Asthma exacerbations and sputum eosinophil counts: a randomised controlled trial

Green, Ruth H.; Brightling, Christopher E.; McKenna, Susan; Hargadon, Beverley; Parker, Debbie; Bradding, Peter; Wardlaw, Andrew J.; Pavord, Ian D.

doi:10.1016/s0140-6736(02)11679-5

Cited by 1,604 publications

(1,289 citation statements)

References 27 publications

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“…In contrast, the measurement of sputum eosinophils is time-consuming and requires specific technical expertise not generally available in clinical settings [32]. Nonetheless, sputum eosinophil counts have been helpful in characterizing airway inflammation, predicting response to corticosteroid treatment, and identifying patients at risk of exacerbations [33–35]. …”

Section: Discussionmentioning

confidence: 99%

Health care resource utilization and characteristics of patients with eosinophilic asthma in secondary health care in Finland

Mäkelä

Christensen

Karlsson

et al. 2018

European Clinical Respiratory Journal

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Background: Eosinophilic airway inflammation is common in asthma patients and appears to be associated with severe exacerbations and loss of asthma control. Objective: To describe the resource utilization and clinical characteristics of patients with eosinophilic asthma. Design: Asthma patients ≥18 years with ≥1 blood eosinophil count in secondary care (South West Finland) during 2003‒2013 were included. Clinical characteristics (age, lung function, body mass index, and comorbidities) and asthma-related resource utilization (hospital admissions, outpatient visits, and emergency room [ER] visits) were retrieved. Resource utilization rates were compared for patients with blood eosinophil ≤ or >300 cells/μL, using adjusted negative binomial regression models. Results: Overall, 4,357 eligible patients were identified (mean age 60 years, females 68%), of which 1,927 (44%) had >300 eosinophil cells/μL blood. Patients with ≤300 and >300 eosinophil counts, exhibited similar clinical characteristics, including advanced age, poor lung function, and overweight. Comorbidities such as pneumonia, sinusitis, and nasal polyps, were more frequent among those with >300 eosinophil cells/μL blood compared with patients with lower counts. Eosinophil counts >300 cells/μL were associated with greater hospital admissions (rate ratio [RR] [95% confidence interval CI]: 1.13 [1.02;1.24]) and outpatient visits (RR [95% CI]: 1.11 [1.03;1.20]) compared with patients with lower eosinophil counts. Rates of ER visits were similar between the patient groups (RR [95% CI]: 0.99 [0.87;1.12]). Conclusions: Hospital admissions and outpatient visits occurred more often for patients with eosinophil counts >300 cells/µL, than for patients with lower eosinophil counts. Routine blood eosinophil screening might be useful to identify patients with an eosinophilic phenotype eligible for more targeted treatments.

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Section: Discussionmentioning

confidence: 99%

Health care resource utilization and characteristics of patients with eosinophilic asthma in secondary health care in Finland

Mäkelä

Christensen

Karlsson

et al. 2018

European Clinical Respiratory Journal

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“…Besides chemotaxis, we have shown that activation of CRTH2 also causes eosinophil respiratory burst and the release of eosinophils from the bone marrow [10]. In vivo, PGD 2 can induce pulmonary eosinophilia [11], and a significant contribution of PGD 2 to the late phase allergic reaction is suggested by enhanced eosinophilic lung inflammation and cytokine release in transgenic mice overexpressing PGD 2 synthase [12]. However, eosinophils also express the DP receptor [13], which is a second receptor for PGD 2 , and DPdeficient mice have reduced pulmonary responses to allergen [14].…”

Section: Introductionmentioning

confidence: 95%

“…It has been shown recently that asthmatic patients that received treatment based on eosinophil counts in sputum had significantly fewer severe asthma exacerbations than patients treated according to standard management therapy [2]. Moreover, genetically modified mice lacking eosinophils are protected against allergen-induced lung injury and asthma [3,4].…”

Section: Introductionmentioning

confidence: 99%

Hierarchy of eosinophil chemoattractants: role of p38 mitogen‐activated protein kinase

et al. 2006

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Several chemoattractants can regulate the recruitment of eosinophils to sites of inflammation, but the hierarchy among them is unknown. We observed here that eosinophil chemotaxis towards eotaxin or 5-oxo-6,8,11,14-eicosatetraenoic acid (5-oxo-ETE) was amplified up to sixfold in the presence of prostaglandin (PG) D 2 . This effect was only seen in eosinophils, and not in neutrophils or basophils. Pretreatment with the chemoattractant receptor-homologous molecule expressed on TH2 cells (CRTH2) antagonist ramatroban prevented the PGD 2 enhancement of eosinophil migrations. In contrast, eotaxin or 5-oxo-ETE inhibited the migration of eosinophils towards PGD 2 . 5-oxo-ETE enhanced the chemotaxis to eotaxin, while eotaxin had no effect on 5-oxo-ETE-induced migration. 5-oxo-ETE induced the phosphorylation of p38 mitogenactivated protein kinase, and inhibition of p38 mitogen-activated protein kinase by SB-202190 converted the effect of 5-oxo-ETE on the chemotaxis to PGD 2 from inhibition to enhancement. The presence of blood or plasma markedly decreased the sensitivity of eosinophils to eotaxin or 5-oxo-ETE, while responses to PGD 2 were unaltered. In conclusion, PGD 2 might be an initial chemoattractant, since it maintains its potency in the circulation and augments the responsiveness of eosinophils to other chemoattractants. In contrast, eotaxin seems to be an end-point chemoattractant, since it has reduced efficacy in blood and is capable of down-modulating eosinophil responsiveness to other chemoattractants. IntroductionAccumulation of eosinophils at sites of allergic reactions, such as eczema or asthma, is associated with tissue injury and lung dysfunction [1]. It has been shown recently that asthmatic patients that received treatment based on eosinophil counts in sputum had significantly fewer severe asthma exacerbations than patients treated according to standard management therapy [2]. Moreover, genetically modified mice lacking eosinophils are protected against allergen-induced lung injury and asthma [3,4].Although several chemoattractants can mediate eosinophil recruitment, none of them could be identified so far as a predominating factor governing eosinophil infiltration, suggesting a co-operative action of multiple chemoattractants in disease. Among these are the CC-chemokines, such as eotaxin, RANTES, or MCP-4 acting through the chemokine receptor CCR3 [5,6]. Prostaglandin (PG) D 2 , a major mast cell mediator released during the allergic response [7] might be of particular importance, since PGD 2 is capable of inducing the chemotaxis of eosinophils, basophils and Th2-type * These authors contributed equally to this study. T cells via a novel receptor, chemoattractant receptorhomologous molecule expressed on TH2 cells (CRTH2) [8,9]. Besides chemotaxis, we have shown that activation of CRTH2 also causes eosinophil respiratory burst and the release of eosinophils from the bone marrow [10]. In vivo, PGD 2 can induce pulmonary eosinophilia [11], and a significant contribution of PGD 2 to the late phase allergi...

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“…Moreover, it has been shown that patients who receive treatment based on eosinophil counts in sputum have significantly fewer severe asthma exacerbations than patients treated according to standard management therapy 9.…”

mentioning

confidence: 99%

Cannabinoid receptor 2 augments eosinophil responsiveness and aggravates allergen‐induced pulmonary inflammation in mice

Frei

Luschnig

Parzmair

et al. 2016

Allergy

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BackgroundAccumulation of activated eosinophils in tissue is a hallmark of allergic inflammation. The endocannabinoid 2‐arachidonoylglycerol (2‐AG) has been proposed to elicit eosinophil migration in a CB 2 receptor/Gi/o‐dependent manner. However, it has been claimed recently that this process may also involve other mechanisms such as cytokine priming and the metabolism of 2‐AG into eicosanoids. Here, we explored the direct contribution of specific CB 2 receptor activation to human and mouse eosinophil effector function in vitro and in vivo.Methods In vitro studies including CB 2 expression, adhesion and migratory responsiveness, respiratory burst, degranulation, and calcium mobilization were conducted in human peripheral blood eosinophils and mouse bone marrow‐derived eosinophils. Allergic airway inflammation was assessed in mouse models of acute OVA‐induced asthma and directed eosinophil migration.Results CB 2 expression was significantly higher in eosinophils from symptomatic allergic donors. The selective CB 2 receptor agonist JWH‐133 induced a moderate migratory response in eosinophils. However, short‐term exposure to JWH‐133 potently enhanced chemoattractant‐induced eosinophil shape change, chemotaxis, CD11b surface expression, and adhesion as well as production of reactive oxygen species. Receptor specificity of the observed effects was confirmed in eosinophils from CB 2 knockout mice and by using the selective CB 2 antagonist SR144528. Of note, systemic application of JWH‐133 clearly primed eosinophil‐directed migration in vivo and aggravated both AHR and eosinophil influx into the airways in a CB 2‐specific manner. This effect was completely absent in eosinophil‐deficient ∆dblGATA mice.ConclusionOur data indicate that CB 2 may directly contribute to the pathogenesis of eosinophil‐driven diseases. Moreover, we provide new insights into the molecular mechanisms underlying the CB 2‐mediated priming of eosinophils. Hence, antagonism of CB 2 receptors may represent a novel pharmacological approach for the treatment of allergic inflammation and other eosinophilic disorders.

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Asthma exacerbations and sputum eosinophil counts: a randomised controlled trial

Cited by 1,604 publications

References 27 publications

Health care resource utilization and characteristics of patients with eosinophilic asthma in secondary health care in Finland

Health care resource utilization and characteristics of patients with eosinophilic asthma in secondary health care in Finland

Hierarchy of eosinophil chemoattractants: role of p38 mitogen‐activated protein kinase

Cannabinoid receptor 2 augments eosinophil responsiveness and aggravates allergen‐induced pulmonary inflammation in mice

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