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

Asthma

Asthma has been recognized as a disease since the earliest times. In the Corpus Hippocraticum, Hippocrates used the term “ασθμα” to indicate any form of breathing difficulty manifesting itself by panting. Aretaeus of Cappadocia, a well-known Greek physician (second century A.D.), is credited with providing the first detailed description of an asthma attack [13], and to Celsus it was a disease with wheezing and noisy, violent breathing. In the history of Rome, we find many members of the Julio-Claudian family affected with probable atopic respiratory disorders: Caesar Augustus suffered from bronchoconstriction, seasonal rhinitis as well as a highly pruritic skin disease. Claudius suffered from rhinoconjunctivitis and Britannicus was allergic to horse dander [529]. Maimonides (1136–1204) warned that to neglect treatment of asthma could prove fatal, whereas until the 19th century, European scholars defined it as “nervous asthma,” a term that was given to mean a defect of conductivity of the ninth pair of cranial nerves.

Bronchial responsiveness to methacholine and adenosine 5'-monophosphate in young children with asthma: their relationship with blood eosinophils and serum eosinophil cationic protein

BACKGROUND

Bronchial hyperresponsiveness is a characteristic feature of asthma, and is usually measured by bronchial challenges using direct or indirect stimuli. Blood eosinophil numbers and serum levels of eosinophil cationic protein (ECP) are considered as indirect measures of airway inflammation in asthma. The aim of this study was to investigate whether bronchial responsiveness to adenosine 5'-monophosphate (AMP) is more closely associated with blood eosinophil markers, compared with that to methacholine, in young children with asthma.

METHODS

Methacholine and AMP bronchial challenges were performed in 4- to 6-year-old children with asthma (n = 77) and in healthy controls (n = 32), using a modified auscultation method. The end-point was defined as the appearance of wheezing and/or oxygen desaturation. The peripheral blood eosinophil counts and serum ECP concentrations were determined in each subject.

RESULTS

A positive response to methacholine (end-point concentration < or =8mg/ml) and to AMP (end-point concentration < or =200 mg/ml) was observed in 74 (96.1%) and 66 asthmatic children (85.7%), respectively. A majority of controls was unresponsive to both challenges. In the asthma group, there was no significant correlation between methacholine end-point concentration and the eosinophil counts (r = -0.111, P = 0.337) or serum ECP levels (r = -0.126, P = 0.274). In contrast, AMP end-point concentration correlated significantly with the eosinophil counts (r = -0.372, P = 0.001) and with serum ECP levels (r = -0.371, P = 0.001).

CONCLUSIONS

Our results suggest that bronchial responsiveness to AMP is more closely related to airway inflammation, compared with that to methacholine, and support the potential usefulness of AMP challenges in detecting inflammatory changes in young children with asthma.

Which factors predict success after discontinuation of inhaled budesonide therapy in children with asthma?

Urinary eosinophil protein X (UEPX) concentration, lung function, and nonspecific bronchial hyperreactivity were determined in 40 asthmatic children (asymptomatic for 6.4 +/- 3.0 months) (mean age 9.8 +/- 2.9 years) receiving inhaled budesonide, in order to establish whether measurement of these parameters is useful in determining discontinuation of inhaled corticosteroid therapy. After the discontinuation of therapy, patients were asked to come to the Outpatient Clinic if symptoms recurred and did not respond to beta2 mimetic usage in 24 hr. Otherwise they were to be seen 2-3 months later for a follow-up visit. UEPX concentration was determined and spirometry was performed on this visit. While UEPX concentrations had increased (p < 0.0001), FEV1, FEF 25-75 and PEF had decreased significantly 2.3 +/- 0.53 months after the cessation of inhaled budesonide therapy in all children (p = 0.004, p = 0.02, p = 0.02, respectively). Due to clinical deterioration, inhaled corticosteroid therapy had to be restarted in 19 (48%) of the children (Group I), while the remaining 21 (52%) (Group II) continued to be asymptomatic during the 2.3 +/- 0.5 months follow-up period. Although the initial UEPX concentrations, spirometer variables, and methacholine PC20 values of these two groups were not statistically different, the duration of clinical remission before discontinuation of budesonide prophylaxis was significantly longer in group II (p = 0.0037). We concluded that, in determining discontinuation of inhaled corticosteroid prophylaxis, duration of clinical remission seems to be a more useful criterion than measurement of UEPX levels, lung function test, and assessment of bronchial hyperreactivity.

IL-10 reduces Th2 cytokine production and eosinophilia but augments airway reactivity in allergic mice

We investigated the effects of interleukin (IL)-10 administration on allergen-induced Th2 cytokine production, eosinophilic inflammation, and airway reactivity. Mice were sensitized by intraperitoneal injection of ragweed (RW) adsorbed to Alum and challenged by intratracheal instillation of the allergen. Sensitization and challenge with RW increased concentrations of IL-10 in bronchoalveolar lavage (BAL) fluid from undetectable levels to 60 pg/ml over 72 h. Intratracheal instillation of 25 ng of recombinant murine IL-10 at the time of RW challenge further elevated BAL fluid IL-10 concentration to 440 pg/ml but decreased BAL fluid IL-4, IL-5, and interferon-gamma levels by 40-85% and eosinophil numbers by 70% (P < 0.0001). Unexpectedly, the same IL-10 treatment increased airway reactivity to methacholine in spontaneously breathing mice that had been sensitized and challenged with RW (P < 0.001). IL-10 treatment in naive animals or RW-sensitized mice challenged with PBS failed to increase airway reactivity, demonstrating that IL-10 induces an increase in airway reactivity only when it is administered in conjunction with allergic sensitization and challenge. The results demonstrate that IL-10 reduces Th2 cytokine levels and eosinophilic inflammation but augments airway hyperreactivity. Thus, despite its potent anti-inflammatory activity, IL-10 could contribute to the decline in pulmonary function observed in asthma.

Serum eosinophil cationic protein and bronchial responsiveness in pediatric and adolescent asthma patients

BACKGROUND

Serum eosinophil cationic protein (ECP) has been promoted as a marker of inflammatory activity in bronchial asthma. Bronchial responsiveness, measured either by inhaling pharmacologically active substances such as histamine or methacholine, or by applying physical stimuli such as the hyperventilation of cold dry air, is also considered to be an indirect marker of bronchial inflammation.

OBJECTIVES

In this study, we investigated the possible relationship between serum ECP and bronchial responsiveness to both cold dry air and histamine in presently symptom- and medication-free pediatric and adolescent asthma patients.

SUBJECTS

Thirty-six children and adolescents with atopic asthma were studied.

METHODS

On 2 consecutive days, bronchial responsiveness was assessed nonpharmacologically by cold dry air and pharmacologically by histamine in random order. Blood samples for determination of ECP were collected before each challenge.

RESULTS

Serum ECP levels correlated with neither cold dry air-induced changes in FEV1 nor the provocation concentrations of histamine causing a 20% fall in FEV1. Subjects with bronchial hyperresponsiveness to cold dry air and histamine had somewhat higher levels of serum ECP than subjects with normal responses, but these differences were insignificant.

CONCLUSIONS

Our results indicate a lack of relationship both between serum ECP and bronchial responsiveness to cold dry air and between serum ECP and bronchial responsiveness to histamine.

Serum eosinophil cationic protein in the evaluation of asthma severity in children

To assess the sensitivity and specificity of serum eosinophil cationic protein (ECP) in the diagnosis of asthma and evaluation of asthma severity, we conducted a prospective study to compare parameters of asthma severity, peripheral blood eosinophilia, and serum ECP concentrations in 88 children presenting to a university hospital outpatient clinic with suspected (n=59) or recently diagnosed asthma (n=29). Serum ECP correlated significantly (r[s]=0.676, P = 0.0001) with peripheral eosinophil counts, but only weakly with asthma severity (r[s]=0.21, P=0.046). Serum ECP was significantly higher in atopic children (25+/-11 microg/l) than in nonatopic children (16+/-15 microg/l) (P=0.01). Bronchial hyperresponsiveness had no significant correlation (r[s]= -0.21, P=0.30) with serum ECP. Lung function test results had no (peak flow) or only a weak (FEV1) correlation with serum ECP. In distinguishing between children with and without asthma or in assessing asthma severity, serum ECP is not superior to the peripheral blood eosinophil count. The diagnostic sensitivity and specificity of ECP in serum for detecting symptomatically active asthma, evaluated against the cutoff level of ECP in serum of 16 mg/l, were 54% and 71%, respectively.