Peak expiratory flow rate (PEF) and serum eosinophil cationic protein (ECP) changes in nocturnal asthmatics

We have investigated the serum ECP and peak expiratory flow rate in 20 patients with nocturnal asthma. Changes of PEF were measured in every 2 hours around the whole day, and the blood samples were obtained at 4:00 and 16:00 to measure the serum ECP level and the peripheral Eo numbers. In addition, 10 asthmatics as well as normal subjects received methacholine challenge at 4:00 and 16:00. It was found that the PEF reached the lowest point at 4:00 and obviously less than that at 16:00 (187.50 +/- 120.31 L/min vs 313.00 +/- 108.14 L/min, P < 0.05), that the airway reactivity at 4:00 was significantly higher than at 16:00 (P < 0.05) and the difference of MCH-PC20 between the two time points was 0.34 +/- 0.31 mg/ml, that the serum ECP level at 4:00 was obviously higher than that at 16:00 (11.14 +/- 7.40 micrograms/ml vs 5.49 +/- 4.12 micrograms/ml, P < 0.05). The change rate of PEF markedly related to the change of serum ECP between the two time points (r = 0.61, P < 0.05). The findings suggested that the activation of Eo and its release of ECP might be effect of the circadian-rhythmic change of pulmonary functions in nocturnal asthma.     

Comparison of basophil histamine release, eosinophil cationic protein and non-specific airway responsiveness between mite-sensitive asthmatic and non-asthmatic children and non-allergic controls

To understand the relevance of allergy to the development of asthma in children, we examined basophil histamine release (HR) with Df antigen, blood eosinophil counts, serum eosinophil cationic protein (ECP) levels, and bronchial responsiveness to methacholine (PC20) in three groups of children, including 36 asthmatics with high RAST titre for Df (group 1), 36 non-asthmatics with similarly high RAST titre for Df (group 2) and 21 non-asthmatics with negative RAST titre for Df (group 3). The amount of Df antigen inducing 50% HR from basophils did not vary significantly between group 1 and 2 (P > 0.05), while none of the cells responded to higher concentrations of Df in group 3. The mean number of blood eosinophils and level of serum ECP were highest in group 1, and lowest in group 3, with group 2 being intermediate, and the differences were significant between all three groups (P < 0.01). The mean PC20 value was the lowest in group 1, intermediate in group 2, and the highest in group 3, and the differences were significant between all three groups (P < 0.01). While correlation studies showed that PC20 values of group 2 subjects significantly correlated with their eosinophil numbers (r = -0.48, P < 0.01) and ECP levels (r = -0.49, P < 0.01), such correlations were not found in group 1 subjects. These results suggest that the degree of the eosinophilic inflammation caused by the allergic reaction to mites is an important factor in determining the clinical expression of asthma in atopic subjects.     

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.     

Total blood eosinophils, serum eosinophil cationic protein and eosinophil protein X in childhood asthma: relation to disease status and therapy

Blood eosinophils, and serum levels of the eosinophil proteins, eosinophil cationic protein (ECP) and eosinophil protein X (EPX) were measured in childhood asthma. Seventeen patients mean age 11.9 years who were symptomatic with asthma, were enrolled in a study examining the eosinophil counts and eosinophil proteins at the onset of study and after treatment in relation to changes in their baseline forced expiratory volume at 1 second (FEV1) and % predicted FEV1. The patients with symptomatic asthma were compared with 17 patients mean age 12.0 years with asymptomatic asthma maintained on daily inhaled steroid and 13 patients, mean age 12.0 years, without asthma but with urticaria who served as non-asthma controls. Patients with symptomatic asthma did not have significantly higher initial eosinophil counts compared with those with asymptomatic asthma (0.43 x 10(9)/l vs 0.26 x 10(9)/l, P = 0.09) but had higher serum ECP levels (28.9 micrograms/l vs 18.5 micrograms/l). Both asthma patient groups had significantly higher serum ECP levels (P < 0.01) than the controls (9.8 micrograms/l). After therapy consisting of increased dose of inhaled steroids and/or oral steroids, patients in the symptomatic asthma group demonstrated a significant rise in FEV1 (1.67 l/sec at Visit 1 vs 2.08 l/sec at Visit 2, P < 0.001). A similar rise was seen for % predicted FEV1.(ABSTRACT TRUNCATED AT 250 WORDS)     

Flow cytometric analysis for the activation of peripheral immunoregulatory cells from patients with bronchial asthma

By use of flow cytometry, we have investigated intracellular activated eosinophil cationic protein (ECP) in eosinophils and mitogen-induced cytokine production of T cells in peripheral blood from children with acute severe asthma. In addition, we measured ECP releasability (serum ECP/lysate ECP) as a maker of activated eosinophils. The monoclonal antibody EG2 (anti-activated ECP/EPX antibody) was used for measuring the amount of intracellular activated ECP. ECP releasability and mean fluorescence intensity (MFI) values of EG2-positive eosinophils increased at the time of asthmatic attack and reduced after treatment with improvement in peak expiratory flow. Furthermore, the frequency of T cells which produced IL-4, IL-5 and IFN-gamma stimulated with phorbol myristate acetate and ionomycin increased and reduced in parallel with MFI of EG2-positive cells. These observations suggest that flow cytometric analysis for intracellular ECP and mitogen-induced cytokine production reflects the activation of T cells in bronchial mucosa, and is useful for monitoring airway inflammation in bronchial asthma.     

Lixelle adsorbent to remove inflammatory cytokines

A 29-year-old man developed atopic bronchial asthma in association with eosinophilia and hyperimmunoglobulinemia E (hyper-IgE). A biopsy specimen from an inguinal lymph node showed changes consistent with Kimura's disease. IPD-1151T (suplatast tosilate), an anti-allergy drug, attenuated eosinophilia and hyper-IgE as well as the serum level of eosinophil cationic protein (ECP). The drug, however, did not affect the positivity for specific IgE antibodies against common allergens or the bronchial hyperresponsiveness to acetylcholine. Interleukin (IL)-2, IL-4, IL-5, interferon (IFN)-gamma, and tumor necrosis factor (TNF)-alpha were measured to be undetectable in serum before or during therapy. However, the expressions of mRNAs for IL-2, IL-4, IL-5, IFN-gamma, and TNF-alpha in peripheral blood T-lymphocytes and the expression of IL-5 mRNA in peripheral blood eosinophils were detected before and during therapy, which were unchanged by therapy with IPD-1151T. The present results suggest that different mechanisms other than the predominance of type 2 helper (T(H2))-like T-lymphocytes may underlie Kimura's disease and atopic bronchial asthma regarding the findings of eosinophilia and hyper-IgE, which could be modulated by IPD-1151T.     

The effect of theophylline on blood and sputum eosinophils and ECP in patients with bronchial asthma

It was recently reported that theophylline has an anti-inflammatory and bronchodilating effect on bronchial asthma. Accordingly, to examine the anti-inflammatory effect of theophylline on asthma, especially its effect on eosinophil activation, a sustained-release theophylline preparation (Theolong) was administered (daily dose: 400 mg) to 18 patients with mild to moderate bronchial asthma. This was done in order to study the preparation's effects on lung function, blood and sputum eosinophils and ECP four weeks pre- and post-administration. Lung function was determined by spirometry and sputum by induced sputum. Blood and sputum ECP levels were determined using an ECP RIA kit. In lung function, there were no differences in vital capacity (VC) or in forced expiratory volume 1 s (FEV 1.0) pre- and post-administration. There were also no differences in the number of blood and sputum eosinophils, but serum and sputum ECP levels decreased. Theophylline is thus expected to exert an inhibitory effect on eosinophil activation and it is suggested as an effective therapeutic drug for bronchial asthma.     

Eosinophil markers in seasonal allergic rhinitis. Intranasal fluticasone propionate inhibits local and systemic increases during the pollen season

BACKGROUND: The purpose was to study activation markers of the eosinophil granulocytes in seasonal allergic rhinitis, and the impact of topical steroid therapy thereupon. METHODS: Sixty-three rhinitis patients with monoallergy to grass were examined before and at peak pollen season. Blood eosinophil count, eosinophil cationic protein (ECP), and eosinophil peroxidase (EPO) in serum and nasal lavage fluid were measured. During the season, patients were randomized to treatment with intranasal fluticasone propionate 0.1 mg o.d. (n=26), 0.2 mg o.d. (n=25), or placebo (n=12). Six healthy persons served as controls. RESULTS: During the season, all parameters, except nasal lavage ECP, increased in the placebo group (P<0.001-P<0.05). Significant differences were seen between the steroid groups and the placebo group for all parameters (P<0.001-P<0.05). Higher eosinophil count (P<0.05), serum EPO (P<0.02), and nasal lavage EPO (P<0.05) were found in patients before season than in controls. The following winter, 44 patients returned for repeated measurement. Lower levels of nasal lavage EPO were observed for patients than levels at the beginning of the season (P<0.0001). CONCLUSIONS: Intranasal fluticasone propionate reduced inflammation of the nasal mucosa, demonstrated locally by nasal lavage ECP and EPO, and systemically by blood eosinophils, serum ECP, and serum EPO. EPO seemed more sensitive than ECP as indicator of allergic inflammation. EPO demonstrated some perennial eosinophil activity in hay fever patients, increasing locally during spring.     

Serum eosinophil cationic protein in infants during first wheezing episode

We measured serum ECP levels in infants during first wheezing episode. Serum ECP in these infants are significantly higher than in control infants, although much higher in children with asthma. Serum ECP in these infants with high serum IgE and/or positive RAST score are higher than in infants with normal serum IgE and negative RAST score. In children with bronchial asthma serum ECP is correlated with peripheral eosinophil counts, but in infants during first wheezing episode serum ECP is often elevated not associated with increased peripheral eosinophil counts. These suggest that activated eosinophils could be responsible for bronchoconstriction in wheezing patients with atopic diathesis even in very early phase and that these eosinophilic inflammations could contribute to formation of increased airway reactivity and bronchial asthma.     

Long-lasting sensitization to food during the first two years precedes allergic airway disease. The MAS Study Group, Germany

Measurement of eosinophil percentages and ECP concentration in induced sputum may be useful in the diagnosis and assessment of the variability of airway inflammation in bronchial asthma (BA). To evaluate the usefulness of sputum eosinophil counts and ECP concentrations in the diagnosis of BA, we measured these parameters in 68 patients with respiratory complaints. In addition, we followed-up 14 BA patients with variable airflow limitation for 45.4 +/- 10.4 days. The BA group (n = 41) showed a higher percentage of sputum eosinophilia (24.5 +/- 7.6 vs. 2.2 +/- 2.9%, p < 0.001) and a higher level of sputum ECP (198.2 vs. 90.6 micrograms/L, p < 0.05) than those in the nonasthmatic group (NBA, n = 27). The sensitivity and specificity of sputum eosinophilia (> or = 5%) for the diagnosis of BA were 85.4% and 92.6%, respectively, which were better than the sensitivity (68.3%) and specificity (55.5%) of the increased level of sputum ECP (> or = 100 micrograms/L). Patients with moderate-to-severe persistent BA had a higher percentage of sputum eosinophil (n = 23, 34.6 +/- 10.6%) than those of mild persistent BA (n = 18, 10.7 +/- 5.2%, p < 0.01), but we could not find significant difference in ECP levels between mild persistent and moderate-to-severe persistent asthma. The percentages of sputum eosinophilia showed a moderate correlation with ECP (r = 0.4358, p < 0.01) and with the peak expiratory flow rate (PFR, r = -0.4746, p < 0.01) but sputum ECP did not correlate with PFR. In 14 BA patients who were followed, there was a relationship between changes of PFR and the percentage of sputum eosinophil (r = -0.7238, p < 0.01), but the change of PFR did not correlate with the change of sputum ECP levels. These results suggest that the sputum eosinophil count and sputum ECP level could be helpful in the diagnosis of BA, but that sputum ECP is not satisfactory for the assessment of variability of airway eosinophilic inflammation during the initial anti-inflammatory management of BA.     

Serum levels of eosinophil cationic protein and eosinophil protein x in pollen atopic patients with stable asthma and its relation with bronchial hyperresponsiveness

Eosinophils are important effector cells in allergic inflammation described in allergic rhinitis (AR) and allergic bronchial asthma (BA). During the pollen season serum levels of eosinophil cationic protein (ECP) and eosinophil X protein/eosinophil-derived neurotoxin (EPX/EDN) are increased in BA. The aim of the present study was to evaluate the serum levels of ECP and EPC in pollen atopic patients with AR and BA during the winter. 92 patients were studied. They were divided into three groups: I 29 patients with AR, II 51 patients with BA and III 12 healthy subjects. Allergic rhinitis and bronchial asthma were diagnosed by routine clinical tests: clinical history, skin tests, total IgE and specific IgE. In addition ECP and EPX were determined in serum. All patients were asymptomatic, stable and without medical treatment. Methacholine challenge test (MCT) was performed in all patients. MCT were positive in 4 patients of group I and 45 patients of group II. ECP levels (ug/l) were: 21 (I), 24 (II) and 7 (III). EPX levels (ug/l) were 35 (I), 45 (II) and 21 (III). Statistical differences (p < 0.01) were observed both in ECP and EPX levels in patients with MCT positive in relation to patients with MCT negative, and in allergic patients (I and II) in comparison with the healthy subjects (III) (p < 0.01). ECP and EPX serum levels are increased in patients with a positive MCT in the winter, out of the pollen season, when patients are asymptomatic, stable and without treatment. This fact suggests that eosinophils play an important role in the pathogenesis of bronchial asthma.     

Son of sevenless binds to the SH3 domain of src-type tyrosine kinase

Measurement of serum levels of ECP has been widely used for monitoring airway inflammation in bronchial asthma and recently been applied to measure anti-inflammatory effect of theophylline. However, reduced levels of ECP in theophylline-administered patients may express not only in vivo effect of theophylline but also in vitro effect after sampling because serum ECP measures released ECP during coagulation and theophylline has been reported to inhibit eosinophil degranulation in vitro. In order to answer the question, we tested whether theophylline added to blood after sampling reduces measured levels of serum ECP. Various concentrations of theophylline were added to SST tube, to which venous blood from atopic patients was drawn. Serum was, then, obtained by centrifugation after 15 min to 6 hours of incubation at room temperature. Theophylline significantly reduced serum ECP in a concentration-dependent manner. Percent reduction of ECP levels at 1 hour of incubation were 11.9%, 18.7%, 22.8%, and 51.7% at theophylline levels of 5, 12.5, 22.5, and 120 micrograms/ml, respectively. Kinetics of serum ECP release was also inhibited in the presence of theophylline. These results suggest that in vitro effect of theophylline on serum ECP levels should be considered when data of serum ECP in patients who take theophylline are interpreted.     

Serum levels of tumor necrosis factor alpha and soluble tumor necrosis factor-receptor I in asthmatic patients and patients with chronic respiratory tract infection

In order to investigate the role of tumor necrosis factor alpha (TNF-alpha) in bronchial asthma or chronic respiratory infection, we measured serum levels of TNF-alpha and serum soluble tumor necrosis factor-receptor I (sTNF-RI) in asthmatic patients (n = 11) and patients (n = 10) with chronic respiratory infection by Pseudomonas aeruginosa. We also measured serum levels of eosinophil cationic protein (ECP) in the asthmatic patients. The serum levels of TNF-alpha in the asthmatic patients, patients with chronic respiratory tract infection and control group were 2.864 +/- 0.719 g/ml, 2.564-1.384 pg/ml and 0.681 +/- 0.453 pg/ml respectively. The levels of the former two groups were higher than those of the control group (p < 0.05). The serum levels of sTNF-RI in the asthmatic patients, the patients with chronic respiratory tract infection, and the control group was 758 +/- 268 pg/ml, 999 +/- 242 pg/ml and 909 +/- 268 pg/ml respectively. The levels of the former two groups did not differ significantly from those of the control group. There were significant correlations between TNF-alpha and sTNF-RI in the control group and in the patients with chronic respiratory tract infection, but there was no significant correlation in the asthmatic patients. In the asthmatic patients. TNF-alpha/s TNF-RI correlated with %best of PEF (r = 0.691, n = 9, p 0.0373). The serum levels of ECP correlated significantly with TNF-alpha, but not with sTNF-RI in the asthmatic patients. It is suggested that TNF-alpha plays a significant role in the pathogenesis of bronchial asthma and chronic respiratory tract infection as a factor causing inflammation and that the increase of TNF-alpha/sTNF-RI reflects the activation of eosinophil functions in an asthmatic attack.     

The correlational analysis assessment of exacerbation in bronchial asthma and treatment efficacy

Blood and sputum eosinophils, eosinophilic cation protein (ECP) in the serum and OPV1 were measured in 30 patients with atopic bronchial asthma (BA) of moderate severity showing eosinophilia at the beginning and the end of treatment week 1 and 4, respectively. In exacerbation of BA relative number of blood eosinophils averaged 10.4 + -1.4%, sputum 35.2 + -5.6%. Serum concentration of ECP, OPV1, IgE averaged 42.6% + -11.9%, 66.8 + -6.3%, 753.7 + -114 IU/ml, respectively. In exacerbation a strong correlation is noted between relative number of eosinophils in the blood and sputum, between the levels of IgE and ECP. At the end of the treatment OPV1 was higher while ECP level in the serum went down. Reduced eosinophilia in the blood and sputum correlated with OPV1 increment. In BA patients with high blood and sputum eosinophilia function of the lungs depends on eosinophilic number, while in normalization of blood eosinophil concentration and in a sharp fall of sputum eosinophil number OPV1 changes correlation with changes in ECP in the course of treatment. A close correlation between changes in eosinophil count, FVD indices, IgE and ECP levels during the treatment indicate relief of inflammation in BA patients.     

Monitoring eosinophil activation and liver function after liver transplantation

BACKGROUND: Portal tract eosinophil infiltration and an increase in the blood eosinophil count (EOS) have been shown to be specific markers of liver allograft rejection. The graft eosinophil infiltration is associated with the local release of eosinophil cationic protein. Therefore, serum eosinophil cationic protein concentration (ECP) is a potential marker for acute allograft rejection. We investigated the chronological relationship among and diagnostic value of serial changes in EOS, ECP, and liver function tests (LFTs) following liver transplantation. METHODS: EOS, ECP, serum alpha-glutathione S-transferase concentration, and conventional LFTs were measured in serial samples collected over the first 3 postoperative months following 58 liver transplants. The diagnostic potential of each test, alone or in combination, was reviewed over the entire follow-up period. RESULTS: EOS and ECP increased at a median period of 3.5 and 4 days, respectively, before the diagnosis of acute rejection, and this increase was significantly earlier than the corresponding changes in LFTs (P<0.05). There was a significant correlation between the day of the first increase in EOS and alpha-glutathione S-transferase (rs=0.535; P=0.009) and EOS and alanine transaminase (rs=0.629; P=0.004). The optimum combination of tests for the diagnosis of acute rejection was an increase in both EOS and GST with a predictive efficiency of 84%. CONCLUSIONS: Increases in EOS and ECP are early indicators of acute liver allograft rejection and precede evidence of hepatocellular damage. However, an increase in ECP was also frequently associated with infection. Therefore, we recommend the regular monitoring of EOS in conjunction with routine LFTs after liver transplantation as an aid to the early diagnosis of acute rejection.     

Chemotherapy as a part of each treatment fraction in a twice-a-day hyperfractionated schedule: a new chemoradiotherapy approach for advanced head and neck cancer

In allergic asthma, there is convincing evidence that changes in eosinophil and lymphocyte state of activation in blood may reflect disease activity. We evaluated whether simple blood eosinophil or lymphocyte counts in atopic children with asthma could reflect the degree of allergic sensitization. Seventy-six asthmatic children, sensitized to house dust mites (HDM), in stable conditions at the time of the study, and 53 sex- and age-matched controls (CTR) were studied. As compared to CTR, allergic patients showed higher eosinophil numbers and percentages (p < 0.001) but similar lymphocyte numbers and proportions (p > 0.1). Both in CTR and in allergic patients, eosinophil counts did not correlate with lymphocyte counts (p > 0.05; each comparison) but positive correlations were observed between eosinophil numbers and percentages and paper radio immunosorbent test (PRIST) levels or radio-allergo sorbent test (RAST) classes (p < 0.001; each comparison). When allergic asthmatic individuals were subdivided according to their age into two subgroups (Gr), no differences were found in eosinophil and lymphocyte counts and in PRIST levels and RAST values between Gr1 (< or =5 years old [preschool children]) and Gr2 (>5 years old [school children]) (p > 0.05; each comparison). Interestingly, although positive correlations between eosinophil counts and PRIST levels were found in both subgroups (p < 0.05; each comparison), only in Gr2 did eosinophil counts correlate positively with RAST classes (p < 0.001). No correlations between lymphocyte counts and PRIST levels or RAST classes were demonstrated (p > 0.05; each comparison). These data suggest that although blood eosinophilia was similar in preschool and in allergic asthmatic school children sensitized to HDM, only in the oldest children did blood eosinophil counts appear to be related to the degree of HDM-specific sensitization.     

Corticosteroid reversibility in COPD is related to features of asthma

Eosinophilic inflammation has been observed in the airways of patients with chronic obstructive pulmonary disease (COPD). A subset of patients clinically diagnosed as having COPD show a reversibility of airflow obstruction when treated with corticosteroids, and may consist of patients with features of asthma including reticular basement membrane thickening and eosinophilic inflammation. Twenty-five unselected patients clinically diagnosed as having COPD received a daily oral dose of 1.5 mg/kg body weight of prednisolone for 15 d to assess the relationships between the functional response to corticosteroids and the presence of features of asthma. Eosinophilic inflammation was characterized before the course of corticosteroid therapy by enumerating eosinophils in peripheral blood, bronchoalveolar lavage fluid (BALF), and bronchial biopsies, using EG2 monoclonal antibody, and by measurement of eosinophil cationic protein (ECP) in BALF. A response to treatment was defined by an increase in FEV1 of at least 12% from baseline values and an absolute value of 200 ml measured at the end of the treatment. Twelve of 25 patients responded to the treatment. By comparison with nonresponders, responders had a significantly larger number of eosinophils (p < 0.015), and higher levels of ECP (p = 0.013) in their BALF. The responders had a thicker reticular basement membrane than the nonresponders (p < 0.04). These results indicate that a response to prednisolone in patients diagnosed as having COPD might occur more readily in a subset of patients presenting with features of asthma.     

Biliary excretion in persons with low blood glutathione levels

To examine their possible predictive value for the development of asthma, the serum concentration of eosinophil cationic protein (ECP) and the total eosinophil count were measured at admission in 25 children aged 1-17 months hospitalized for their first episode of bronchiolitis. After an average of three years the parents of 23 index patients answered a questionnaire to determine development of asthma. Eight children were defined as having asthma at follow-up based on at least three episodes of wheezing. The remaining 15 children had experienced only one or two episodes of wheezing, and all of these children had been wheeze free for the last year. The serum concentrations of ECP were similar in children who subsequently developed asthma (8.0 microg/l; 3.6 to 14.2 (median; quartiles)) and in those who did not (12 microg/l; 4.5 to 16.8). Moreover, the total eosinophil counts were similar in asthmatic (0.10 x 10(9)/l; 0.04 to 0.20) and non-asthmatic patients (0.09 x 10(9)/l; 0.02 to 0.13). In conclusion, our study suggest that neither the serum concentration of ECP nor the total eosinophil count can predict the development of asthma when measured in children admitted for their first episode of bronchiolitis, but larger studies need to be carried out to confirm these results.     

Interleukin-5 expression in the bone marrow of sensitized Balb/c mice after allergen challenge

Interleukin-5 (IL-5) is a potent eosinophilopoietic factor implicated in the chronic inflammatory cell accumulation accompanying bronchial asthma. However, its role in stimulating eosinophil differentiation within the bone marrow following allergen exposure remains to be elucidated. The aims of our study were to determine the expression of IL-5 within the bone marrow of sensitized and control mice after allergen exposure, and to investigate the cellular phenotype of IL-5-producing cells. Sensitized Balb/c mice were challenged with either ovalbumin (OVA) or sterile saline. After 6 h, the mice were exsanguinated and the bone marrow prepared for cytospins. Bone marrow-derived cells from OVA-sensitized mice exhibited an increase in IL-5 immunoreactivity and mRNA compared with those from nonsensitized control mice (p < 0. 05). After allergen challenge, there was a further increase in IL-5 expression (p < 0.05) within the bone marrow. Both sensitization and allergen challenge resulted in an increase in the number of cells expressing major basic protein (MBP) (p < 0.05). In nonsensitized mice, the IL-5 mRNA was expressed predominantly by CD34-positive (CD34+) progenitor cells. Following sensitization and allergen challenge, CD3-positive (CD3+) T lymphocytes were the major source of this cytokine. These results demonstrate the presence of IL-5 within the bone marrow of normal Balb/c mice. After sensitization and allergen challenge, the increase in IL-5-producing cells within the bone marrow is attributed by T lymphocytes.