spirometry, oximetry, ECG, and clinical laboratory testing. However, a randomized, double-blind, placebo-controlled, multinational, phase II trial (Boehringer Ingelheim 543.45) was conducted to investigate the clinical efficacy of 24 weeks of treatment with amelubant in patients with CF with mild-to-moderate lung disease. Two doses of amelubant (75 and 150 mg) were tested in adult patients (> or = 18 years) and one dose of amelubant (75mg) was tested in pediatric (6-17 years) patients. The trial was terminated early due to a statistically significant increase in the risk of pulmonary-related, serious adverse events in adults receiving amelubant. Cysteinyl leukotrienes, eosinophilic inflammation, and viral infections also contribute to progressive pulmonary destruction in CF. Cysteinyl leukotrienes are potential targets for cysteinyl leukotriene receptor antagonist use. A study on the pharmacokinetics of montelukast in children with CF provided evidence that the dose of montelukast and the administration interval does not need to be modified if the goal is to mimic the serum concentrations used to treat asthma. In a randomized, double-blind, crossover, placebo-controlled study, 16 children with mild CF (median age 9.5 years; vital capacity [VC] >70%) were treated with montelukast (5 to < or =14 years; 5 mg; >14 years; 10 mg) or placebo as a once-daily tablet for 21 days. There was a significant (p < or = 0.02) reduction in serum eosinophil cationic protein levels and eosinophils (p < or = 0.027) with montelukast. However, neither lung function tests (VC, forced expiratory volume in 1 second [FEV1], maximum expiratory flow at 25% of forced VC), nor clinical symptom scores changed significantly. In another study, 26 patients aged 6-18 years with moderate CF (VC between 40% and 69% predicted) received montelukast or placebo for 8 weeks in a 20-week, randomized, double-blind, crossover, placebo-controlled trial. After treatment with montelukast there was a significant improvement in FEV1, peak expiratory flow, and forced expiratory flow between 25% and 75%, and a significant decrease in cough and wheezing scale scores (p < 0.001 for all). Montelukast treatment decreased serum and sputum levels of eosinophil cationic protein and interleukin-8 (IL-8), decreased sputum levels of myeloperoxidase, and increased serum and sputum levels of IL-10 (p < 0.001 for all) compared with placebo. To date, clinical experience and research data on the anti-inflammatory effects of leukotriene receptor antagonists in CF are limited. Multicenter trials with longer observation periods and greater patient numbers are needed to prove the hypothesis that leukotriene receptor antagonists have the potential to ameliorate CF lung disease with long term use.

Effects of montelukast treatment on clinical and inflammatory variables in patients with cystic fibrosis

BACKGROUND

In cystic fibrosis (CF), the inflammatory process contributes to progressive lung tissue damage. Cysteinyl leukotrienes have been found in the sputum of patients with CF at high concentrations sufficient to cause potent biological effects.

OBJECTIVE

To evaluate the effect of anti-inflammatory treatment with montelukast sodium in patients with CF.

METHODS

Twenty-six patients aged 6 to 18 years were recruited to this 20-week, randomized, double-blind, placebo-controlled, crossover trial. Patients received montelukast or placebo for 8 weeks in addition to their regular CF treatment. Before and after treatment, findings from spirometry, whole-body plethysmography, and the clinical wheezing and cough scales were evaluated. At the same time, serum and sputum samples were obtained for the measurement of eosinophil cationic protein, interleukin 10 (IL-10), IL-8, and myeloperoxidase levels.

RESULTS

Twenty-three patients completed the study. Compared with placebo use, montelukast treatment significantly improved forced expiratory volume in I second, peak expiratory flow, and forced expiratory flow between 25% and 75% and significantly decreased cough and wheezing scale scores (P < .001 for all). There were no significant changes in vital capacity, thoracic gas volume, airway resistance, and residual volume after treatment. Compared with placebo use, montelukast treatment decreased serum and sputum levels of eosinophil cationic protein and IL-8, decreased sputum levels of myeloperoxidase, and increased serum and sputum levels of IL-10 (P < .001 for all).

CONCLUSIONS

Montelukast may have measurable anti-inflammatory properties in patients with CF.

Myeloperoxidase and Protein Oxidation in the Airways of Young Children with Cystic Fibrosis

Cystic fibrosis (CF) is characterized by considerable oxidative stress. However, it is not known whether oxidative stress is an important feature early in this disease. We have investigated a group of infants and young children with CF to establish whether oxidants are produced in their airways. Bronchoalveolar lavage fluid (BALF) was assayed for myeloperoxidase as a measure of neutrophilic inflammation, and 3-chlorotyrosine as a biomarker of the potent oxidant hypochlorous acid, which is formed by myeloperoxidase. Protein carbonyls were also measured as a nonspecific indicator of reactive oxidant production. Myeloperoxidase and 3-chlorotyrosine levels in BALF from children with CF were 10- and fivefold higher, respectively, than in disease control subjects. There was a strong correlation between myeloperoxidase and 3-chlorotyrosine. Myeloperoxidase levels were fourfold higher in children with infections in their airways. Median protein carbonyls were elevated by only twofold compared with disease control subjects, but some children had extremely high levels of protein oxidation. We conclude that hypochlorous acid is produced early in CF and that it is a candidate for precipitating the fatal decline in lung function associated with this disease. Also, there must be other sourcesof oxidants because protein carbonyls were not related to either inflammation or infection.

Cell and cytokine profile in nasal secretions in cystic fibrosis

BACKGROUND

Nasal polyposis (NP) frequently complicates the course of cystic fibrosis (CF). The aim of this study was to determine the pattern of inflammatory cells and mediators in nasal secretions from patients with or without NP compared to patients with idiopathic NP and healthy controls.

METHODS

Eighteen CF patients with NP (NP+ group: 6 untreated, 12 treated with nasal steroids), and 15 without NP (NP- group) were included in this prospective study and compared to 9 patients with idiopathic NP and 12 healthy controls. Differential cell count eosinophil cationic protein (ECP), interleukin-5 (IL-5) and IL-8 were determined in nasal lavage fluids.

RESULTS

The total cell count, the number and the percentage of neutrophils and eosinophils, the levels of IL-8, IL-5 and ECP were significantly higher in nasal secretions from both NP+ and NP- as compared with controls. No difference was found between untreated and treated CF patients with NP. No difference was found between NP+ and NP- groups. Compared to idiopathic NP group, both NP+ and NP- groups had higher percentage of neutrophils and lower percentage of eosinophils. There were no differences according to the use of topical steroids, systemic antibiotherapy, or the type of mutation. CF patients with positive nasal culture had a higher percentage of neutrophils than those with negative culture. CF patients with atopy had a higher percentage of eosinophils than non-atopic patients.

CONCLUSION

Our results demonstrate that nasal inflammation is a prominent feature in patients with CF and does not differ according to the presence of NP. IL-8 and IL-5 may play crucial roles in recruitment and activation of neutrophils and eosinophils in upper airways of CF patients.

Anti-inflammatory effects of montelukast in mild cystic fibrosis

BACKGROUND

Immune-mediated inflammation contributes to progressive pulmonary damage in cystic fibrosis (CF). Sputum cysteinyl leukotriene levels, eosinophil cationic protein (ECP), and interleukin-8 (IL-8) are significantly related to disease severity.

OBJECTIVE

The aim of this study was to evaluate the anti-inflammatory and clinical effects of the cysteinyl leukotriene receptor antagonist montelukast in children with CF.

METHODS

A double-blind, randomized, crossover design was used. Patients received montelukast (6 to < or = 14 years, 5 mg; > 14 years, 10 mg) or placebo as a once-daily tablet for 21 days and then, after a washout period of at least 4 weeks, crossed over to receive the alternative treatment. Blood and native nasal fluid were taken on days 1 and 21 of each treatment block, and WBC count, ECP, and IL-8 were analyzed using a chemiluminescent immunometric assay.

RESULTS

Sixteen CF patients (10 boys, 6 girls; age, 5 to 18 years, median 9.5 years) completed the trial. There was a significant (P < or = 0.02) reduction of serum ECP (median reduction: montelukast 7.7 microg/L vs placebo 0.15 microg/L) and eosinophils (P < or = 0.027; median reduction: montelukast 85/microL vs placebo 0/microL). There was no significant change in nasal ECP, IL-8, or serum IL-8 after a 21-day course of montelukast. Clinical symptom scores did not change significantly.

CONCLUSIONS

Montelukast reduces eosinophilic inflammation in CF patients. Multicenter trials providing more patients to create more data to prove the hypothesis that montelukast is an effective tool to cut down disease severity in CF patients are needed.

Effects of recombinant human DNase and hypertonic saline on airway inflammation in children with cystic fibrosis

Recombinant human DNase (rhDNase) is an established treatment in cystic fibrosis (CF), but it may liberate cationic mediators bound to DNA in the airways. An alternative mucolytic therapy is hypertonic saline (HS); however, HS may potentiate neutrophilic inflammation. We compared the effect of rhDNase and HS on cationic proinflammatory mediators in CF sputum. In a randomized, crossover trial, 48 children with CF were allocated consecutively to 12 weeks of once-daily 2.5 mg rhDNase, alternate-day 2.5 mg rhDNase, and twice-daily 7% HS. Sputum levels of total interleukin-8 (IL-8), free IL-8, myeloperoxidase, eosinophil cationic protein, and neutrophil elastase (NE) activity were measured before and after each treatment. The change in mediator levels from baseline with daily rhDNase and HS was not significant; however, with alternate-day rhDNase, there was an increase in free IL-8. When changes in mediator levels with daily rhDNase were compared with alternate-day rhDNase and HS, no significant differences were detected. Only changes in NE activity were associated with changes in lung function. In summary, we were unable to show that rhDNase or HS promote airway inflammation in CF.

Sputum processing for evaluation of inflammatory mediators

Neutrophil-dominated inflammation is prominent in the cystic fibrosis (CF) and chronic bronchitis (CB) airways. We assessed the degree of airway inflammation by measuring the sputum concentrations of interleukin (IL)-8, myeloperoxidase (MPO), and deoxyribonucleic acid (DNA). We determined the relationship among the concentrations of these mediators and investigated methodological problems that may be responsible for reported variability in measurements. Sputa obtained from 31 patients were solubilized with phosphate-buffered saline, dithiothreitol (DTT) (0.1% or 1%), or dornase alfa (0.2 mg/mL). The sputum concentration of IL-8 and MPO was measured by enzyme-linked immunosorbent assay (ELISA), and DNA was measured using microfluorimetry. There was a significant relationship among sputum IL-8, MPO, and DNA. For MPO (means +/- SD), CF was 1,392 +/- 771 vs. CB at 75 +/- 65 mcg/mL; P < 0.0001. For IL-8: CF was 239 +/- 154 vs. CB at 121 +/- 108 ng/mL; P = 0.0002. For DNA, CF was 1.707 +/- 1.25 vs. CB at 0.184 +/- 0.272 mg/mL; P < 0.0001. The MPO concentration in CF sputum was approximately double after in vitro treatment with dornase alfa (P < 0.0001). There is a greater concentration of IL-8, MPO, and DNA in CF than in CB sputa. There is a significant relationship among these inflammatory markers in sputum. DNA polymers bind myeloperoxidase in the sputum, and we speculate that treatment with dornase alfa may remove a source of MPO inhibition.

Ambient ozone exposure is associated with eosinophil activation in healthy children

BACKGROUND

Eosinophil activation is characteristic for allergic airways disease. However, eosinophilic airways inflammation has also been observed subsequent to ambient ozone exposure.

METHODS

For a population sample of 877 children living at nine sites with different ozone exposure we measured urinary eosinophil protein X (U-EPX) as a marker of eosinophil activation. U-EPX was determined from a single spot urine sample during autumn 1997. Children were participants in a longitudinal study of ozone effects on lung function.

RESULTS

The 5-95% percentiles of ozone exposure (30-day mean before test) were 11.8-51.5 p.p.b. (mean: 31.6 ppb). U-EPX was measured by radioimmunoassay and expressed as ratio to urinary creatinine (microg EPX/mmol creatinine). Log transformation was performed to achieve a normal distribution. LogU-EPX was associated with gender, a diagnosis of asthma and atopy (skin test sensitivity to any of seven aeroallergens). LogU-EPX increased with ozone exposure for all children. The medians of LogU-EPX according to the first-fourth quartiles of ozone exposure were: 1.82, 1.88, 1.95 and 2.03. For 172 non-asthmatic children who had spent the whole summer at their site corresponding figures were 1.57, 1.78, 2.07 and 2.13. In a multivariate model with logU-EPX being the dependent variable and adjusted for gender, site and atopy, ozone was found to be significant (estimate: 0.007 microg/mmol creatinine per ppb ozone; SE:0.02; P < 0.001).

CONCLUSION

Our observation supports the hypothesis that ozone in healthy children is associated with eosinophil inflammation, most likely in the airways.

The relationship of eosinophil granule proteins to ions in the sputum of patients with cystic fibrosis

Increased sputum levels of eosinophil granule proteins have been reported despite normal eosinophil numbers in peripheral blood and in the lung in cystic fibrosis (CF). Mechanisms of eosinophil priming and activation are still unclear in CF. In the present study we investigated whether ion concentrations in the sputa of CF patients are related to eosinophil activity. We assessed concentrations of eosinophil cationic protein (ECP), eosinophil protein X (EPX), major basic protein (MBP) and ions (Na+, Cl-, Ca2+, Mg2+) in sputum samples of 29 children with CF as well as in 10 controls with bronchial asthma. Patients with CF demonstrated significantly higher levels of ECP, Na+, Cl- and Ca2+ levels than asthmatics (P < 0.04, P < 0.0001, P < 0.0001, P < 0.02). No differences were seen between concentrations of EPX and Mg2+ in the two groups. In CF, eosinophil granule proteins correlated significantly with Ca2+ and Mg2+ concentrations (ECP, P < 0.0001, r = 0.65, P < 0.0001, r = 0.66; MBP, P < 0.03, r = 0.41, P < 0.03, r = 0.42), furthermore inversely with Cl- concentrations (ECP, P < 0. 0003, r = - 0.63; EPX, P < 0.02, r = - 0.45; MBP, P < 0.03, r = - 0. 41) but not with Na+ levels. ECP, Na+ and Cl- were also correlated with lung function variables (FVC, P < 0.04, r = - 0.38, P < 0.02, r = 0.44, P < 0.03, r = 0.41; FEV1, P < 0.007, r = - 0.49, P < 0.006, r = 0.5, P < 0.008, r = 0.48; MEF50, P < 0.003, r = - 0.54, NS, P < 0.03, r = 0.42; MEF25, P < 0.039, r = - 0.4, P < 0.005, r = 0.51, P < 0.05, r = 0.37). Our results demonstrated a significant relationship of eosinophil degranulation and ions in CF, indicating that ion composition in CF sputa may be at least partly be responsible for high levels of eosinophil products despite low eosinophil numbers.

Intrapulmonary concentrations of inflammatory cytokines in a mouse model of chronic respiratory infection caused by Pseudomonas aeruginosa

We investigated the role of inflammatory cytokines in a mouse model of chronic Pseudomonas aeruginosa infection mimicking diffuse panbronchiolitis (DPB), and determined the effects of clarithromycin therapy on the production of these cytokines. The concentrations of IL-1beta, IL-2, IL-4, IL-5, interferon-gamma (IFN-gamma) and tumour necrosis factor-alpha (TNF-alpha) were measured serially in the lungs of mice with experimentally induced chronic respiratory P. aeruginosa infection until 60 days after inoculation. The concentrations of these cytokines during the course of the disease were significantly higher than baseline (before inoculation, P<0.01 for all cytokines). Clarithromycin significantly inhibited the production of IL-1beta and TNF-alpha in the lung (P<0.01). The same treatment also reduced the levels of other cytokines, albeit insignificantly. Treatment with anti-TNF-alpha antibody significantly reduced the number of pulmonary lymphocytes and concentration of IL-1beta in the lung (P<0.01), but did not change the number of viable bacteria. Our findings resemble those detected in bronchoalveolar lavage fluid of patients with DPB and indicate that inflammatory cytokines play an important role in chronic P. aeruginosa lung infection. Our results also show that macrolides modulated the production of these cytokines, ultimately reducing lymphocyte accumulation in the lung. Our data suggest that anti-TNF-alpha antibody might be a useful new strategy for the treatment of chronic respiratory P. aeruginosa infection.

Intestinal inflammation in cystic fibrosis

BACKGROUND

There is controversy about whether the inflammatory response observed in the cystic fibrosis (CF) lung occurs secondary to bacterial infection or is caused by a dysregulation of the inflammatory response associated with the basic cellular defect of CF.

AIMS

To study the inflammatory response in the gastrointestinal tract of children with CF; and to investigate whether there is increased inflammation in the gastrointestinal tract of CF children with fibrosing colonopathy.

METHODS

Whole gut lavage was performed on 21 pancreatic insufficient children with CF, who were clinically well, five children with CF and fibrosing colonopathy, and 12 controls. Intestinal outputs of plasma derived proteins (albumin, alpha(1) antitrypsin, IgG), secretory immunoglobulins (IgA and IgM), cellular constituents (eosinophil cationic protein and neutrophil elastase), and cytokines (interleukin 8 and interleukin 1beta) were measured.

RESULTS

Compared to controls, the 21 CF patients, with no intestinal complications, had increased intestinal outputs of albumin, IgG, IgM, eosinophil cationic protein, neutrophil elastase, interleukin 1beta, and interleukin 8. Similar values were obtained for the CF patients with fibrosing colonopathy.

CONCLUSIONS

These data suggest that there is immune activation in the gastrointestinal mucosa of children with cystic fibrosis, which may result from the basic cellular defect. Fibrosing colonopathy does not appear to be associated with increased inflammation.

Major basic protein, but not eosinophil cationic protein or eosinophil protein X, is related to atopy in cystic fibrosis

Increased eosinophil granule proteins have been described in serum and sputum samples of patients with cystic fibrosis (CF). It has been assumed that eosinophil degranulation is enhanced in atopic subjects - as in asthmatics. Since in CF no differences in eosinophil cationic protein (ECP), eosinophil protein X (EPX), and eosinophil peroxidase between atopic and nonatopic subjects have been detected, we investigated whether major basic protein (MBP) is increased in serum and sputum samples derived from atopic (n = 14) compared with nonatopic CF subjects (n = 26). In CF patients, high mean serum (sputum) levels of ECP 29.7 microg/l (2.7 mg/l), EPX 53.7 microg/l (7.9 mg/l), and MBP 984.6 microg/l but low sputum MBP levels (57.4 microg/l) were measured. In addition, in serum and in sputum samples, a significant correlation between MBP and ECP (P<0.03 and P<0.0001, respectively) or EPX (P<0.05 and P<0.0004, respectively) was detected. By subdivision of the patients into allergic and nonallergic subjects, significant differences were found for serum MBP values only(mean 1382.2 microg/l vs. 770.5 microg/l; P<0.0001), but not for ECP or EPX serum levels or for eosinophil proteins in sputum. Although no differences between atopic and nonatopic CF patients in ECP and EPX were found, serum MBP levels were higher in patients sensitized to inhalant allergens than in nonsensitized subjects. These results indicate differential release of eosinophil granule proteins in peripheral blood from eosinophils, and they also indicate that MBP in serum likely is to be a better discriminator of atopy in CF.

Assessment of eosinophil granule proteins in various body fluids: is there a relation to clinical variables in childhood asthma?

BACKGROUND

The eosinophil plays a central role in the inflammatory process in bronchial asthma. Recent studies have indicated that the assessment of eosinophil-derived proteins in various body fluids could be used for monitoring disease activity of childhood asthma. Till now, no study exists which compared the levels of eosinophil-derived proteins in various body fluids such as serum, nasal lavage fluid (NALF) and urine.

OBJECTIVE

To investigate whether eosinophil granule proteins in different compartments were correlated and whether there is a relationship between disease activity, pulmonary function and bronchial hyperreactivity.

METHODS

Twenty-eight children with atopic bronchial asthma were recruited. Serum, NALF and urine samples were obtained and assessed for eosinophil cationic protein (ECP) and eosinophil protein X (EPX). The levels of eosinophil proteins were analysed for a relationship with lung function variables, bronchial hyperreactivity and disease activity. Eleven healthy control subjects were used as controls.

RESULTS

Median ECP and EPX concentrations in serum (31.4 and 74.8 microg/L vs 15.8 and 24.3 microg/L, respectively), NALF (9.9 and 44. 9 microg/L vs 0 and 2.5 microg/L, respectively) and urine (49.4 vs 16.5 microg/mmol creatinine) were significantly raised in children with bronchial asthma compared with healthy control subjects. In addition, ECP and EPX levels in serum and urine samples were significantly higher in symptomatic patients compared with asymptomatic subjects with asthma. Although no relationship between eosinophil-derived proteins in serum, NALF or urine and the level of nonspecific bronchial hyperreactivity could be detected, the concentrations of EPX in serum and urine were correlated with variables of pulmonary function.

CONCLUSION

Our findings demonstrate increased eosinophil activity in serum, NALF and urine derived from children with bronchial asthma. Due to the relationship between levels of eosinophil proteins in serum/urine samples and lung function, as well as significant concentration differences between symptomatic and asymptomatic asthmatic children, the assessment of eosinophil proteins in serum or urine samples appear to be more appropriate in monitoring disease activity than measurement of ECP or EPX in NALF. Thus, the determination of serum ECP/EPX or urinary EPX may be preferentially used in monitoring eosinophilic inflammation in childhood asthma.

Bronchoalveolar cell profiles in children with asthma, infantile wheeze, chronic cough, or cystic fibrosis

Differential cell counts of bronchoalveolar lavage (BAL) have been reported in normal children but few data on cellular profiles in bronchial diseases in childhood are available. We determined the BAL cell profiles of 72 children divided into 5 groups: asthma (n = 14), chronic cough (n = 12), infantile wheeze (n = 26), cystic fibrosis (n = 10), and control (n = 10). The highest total cell, eosinophil, and neutrophil counts were found in children with cystic fibrosis. The cell profile of children with chronic cough was similar to that of control children. Asthma and infantile wheeze were characterized by a high median ratio of eosinophils (3%) and neutrophils (12%), respectively. In both diseases, epithelial shedding was suggested by an elevated epithelial cell count, 13.5 and 12%, respectively. Lymphocyte subset analysis showed a higher proportion of CD8 cells (58 versus 40%) and therefore a lower CD4/CD8 ratio (0.266 versus 0. 455) in children with asthma compared with infantile wheezers (p = 0. 02). Irrespective of the presence or absence of radiological abnormalities, a proportion of neutrophils > 10%, was found in one-third of the children with asthma and in half of the infantile wheezers, and was related to symptom severity. We suggest that neutrophil-mediated inflammation, with or without bacterial infection, may contribute to symptoms of asthma in childhood. Chronic cough, however, is not associated with the cell profiles suggestive of asthma and in isolation should not be treated with prophylactic antiasthma drugs.

Chemokine expression in CF epithelia: implications for the role of CFTR in RANTES expression

To delineate the mechanisms that facilitate leukocyte migration into the cystic fibrosis (CF) lung, expression of chemokines, including interleukin-8 (IL-8), monocyte chemoattractant protein-1 (MCP-1), and RANTES, was compared between CF and non-CF airway epithelia. The findings presented herein demonstrate that, under either basal conditions or tumor necrosis factor-alpha (TNF-alpha)- and/or interferon-gamma (IFN-gamma)-stimulated conditions, a consistent pattern of differences in the secretion of IL-8 and MCP-1 between CF and non-CF epithelial cells was not observed. In contrast, CF epithelial cells expressed no detectable RANTES protein or mRNA under basal conditions or when stimulated with TNF-alpha and/or IFN-gamma (P </= 0.05), unlike their non-CF counterparts. Correction of the CF transmembrane conductance regulator (CFTR) defect in CF airway epithelial cells restored the induction of RANTES protein and mRNA by TNF-alpha in combination with IFN-gamma (P </= 0.05) but had little effect on IL-8 or MCP-1 production compared with mock controls. Transfection studies utilizing RANTES promoter constructs suggested that CFTR activates the RANTES promoter via a nuclear factor-kappaB-mediated pathway. Together, these results suggest that 1) RANTES expression is altered in CF epithelia and 2) epithelial expression of RANTES, but not IL-8 or MCP-1, is dependent on CFTR.

Assessment of serum myeloperoxidase in children with bronchial asthma

BACKGROUND

The role of neutrophils and myeloperoxidase (MPO) - assumed to be a marker of neutrophil activation - in bronchial asthma is still unclear, and the literature is controversial.

METHODS

To investigate the participation of neutrophils and their products in childhood asthma, we assessed neutrophil counts and serum MPO in 175 children with bronchial asthma. Ninety of them were asymptomatic, and 85 of them were symptomatic within the last 2 weeks before examination. Bacterial infection of the lower respiratory tract (LRTI) was present in 34 and viral infection in 49 patients. As controls, 45 patients with cystic fibrosis, 23 patients with bacterial LRTI, and 87 healthy children were recruited.

RESULTS

Median neutrophil counts (3135 cells/microl) and serum MPO levels (352 microg/l) were not different in children with bronchial asthma from healthy controls (2220 cells/microl and 401 microg/l, respectively), whereas in patients with cystic fibrosis and bacterial LRTI, neutrophil counts and MPO levels were increased. Asthmatic children with bacterial infection had significantly higher serum MPO and neutrophil counts then asthmatic children with viral infection or without infection. In addition, a significant correlation was found between serum MPO and neutrophil counts and C-reactive protein (CRP), and between neutrophil counts and CRP, but no relationship was detected for serum MPO and disease activity or lung function.

CONCLUSIONS

Our data indicate that serum MPO - a marker of neutrophil activation - does not contribute to the assessment of the inflammatory process in childhood asthma. In addition, measurement of serum MPO appears not to be useful in assessing the participation of the neutrophil in asthmatic children. However, assessment of MPO may be useful to distinguish between bacterial and viral infection.

Induced sputum eosinophil cationic protein (ECP) measurement in asthma and chronic obstructive airway disease (COAD)

BACKGROUND

Induced sputum is a useful way to monitor airway inflammation in asthma, but cell counts are time-consuming and labour intensive.

OBJECTIVE

The aim of this study was to evaluate a novel processing method using eosinophil cationic protein (ECP) as a biochemical marker of sputum eosinophil number and activation in subjects with asthma and other airway diseases.

METHODS

Sputum was dispersed with dithiothreitol and centrifuged to yield cell free supernatant and a cell pellet. The pellet was treated with a cellular lysis buffer to release cell-associated ECP. ECP was measured in sputum supernatant and in the lysed cell pellet and was compared with sputum eosinophil counts in 31 adults with asthma, chronic obstructive airway disease (COAD), bronchiectasis and healthy controls. The ratio of supernatant to pellet ECP was evaluated as an index of eosinophil degranulation. The effect of sputum processing reagents and storage time on ECP measurement was also evaluated.

RESULTS

ECP measured in the cell pellet lysate correlated closely with sputum absolute eosinophil counts across a range of subject groups (r = 0.72, P = 0.004). Sputum eosinophil counts were less well correlated with supernatant ECP levels (r = 0.54, P < 0.05). Incubation with dithiothreitol or lysis buffer did not influence ECP measurement and sputum ECP levels were stable over a 6-9 month period. Sputum supernatant and pellet lysate ECP concentrations were increased in stable asthma, asthma exacerbations and COAD/bronchiectasis (P < 0.05). The ratio of supernatant to pellet ECP was used as an index of eosinophil degranulation and found to be elevated in asthma exacerbations, COAD and bronchiectasis, but not in stable asthma.

CONCLUSION

The measurement of ECP in the sputum cell pellet provides a reliable and efficient estimate of sputum eosinophil counts which can potentially be used in clinical trials and epidemiological surveys. The ECP ratio may be a useful marker of eosinophil activation, and was increased in asthma exacerbation and COAD. The increased ECP in COAD reflects a non-selective accumulation of eosinophils in this condition.

Evidence for eosinophil activation in bronchiectasis unrelated to cystic fibrosis and bronchopulmonary aspergillosis: discrepancy between blood eosinophil counts and serum eosinophil cationic protein levels

BACKGROUND

Increased serum levels of eosinophil cationic protein (ECP) have been detected in adolescent patients with cystic fibrosis. However, ECP concentrations in adult patients with bronchiectasis unrelated to cystic fibrosis have not been studied.

METHODS

Eosinophil numbers and serum concentrations of ECP were determined in 14 patients with known or newly diagnosed bronchiectasis and compared with age and sex matched patients with allergic bronchial asthma, chronic obstructive pulmonary disease (COPD), and controls in whom bronchiectasis or obstructive pulmonary disease could be excluded.

RESULTS

Serum ECP levels were significantly raised both in patients with bronchiectasis (median (range) 22.5 micrograms/l (7-85)) and allergic asthma (35.0 micrograms/l (7-128)) compared with the sex and age matched subjects suffering from COPD (6.7 micrograms/l (1.5-28); p < 0.006) and non-obstructive normal controls (7.5 micrograms/l (3.5-19); p < 0.003). In contrast, significantly increased peripheral eosinophil numbers were observed in patients with bronchial asthma (305 x 10(6)/l; p < 0.01) but not in those with bronchiectasis (10(2) x 10(6)/l), COPD (117 x 10(6)/l), and healthy controls (101 x 10(6)/l).

CONCLUSIONS

The discrepancy between eosinophil counts and eosinophil numbers in patients with bronchiectasis suggests that serum ECP levels may be more relevant in assessing local eosinophil involvement than blood eosinophil numbers.

Serum eosinophil cationic protein, eosinophil protein X and eosinophil peroxidase in relation to pulmonary function in cystic fibrosis

BACKGROUND

Recently, increased serum levels of eosinophil cationic protein (ECP) in cystic fibrosis (CF) have been reported which were closely related to the levels in sputum. In the present study we investigated other eosinophil proteins such as eosinophil peroxidase (EPO) and eosinophil protein X (EPX) in sera of patients with CF and their relation to pulmonary function.

METHODS

Serum samples from 42 patients with CF and from 25 healthy control subjects were measured for ECP, EPO and EPX. Lung function tests were performed by using whole body plethysmographic technique, and the results were correlated with the levels of eosinophil granule proteins.

RESULTS

Serum ECP (median: 20.9 microg/L), EPO (median: 30.3 microg/L) and EPX (median: 37.9 microg/L) levels were significantly increased in CF compared with healthy controls (3.5 microg/L, P < 0.0001, 5.6 microg/L, P < 0.0001 and 14.6 microg/L, P < 0.0001, respectively) whereas eosinophil counts were not different. There was a strong correlation between the levels of eosinophil proteins and variables of pulmonary function, like between ECP and forced vital capacity (r = -0.764, P < 0.0001). In addition, ECP concentrations were significantly related to the levels of EPO and EPX, albeit, in some patients with low ECP levels, increased EPO and EPX concentrations were observed.

CONCLUSION

These results indicate that in patients with CF, ECP, EPO and EPX concentrations also were increased with a significant relationship between these three eosinophil proteins. Since eosinophil activity in patients with CF is strongly correlated with pulmonary function, the assessment of eosinophil granule proteins might be useful for clinical monitoring in CF.

Controlled trial of inhaled budesonide in patients with cystic fibrosis and chronic bronchopulmonary Psuedomonas aeruginosa infection

The efficacy and safety of anti-inflammatory treatment with inhaled glucocorticosteroids in patients with cystic fibrosis (CF) and complicating chronic Pseudomonas aeruginosa (P.a.) lung infection was studied in a placebo-controlled, parallel, double-blind single center trial. Active treatment consisted of budesonide dry powder, 800 microg twice daily, delivered from a Turbuhaler. The study period covered two successive 3-mo intervals between elective courses of intravenous anti-Pseudomonas antibiotics. Fifty-five patients entered the study, with a mean age of 20 yr and a mean FEV1 of 63% of predicted. Analysis of all patients entered, irrespective of trial adherence ("intention to treat"), showed a decrease in FEV1 in the first period of -0.032 L in patients on budesonide versus -0.187 L in patients on placebo (p = 0.08). The corresponding figures for the patients adhering to the protocol during the first period were -0.017 L versus -0.198 L (p < 0.05, confidence interval of the difference: -0.035 to +0.327 L). For all patients entered, as well as for patients adhering to the trial, there was always a trend in favor of budesonide, as judged by changes in FEV1 and FVC in both 3-mo periods. None of the patients had asthma, but the patients on budesonide had a mean improvement in histamine reactivity of +1.15 dose steps over the entire 6-mo period, as opposed to +0.017 dose steps in patients on placebo (p < 0.05). There was also a significant (p = 0.01) correlation between pre-trial histamine reactivity and the change in FEV1 in the first period in patients on budesonide. We conclude that inhaled glucocorticosteroids can be of short-term benefit in patients with CF and chronic P.a. infection and that those patients most likely to benefit from this treatment are patients with hyperreactive airways. Prolonged studies in larger number of patients are necessary to determine the long-term efficacy of this treatment.