Effect of ciclesonide treatment on allergen-induced changes in T cell regulation in asthma

Critical role of CCL4 in eosinophil recruitment into the airway

BACKGROUND

Excessive eosinophil airway infiltration is a clinically critical condition in some cases. Eosinophilic pneumonia (EP) is a pulmonary condition involving eosinophil infiltration of the lungs. Although several chemokines, including eotaxin-1 (CCL11), RANTES (CCL5) and macrophage inflammatory protein 1β (MIP-1β or CCL4), have been detected in bronchoalveolar lavage fluid (BALF) from patients with EP, the pathophysiological mechanisms underlying EP, including potential relationships between eosinophils and CCL4, have not been fully elucidated.

OBJECTIVE

To examine the involvement of CCL4 in eosinophilic airway inflammation.

METHODS

We analysed supernatants of activated eosinophils and BALF from 16 patients with eosinophilic pneumonia (EP). Further, we examined the effects of CCL4 on eosinophil functions in vitro and those of anti-CCL4 neutralizing antibody in an in vivo model.

RESULTS

We found that purified human eosinophils stimulated with IL-5 predominantly secreted CCL4 and that patients with EP had elevated CCL11 and CCL4 levels in BALF compared with samples from individuals without EP. Because CCL4 levels were more strongly correlated with eosinophil count and expression of eosinophil granule proteins than CCL11, in vitro experiments using purified eosinophils concentrated on the former chemokine. Interestingly, CCL4 acted as a chemoattractant for eosinophils. In a mouse model, administration of a CCL4-neutralizing antibody attenuated eosinophilic airway infiltration and airway hyperresponsiveness.

CONCLUSIONS AND CLINICAL RELEVANCE

Overall, these findings highlight an important role of CCL4 in the mechanisms underlying eosinophil recruitment into the airway and may provide a novel insight into this potential therapeutic target.

IL-33 promotes airway remodeling in pediatric patients with severe steroid-resistant asthma

BACKGROUND

TH2 cytokines are not responsible for the ongoing symptoms and pathology in children with severe therapy-resistant asthma (STRA). IL-33 induces airway hyperresponsiveness, but its role in airway remodeling and steroid resistance is unknown.

OBJECTIVE

We sought to investigate the relationship between IL-33 and airway remodeling in pediatric patients with STRA.

METHODS

IL-33 levels were quantified in neonatal mice given inhaled house dust mite (HDM), and the effect of blocking IL-13 on remodeling and IL-33 levels was assessed. HDM-induced allergic airways disease (AAD) in neonatal ST2(-/-) mice lacking the IL-33 receptor was assessed, together with collagen production after IL-33 administration. The effect of steroid therapy on IL-33 levels in patients with neonatal AAD was explored. IL-33 expression was quantified in endobronchial biopsy (EB) specimens from children with STRA and related to remodeling, and collagen production by airway fibroblasts from pediatric patients stimulated with IL-33 and budesonide was quantified.

RESULTS

Blocking IL-13 after AAD was established in neonatal mice and did not reduce remodeling or IL-33 levels; airway hyperresponsiveness was only partially reduced. IL-33 promoted collagen synthesis both from asthmatic fibroblasts from pediatric patients and after intranasal administration in mice. Increased cellular expression of IL-33, but not IL-13, was associated with increased reticular basement membrane thickness in EB specimens from children with STRA, whereas remodeling was absent in HDM-exposed ST2(-/-) mice. IL-33 levels were maintained, whereas IL-13 levels were abrogated by steroid treatment in neonatal HDM-exposed mice and in EB specimens from children with STRA.

CONCLUSION

IL-33 is a relatively steroid-resistant mediator that promotes airway remodeling in patients with STRA and is an important therapeutic target.

Profile of ciclesonide for the maintenance treatment of asthma

Ciclesonide is a nonhalogenated synthetic inhaled corticosteroid (ICS) that has been approved by the US Food and Drug Administration for the treatment of all severities of persistent asthma. It is available as a hydrofluroalkane pressurized metered-dose inhaler in two strengths, 80 mcg/activation and 160 mcg/activation, with the recommenced dosage being two inhalations twice-daily. It is a prodrug that is converted in the lung to its active form, which possesses 100-fold greater glucocorticoid-receptor-binding affinity than the parent compound. Its relative receptor affinity is similar to budesonide. In clinical studies, ciclesonide was effective in improving pulmonary function, reducing asthma symptoms, and reducing or eliminating the need for oral corticosteroids (OCSs). Patients with severe asthma dependent on OCSs and high doses of ICSs were able to achieve greater asthma control and reduce or even eliminate the use of OCSs when switched to ciclesonide. In comparison with fluticasone propionate and budesonide, ciclesonide was demonstrated to be at least as effective in maintaining pulmonary function and asthma control. In clinical trials, ciclesonide was well tolerated, with the majority of adverse events considered mild or moderate in intensity. It had low systemic bioavailability and no clinically significant hypothalamic–pituitary–adrenal axis suppression at therapeutic doses. Its safety profile establishes ciclesonide as an important addition to the currently available ICSs.

TRP channels: emerging targets for respiratory disease

The mammalian transient receptor potential (TRP) superfamily of cation channels is divided into six subfamilies based on sequence homology TRPC (canonical), TRPV (vanilloid), TRPM (melastatin), TRPA (ankyrin), TRPP (polycystin) and TRPML (mucolipin). The expression of these channels is especially abundant in sensory nerves, and there is increasing evidence demonstrating their existence in a broad range of cell types which are thought to play a key role in respiratory diseases such as asthma and chronic obstructive pulmonary disease (COPD). These ion channels can be activated by a diverse range of chemical and physical stimuli. Physical stimuli include temperature, membrane potential changes and osmotic stress, and some of the more well known chemical stimuli include capsaicin (TRPV1), menthol (TRPM8) and acrolein (TRPA1). There is increasing evidence in this rapidly moving field to suggest that selective blockers of these channels may represent attractive novel strategies to treat characteristic features of respiratory diseases such as asthma and COPD. This review focuses on summarising the evidence that modulation of selected TRP channels may have beneficial effects at targeting key features of these respiratory diseases including airways inflammation, airways hyper-reactivity, mucus secretion and cough.

Ciclesonide and the treatment of asthma

IMPORTANCE OF THE FIELD

Asthma is a chronic disease characterized by airway inflammation and hyper-responsiveness. Inhaled corticosteroids (ICSs) constitute the guideline-recommended first-line therapy for persistent asthma. However, concerns regarding ICS-related adverse events may contribute to their underutilization by physicians and patients.

AREAS COVERED IN THIS REVIEW

The currently available published data on the pharmacokinetic and pharmacodynamic properties, safety and efficacy of the ICS, ciclesonide, is described. Peer-reviewed publications (1996 - 2009) on the pharmacodynamic and pharmacokinetic profile, safety and efficacy of ciclesonide were reviewed.

WHAT THE READER WILL GAIN

Ciclesonide is delivered as an inactive prodrug, which is cleaved to the active molecule by intracellular esterases located in the lungs. This and other pharmacodynamic and pharmacokinetic properties may limit the amount of active molecule outside the lung and may reduce the incidence of side effects. Randomized placebo-controlled studies found that ciclesonide can initiate and maintain disease control in subjects with persistent asthma of all disease severities. Moreover, studies have found that ciclesonide is as effective as other ICSs in establishing and controlling disease symptoms. Controlled clinical trials also showed that ciclesonide is associated with minimal systemic and local treatment-related adverse events.

TAKE HOME MESSAGE

Published findings indicate that ciclesonide is effective at initiating and maintaining asthma control and is well tolerated, with a positive safety profile.

Ciclesonide: a review of its use in the management of asthma

Ciclesonide (Alvesco) is an inhaled corticosteroid used in the preventative treatment of persistent bronchial asthma in adults, adolescents and, in some countries, children. The drug is delivered by a non-chlorofluorocarbon hydrofluoroalkane (HFA) metered-dose inhaler (MDI). In the lungs, ciclesonide is converted to an active metabolite, which is responsible for the beneficial effects of the drug in patients with asthma. Ciclesonide and its active metabolite have low systemic bioavailability and therefore have a low potential to produce systemic adverse events. Inhaled ciclesonide delivered by HFA-MDI is effective in the prophylactic treatment of persistent asthma in adults, adolescents and children, and is generally well tolerated. In general, ciclesonide improves lung function and reduces asthma symptoms and rescue medication use in adults and adolescents with asthma of varying severity. The drug is generally no less effective than other inhaled corticosteroids with regard to maintaining or improving lung function and may have a more favourable tolerability profile than some other agents in this class. Ciclesonide has also shown efficacy in paediatric patients with asthma. Data on its long-term effects on other clinical outcomes, such as asthma exacerbations, would be of interest. Further comparative and long-term studies would also be beneficial in order to definitively position ciclesonide with respect to other inhaled corticosteroids. In the meantime, ciclesonide offers an effective and well tolerated first-line preventative treatment option for persistent asthma.