Total eosinophil cationic protein levels in induced sputum as a marker of changes in eosinophilic inflammation in a patient with allergic asthma

Regulation and directed inhibition of ECP production by human neutrophils

Background

Neutrophils are involved in the pathophysiology of allergic asthma, where the Eosinophil Cationic Protein (ECP) is a critical inflammatory mediator. Although ECP production is attributed to eosinophils, we reported that ECP is also present in neutrophils from allergic patients where, in contrast to eosinophils, it is produced in an IgE-dependent manner. Given the key role of ECP in asthma, we investigated the molecular mechanisms involved in ECP production as well as the effects induced by agonists and widely used clinical approaches. We also analyzed the correlation between ECP production and lung function.

Methods

Neutrophils from allergic asthmatic patients were challenged with allergens, alone or in combination with cytokines, in the presence of cell-signaling inhibitors and clinical drugs. We analyzed ECP levels by ELISA and confocal microscopy. Lung function was assessed by spirometry.

Results

IgE-mediated ECP release is dependent on phosphoinositide 3-kinase, the extracellular signal-regulated kinase (ERK1/2) and the production of reactive oxygen species by NADPH-oxidase. Calcineurin phosphatase and the transcription factor NFAT are also involved. ECP release is enhanced by the cytokines interleukin (IL)-5 and granulocyte macrophage-colony stimulating factor, and inhibited by interferon-γ, IL-10, clinical drugs (formoterol, tiotropium and budesonide) and allergen-specific IT. We also found an inverse correlation between asthma severity and ECP levels.

Conclusions

Our results suggest the molecular pathways involved in ECP production and potential therapeutic targets. We also provide a new method to evaluate disease severity in asthmatic patients based on the quantification of in vitro ECP production by peripheral neutrophils.

Eosinophil cationic protein (ECP) correlates with eosinophil cell counts in the induced sputum of elite swimmers

Introduction

Swimming practice has been associated with eosinophilic inflammation, however, the underlying mechanisms are not fully understood. The eosinophil cationic protein (ECP) in induced sputum may be used as a potential biomarker to assess airway eosinophilic inflammation among elite swimmers. The objective of this study is to characterize ECP levels in sputum supernatant in elite swimmers and evaluate ECP as an eosinophilic inflammatory marker.

Material and methods

Elite swimmers annually screened in our department (n = 27) were invited to participate in this cross-sectional study. Swimmers who agreed to participate (n = 24, 46% girls) performed lung function and skin-prick tests. Induced sputum was also collected and analyzed for differential cell counts and ECP measurements in sputum supernatant (ImmunoCAPTM 100, ECP, Thermo Fisher Scientific, Uppsala, Sweden).

Results

The median ECP level was 15.60 μg/L (6.02-38.75 μg/L) and higher levels were found among boys (27.90 (11.20-46.30) μg/L vs 6.65 (2.82-22.80) μg/L, P = .02). In addition, ECP levels in the sputum supernatant were positively correlated with eosinophil cell counts in the induced sputum (r = 0.583, P = .08).

Conclusions

ECP levels correlated positively with eosinophil counts in the induced sputum in elite swimmers. The measurement of ECP in sputum supernatant may be a useful marker to assess and manage eosinophilic inflammatory changes in the airways of elite swimmers.

Identifying phenotypes and factors impacting outcomes in older adults with asthma: A research protocol and recruitment results

Success in testing research outcomes requires identification of effective recruitment strategies in the targeted population. In this paper, we present the protocol for our NIH-funded study as well as success rates for the various recruitment strategies employed. This longitudinal observational study is: developing a phenotyping algorithm for asthma in older adults, exploring the effects of the asthma phenotype and of volatile organic compounds on asthma control, and developing a predictive model of asthma quality of life. A sub-aim is to characterize barriers to successful medication management in older adults with asthma. Individuals are eligible if they are ≥60 years, have a positive response to at least 1 of 6 asthma screening questions, are non-smokers, and demonstrate bronchodilator reversibility or a positive bronchial challenge test with methacholine. Exclusion criteria are smokers who quit <5 years ago or with a >20 pack year smoking history, and those having other chronic pulmonary diseases. Participants (N = 190) complete baseline pulmonary function testing, questionnaires, sputum induction, skin prick testing, and have blood drawn for Vitamin D and Immunoglobulin E. Home environmental assessments are completed including 24-hr particulate and volatile organic compound measurements. At 9-months post-baseline, home spirometry, medication assessment, and assessment of asthma quality of life and asthma control are assessed. At 18-months post-baseline, home spirometry, completion of baseline questionnaires, and a home environmental assessment are completed. We have employed multiple recruitment efforts including referrals from clinical offices, no-cost media events, flyers, and ads. The most successful efforts have been referrals from clinical offices and media events.

Eosinophil Cationic Protein Concentrations among Crop and Dairy Farmers with Asthma

OBJECTIVE

To assess the mean serum eosinophil cationic protein (s-ECP) concentrations among crop and dairy farmers and office controls, and further examine its relation to exposure duration, smoking habit, as well as presence or absence of asthma.

METHODS

A cross-sectional survey was performed including examined group (EG), composed by agricultural workers (87 crop - EG1 and 83 dairy farmers - EG2), and control group (CG) composed by 80 office workers within the same enterprise. We have used a questionnaire to record the chronic respiratory symptoms, detailed work history, specific farming activities and tasks performed and smoking history. Evaluation of examined subjects also included lung function tests, diagnosis of asthma, and measurement of s-ECP as a marker of inflammation.

RESULTS

The main finding of the present study is that s-ECP concentrations were raised in subjects with asthma independent of the smoking habit. The mean s-ECP concentrations were higher in subjects of EG1 and EG2 compared with those in CG, but without reaching statistical significance. Mean s-ECP concentrations were significantly higher among subjects in EG1 exposed more than 20 years, while mean s-ECP concentrations were non-significantly higher in subjects of EG2 exposed more than 20 years, compared to those exposed less than 20 years. Mean s-ECP concentrations were higher among smokers within all three groups, but without reaching statistical significance between smokers and non-smokers. Mean s-ECP concentrations were significantly higher in subjects with asthma within EG1 (P = 0.049) and EG2 (P = 0.040), but also within those in CG (P = 0.046).

CONCLUSION

Data obtained suggest that airway inflammation is present in farmers with asthma, and s-ECP is an important biomarker in means of reflecting disease severity and prognosis among exposed workers.

Bronchial inflammation in seasonal allergic rhinitis with or without asthma in relation to natural exposure to pollen allergens

BACKGROUND

Nasal inflammation in allergic rhinitis enhances bronchial Th2 driven inflammation and development of asthma. We assessed bronchial inflammation induced by natural allergen exposure during pollen season in patients with pollinosis with or without asthma to show the intensity of inflammation in asthma and rhinitis and possible persistence of inflammation in periods without allergen exposure.

METHODS

Sputum was induced in 52 patients with seasonal allergic rhinitis without asthma, 38 patients with seasonal allergic rhinitis and seasonal asthma and 23 healthy volunteers. Sampling was performed 6-8 weeks before the expected beginning of symptoms, during symptomatic period and 6-8 weeks after the end of symptoms. Sputum ECP was measured by means of chemi-luminiscent immunometric assay and sputum cell counts were assessed by classical staining and immunocytochemistry.

RESULTS

Sputum eosinophils were on the whole higher in both asthma and rhinitis compared to controls (p<0.001, p=0.003). The rise of eosinophils during pollen season compared with values out of pollen season was significant in asthma (classical staining) (p=0.014) and slightly apparent in rhinitis (immunocytochemistry) (p=0.073). The seasonal rise of sputum ECP was observed only in rhinitis (p=0.006).

CONCLUSIONS

Inflammation of the lower airway in patients with allergic rhinitis with and without asthma has been confirmed by means of both sputum eosinophil count and sputum ECP level. Persistent inflammation of lower airway in periods without allergen exposure was proven in seasonal asthma. This may have implications for the therapy of seasonal allergic rhinitis with and without asthma in terms of promoting long-term anti-inflammatory treatment.

Comparison of different non-invasive methods for detection of allergic asthma

Non-invasive methods to assess inflammation of lower airways are induced sputum (IS), exhaled nitric oxide (eNO), and exhaled breath condensate (EBC). Here we focused on the assessment of airway inflammation with a panel of non-invasive methods in health care workers (HCWs) with suspected latex allergy with and without current allergic respiratory symptoms about 10 years after the latex ban in German health care facilities. Seventy-seven non-smoking subjects were examined by skin prick test and specific IgE measurements, eNO, IS, and EBC. Sensitivity, specificity, and positive and negative predicted values for relevant biomarkers were calculated using current asthma symptoms as the gold standard. Twenty-nine subjects (38%) reported ongoing asthmatic symptoms (AS). In these subjects the EBC concentrations of nitrogen oxides (NO(x); p=0.027) and leukotriene B(4) (p=0.025) were significantly higher than in subjects without AS. In addition, in the subjects with AS the numbers of eosinophils (p=0.015) and the concentrations of IL-5 (p= 0.021) in IS samples were significantly higher than in the subjects without AS. A good correlation between several inflammatory markers in IS was detected. The maximum Youden Index was reached for IS total eosinophils ≥3.5·10(4) with a test efficiency of 0.72. In conclusion, non-invasive inflammatory monitoring with EBC and IS may assist the diagnosis of allergic asthma. Self-reported current asthmatic symptoms were reflected by eosinophilic inflammation and the best parameter to support the asthma diagnosis is a total number of eosinophils ≥3.5·10(4) in IS.

Delayed asthmatic response to bronchial challenge with allergen-mediators, eicosanoids, eosinophil and neutrophil constituents in the blood and urine

BACKGROUND

In patients with allergic bronchial asthma, different immunologic mechanisms may participate and lead to different types of asthmatic response to allergen challenge, such as immediate/early (IAR/EAR), late (LAR) or delayed asthmatic response (DYAR).

OBJECTIVES

In 55 of 397 asthmatics, DYAR has been recorded (p < 0.001) and confirmed by repeated bronchial challenge with the same allergen (p < 0.001). DYAR began between 26 and 32 h, reached a maximum between 32 and 48 h and resolved within 56 h after the challenge. DYAR was associated with various clinical symptoms and diagnostic parameters having diverged from those recorded during the IARs/EARs and LARs.

METHODS

In 25 of 55 patients, repeated DYAR has been supplemented with the recording of leukotriene B(4) (LTB(4)), LTC(4), LTE(4), prostaglandin D(2) (PGD(2)), PGE(2), PGF(2)(α), thromboxane B(2), lipoxin A(4), eosinophil cationic protein, eosinophil-derived neurotoxin/eosinophil protein X, eosinophilic peroxidase, myeloperoxidase, histamine and tryptase in peripheral blood, and of LTC(4), thromboxane B(2), eosinophil-derived neurotoxin and 9α,11β-PGF(2) in urine, before and up to 72 h after the bronchial allergen challenge, by means of enzyme-linked immunoassay (ELISA/EIA) or ImmunoCAP.

RESULTS

DYAR was accompanied by a significant increase in the plasma concentrations of LTB(4) (p < 0.05) and myeloperoxidase (p < 0.05) at 24, 36 and 48 h after the challenge, whereas the plasma/serum or urine concentrations of the other factors did not demonstrate any significant changes (p > 0.05).

CONCLUSIONS

These results would indicate an active and prominent involvement of neutrophils, in addition to the previously demonstrated role of the Th1 lymphocytes, in the clinical DYAR.

Role of IgE in eosinophilic otitis media

Eosinophilic otitis media (EOM) is an intractable otitis media characterized by the presence of a highly viscous yellow effusion containing eosinophils. It mainly occurs in patients with bronchial asthma and is resistant to conventional treatments for otitis media. Here we discuss the role of IgE in the pathogenesis of EOM. In middle ear effusion, a significantly higher IgE level was detected in EOM patients than in control patients with common otitis media with effusion. This IgE level was significantly higher (about 10 fold) than the serum IgE level. In addition, many IgE-immunopositive cells were found in the middle ear mucosa. The IgE staining was mainly observed on mast cell surfaces, but also partially in the cytoplasm of cells that appeared to be plasma cells. These results suggested that IgE is produced locally in the middle ear mucosa. The existence of high-level IgE may exacerbate eosinophilic inflammation in the middle ear. One of the most distinct characteristics of EOM is the high incidence of sensory hearing loss independent of age. High-tone hearing loss is more frequently found and more severe in EOM patients than in control patients with common chronic otitis media. The concentration of IgE in middle ear effusion significantly and positively correlated with bone conduction hearing levels at 2 kHz and 4 kHz in EOM patients. Overproduction of IgE locally in the middle ear may be related to the pathological condition of EOM and eventually cause inner ear damage.

Eosinophilic inflammation in the middle ear induces deterioration of bone-conduction hearing level in patients with eosinophilic otitis media

OBJECTIVE

Eosinophilic otitis media (EOM) is characterized by the extensive accumulation of eosinophils in the middle ear mucosa and middle ear effusion and is usually associated with bronchial asthma. Eosinophilic otitis media patients show gradual or sudden deterioration of hearing. In our previous study, we reported that high-tone loss was more frequently found and more severe in EOM patients than in control patients with chronic otitis media. These findings suggest that not only bacterial infection but also eosinophilic inflammation in the middle ear may damage the inner ear. The present study was performed to determine whether eosinophilic inflammation is indeed related to deterioration of bone-conduction hearing level (BCHL).

PATIENTS

Fifty-five ears of 28 patients with EOM associated with bronchial asthma were included in this study. Middle ear effusion (MEE) samples were collected from all the patients, and the concentrations of eosinophilic cationic protein (ECP) and immunoglobulin E (IgE) were measured by fluorescence enzyme immunoassay. The BCHLs at 2 and 4 kHz for the worse-hearing ear of each patient were correlated with the concentrations of ECP and IgE.

RESULTS

The concentration of IgE in MEE significantly and positively correlated with BCHL at 2 and 4 kHz. The ears with a higher concentration of ECP in MEE also tended to show deterioration of BCHL at 4 kHz. Other clinical risk factors for BCHL deterioration were male sex, long duration of EOM, association with bacterial infection, severe inflammatory changes of the middle ear mucosa, and high serum IgE concentration.

CONCLUSION

Eosinophilic-inflammation-related substances such as ECP and IgE are closely related to the deterioration of BCHL at high frequencies. Particularly, IgE concentration in MEE is a good indicator of BCHL elevation. We should always pay attention to the hearing acuity of EOM patients with the risk factors.

The predictive value of eosinophil cationic protein and lactate dehydrogenase in asthma: a comparative study of serum versus sputum

BACKGROUND

: Serum and sputum eosinophil cationic protein (ECP) levels are correlated with asthma disease severity.

OBJECTIVE

: To establish a diagnostic accuracy of ECP and lactate dehydrogenase (LDH) in serum (indirectly) and sputum (directly) as inflammatory markers in asthma.

PATIENTS AND METHODS

: In a cross sectional study, 76 asthmatic patients with exacerbation were enrolled in the study. ECP was determined using enzyme linked immuno-assay.

RESULTS

: Asthmatic patients compared with control subjects, had a significant higher levels of ECP and LDH in sputum. Both sputum and serum ECP and LDH were reduced significantly with prednisolone treatment. FEV1 was inversely correlated with sputum ECP, serum ECP, and sputum LDH. A significant positive correlation was noted between sputum ECP and sputum LDH. Serum LDH does not demonstrate any significant correlations with other variables. The area under receiver operating characteristic curve showed that sputum ECP (0.92) was a significantly an accurate marker more than serum ECP (0.81), sputum (0.80) LDH, and serum (0.65) LDH. Furthermore, the area under curve was lower for serum ECP (0.81) than that for sputum ECP (0.92). However, serum ECP (0.81) was more accurate marker than serum LDH (0.65).

CONCLUSION

: Serum and sputum ECP as eosinophilic inflammatory markers are associated with poor asthma control. Sputum ECP and LDH were significantly an accurate markers more than serum ECP and LDH.

Biomarkers in asthma

PURPOSE OF REVIEW

The purpose of this review is to highlight seminal and current literature that informs our understanding of the clinical and investigative utility of biomarkers in asthma. Biomarkers derive from a variety of sources [bronchiolar lavage (BAL), sputum, exhaled breath, and blood], and have widely variant performance characteristics, and applicability.

RECENT FINDINGS

Increasing attention is given to biomarkers in exhaled breath, both gaseous (exhaled nitric oxide) and higher molecular weight moieties [in exhaled breath condensate (EBC)]. Current research in EBC analysis has focused on validation, standardization, and technical considerations, whereas research on exhaled nitric oxide (ENO) has moved to testing its predictive value in clinical situations. The use of advanced biostatistical techniques, and combinatorial analyses has led to additional advances in the utility of biomarkers.

SUMMARY

To date, the best validated, and best performing biomarkers for clinical asthma appear to be measures of inflammation in induced sputum, and measures of ENO. Some trials using ENO appear particularly promising for early clinical use. EBC metrics are at present too inchoate for clinical purposes. However, not all important clinical and research questions can be addressed with sputum, EBC, or ENO metrics, leaving an important place for BAL, bronchial biopsy, and perhaps EBC measurements in the research arena.

Prolonged eosinophil production after allergen exposure in IFN-gammaR KO mice is IL-5 dependent

Asthma is a T helper 2 (Th2)-driven inflammatory process characterized by eosinophilia. Prolonged airway eosinophilia is commonly observed in asthma exacerbations. Our aim was to evaluate whether eosinophilia in prolonged allergic inflammation is associated with a continuous supply of new eosinophils to the airways, and how this is regulated. Ovalbumin (OVA)-sensitized interferon-gamma receptor knockout mice (IFN-gammaR KO), known to maintain a long-lasting eosinophilia after allergen exposure, were compared to wild type (wt) controls. Animals were exposed to OVA or phosphate-buffered saline on three consecutive days, and bone marrow (BM), blood and bronchoalveolar lavage (BAL) samples were collected 24 h, 7 and 21 days later. Newly produced cells were labelled using bromodeoxyuridine (BrdU). Serum IL-5 was measured and its role was investigated by administration of a neutralizing anti-IL-5 antibody. In-vitro eosinophilopoiesis was examined in both groups by a colony-forming assay. Allergen challenge increased eosinophils in BM, blood and BAL, in both IFN-gammaR KO and wt mice, both 24 h and 7 days after the last allergen exposure. At 21 days after the last exposure, only IFN-gammaR KO mice maintained significantly increased eosinophil numbers. Approximately 50% of BAL granulocytes in IFN-gammaR KO were produced during the last 6 days. Interleukin (IL)-5 concentration was increased in IFN-gammaR KO mice, and anti-IL-5 reduced eosinophil numbers in all compartments. Increased numbers of eosinophil colonies were observed in IFN-gammaR KO mice after allergen exposure versus controls. In this model of a Th2-driven prolonged allergic eosinophilia, new eosinophils contribute to the extended inflammation in the airways by enhanced BM eosinophilopoiesis in an IL-5-dependent manner.

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.