Eosinophil Protein X Research Articles

A microtiter assay for activation of eosinophils

A simple microtiter assay for eosinophil activation is described. The assay used 1000-4000 eosinophils/microtiter well, and the design allows for a separate or simultaneous quantitative assessment of eosinophil adhesion to protein-coated microtiter wells and degranulation after stimulation with eosinophil-activating factors. The number of adherent eosinophils is quantified indirectly by expressing the amount of eosinophil cationic protein (ECP) extracted from the adherent fraction of cells in percentage of the total amount of ECP extracted from the cells added to the wells. Degranulation is quantified in the same way by expressing the amount of ECP or eosinophil protein X (EPX) released to the supernatant in percentage of the total amount of ECP or EPX. Known eosinophil-activating agents such as PMA, interleukin (IL)-3, IL-5, GM-CSF, and platelet-activating factor (PAF) all induced a time- and dose-dependent adhesion to albumin-coated wells, whereas L-PAF did not. Kinetic experiments showed that most adhesion occurred within the first 15-30 min, reaching a plateau around 60 min. After prolonged incubation, a decline in adhesion was detected. GM-CSF-induced adhesion was completely inhibited by incubation with monoclonal antibodies directed against the common beta 2-chain (CD18) of the LFA-1, Mac-1, p150,95 complexes. Monoclonal antibodies against CD11a, CD11b, CD11c, VLA-4 ALFA, ICAM-1, VCAM-1, Sialyl-Le(x), ELAM-1, and LECAM had no inhibitory effect. Simultaneous monitoring of adhesion and degranulation after stimulation of eosinophils in albumin-coated wells with either PMA or GM-CSF showed that adhesion always preceded degranulation. Replacing the albumin coating of the microtiter wells with IgG or secretory IgA augmented both the spontaneous and the PMA- or GM-CSF-stimulated responses. In conclusion, the assay allows dynamic evaluation of eosinophil activation and can be used to assess soluble eosinophil-activating factors as well as to study eosinophil activation by solid-phase-bound proteins.

The eosinophil granule proteins in serum, but not the oxidative metabolism of the blood eosinophils, are increased in cancer.

The eosinophil activity in patients with renal cell adenocarcinoma during treatment with interleukin-2 (IL-2) and interferon-alpha (IFN-alpha) was reduced when measured as zymosan-induced lucigenin-enhanced chemiluminescence (CL). Eosinophil cationic protein (ECP), eosinophil peroxidase (EPO) and eosinophil protein-X (EPX) were significantly elevated before and during treatment (P<0.001) when compared with the controls. ECP and EPO were unaffected by the treatment whereas it induced an increased EPX level compared with values measured before treatment (P<0.05). The propensity of eosinophils to secrete their granule proteins may reflect the fact that eosinophils in cancer patients have an enhanced capacity to kill cancer cells.

Leucocyte and platelet-derived bioactive substances in stored blood: effect of prestorage leucocyte filtration.

Adverse reactions to transfusion of allogeneic blood may depend on content of leucocytes and platelets and on storage-time of the erythrocyte suspensions. Therefore, we studied the efficacy of prestorage leucocyte reduction by filtration on total content and extracellular accumulation of histamine, eosinophil cationic protein (ECP), eosinophil protein X (EPX), myeloperoxidase (MPO), plasminogen activator inhibitor type-1 (PAI-1) and interleukin-6 (IL-6) in samples obtained from 5 units of SAGM blood, 7 units of plasma-reduced whole-blood and 6 units of whole-blood before and after filtration, respectively. In addition, we analysed supernatants from the same units after storage at +4 degrees C for 0, 21 and 35 d, respectively. The filtration was performed at room temperature within 2-4 h after donation. The substances were analysed by ELISA and RIA methods and we also analysed the donor plasma levels of the same bioactive substances. The total content of histamine, ECP, EPX, and MPO were 10-70-fold higher in all unfiltered erythrocyte products compared to donor plasma concentrations, while PAI-1 content was 15-20-fold higher only in plasma-reduced whole-blood and whole-blood. Prestorage leucocyte filtration significantly reduced the total histamine, ECP, EPX, MPO and PAI-1 content to levels similar to donor plasma levels in plasma-reduced whole-blood and whole-blood, while PAI-1 was still low in filtered SAGM blood. In addition, the levels of extracellular bioactive substances at d 0 after donation and filtration were within the range of concentrations in donor plasma, and there was no time-dependent accumulation during storage for 35 d at +4 degrees C. IL-6 was not detected in either plasma or samples obtained from the blood bags. These results suggest prestorage leucocyte filtration to deplete leucocyte contents to levels, which prevent the previously shown time-dependent accumulation of leucocyte derived bioactive substances in various erythrocyte suspensions. In addition, the PAI-1 results suggest leucocyte filters to reduce the obligatory platelet content in whole-blood products.

Cytokine concentrations in sputum from patients with cystic fibrosis and their relation to eosinophil activity.

To evaluate whether concentrations of cytokines supposed to be involved in eosinophil recruitment and activation were elevated in cystic fibrosis (CF), we assessed interleukin-3 (IL-3), IL-5, IL-8, regulated on activation, normal T-cell expressed and secreted (RANTES); and granulocyte-macrophage colony stimulating factor (GM-CSF) in sputa from 32 patients with CF, eight patients with atopic bronchial asthma, and six patients with bacterial pneumonia. In addition, eosinophil cationic protein (ECP) and eosinophil protein X (EPX) were measured as markers of eosinophil activation. In patients with CF, sputum levels of IL-8 were elevated (p < 0.01) as compared with asthmatic patients. Concentrations of IL-3, ECP, and EPX were not different in the two groups. However, IL-5 (p < 0.0001), RANTES (p < 0.003), and GM-CSF (p < 0.0001) were significantly lower in the CF group than in subjects with asthma. IL-5 was detected only in sputum samples from CF patients with Aspergillus sensitization. In patients with pneumonia, IL-8 levels only were increased. In CF sputum, ECP levels were significantly correlated with the levels of IL-8 (r = 0.626, p < 0.0001) and IL-3 (r = 0.642; p < 0.0001), whereas in asthmatic patients IL-5, IL-8, and RANTES concentrations were significantly related to ECP in sputum. These findings suggest that different cytokine profiles are responsible for eosinophil activation in patients with CF as compared with asthmatic patients. In CF, IL-8 and IL-3 appear to be responsible for increased degranulation of eosinophils.

Administration of G-CSF to healthy subjects: the effects on eosinophil counts and mobilization of eosinophil granule proteins.

Any influence of G-CSF on eosinophils is mostly negative, although reports which have studied this relationship are few with varied results. The aim of this study was to investigate the influence of G-CSF administration to healthy subjects on eosinophils in peripheral blood. Blood eosinophil counts, serum levels of eosinophil cationic protein (ECP), eosinophil peroxidase (EPO) and eosinophil protein X (EPX), as well as cell morphology were studied. 14 healthy volunteers received 7.5 microg (n = 8) or 10 microg/kg body weight (n = 6) G-CSF daily for six consecutive days. ECP and EPX were assessed by specific RIAs and EPO by a specific FEIA. Cell morphology was examined by electron microscopy. During G-CSF administration, eosinophil counts increased from 0.22 +/- 0.04 x 10(9)/l to 0.61 +/- 0.098 x 10(9)/l (P = 0.001), serum ECP from 12.39 +/- 2.45 microg/l to 61.82 +/- 7.38 microg/l (P = 0.0014), serum EPX from 28.05 +/- 4.54 microg/l to 87.86 +/- 9.84 microg/l (P = 0.002) and serum EPO from 8.89 +/- 2.2 microg/l to 19.98 +/- 5.1 microg/l (P = 0.003). All variables returned gradually to initial values after discontinuation of G-CSF. Distinct changes in the morphology of secondary granules were observed 24 h after G-CSF administration. The granules became irregular and their matrix less electron dense. We conclude that administration of G-CSF to healthy humans increases the number of circulating eosinophils and affects the mobilization of eosinophil granule proteins.

Bioactive substance accumulation and septic complications in a burn trauma patient: effect of perioperative blood transfusion?

Evidence has emerged that suggests adverse effects to perioperative homologous blood transfusion are related to the age of the blood products. Recently, time-dependent accumulation of bioactive substances in red cell suspensions, standard platelet concentrates and fresh frozen plasma during storage have been shown. The potential adverse effects of these bioactive substances were analysed in a burn trauma patient. A patient with 40 per cent second and third degree burn trauma without other injuries underwent a two-step transplantation operation. Samples for analyses of histamine, eosinophil cationic protein (ECP), eosinophil protein X (EPX), neutrophil myeloperoxidase (MPO) and interleukin 6 (IL-6) were drawn frequently from the patient before, during and after the operations, and from all transfused red cell, platelet and fresh frozen plasma units. Urine was sampled every hour during the first operation for analyses of ECP and EPX excretion. All analyses were performed by ELISA and RIA methods, and results compared to patient outcome. The patient received a total of 48 and 8 SAGM blood, 6 and O platelet and 12 and 4 fresh frozen plasma units at the two operations, respectively. Transfused products contained a total of 64.54 nmol and 17.50 nmol histamine, 115518 ng and 25764 ng ECP, 174457 ng and 38770 ng EPX, 6950915 ng and 1505125 ng MPO, and 14740 pg and 5600 pg IL-6 at the two operations, respectively. The accumulation of the substances in patient plasma correlated to postoperative septic reactions, without any disclosure of bacteraemia after the first operation, while the accumulation at the second operation correlated to the septic reaction and Pseudomonas aeruginosa infection. Timedependent accumulation of bioactive substances in blood products during storage may be related to the development of post-transfusion adverse effects.

Quantification of inflammatory mediators in stool samples of patients with inflammatory bowel disorders and controls.

Previous studies indicated that eosinophils and mast cells accumulate and become activated in inflammatory bowel disorders. The aim of the study was to examine the presence of eosinophil and mast cell mediators in human stool samples of patients with inflammatory bowel disorders. We measured eosinophil cationic protein (ECP), eosinophil protein X (EPX), methylhistamine, and alpha 1-antitrypsin in fecal samples of 136 patients (62 Crohn's disease, 24 ulcerative colitis, 15 intestinal food allergy, 35 other gastrointestinal diseases) and 8 healthy controls. We found strongly elevated levels of ECP (median: 29, range: 0.4-1783 ng/g feces) and EPX (803, 10-33,225 ng/g) in all patients groups compared to controls (ECP: 1.5, 0.5-55 ng/g; EPX: 235, 12-746 ng/g). Similar results, albeit less pronounced, were obtained for methylhistamine and alpha 1-antitrypsin. Particularly high concentrations of ECP and EPX were found in patients with active mucosal inflammation. In conclusion, the study presents an easy and reliable method for the detection of fecal ECP, EPX, and methylhistamine and may provide a tool to gain insight into the pathogenesis of inflammatory bowel diseases and have potential as diagnostic test.

Granulocyte proteins in serum in childhood asthma: relation to spirometry and therapy

Measurement of markers of eosinophil activation in asthmatics provides information indicative of ongoing inflammatory processes in the airways. This study was conducted to determine the correlations between serum markers of allergic inflammation with spirometry parameters in asthmatic children in different treatment groups. Blood eosinophils, serum levels of eosinophil cationic protein (ECP), eosinophil protein X (EPX), myeloperoxidase (MPO) and tryptase were measured simultaneously with serial measurements of FEV1/FVC, FEF25-75 and FEF in 60 children with acute asthma on admission and after 2, 14, 30 and 60 days. Group A received bronchodilators only (n = 20), group B received sodium cromoglycate (SCG) (n = 20) and group C received oral and/or inhaled corticosteroids (n = 20). Oral steroid treatment (2 mg/kg/day), given at the onset of the asthma attack, resulted in significant reduction in the ECP and EPX levels in all the children. However, these reduced ECP and EPX levels were not sustained in the children, even in those who continued on maintenance steroid treatment. Significant, but inconsistent, correlations between ECP, EPX with total eosinophil count, Percentage eosinophils and spirometry parameters were observed at the different time-points. Tryptase levels were normal in all subjects. There were no significant correlations between myeloperoxidase levels and the spirometry parameters or eosinophil parameters. Serial monitoring of ECP and EPX levels was found to be of some use in predicting clinical outcome in certain steroid-dependent asthmatics (group C) but of no value in the mild asthmatics (group A). While elevation of ECP, EPX and MPO in the serum of childhood asthmatics suggests ongoing inflammation and may inversely correlate with spirometry parameters in some patients, the relationship between these markers and airway function is not a simple one.

Airway function correlates with circulating eosinophil, but not mast cell, markers of inflammation in childhood asthma

Lung function tests, including forced expiratory volume in one second (FEV1), forced expiratory flow at 25-75% of vital capacity (FEF25-75%) and provocation concentrations of histamine which reduce FEV1 by 20% (PC20), are used as indicators of airway form and function in bronchial asthma. Recently, markers of eosinophil activation in bronchial lavage and serum have been suggested as a measure of eosinophil mediated inflammation in the airways. These include eosinophil cationic protein (ECP), eosinophil protein X (EPX) (also known as eosinophil derived neurotoxin) and eosinophil peroxidase (EPO). Similarly, serum tryptase has been used as a marker of mast cell activation in systemic anaphylaxis. We measured both sets of indices in a group of children with moderately severe asthma to assess the contribution of eosinophil and mast cell mediated events to airflow limitation and bronchial hyperresponsiveness. Forty-eight children aged 5-10 years had spirometric assessments, histamine challenges and blood sampling on the same occasion. After analysis of sera, the indices were compared. The eosinophil markers ECP and EPX correlated very well with each other. They showed a moderate negative correlation with PC20 for histamine. EPX was also found to negatively correlate with FEV1 and FEF25-75%. Serum tryptase levels showed no such correlates with airway function. These results suggest that serum markers of eosinophil activation correlate with airway function in childhood asthma, and may be of value in assessing the severity of the disease. It further supports the notion that childhood asthma has a similar immunopathology to that occurring in adults, with predominance of eosinophil mediated inflammation.

Urinary eosinophil protein X in children with atopic asthma: A useful marker of antiinflammatory treatment

BACKGROUND: Bronchial asthma is associated with elevated serum levels of eosinophil products, such as eosinophil protein X (EPX), but the occurrence in urine of this substance in patients with asthma has not previously been studied. OBJECTIVE: This study was performed to clarify whether increased amounts of eosinophil granulocyte proteins in urine and serum reflect ongoing asthmatic inflammation and whether decreasing values reflect successful treatment. METHODS: Twelve children with a median age of 12.5 years who had mild or moderate atopic asthma were studied for 3 months. At the time of inclusion in the study, treatment with inhaled budesonide was initiated. Nine children of the same age without atopic disease served as control subjects. Levels of EPX, eosinophil cationic protein (ECP), and myeloperoxidase in serum and in urine (urinary EPX) were determined at inclusion and then after 3 months of treatment. Spirometry was performed on the same occasions. RESULTS: At the time of inclusion, urinary EPX and serum ECP were significantly higher in children with atopic asthma than in the control subjects (mean, 116.4 vs 43.0 μg/mmol creatinine [p = 0.004] and 37.0 vs 14.8 μg/L [p = 0.004]). In the asthma group urinary EPX, as well as serum ECP, decreased significantly after 3 months of treatment with budesonide (116.4 to 68.4 μg/mmol creatinine [p = 0.005] and 37.0 to 24.0 μg/L [p = 0.04]). At the same time, peak expiratory flow values increased significantly in the children with asthma (76.0% to 87.8% of predicted value [p = 0.005]) but not in the control subjects (87.0% to 90.1%). In the asthma group the levels of myeloperoxidase were similar to those in the control group, both at inclusion and after 3 months. CONCLUSION: Increased urinary EPX and serum ECP levels seem to reflect active atopic asthma, whereas decreased levels after antiinflammatory treatment probably reflect normalization of airway inflammation, and indirectly, improved lung function. (J Allergy Clin Immunol 1996;97:1179-87.)

Ultrastructural and immunohistochemical studies on myocardial biopsies from a patient with eosinophilic endomyocarditis

Right ventricular endomyocardial biopsy specimens from a 13-year-old boy with hypereosinophilia were studied by light and electron microscopy using the EG2 monoclonal antibody, which recognizes a common epitope of eosinophil cationic protein and eosinophil protein-X. Although the endocardial layer was of normal thickness, many eosinophils, mononuclear cells, and free eosinophil granules were observed in the endocardium and in the vicinity of degenerated myocardial cells. Under electron microscopy, many of the specific granules in and out of eosinophils had lost their crystalloid internae and displayed reversed density, and there were many degranulated eosinophils with reduced number of granules. Immunohistochemically, large amounts of eosinophil cationic protein and protein-X were observed within cardiocytes when many of them were degenerated. Deposits of the proteins were also found in some small vessels. On electron microscopy, accumulations of gold particles, which bind to eosinophil cationic protein and protein-X, were seen in association with specific granules and on the myofilaments in both degenerated and normal-appearing cardiocytes. The presence of eosinophil cationic proteins within cardiocytes may play an important role in the pathogenesis of eosinophilic endomyocardial disease.

413 Urinary eosinophil protein X (EPX) in children with atopic asthma. A useful marker of antiinflammatory treatment

413 Urinary eosinophil protein X (EPX) in children with atopic asthma. A useful marker of antiinflammatory treatment

Inflammatory markers in childhood asthma.

The importance of airway inflammation in the pathogenesis of asthma is clearly established. Studies in adults as well as in children have led to the concept that asthma is a chronic inflammatory disease. Airway inflammation is found even in mild asthma. Bronchoconstriction and hyper-reactivity appear to be secondary to the release of inflammatory mediators. The changed view of the pathogenesis of asthma and current emphasis on anti-inflammatory treatment have raised a need for markers that reflect the inflammatory status in the airways. This is of special importance in paediatric practice because lung function tests are less easily performed in young children, and it is preferable to keep steroid doses as low as possible. The eosinophil granulocyte has a multitude of proinflammatory functions and plays a key role in the asthmatic inflammation. It secretes toxic proteins and produces cytokines, which have important roles in airway inflammation. Use of eosinophil granula proteins to monitor inflammation is now finding its place. Measurement of eosinophil cationic protein (ECP) seems to be a valuable complement to the recording of lung function. For paediatric use, measurement of urinary eosinophil protein X (EPX) is promising because it does not require blood sampling.

Eosinophil cationic protein(ECP) and eosinophil protein X (EXP) concentrations in serum and bronchial lavage fluid in asthma. effect of prednisolone treatment.

Eosinophil granule proteins may contribute to bronchial hyperresponsiveness in asthma. To measure eosinophil cationic protein (ECP) and eosinophil protein X (EPX) in serum and bronchial lavage fluid from 20 asthmatics and 16 control subjects. To assess the effect on these eosinophil proteins of corticosteroid treatment of asthma. To determine whether serum ECP and EPX measured weekly in a longitudinal study for 10 weeks reflected changes in lung function. Eosinophil granule proteins were measured by radioimmunoassay of bronchial wash (BW), bronchoalveolar lavage (BAL) and serum. Eosinophils were elevated in BAL (P < 0.01), BW (P < 0.01) and blood (P < 0.01) from asthmatics compared with control subjects. Eosinophils cationic protein concentration was significantly elevated in BAL (P < 0.05) and BW from asthmatics (P < 0.01) and EPX was increased in BAL (P < 0.05) and BW (P < 0.01). These changes were also reflected in elevated serum ECP (P < 0.01) and EPX (P < 0.01) concentrations in asthmatic subjects. There was no significant difference between subjects receiving prednisolone and the placebo group, but there was a fall in ECP in BW (P < 0.05) and serum (P < 0.01) and in EPX in BW (P < 0.01) and serum (P < 0.01) within the group receiving prednisolone. In the longitudinal study there was only a significant difference between ECP values associated with highest and lowest peak expiratory flow rate (PEFR) (P < 0.05). These data confirm a role for eosinophil activation in the airway in asthma pathogenesis, and add some support to the hypothesis that corticosteroids may inhibit eosinophil activation in asthma.

597 Eosinophils and clinical response to the therapy with IL-2 plus INF-α in patients with kidney cancer

In a group of 5 patients (pts.) affected by kidney cancer (3 of these reached a complete remission (CR), 2 reached a stabilization (S) of the disease), the treatment with low doses IL-2 s.c. plus IFN-α caused an increment of 11% (mean value) of eosinophils. The aim of our study is to evaluate if the eosinophils’ increment and their activation could have a correlation with the clinical response. We have assessed the following parameters: percentage and total number of eosinophils, serum ECP (Eosinophil cationic protein), serum EPX (Eosinophil protein X) before and during the treatment course. The comparison between the results of CR and S pts. showed a statistical significance only for these ECP values: ECP (μg/1) (basal serum level): S = (3697 ± 830) versus CR (1945 ± 77) P ± 0.028; basal ECP % /WBC: S = (2.06 ± 0.431) versus CR (0.51 ± 0.26) P = 0.01; serum ECP difference after therapy: S = −1280 vs. CR = −130 (P = 0.0024). Our preliminary data suggest that a stable serum level of ECP during the treatment could have a correlation with the good outcome of the therapy. A randomized controlled study is necessary to clarify the possible role of eosinophils and their basic proteins as mediators and/or predictive factors of the clinical response to IL-2 therapy.

Individual time-courses of ECP and EPX during allergen provocation tests in asthmatic children.

To study the time-course of eosinophil cationic protein (ECP) and eosinophil protein X (EPX) during bronchial allergen provocation, we investigated 32 asthmatic children sensitive to house-dust mites as well as 6 non-atopic young adult controls. In all subjects, allergen challenges were performed with house dust mite extracts of Dermatophagoides pteronys-sinus or Dermatophagoides farinae. Blood samples were taken at regular intervals during the 24-h observation period. The individual time-courses of ECP and EPX revealed different characteristic groups of patterns: (1) an isolated early serum peak of both mediators during or within the first 60 min after provocation (2) an early plus a late peak (3) an isolated late peak 12 h after provocation (4) an isolated late peak 24 h after provocation, and (5) no significant variation during the 24-h observation period. The early peak could be due to short-term changes in eosinophil activation, while late peaks may reflect eosinophil proliferation, recruitment, subsequent priming and enhancing of the propensity to release their proteins. ECP and EPX showed a corresponding parallel time-course in nearly all challenges, with EPX-concentration exceeding that of ECP. There was no correlation between ECP/EPX serum concentrations and clinical parameters such as lung function data. From our results we conclude that the striking groups of time-courses of ECP/EPX serum concentration indicate different uniform patterns of eosinophil activation during allergen challenge-but do not predict clinical outcome of provocation. The role of the eosinophil in early asthmatic reactions remains to be established in further studies.

311 SERUM LEVELS ECP AND EPX INCREASE DURING THE SEASON AND ARE ASSOCIATED TO BRONCHIAL HYPERREACTIVITY (BHR): Report from the Preventive Allergy Treatment study (PAT)

Eosinophil cationic protein (ECP) and eosinophil protein X (EPX) are markers of allergic inflammation. PEF-variability is a diagnostic criterion for asthma. We investigated the relationship between asthma and mediators in serum of 28 children with birch (B; n=12) and/or grass (n-B; n=16) pollinosis followed for one year. Asthma was graded using a visual analogue scale, methacholine bronchial provocation tests (MBPT) were done and PEF variability was recorded, during the birch grass and winter seasons. Serum was drawn before the birch season and during the seasons. s-ECP and s-EPX were determined by a sandwich RIA. In B, ECP and EPX, levels were higher during than before and after the seasons B and n-B (p< 0.02). PEF variability vas higher in B (p < 0.01) but not n-B during season. MBPT conc. were lower for B AND N-B during than after the season (p <0.01). ECP was higher in children with than without increased MBPT sensitivity (<1500 μg)(p <0.05) during the grass season, whereas EPX was higher in the same children (p <0.05) during the birch season. No correlation was found between other parameters, probably due to non-awareness of asthma among children and parents. Thus, in groups of patients with lowered threshold in MBPT, ECP and EPX increased during the season, but was not associated to the degree of asthma or BHR.

310 SERUM LEVELS OF ECP AND EPX ARE NOT CORRELATED TO BRONCHIAL HYPERREACTIVITY (BHR) AS MEASURED BY METHACHOLINE BRONCHIAL PROVOCATION TEST (MBPT): Report from the Preventive Allergy Treatment study (PAT)

Eosinophil cationic protein (ECP) and eosinophil protein X (EPX) are markers of allergic inflammation. MBPT is a marker for BHR. We investigated the relationship between asthma and mediators in serum of 28 children, 7-13 y with birch and (B; n=12) or grass (n-B; n=16) pollinosis, included in the sc. PAT-study, were followed for one year. MBPT was done and blood was drawn on the day of MBPT during the birch, grass and winter seasons. s-ECP and s-EPX were determined by a sandwich RIA. MBPT and PEF variability did not correlate to s-ECP and s-EPX (any season). In the winter season, most children were sensitive to methacholine but had normal levels of s-ECP and s-EPX. We interpret this finding that inflammation was not present but BHR persisted in the winter season. Thus, elevated s-ECP and s-EPX do not reflect BHR / asthma but can still be used as markers of (bronchial) inflammation, which will have theraputic impact.

Eosinophil activity in bronchial asthma.

Eosinophil cationic proteins (ECP), eosinophil protein X (EPX), eosinophil peroxidase (EPO), eosinophil-derived neurotoxin (EDN), and the major basic protein (MBP) have been identified as potent cytotoxic secretory proteins in degranulated eosinophils. Studies of these proteins have clearly indicated a role for eosinophil-derived proteins in inflammatory diseases, including asthmatic inflammation. It has been shown that higher levels of ECP in asthmatics were concomitant with severity of the disease and related to efficacy of treatment of asthma. Proper handling of blood serum for measurement of eosinophil and neutrophil markers including myeloperoxidase (MPO) is essential. Moreover, the time factor in ECP measurement is an important variable because ECP levels differ in chronic stable asthma, during acute exacerbations of asthma, and after allergen challenge. Simultaneous measurements of ECP and MPO may prove to be useful in determining various causes of asthma exacerbations, helping to discriminate between allergic etiologies wherein ECP levels may increase versus infectious etiologies wherein MPO levels may increase. Monitoring the efficacy of anti-inflammatory therapies such as corticosteroids may be enhanced by serial determinations of ECP levels in the blood.

Twenty‐four‐hour time course of eosinophil granule proteins ECP and EPX during bronchial allergen challenges in serum of asthmatic children

To study in vivo monitoring variables for bronchial allergen challenges, we investigated the time course of the eosinophil granule proteins, eosinophil cationic protein (ECP) and eosinophil protein X (EPX) after allergen provocation in serum. Thirty-two asthmatic children sensitive to house-dust mites and six healthy young adult controls were challenged by bronchial allergen provocations with Dermatophagoides pteronyssinus and D. farinae. Blood samples were taken at regular intervals up to 24 h. Base-line concentrations of ECP (P < 0.004), EPX (P < 0.002), and eosinophils (P < 0.001) were found to be increased in asthmatic children, as compared with healthy controls. ECP and EPX concentrations showed a uniform pattern with two characteristic features: 1) a rapid increase for both mediators up to 30 min after provocation over base-line values (P < 0.0001 and P < 0.001), followed by a rapid decrease nearly to base-line values in the next 30 min; and 2) a steady increase for ECP and EPX up to 10 h (P < 0.02 and P < 0.01), and even higher levels at 24 h, after challenge (P < 0.002 and P < 0.003). We conclude that although eosinophils are activated in asthmatic children after bronchial allergen challenge, ECP and EPX concentrations are not suitable monitoring variables. Base-line eosinophils seem to predict the occurrence of a late-phase asthmatic reaction after allergen provocation.