American Lung Association Asthma Clinical Research Centers. Clinical trial of low-dose theophylline and montelukast in patients with poorly controlled asthma

The Saudi initiative for asthma - 2024 update: Guidelines for the diagnosis and management of asthma in adults and children

The Saudi Initiative for Asthma 2024 (SINA-2024) is the sixth version of asthma guidelines for the diagnosis and management of asthma for adults and children that was developed by the SINA group, a subsidiary of the Saudi Thoracic Society. The main objective of the SINA is to have guidelines that are up-to-date, simple to understand, and easy to use by healthcare workers dealing with asthma patients. To facilitate achieving the goals of asthma management, the SINA Panel approach is mainly based on the assessment of symptom control and risk for both adults and children. The approach to asthma management is aligned for age groups: adults, adolescents, children aged 5-12 years, and children aged <5 years. SINA guidelines have focused more on personalized approaches reflecting a better understanding of disease heterogeneity with the integration of recommendations related to biologic agents, evidence-based updates on treatment, and the role of immunotherapy in management. The medication appendix has also been updated with the addition of recent evidence, new indications for existing medication, and new medications. The guidelines are constructed based on the available evidence, local literature, and the current situation at national and regional levels. There is also an emphasis on patient-doctor partnership in the management that also includes a self-management plan.

Montelukast in paediatric asthma and allergic rhinitis: a systematic review and meta-analysis

BACKGROUND

We aim to assess the impact of montelukast on paediatric patients with asthma/allergic rhinitis, measured using patient-reported outcome measures, compared with other treatments or placebo.

METHODS

Protocol registration CRD42020216098 (www.crd.york.ac.uk/PROSPERO). MEDLINE and Embase databases were used to conduct the search. Two authors independently selected studies and extracted data, and a third reviewer resolved discrepancies. Meta-analyses were constructed to estimate the standardised mean difference (SMD) using a random-effects model.

RESULTS

Out of 3937 articles identified, 49 studies met the inclusion criteria, mostly randomised clinical trials (sample sizes: 21-689 patients). The SMD of change pooled estimators for the global, mental and physical domains of health-related quality of life were not statistically significant. For daytime and night-time symptoms scores, the SMD (95% CI) was in favour of inhaled corticosteroids (-0.12, -0.20- -0.05 and -0.23, -0.41- -0.06, respectively). The pooled estimator for global asthma symptoms was better for montelukast when compared with placebo (0.90, 0.44-1.36).

CONCLUSIONS

The synthesis of the available evidence suggests that, in children and adolescents, montelukast was effective in controlling asthma symptoms when compared with placebo, but inhaled corticosteroids were superior in controlling symptoms, especially at night-time. These findings of our systematic review concur with current guidelines for asthma treatment.

Meta-analysis of the relationship between montelukast use and neuropsychiatric events in patients with allergic airway disease

Use of montelukast, as a cause of neuropsychiatric events, in patients with asthma or allergic rhinitis is controversial, and comprehensive statistical analyses verifying this relationship remain lacking. To better understand the relationship between montelukast and neuropsychiatric events, it is vital to guide patients in the effective use of the drug, especially in children whose mothers are concerned about its side effects. In this study, randomized controlled trials (RCTs) investigating montelukast and neuropsychiatric events were retrieved from a literature search of the Medline (1966 to February 2023), Embase (1974 to February 2023), Web of Science, and other related databases. After screening, 18 RCTs were ultimately included in a meta-analysis to merge statistics, which demonstrated no significant increase in neuropsychiatric events compared with placebo. A similar pattern of adverse neuropsychiatric events was observed in patients grouped according to age, with headache being the most common adverse neuropsychiatric event. Overall, montelukast did not significantly increase neuropsychiatric events in patients with allergic rhinitis and/or asthma compared with placebo. Large-sample RCTs are needed to verify the association between neuropsychiatric events and montelukast use in children, and attention is also devoted to FDA warnings.

Theophylline for the management of respiratory disorders in adults in the 21st century: A scoping review from the American College of Clinical Pharmacy Pulmonary Practice and Research Network

Theophylline is an oral methylxanthine bronchodilator recommended as alternate therapy for the treatment of asthma and chronic obstructive pulmonary disease (COPD). However, it is not generally recommended for the treatment of other respiratory disorders such as obstructive sleep apnea (OSA) or hypoxia. Most clinical practice guidelines rely on evidence published prior to the year 2000 to make these recommendations. This scoping review aimed to gather and characterize evidence describing theophylline for the management of respiratory disorders in adults between January 1, 2000 and December 31, 2020. Databases searched included Ovid MEDLINE, Embase, CINAHL Complete, Scopus, and International Pharmaceutical Abstracts. This review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) extension for scoping reviews. Studies were included if they were published in English, theophylline was used for any respiratory disorder, and the study outcomes were disease- or patient-oriented. After removal of duplicates, 841 studies were screened and 55 studies were included. Results aligned with current clinical guideline recommendations relegating theophylline as an alternative therapy for the treatment of respiratory disorders, in favor of inhaled corticosteroids and inhaled bronchodilators. This scoping review identified the need for future research including: theophylline versus other medications deemed alternative therapies for asthma and COPD, meta-analyses of low-dose theophylline, and studies evaluating evidence-based patient-oriented outcomes for OSA, hypoxia, ventilator-induced diaphragmatic dysfunction, and spinal cord injury-related pulmonary function.

Pharmacogenomics and Pediatric Asthmatic Medications

Asthma is a respiratory condition often stemming from childhood, characterized by difficulty breathing and/or chest tightness. Current treatment options for both adults and children include beta-2 agonists, inhaled corticosteroids (ICS), and leukotriene modifiers (LTM). Despite recommendations by the Global Initiative for Asthma, a substantial number of patients are unresponsive to treatment and unable to control symptoms. Pharmacogenomics have increasingly become the front line of precision medicine, especially with the recent use of candidate gene and genome- wide association studies (GWAS). Screening patients preemptively could likely decrease adverse events and therapeutic failure. However, research in asthma, specifically in pediatrics, has been low. Although numerous adult trials have evaluated the impact of pharmacogenomics and treatment response, the lack of evidence in children has hindered progress towards clinical application. This review aims to discuss the impact of genetic variability and response to asthmatic medications in the pediatric population.

Using marginal structural models to analyze randomized clinical trials with non-adherence and lost to follow up

BACKGROUND

In the presence of non-adherence and lost to follow up, results of an Intention to Treat (ITT) analysis may be biased as it is measuring the effect of assignment rather than the effect of treatment. Given that Marginal Structural Models (MSMs) adjust for such issues, this study examines the use of MSMs to assess the validity of ITT analyses in the presence of non-adherence and lost to follow up in an existing randomized clinical trial on asthma treatment.

METHODS

Inverse probability weights were obtained from a pooled logistic regression assessing the probability of staying on assigned treatment (adherence) and of remaining uncensored (censored) for subjects at each visit by treatment arm. Weights were then pooled into a MSM analysis using a Poisson generalized estimating equation with an independent correlation matrix.

RESULTS

Out of 488 participants, 174 (36%) did not adhere to the baseline assignment and 85 (17%) were lost to follow up by the end of the study. The adjusted relative risks (RR), and 95% confidence intervals (CI), obtained from the MSMs (theophylline vs. montelukast; RR=1.24; 95% CI: 0.83,1.84; theophylline vs. placebo: RR=1.01; 95% CI: 0.70,1.48; and montelukast vs. placebo: RR=0.83; 95% CI: 0.57,1.19) were nearly identical to that of the ITT analysis (theophylline vs. montelukast: RR=1.22; 95% CI: 0.82,1.86; theophylline vs. placebo: RR=0.99; 95% CI: 0.67,1.50; and montelukast vs. placebo: RR=0.82; 95% CI: 0.55,1.21).

CONCLUSION

Concordance between the results of ITT and MSMs indicate adherence and censoring may not invalidate ITT analysis. However, no adherence or censorship thresholds currently exist to assist researchers in determining when MSMs may be superior to ITT in the analysis of clinical trials with non-adherence or censorship issues, and therefore, MSMs should be conducted as a sensitivity analysis to the ITT approach in clinical trials.

Usage of long-acting muscarinic antagonists and biologics as add-on therapy for patients in the United States with moderate-to-severe asthma

Many asthma patients remain uncontrolled on inhaled corticosteroids (ICS) and long-acting beta agonists (LABAs), but guidance for selecting add-on therapies, including long-acting muscarinic antagonists (LAMAs) or biologics, is limited. We describe how prescribing practices for add-on LAMA and biologic therapy have changed with increased treatment options and revised treatment guidelines. We further identify differences in treatment initiation and discontinuation rates by patient characteristics, including concomitant COPD.

This retrospective cohort study analyzed insurance claims in the IBM Marketscan database for adult US asthma patients treated with medium- or high-dose ICS/LABA between 2012 and 2019 (n = 277,373). We used negative binomial regression models to evaluate LAMA and biologic initiation rates and their association with patient characteristics, and survival analysis methods for assessing discontinuation rates.

Between 2012 and 2019, LAMA and biologic uptake increased approximately 5-fold and 20-fold, respectively. LAMA initiation was significantly higher among patients with concomitant COPD, a group typically unstudied in clinical trials, versus those with asthma only (rate ratio of 5.90, 95% CI: 5.76-6.04). High-dose ICS/LABA treatment and the need for oral corticosteroid (OCS) bursts had stronger associations with biologic initiation. Probability of discontinuation (i.e. non-persistence) in the first year was 40.5% and 22.7% for those initiating LAMAs and biologics, respectively, with higher LAMA discontinuation rates among patients with asthma only versus those with concomitant COPD.

Our results provide insights into how clinicians apply treatment guidelines for initiating add-on LAMA and biologic therapies in moderate-to-severe asthma patients and highlight patients who have an unmet treatment need after discontinuation.

Pharmacogenetic Polygenic Risk Score for Bronchodilator Response in Children and Adolescents with Asthma: Proof-of-Concept

Genome-wide association studies (GWAS) of response to asthma medications have primarily focused on Caucasian populations, with findings that may not be generalizable to minority populations. We derived a polygenic risk score (PRS) for response to albuterol as measured by bronchodilator response (BDR), and examined the PRS in a cohort of Hispanic school-aged children with asthma. We leveraged a published GWAS of BDR to identify relevant genetic variants, and ranked the top variants according to their Combined Annotation Dependent Depletion (CADD) scores. Variants with CADD scores greater than 10 were used to compute the PRS. Once we derived the PRS, we determined the association of the PRS with BDR in a cohort of Hispanic children with asthma (the Genetics of Asthma in Costa Rica Study (GACRS)) in adjusted linear regression models. Mean BDR in GACRS participants was5.6% with a standard deviation of 10.2%. We observed a 0.63% decrease in BDR in response to albuterol for a standard deviation increase in the PRS (p = 0.05). We also observed decreased odds of a BDR response at or above the 12% threshold for a one standard deviation increase in the PRS (OR = 0.80 (95% CI 0.67 to 0.95)). Our findings show that combining variants from a pharmacogenetic GWAS into a PRS may be useful for predicting medication response in asthma.

The Role of SNP Interactions when Determining Independence of Novel Signals in Genetic Association Studies-An Application to ARG1 and Bronchodilator Response

Genome-wide association studies (GWAS) play a critical role in identifying many loci for common diseases and traits. There has been a rapid increase in the number of GWAS over the past decade. As additional GWAS are being conducted, it is unclear whether a novel signal associated with the trait of interest is independent of single nucleotide polymorphisms (SNPs) in the same region that has been previously associated with the trait of interest. The general approach to determining whether the novel association is independent of previous signals is to examine the association of the novel SNP with the trait of interest conditional on the previously identified SNP and/or calculate linkage disequilibrium (LD) between the two SNPs. However, the role of epistasis and SNP by SNP interactions are rarely considered. Through simulation studies, we examined the role of SNP by SNP interactions when determining the independence of two genetic association signals. We have created an R package on Github called gxgRC to generate these simulation studies based on user input. In genetic association studies of asthma, we considered the role of SNP by SNP interactions when determining independence of signals for SNPs in the ARG1 gene and bronchodilator response.

Age by Single Nucleotide Polymorphism Interactions on Bronchodilator Response in Asthmatics

An unaddressed and important issue is the role age plays in modulating response to short acting β2-agonists in individuals with asthma. The objective of this study was to identify whether age modifies genetic associations of single nucleotide polymorphisms (SNPs) with bronchodilator response (BDR) to β2-agonists. Using three cohorts with a total of 892 subjects, we ran a genome wide interaction study (GWIS) for each cohort to examine SNP by age interactions with BDR. A fixed effect meta-analysis was used to combine the results. In order to determine if previously identified BDR SNPs had an age interaction, we also examined 16 polymorphisms in candidate genes from two published genome wide association studies (GWAS) of BDR. There were no significant SNP by age interactions on BDR using the genome wide significance level of 5 × 10⁻⁸. Using a suggestive significance level of 5 × 10⁻⁶, three interactions, including one for a SNP within PRAG1 (rs4840337), were significant and replicated at the significance level of 0.05. Considering candidate genes from two previous GWAS of BDR, three SNPs (rs10476900 (near ADRB2) [p-value = 0.009], rs10827492 (CREM) [p-value = 0.02], and rs72646209 (NCOA3) [p-value = 0.02]) had a marginally significant interaction with age on BDR (p < 0.05). Our results suggest age may be an important modifier of genetic associations for BDR in asthma.

Comparing LAMA with LABA and LTRA as add-on therapies in primary care asthma management

The Global Initiative for Asthma recommends a stepwise approach to adjust asthma treatment to the needs of individual patients; inhaled corticosteroids (ICS) remain the core pharmacological treatment. However, many patients remain poorly controlled, and evidence-based algorithms to decide on the best order and rationale for add-on therapies are lacking. We explore the challenges of asthma management in primary care and review outcomes from randomised controlled trials and meta-analyses comparing the long-acting muscarinic antagonist (LAMA) tiotropium with long-acting β₂-agonists (LABAs) or leukotriene receptor antagonists (LTRAs) as add-on to ICS in patients with asthma. In adults, LAMAs and LABAs provide a greater improvement in lung function than LTRAs as add-on to ICS. In children, results were positive and comparable between therapies, but data are scarce. This information could aid decision-making in primary care, supporting the use of add-on therapy to ICS to help improve lung function, control asthma symptoms and prevent exacerbations.

Evaluation and Management of Difficult-to-Treat and Severe Asthma: An Expert Opinion From the Korean Academy of Asthma, Allergy and Clinical Immunology, the Working Group on Severe Asthma

Severe asthma (SA) presents in about 3%-5% of adult asthmatics and is responsible for over 60% of asthma-related medical expenses, posing a heavy socioeconomic burden. However, to date, a precise definition of or clear diagnostic criteria for SA have not been established, and therefore, it has been challenging for clinicians to diagnose and treat this disease. Currently, novel biologics targeting several molecules, such as immunoglobulin E, interleukin (IL)5, and IL4/IL13, have emerged, and many new drugs are under development. These have brought a paradigm shift in understanding the mechanism of SA and have also provided new treatment options. However, we need to agree on a precise definition of and its diagnostic criteria for SA. Additionally, it is necessary to explain the diagnostic criteria and to summarize current standard and additional treatment options. This review is an experts' opinion on SA from the Korean Academy of Asthma, Allergy, and Clinical Immunology, the Working Group on Severe Asthma, and aims to provide a definition of and diagnostic criteria for SA, and propose future direction for SA diagnosis and management in Korea.

Management of asthma COPD overlap

OBJECTIVE

To review the latest literature on management approaches to patients with asthma chronic obstructive pulmonary disease (COPD) overlap (ACO).

DATA SOURCES

Studies and reports were identified from the databases of PubMed/Medline and ClinicalTrials.gov from the US National Institutes of Health and the Cochrane Register of Controlled Trials.

STUDY SELECTIONS

Studies on the management of asthma, COPD, and ACO were included in this review.

RESULTS

Patients with asthma COPD overlap tend to have greater morbidity than those with asthma or COPD alone, but the information on the best therapeutic approach to this group of patients is still limited. Current treatment recommendations rely on expert opinions, roundtable discussions, and strategy documents, because most clinical studies in asthma and COPD have excluded patients with ACO. Because of the potential risk described in patients with asthma with the use of long-acting 2 agonist monotherapy, initial therapy for patients with ACO is recommended to include a long-acting bronchodilator in conjunction with inhaled corticosteroids. Long-acting muscarinic antagonists are effective in both asthma and COPD and should be considered in ACO as an add-on treatment. If inhaler therapy is not effective, advanced therapies based on phenotyping and identification of treatable traits may be considered.

CONCLUSION

Few studies have evaluated prospectively therapies in the ACO population, and future studies need to determine best strategies for the treatment of these patients, focusing on targeting its different phenotypes and its treatable traits.

Older age and obesity are associated with increased airway closure in response to methacholine in patients with asthma

BACKGROUND AND OBJECTIVE

The reduction of forced expiratory volume in 1 s (FEV₁ ) in response to methacholine challenge in asthma may reflect two components: airway narrowing, assessed by the change in FEV₁ /forced vital capacity (FVC), and airway closure, assessed by the change in FVC. The purpose of this study was to determine the degree and determinants of airway closure in response to methacholine in a large group of asthmatic patients participating in studies conducted by the American Lung Association-Airways Clinical Research Centers (ALA-ACRC).

METHODS

We used the methacholine challenge data from participants in five studies of the ALA-ACRC to determine the closing index, defined as the contribution of airway closure to the decrease in FEV₁ , and calculated as %ΔFVC/%ΔFEV₁ .

RESULTS

There were a total of 936 participants with asthma, among whom the median closing index was 0.67 relative to that of a published healthy population of 0.54. A higher closing index was associated with increased age (10-year increments) (0.04, 95% CI = 0.02, 0.05, P < 0.005) and obesity (0.07, 95% CI = 0.03, 0.10, P < 0.001). There was no association between the closing index and asthma control.

CONCLUSION

Our findings confirm that airway closure in response to methacholine occurs in a large, diverse population of asthmatic participants, and that increased airway closure is associated with older age and obesity. These findings suggest that therapies targeting airway closure may be important in patients with a high closing index.

The Saudi Initiative for Asthma - 2019 Update: Guidelines for the diagnosis and management of asthma in adults and children

This is the fourth version of the updated guidelines for the diagnosis and management of asthma, developed by the Saudi Initiative for Asthma (SINA) group, a subsidiary of the Saudi Thoracic Society. The main objective of the SINA is to have guidelines that are up to date, simple to understand, and easy to use by healthcare workers dealing with asthma patients. To facilitate achieving the goals of asthma management, the SINA panel approach is mainly based on the assessment of symptom control and risk for both adults and children. The approach to asthma management is now more aligned for different age groups. The guidelines have focused more on personalized approaches reflecting better understanding of disease heterogeneity with integration of recommendations related to biologic agents, evidence-based updates on treatment, and role of immunotherapy in management. The medication appendix has also been updated with the addition of recent evidence, new indications for existing medication, and new medications. The guidelines are constructed based on the available evidence, local literature, and current situation at national and regional levels. There is also an emphasis on patient–doctor partnership in the management that also includes a self-management plan.

Glucocortiosteroid subsensitivity and asthma severity

PURPOSE OF REVIEW

Glucocorticosteroids (GCSs) remain the cornerstone of therapy for treating the inflammatory component of asthma. Clinical response to GCS is heterogeneous, varying both within asthma 'endotypes', as well as the same individual. Different factors and micro-environment can alter the canonical GCS-induced signalling pathways leading to reduced efficacy, collectively termed as GCS subsensitivity, which includes the entire spectrum of steroid insensitivity and steroid resistance.

RECENT FINDINGS

In the past, steroid subsensitivity has been associated with dysregulated expression of glucocorticoid-receptor isoforms, neutrophilic inflammation and Th17 cytokines, oxidative stress-inducing factors and their downstream effect on histone deacetylase activities and gene expression. The review highlights recent observations, such as GCS-induced dysregulation of key transcription factors involved in host defence, role of airway infections altering expression of critical regulatory elements like the noncoding microRNAs, and the importance of interleukin (IL)-10 in reinstating steroid response in key immune cells. Further, emerging concepts of autoimmunity triggered because of delayed resolution of eosinophilic inflammation (due to GCS subsensitivity) and observed lymphopenia (plausibly a side-effect of continued GCS use) are discussed.

SUMMARY

This review bridges concepts that have been known, and those under current investigation, providing both molecular and clinical insights to aid therapeutic strategies for optimal management of asthmatics with varying degree of steroid subsensitivity and disease severity, with particular emphasis on the PI3 kinase pathways.

Tiotropium for the Treatment of Asthma: Patient Selection and Perspectives

Asthma is a chronic disease of airway inflammation with a large global burden. Despite established, guideline-based stepwise therapy, a significant proportion of patients remain symptomatic and poorly controlled. As such, there is a need for additional safe, effective, convenient, and cost-effective therapies that can be broadly applied across a range of asthma phenotypes. Tiotropium is a long-acting muscarinic antagonist (LAMA) that leads to bronchodilation by blocking endogenous acetylcholine receptors in the airways. Tiotropium has long been approved for the treatment of chronic obstructive pulmonary disease, and it has recently been recognized for its safety and efficacy in improving lung function and controlling asthma. Evidence from several Phase III trials in the adult and paediatric population has shown that tiotropium is well tolerated and significantly improves a range of endpoints as an add-on treatment to ICS therapy, regardless of baseline characteristics and clinical phenotypes. Consequently, regulatory authorities worldwide have recently licensed tiotropium as the only LAMA approved for the treatment of asthma. This review provides an overview of safety and efficacy data and discusses the use of tiotropium in patients across the range of asthma severities, ages, and phenotypes.

Traditional Therapies for Severe Asthma

Severe asthma is a complex and heterogeneous disease. The European Respiratory Society and American Thoracic Society guidelines define severe asthma for patients 6 years or older as "asthma which requires treatment with high-dose inhaled corticosteroids…plus a second controller or systemic corticosteroids to prevent it from becoming 'uncontrolled' or which remains 'uncontrolled' despite this therapy." This article reviews available traditional therapies, data behind their uses in severe asthma, and varying recommendations. As various asthma endotypes and phenotypes are better understood and characterized, targeted therapies should help improve disease outcomes, efficacy, and cost-effectiveness.

The Duffy antigen receptor for chemokines regulates asthma pathophysiology

BACKGROUND

The Duffy antigen receptor for chemokines (DARC) is an atypical receptor that regulates pro-inflammatory cytokines. However, the role of DARC in asthma pathophysiology is unknown.

OBJECTIVE

To determine the role of DARC in allergic airways disease in mice, and the association between DARC single nucleotide polymorphisms (SNPs) and clinical outcomes in patients with asthma.

METHODS

Mice with targeted disruption of the Darc gene (Darc∆E2 ) or WT mice were challenged over 3 weeks with house dust mite (HDM) antigen. Allergic airways disease was assessed 24 hours and 7 days following the final challenge. Additionally, associations between DARC SNPs and clinical outcomes were analysed in a cohort of poorly controlled asthmatics.

RESULTS

Total airway inflammation following HDM did not differ between Darc∆E2 and WT mice. At 24 hours, Darc∆E2 mice had increased airway hyperresponsiveness; however, at 7 days airway hyperresponsiveness had completely resolved in Darc∆E2 but persisted in WT mice. In poorly controlled asthmatics, DARC SNPs were associated with worse asthma control at randomization and subsequent increased risk of healthcare utilization (odds ratio 3.13(1.37-7.27), P=.0062).

CONCLUSIONS AND CLINICAL RELEVANCE

Our animal model and human patient data suggest a novel role for DARC in the temporal regulation in asthma pathophysiology and symptoms.

Addition of anti-leukotriene agents to inhaled corticosteroids for adults and adolescents with persistent asthma

BACKGROUND

Asthma management guidelines recommend low-dose inhaled corticosteroids (ICS) as first-line therapy for adults and adolescents with persistent asthma. The addition of anti-leukotriene agents to ICS offers a therapeutic option in cases of suboptimal control with daily ICS.

OBJECTIVES

To assess the efficacy and safety of anti-leukotriene agents added to ICS compared with the same dose, an increased dose or a tapering dose of ICS (in both arms) for adults and adolescents 12 years of age and older with persistent asthma. Also, to determine whether any characteristics of participants or treatments might affect the magnitude of response.

SEARCH METHODS

We identified relevant studies from the Cochrane Airways Group Specialised Register of Trials, which is derived from systematic searches of bibliographic databases including the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, PsycINFO, the Allied and Complementary Medicine Database (AMED), the Cumulative Index to Nursing and Allied Health Literature (CINAHL) and the trial registries clinicaltrials.gov and ICTRP from inception to August 2016.

SELECTION CRITERIA

We searched for randomised controlled trials (RCTs) of adults and adolescents 12 years of age and older on a maintenance dose of ICS for whom investigators added anti-leukotrienes to the ICS and compared treatment with the same dose, an increased dose or a tapering dose of ICS for at least four weeks.

DATA COLLECTION AND ANALYSIS

We used standard methods expected by Cochrane. The primary outcome was the number of participants with exacerbations requiring oral corticosteroids (except when both groups tapered the dose of ICS, in which case the primary outcome was the % reduction in ICS dose from baseline with maintained asthma control). Secondary outcomes included markers of exacerbation, lung function, asthma control, quality of life, withdrawals and adverse events.

MAIN RESULTS

We included in the review 37 studies representing 6128 adult and adolescent participants (most with mild to moderate asthma). Investigators in these studies used three leukotriene receptor antagonists (LTRAs): montelukast (n = 24), zafirlukast (n = 11) and pranlukast (n = 2); studies lasted from four weeks to five years. Anti-leukotrienes and ICS versus same dose of ICSOf 16 eligible studies, 10 studies, representing 2364 adults and adolescents, contributed data. Anti-leukotriene agents given as adjunct therapy to ICS reduced by half the number of participants with exacerbations requiring oral corticosteroids (risk ratio (RR) 0.50, 95% confidence interval (CI) 0.29 to 0.86; 815 participants; four studies; moderate quality); this is equivalent to a number needed to treat for additional beneficial outcome (NNTB) over six to 16 weeks of 22 (95% CI 16 to 75). Only one trial including 368 participants reported mortality and serious adverse events, but events were too infrequent for researchers to draw a conclusion. Four trials reported all adverse events, and the pooled result suggested little difference between groups (RR 1.06, 95% CI 0.92 to 1.22; 1024 participants; three studies; moderate quality). Investigators noted between-group differences favouring the addition of anti-leukotrienes for morning peak expiratory flow rate (PEFR), forced expiratory volume in one second (FEV1), asthma symptoms and night-time awakenings, but not for reduction in β2-agonist use or evening PEFR. Anti-leukotrienes and ICS versus higher dose of ICSOf 15 eligible studies, eight studies, representing 2008 adults and adolescents, contributed data. Results showed no statistically significant difference in the number of participants with exacerbations requiring oral corticosteroids (RR 0.90, 95% CI 0.58 to 1.39; 1779 participants; four studies; moderate quality) nor in all adverse events between groups (RR 0.96, 95% CI 0.89 to 1.03; 1899 participants; six studies; low quality). Three trials reported no deaths among 834 participants. Results showed no statistically significant differences in lung function tests including morning PEFR and FEV1 nor in asthma control measures including use of rescue β2-agonists or asthma symptom scores. Anti-leukotrienes and ICS versus tapering dose of ICSSeven studies, representing 1150 adults and adolescents, evaluated the combination of anti-leukotrienes and tapering-dose of ICS compared with tapering-dose of ICS alone and contributed data. Investigators observed no statistically significant difference in % change from baseline ICS dose (mean difference (MD) -3.05, 95% CI -8.13 to 2.03; 930 participants; four studies; moderate quality), number of participants with exacerbations requiring oral corticosteroids (RR 0.46, 95% CI 0.20 to 1.04; 542 participants; five studies; low quality) or all adverse events (RR 0.95, 95% CI 0.83 to 1.08; 1100 participants; six studies; moderate quality). Serious adverse events occurred more frequently among those taking anti-leukotrienes plus tapering ICS than in those taking tapering doses of ICS alone (RR 2.44, 95% CI 1.52 to 3.92; 621 participants; two studies; moderate quality), but deaths were too infrequent for researchers to draw any conclusions about mortality. Data showed no improvement in lung function nor in asthma control measures.

AUTHORS' CONCLUSIONS

For adolescents and adults with persistent asthma, with suboptimal asthma control with daily use of ICS, the addition of anti-leukotrienes is beneficial for reducing moderate and severe asthma exacerbations and for improving lung function and asthma control compared with the same dose of ICS. We cannot be certain that the addition of anti-leukotrienes is superior, inferior or equivalent to a higher dose of ICS. Scarce available evidence does not support anti-leukotrienes as an ICS sparing agent, and use of LTRAs was not associated with increased risk of withdrawals or adverse effects, with the exception of an increase in serious adverse events when the ICS dose was tapered. Information was insufficient for assessment of mortality.

The neurophysiological effects of single-dose theophylline in patients with chronic stroke: A double-blind, placebo-controlled, randomized cross-over study

BACKGROUND

Reducing inhibitory neurotransmission with pharmacological agents is a potential approach for augmenting plasticity after stroke. Previous work in healthy subjects showed diminished intracortical inhibition after administration of theophylline.

OBJECTIVE

We assessed the effect of single-dose theophylline on intracortical and interhemispheric inhibition in patients with chronic stroke, in a double-blind, placebo-controlled, cross-over study.

METHODS

Eighteen subjects were randomly administered 300 mg of extended-release theophylline or placebo. Immediately and 5 hours following administration, transcranial magnetic stimulation was used to assess bihemispheric resting motor threshold, short-interval intracortical inhibition, long-interval intracortical inhibition, and interhemispheric inhibition. Adverse effects on cardiovascular, neurological, and motor performance outcomes were also surveilled. Change between morning and afternoon sessions were compared across conditions. One week later, patients underwent the same assessments after crossing over to the opposite experimental condition. Subjects and investigators were blinded to the experimental condition during data acquisition and analysis.

RESULTS

For both hemispheres, changes in intracortical or interhemispheric neurophysiology were comparable under theophylline and placebo conditions. Theophylline induced no adverse neurological, cardiovascular, or motor performance effects. For both conditions and hemipsheres, the baseline level of inhibition inversely correlated with its change between sessions: less baseline inhibition (i.e. disinhibition) was associated with a strengthening in inhibition over the day, and vice versa.

CONCLUSION

A single dose of theophylline is well-tolerated by patients with chronic stroke, but does not alter cortical excitability. The inverse relationship between baseline inhibition and its change suggests the existence of a homeostatic process. The lack of effect on cortical inhibition may be related to an insufficiently long exposure to theophylline, or to differential responsiveness of disinhibited neural circuitry in patients with stroke.

[Functional and laboratory characteristics in the concomitance of asthma and obesity at a young age]

AIM

To study the peripheral blood level of leptin and adiponectin and their possible effect on the functional status of the respiratory system in young asthmatic patients in relation to body mass index (BMI) for the optimization of asthma therapy.

MATERIALS AND METHODS

Examinations were made in 133 people, including a study group of 93 patients with asthma who were divided into 2 groups according to BMI: 1) those with a BMI of less 25 kg/m2 and 2) those with a BMI of 30 kg/m2 or more, as well as a control group of 40 apparently healthy patients. The investigators studied external respiratory function (ERF), the peripheral blood levels of leptin and adiponectin, the biochemical composition of plasma, by determining total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, and triglycerides.

RESULTS

Lipid metabolic disorders as dyslipidemia and hypercholesterolemia, increased severity of disease, and decreased ERF were recorded in the concomitance of obesity and asthma. The peripheral blood level of leptin in young asthmatic patients with obesity was found to be associated with higher BMI.

CONCLUSION

A more severe course of disease presenting with decreased ERF, impaired lipid metabolism, and elevated peripheral blood leptin levels were noted in the concomitance of asthma and obesity at a young age.

Genome-wide association study of leukotriene modifier response in asthma

Heterogeneous therapeutic responses to leukotriene modifiers (LTMs) are likely due to variation in patient genetics. Although prior candidate gene studies implicated multiple pharmacogenetic loci, to date, no genome-wide association study (GWAS) of LTM response was reported. In this study, DNA and phenotypic information from two placebo-controlled trials (total N=526) of zileuton response were interrogated. Using a gene-environment (G × E) GWAS model, we evaluated 12-week change in forced expiratory volume in 1 second (ΔFEV1) following LTM treatment. The top 50 single-nucleotide polymorphism associations were replicated in an independent zileuton treatment cohort, and two additional cohorts of montelukast response. In a combined analysis (discovery+replication), rs12436663 in MRPP3 achieved genome-wide significance (P=6.28 × 10(-08)); homozygous rs12436663 carriers showed a significant reduction in mean ΔFEV1 following zileuton treatment. In addition, rs517020 in GLT1D1 was associated with worsening responses to both montelukast and zileuton (combined P=1.25 × 10(-07)). These findings implicate previously unreported loci in determining therapeutic responsiveness to LTMs.

The Saudi Initiative for Asthma - 2016 update: Guidelines for the diagnosis and management of asthma in adults and children

This is an updated guideline for the diagnosis and management of asthma, developed by the Saudi Initiative for Asthma (SINA) group, a subsidiary of the Saudi Thoracic Society. The main objective of SINA is to have guidelines that are up to date, simple to understand and easy to use by nonasthma specialists, including primary care and general practice physicians. SINA approach is mainly based on symptom control and assessment of risk as it is the ultimate goal of treatment. The new SINA guidelines include updates of acute and chronic asthma management, with more emphasis on the use of asthma control in the management of asthma in adults and children, inclusion of a new medication appendix, and keeping consistency on the management at different age groups. The section on asthma in children is rewritten and expanded where the approach is stratified based on the age. The guidelines are constructed based on the available evidence, local literature, and the current situation in Saudi Arabia. There is also an emphasis on patient-doctor partnership in the management that also includes a self-management plan.

Leukotriene-receptor antagonists versus placebo in the treatment of asthma in adults and adolescents: a systematic review and meta-analysis

BACKGROUND

Leukotriene-receptor antagonists (LTRAs) are recommended as an alternative treatment in patients with mild asthma, but their effect compared with placebo is unclear.

PURPOSE

To determine the benefits and harms of LTRAs as monotherapy or in combination with inhaled corticosteroids compared with placebo in adults and adolescents with asthma.

DATA SOURCES

MEDLINE and the Cochrane Central Register of Controlled Trials from inception through June 2015.

STUDY SELECTION

Peer-reviewed, English-language, randomized, controlled trials in patients with asthma that reported the effect of LTRAs versus placebo on measures of asthma control.

DATA EXTRACTION

Three researchers extracted data on study population, interventions, outcome measures, and adverse events. One researcher assessed risk of bias.

DATA SYNTHESIS

Of the 2008 abstracts that were screened, 50 trials met eligibility criteria. Random-effects meta-analyses of 6 trials of LTRA monotherapy showed that LTRAs reduced the risk for an exacerbation (summary risk ratio [RR], 0.60 [95% CI, 0.44 to 0.81]). In 4 trials of LTRAs as add-on therapy to inhaled corticosteroids, the summary RR for exacerbation was 0.80 (CI, 0.60 to 1.07). Leukotriene-receptor antagonists either as monotherapy or as add-on therapy to inhaled corticosteroids increased FEV1, whereas FEV1 percentage of predicted values was improved only in trials of LTRA monotherapy. Adverse event rates were similar in the intervention and comparator groups.

LIMITATION

Variation in definitions and reporting of outcomes, high risk of bias in some studies, heterogeneity of findings, possible selective outcome reporting bias, and inability to assess the effect of asthma severity on summary estimates.

CONCLUSION

Leukotriene-receptor antagonists as monotherapy improved asthma control compared with placebo, but which patients are most likely to respond to treatment with LTRAs remains unclear.

PRIMARY FUNDING SOURCE

National Institutes of Health.

Pharmacotherapy of critical asthma syndrome: current and emerging therapies

The critical asthma syndrome (CAS) encompasses the most severe, persistent, refractory asthma patients for the clinician to manage. Personalized pharmacotherapy is necessary to prevent the next acute severe asthma exacerbation, not just the control of symptoms. The 2007 National Asthma Education and Prevention Program Expert Panel 3 provides guidelines for the treatment of uncontrolled asthma. The patient's response to recommended pharmacotherapy is highly variable which risks poor asthma control leading to frequent exacerbations that can deteriorate into CAS. Controlling asthma symptoms and preventing acute exacerbations may be two separate clinical activities with their own unique demands. Clinicians must be prepared to use the entire spectrum of asthma medications available but must concurrently be aware of potential drug toxicities some of which can paradoxically worsen asthma control. Medications normally prescribed for COPD can potentially be useful in the CAS patient, particularly those with asthma-COPD overlap syndrome. Immunomodulation with drugs like omalizumab in IgE-mediated asthma syndromes is one important approach. New and emerging drugs address unique aspects of airway inflammation and biology but at a significant financial cost. The pharmacology and toxicities of the agents that may be used in the treatment of CAS to control asthma symptoms and prevent severe exacerbations are reviewed.

Diagnostic accuracy of FEV1/forced vital capacity ratio z scores in asthmatic patients

BACKGROUND

The FEV1/forced vital capacity (FVC) ratio is used as a criterion for airflow obstruction; however, the test characteristics of spirometry in the diagnosis of asthma are not well established. The accuracy of a test depends on the pretest probability of disease.

OBJECTIVE

We wanted to estimate the FEV1/FVC ratio z score threshold with optimal accuracy for the diagnosis of asthma for different pretest probabilities.

METHODS

Asthmatic patients enrolled in 4 trials from the Asthma Clinical Research Centers were included in this analysis. Measured and predicted FEV1/FVC ratios were obtained, with calculation of z scores for each participant. Across a range of asthma prevalences and z score thresholds, the overall diagnostic accuracy was calculated.

RESULTS

One thousand six hundred eight participants were included (mean age, 39 years; 71% female; 61% white). The mean FEV1 percent predicted value was 83% (SD, 15%). In a symptomatic population with 50% pretest probability of asthma, optimal accuracy (68%) is achieved with a z score threshold of -1.0 (16th percentile), corresponding to a 6 percentage point reduction from the predicted ratio. However, in a screening population with a 5% pretest probability of asthma, the optimum z score is -2.0 (second percentile), corresponding to a 12 percentage point reduction from the predicted ratio. These findings were not altered by markers of disease control.

CONCLUSION

Reduction of the FEV1/FVC ratio can support the diagnosis of asthma; however, the ratio is neither sensitive nor specific enough for diagnostic accuracy. When interpreting spirometric results, consideration of the pretest probability is an important consideration in the diagnosis of asthma based on airflow limitation.

Genome-Wide Association Study Identifies Novel Pharmacogenomic Loci For Therapeutic Response to Montelukast in Asthma

Background

Genome-wide association study (GWAS) is a powerful tool to identify novel pharmacogenetic single nucleotide polymorphisms (SNPs). Leukotriene receptor antagonists (LTRAs) are a major class of asthma medications, and genetic factors contribute to variable responses to these drugs. We used GWAS to identify novel SNPs associated with the response to the LTRA, montelukast, in asthmatics.

Methods

Using genome-wide genotype and phenotypic data available from American Lung Association - Asthma Clinical Research Center (ALA-ACRC) cohorts, we evaluated 8-week change in FEV₁ related to montelukast administration in a discovery population of 133 asthmatics. The top 200 SNPs from the discovery GWAS were then tested in 184 additional samples from two independent cohorts.

Results

Twenty-eight SNP associations from the discovery GWAS were replicated. Of these, rs6475448 achieved genome-wide significance (combined P = 1.97 x 10^-09), and subjects from all four studies who were homozygous for rs6475448 showed increased ΔFEV₁ from baseline in response to montelukast.

Conclusions

Through GWAS, we identified a novel pharmacogenomic locus related to improved montelukast response in asthmatics.

Addition to inhaled corticosteroids of leukotriene receptor antagonists versus theophylline for symptomatic asthma: a meta-analysis

BACKGROUND

Inhaled corticosteroids (ICSs) are widely used in combination with second controller medications in the management of asthma in adults and children. There lacks a systematic comparison between addition of leukotriene receptor antagonists (LTRAs) and theophylline to ICS. The purpose of this meta-analysis was to evaluate the difference of the efficacy and safety profile of adding either LTRAs or theophylline to ICS in adults and children with symptomatic asthma.

METHODS

Randomised controlled trials (RCTs) published prior to November 2014 were acquired through systematically searching and selected based on the established inclusion criteria for publications. The data extracted from the included studies were further analyzed by a meta-analysis.

RESULTS

We included eight RCTs, of which six recruited adults and two recruited children aged 5 to 14 years. The primary outcomes were changes in lung function from baseline, including forced expiratory volume in the first second (FEV1) and peak expiratory flow (PEF). Overall, addition of LTRAs led to significantly better morning PEF {mean difference (MD) 16.94 [95% confidence interval (CI): 11.49-22.39] L/min, P<0.01} and FEV1 [MD 0.09 (95% CI: 0.03-0.15) L, P=0.005] as compared to addition of theophylline. There were no differences between the two treatments in terms of evening PEF, adverse events, rescue medication use and asthma exacerbation.

CONCLUSIONS

The combination of LTRA and ICS leads to modestly greater improvement in lung function than the combination of theophylline and ICS in the treatment of symptomatic asthma. Long-term trials are required to assess the efficacy and safety of these two therapies.

Economic and health effect of full adherence to controller therapy in adults with uncontrolled asthma: a simulation study

BACKGROUND

Adherence to evidence-based controller treatments for asthma is disappointingly low in many jurisdictions. Quantifying the burden associated with suboptimal adherence in patients with uncontrolled asthma will help establish the priorities for policymakers.

OBJECTIVE

We sought to quantify the benefits in the United States of improving adherence to controller therapies in adults with uncontrolled asthma in terms of health care costs and quality-adjusted life years (QALYs).

METHODS

A Markov model of asthma was created to simulate the effect of treatment with controller medications on asthma control and exacerbations over a 10-year time horizon. Health care costs and QALYs associated with the current level of adherence (status quo) were compared with a hypothetical scenario in which each patient with uncontrolled asthma at baseline will be fully adherent to an evidence-based controller therapy (the full-adherence scenario). We also evaluated the cost-effectiveness of adherence interventions as a function of their costs and improvement in the adherence.

RESULTS

The status quo level of asthma management was associated with $2,786 costs and 7.55 QALYs over 10 years, whereas the corresponding values for the full-adherence scenario were $5,973 and 7.68, respectively. Consequently, the incremental cost-effectiveness ratio of the full-adherence versus the status quo was $24,515/QALY. To be cost-effective, a program that improves adherence by 50% should cost less than $130 ($450) per person annually at a willingness-to-pay value of $50,000/QALY ($100,000/QALY). Inclusion of productivity loss in the analysis resulted in the full-adherence scenario being cost-saving.

CONCLUSION

Considering the extent of suboptimal adherence, our study shows that attempts in improving adherence to evidence-based therapies in patients with uncontrolled asthma can be associated with significant return on investment.

Comparative effectiveness of long term drug treatment strategies to prevent asthma exacerbations: network meta-analysis

OBJECTIVE

To determine the comparative effectiveness and safety of current maintenance strategies in preventing exacerbations of asthma.

DESIGN

Systematic review and network meta-analysis using Bayesian statistics.

DATA SOURCES

Cochrane systematic reviews on chronic asthma, complemented by an updated search when appropriate. ELIGIBILITY CRITERIA TRIALS OF Adults with asthma randomised to maintenance treatments of at least 24 weeks duration and that reported on asthma exacerbations in full text. Low dose inhaled corticosteroid treatment was the comparator strategy. The primary effectiveness outcome was the rate of severe exacerbations. The secondary outcome was the composite of moderate or severe exacerbations. The rate of withdrawal was analysed as a safety outcome.

RESULTS

64 trials with 59,622 patient years of follow-up comparing 15 strategies and placebo were included. For prevention of severe exacerbations, combined inhaled corticosteroids and long acting β agonists as maintenance and reliever treatment and combined inhaled corticosteroids and long acting β agonists in a fixed daily dose performed equally well and were ranked first for effectiveness. The rate ratios compared with low dose inhaled corticosteroids were 0.44 (95% credible interval 0.29 to 0.66) and 0.51 (0.35 to 0.77), respectively. Other combined strategies were not superior to inhaled corticosteroids and all single drug treatments were inferior to single low dose inhaled corticosteroids. Safety was best for conventional best (guideline based) practice and combined maintenance and reliever therapy.

CONCLUSIONS

Strategies with combined inhaled corticosteroids and long acting β agonists are most effective and safe in preventing severe exacerbations of asthma, although some heterogeneity was observed in this network meta-analysis of full text reports.

A genome-wide association study of bronchodilator response in asthmatics

Reversibility of airway obstruction in response to β2-agonists is highly variable among asthmatics, which is partially attributed to genetic factors. In a genome-wide association study of acute bronchodilator response (BDR) to inhaled albuterol, 534 290 single-nucleotide polymorphisms (SNPs) were tested in 403 white trios from the Childhood Asthma Management Program using five statistical models to determine the most robust genetic associations. The primary replication phase included 1397 polymorphisms in three asthma trials (pooled n=764). The second replication phase tested 13 SNPs in three additional asthma populations (n=241, n=215 and n=592). An intergenic SNP on chromosome 10, rs11252394, proximal to several excellent biological candidates, significantly replicated (P=1.98 × 10(-7)) in the primary replication trials. An intronic SNP (rs6988229) in the collagen (COL22A1) locus also provided strong replication signals (P=8.51 × 10(-6)). This study applied a robust approach for testing the genetic basis of BDR and identified novel loci associated with this drug response in asthmatics.

Genetic influences on response to asthma pharmacotherapy

Asthma is a complex inflammatory disease that affects 300 million people worldwide. Safe and effective drugs control the symptoms but heterogeneity in response is large and attributable, in part, to genetic variation. Polymorphisms in several genes influence response to asthma drugs. The genotype of the ADRB2 Gly16Arg single nucleotide polymorphism (SNP) associates with asthma worsening during continuous therapy with β-agonists. SNPs in four genes influence response to inhaled corticosteroids: CRHR1, ACP, TBX21 and FCER2. Polymorphisms in leukotriene pathway and transporter genes influence response to zileuton and the leukotriene receptor antagonists, including ALOX5, LTA4H, LTC4S, ABCC1 and SLCO2B1. Known sequence variants explain a small fraction of response heterogeneity to asthma drugs. More studies are required to formulate a genetic signature that will lead to the personalization of asthma treatment.

Polygenic heritability estimates in pharmacogenetics: focus on asthma and related phenotypes

Although accurate measures of heritability are required to understand the pharmacogenetic basis of drug treatment response, these are generally not available, as it is unfeasible to give medications to individuals for which treatment is not indicated. Using a polygenic linear mixed modeling approach, we estimated lower bounds on the heritability of asthma and the heritability of two related drug-response phenotypes, bronchodilator response and airway hyperreactivity, using genome-wide single nucleotide polymorphism (SNP) data from existing asthma cohorts. Our estimate of the heritability for bronchodilator response is 28.5% (SE 16%, P=0.043) and airway hyperresponsiveness is 51.1% (SE 34%, P=0.064), whereas we estimate asthma genetic liability at 61.5% (SE 16%, P<0.001). Our results agree with the previously published estimates of the heritability of these traits, suggesting that the linear mixed modeling method is useful for computing the heritability of other pharmacogenetic traits. Furthermore, our results indicate that multiple SNP main effects, including SNPs as yet unidentified by genome-wide association study methods, together explain a sizable portion of the heritability of these traits.

Addition of anti-leukotriene agents to inhaled corticosteroids in children with persistent asthma

BACKGROUND

In the treatment of children with mild persistent asthma, low-dose inhaled corticosteroids (ICS) are recommended as the preferred monotherapy (referred to as step 2 of therapy). In children with inadequate asthma control on low doses of ICS (step 2), asthma management guidelines recommend adding an anti-leukotriene agent to existing ICS as one of three therapeutic options to intensify therapy (step 3).

OBJECTIVES

To compare the efficacy and safety of the combination of anti-leukotriene agents and ICS to the use of the same, an increased, or a tapering dose of ICS in children and adolescents with persistent asthma who remain symptomatic despite the use of maintenance ICS. In addition, we wished to determine the characteristics of people or treatments, if any, that influenced the magnitude of response attributable to the addition of anti-leukotrienes.

SEARCH METHODS

We identified trials from the Cochrane Airways Group Specialised Register of Trials (CAGR), which were derived from systematic searches of bibliographic databases including the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, PsycINFO, AMED, and CINAHL; and the handsearching of respiratory journals and meeting abstracts, as well as the www.clinicaltrials.gov website. The search was conducted until January 2013.

SELECTION CRITERIA

We considered for inclusion randomised controlled trials (RCTs) conducted in children and adolescents, aged one to 18 years, with asthma, who remained symptomatic despite the use of a stable maintenance dose of ICS and in whom anti-leukotrienes were added to the ICS if they were compared to the same, an increased, or a tapering dose of ICS for at least four weeks.

DATA COLLECTION AND ANALYSIS

We used standard methods expected by The Cochrane Collaboration.

MAIN RESULTS

Five paediatric (parallel group or cross-over) trials met the inclusion criteria. We considered two (40%) trials to be at a low risk of bias. Four published trials, representing 559 children (aged ≥ six years) and adolescents with mild to moderate asthma, contributed data to the review. No trial enrolled preschoolers. All trials used montelukast as the anti-leukotriene agent administered for between four and 16 weeks. Three trials evaluated the combination of anti-leukotrienes and ICS compared to the same dose of ICS alone (step 3 versus step 2). No statistically significant group difference was observed in the only trial reporting participants with exacerbations requiring oral corticosteroids over four weeks (N = 268 participants; risk ratio (RR) 0.80, 95% confidence interval (CI) 0.34 to 1.91). There was also no statistically significant difference in percentage change in FEV₁ (forced expiratory volume in 1 second) with mean difference (MD) 1.3 (95% CI -0.09 to 2.69) in this trial, but a significant group difference was observed in the morning (AM) and evening (PM) peak expiratory flow rates (PEFR): N = 218 participants; MD 9.70 L/min (95% CI 1.27 to 18.13) and MD 10.70 (95% CI 2.41 to 18.99), respectively. One trial compared the combination of anti-leukotrienes and ICS to a higher-dose of ICS (step 3 versus step 3). No significant group difference was observed in this trial for participants with exacerbations requiring rescue oral corticosteroids over 16 weeks (N = 182 participants; RR 0.82, 95% CI 0.54 to 1.25), nor was there any significant difference in exacerbations requiring hospitalisation. There was no statistically significant group difference in withdrawals overall or because of any cause with either protocol. No trial explored the impact of adding anti-leukotrienes as a means to taper the dose of ICS.

AUTHORS' CONCLUSIONS

The addition of anti-leukotrienes to ICS is not associated with a statistically significant reduction in the need for rescue oral corticosteroids or hospital admission compared to the same or an increased dose of ICS in children and adolescents with mild to moderate asthma. Although anti-leukotrienes have been licensed for use in children for over 10 years, the paucity of paediatric trials, the absence of data on preschoolers, and the variability in the reporting of relevant clinical outcomes considerably limit firm conclusions. At present, there is no firm evidence to support the efficacy and safety of anti-leukotrienes as add-on therapy to ICS as a step-3 option in the therapeutic arsenal for children with uncontrolled asthma symptoms on low-dose ICS.

Sex differences in asthma symptom profiles and control in the American Lung Association Asthma Clinical Research Centers

OBJECTIVE

Important differences between men and women with asthma have been demonstrated, with women describing more symptoms and worse asthma-related quality of life (QOL) despite having similar or better pulmonary function. While current guidelines focus heavily on assessing asthma control, they lack information about whether sex-specific approaches to asthma assessment should be considered. We sought to determine if sex differences in asthma control or symptom profiles exist in the well-characterized population of participants in the American Lung Association Asthma Clinical Research Centers (ALA-ACRC) trials.

METHODS

We reviewed baseline data from four trials published by the ALA-ACRC to evaluate individual item responses to three standardized asthma questionnaires: the Juniper Asthma Control Questionnaire (ACQ), the multi-attribute Asthma Symptom Utility Index (ASUI), and Juniper Mini Asthma Quality of Life Questionnaire (mini-AQLQ).

RESULTS

In the poorly-controlled population, women reported similar overall asthma control (mean ACQ 1.9 vs. 1.8; p = 0.54), but were more likely to report specific symptoms such as nocturnal awakenings, activity limitations, and shortness of breath on individual item responses. Women reported worse asthma-related QOL on the mini-AQLQ (mean 4.5 vs. 4.9; p < 0.001) and more asthma-related symptoms with a lower mean score on the ASUI (0.73 vs. 0.77; p ≤ 0.0001) and were more likely to report feeling bothered by particular symptoms such as coughing, or environmental triggers.

CONCLUSIONS

In participants with poorly-controlled asthma, women had outwardly similar asthma control, but had unique symptom profiles on detailed item analyses which were evident on evaluation of three standardized asthma questionnaires.

Association of CYP2C19 polymorphisms and lansoprazole-associated respiratory adverse effects in children

OBJECTIVE

To determine whether cytochrome P450 (CYP)2C19 haplotype associates with lansoprazole-associated adverse event frequency.

STUDY DESIGN

Respiratory adverse events from a clinical trial of lansoprazole in children with asthma were analyzed for associations with extensive or poor metabolizer (PM) phenotype based on CYP2C19 haplotypes. Carriers of CYP2C19*2, *3, *8, or *9 alleles were PMs; carriers of 2 wild-type alleles were extensive metabolizers (EMs). Plasma concentrations of lansoprazole were determined in PM and EM phenotypes.

RESULTS

The frequency of upper respiratory infection among PMs (n = 45) was higher than that among EMs (n = 91), which in turn was higher than that in placebo subjects (n = 135; P = .0039). The frequency of sore throat (ST) was similarly distributed among EMs and PMs (P = .0015). The OR (95% CI) for upper respiratory infections in PMs was 2.46 (1.02-5.96) (P = .046); for EMs, the OR (95% CI) was 1.55 (0.86-2.79). The OR (95% CI) for ST in EMs and PMs was 2.94 (1.23-7.05, P = .016) vs 1.97 (1.09-3.55, P = .024), respectively. Mean ± SD plasma concentrations of lansoprazole were higher in PMs than in EMs: 207 ± 179 ng/mL vs 132 ± 141 ng/mL (P = .04).

CONCLUSIONS

Lansoprazole-associated upper respiratory infections and ST in children are related in part to CYP2C19 haplotype. Our data suggest that lansoprazole-associated adverse events in children may be mitigated by adjusting the conventional dose in PMs. Additional studies are required to replicate our findings.

A polymorphism in the thyroid hormone receptor gene is associated with bronchodilator response in asthmatics

A pro-asthmatic culture milieu and β2-agonist (isoproterenol) were previously shown to regulate the expression of select transcription factors (TFs) within human airway epithelial and smooth muscle cells. This study tests 1116 single-nucleotide polymorphisms (SNPs) across 98 of these TF genes for association with bronchodilator response (BDR) in asthma patients. Genotyping was conducted using the Illumina HumanHap550v3 Beadchip in 403 non-Hispanic White asthmatic children and their parents. SNPs were evaluated for association with BDR using family and population-based analyses. Forty-two SNPs providing P-values <0.1 in both analyses were then genotyped in three adult asthma trials. One SNP 5' of the thyroid hormone receptor-β gene was associated with BDR in the childhood population and two adult populations (P-value=0.0012). This investigation identified a novel locus for inter-individual variability in BDR and represents a translation of a cellular drug-response study to potential personalization of clinical asthma management.

Considerations for Care: Management of Asthma in the Child with Sickle Cell Disease

Asthma is difficult to diagnose in the child with sickle cell disease because symptoms and pulmonary function abnormalities are similar to the spectrum of pulmonary manifestations in sickle cell disease. There are no published reports of controlled trials of asthma medications in children with sickle cell disease. Thus, treatment decisions should be guided by the Expert Panel Report 3: Guidelines for the Diagnosis and Management of Asthma (www.nhlbi.nih.gov/guidelines/asthma/asthgdln.pdf). However, issues specific to children with sickle cell disease should be considered. Initial strategies should focus on control of environmental triggers, as effectiveness on asthma outcomes is proven and the cost for implementation can be low. Use of short- and long-acting β₂-agonists may prolong QTc, particularly in this population of children who already have a higher prevalence of prolonged QTc than the general population. Long-acting β₂-agonist use has been associated with life-threatening asthma exacerbations with potentially higher risks in African Americans. Montelukast has been reported to increase suicidal thinking and behavior, and persons with asthma and sickle cell disease are already at risk for these events. Oral corticosteroids in the treatment of acute chest syndrome may increase risk of readmission even in children with asthma. The lack of prospective controlled trials of asthma drug treatment in children with asthma and sickle cell disease compels us to move this issue forward.

Integration of mouse and human genome-wide association data identifies KCNIP4 as an asthma gene

Asthma is a common chronic respiratory disease characterized by airway hyperresponsiveness (AHR). The genetics of asthma have been widely studied in mouse and human, and homologous genomic regions have been associated with mouse AHR and human asthma-related phenotypes. Our goal was to identify asthma-related genes by integrating AHR associations in mouse with human genome-wide association study (GWAS) data. We used Efficient Mixed Model Association (EMMA) analysis to conduct a GWAS of baseline AHR measures from males and females of 31 mouse strains. Genes near or containing SNPs with EMMA p-values <0.001 were selected for further study in human GWAS. The results of the previously reported EVE consortium asthma GWAS meta-analysis consisting of 12,958 diverse North American subjects from 9 study centers were used to select a subset of homologous genes with evidence of association with asthma in humans. Following validation attempts in three human asthma GWAS (i.e., Sepracor/LOCCS/LODO/Illumina, GABRIEL, DAG) and two human AHR GWAS (i.e., SHARP, DAG), the Kv channel interacting protein 4 (KCNIP4) gene was identified as nominally associated with both asthma and AHR at a gene- and SNP-level. In EVE, the smallest KCNIP4 association was at rs6833065 (P-value 2.9e-04), while the strongest associations for Sepracor/LOCCS/LODO/Illumina, GABRIEL, DAG were 1.5e-03, 1.0e-03, 3.1e-03 at rs7664617, rs4697177, rs4696975, respectively. At a SNP level, the strongest association across all asthma GWAS was at rs4697177 (P-value 1.1e-04). The smallest P-values for association with AHR were 2.3e-03 at rs11947661 in SHARP and 2.1e-03 at rs402802 in DAG. Functional studies are required to validate the potential involvement of KCNIP4 in modulating asthma susceptibility and/or AHR. Our results suggest that a useful approach to identify genes associated with human asthma is to leverage mouse AHR association data.

The Saudi initiative for asthma - 2012 update: Guidelines for the diagnosis and management of asthma in adults and children

This an updated guidelines for the diagnosis and management of asthma, developed by the Saudi Initiative for Asthma (SINA) group, a subsidiary of the Saudi Thoracic Society. The main objective of SINA is to have updated guidelines, which are simple to understand and easy to use by non-asthma specialists, including primary care and general practice physicians. This new version includes updates of acute and chronic asthma management, with more emphasis on the use of Asthma Control Test in the management of asthma, and a new section on "difficult-to-treat asthma." Further, the section on asthma in children was re-written to cover different aspects in this age group. The SINA panel is a group of Saudi experts with well-respected academic backgrounds and experience in the field of asthma. The guidelines are formatted based on the available evidence, local literature, and the current situation in Saudi Arabia. There was an emphasis on patient-doctor partnership in the management that also includes a self-management plan. The approach adopted by the SINA group is mainly based on disease control as it is the ultimate goal of treatment.

Genome-wide association analysis in asthma subjects identifies SPATS2L as a novel bronchodilator response gene

Bronchodilator response (BDR) is an important asthma phenotype that measures reversibility of airway obstruction by comparing lung function (i.e. FEV₁) before and after the administration of a short-acting β₂-agonist, the most common rescue medications used for the treatment of asthma. BDR also serves as a test of β₂-agonist efficacy. BDR is a complex trait that is partly under genetic control. A genome-wide association study (GWAS) of BDR, quantified as percent change in baseline FEV₁ after administration of a β₂-agonist, was performed with 1,644 non-Hispanic white asthmatic subjects from six drug clinical trials: CAMP, LOCCS, LODO, a medication trial conducted by Sepracor, CARE, and ACRN. Data for 469,884 single-nucleotide polymorphisms (SNPs) were used to measure the association of SNPs with BDR using a linear regression model, while adjusting for age, sex, and height. Replication of primary P-values was attempted in 501 white subjects from SARP and 550 white subjects from DAG. Experimental evidence supporting the top gene was obtained via siRNA knockdown and Western blotting analyses. The lowest overall combined P-value was 9.7E-07 for SNP rs295137, near the SPATS2L gene. Among subjects in the primary analysis, those with rs295137 TT genotype had a median BDR of 16.0 (IQR = [6.2, 32.4]), while those with CC or TC genotypes had a median BDR of 10.9 (IQR = [5.0, 22.2]). SPATS2L mRNA knockdown resulted in increased β₂-adrenergic receptor levels. Our results suggest that SPATS2L may be an important regulator of β₂-adrenergic receptor down-regulation and that there is promise in gaining a better understanding of the biological mechanisms of differential response to β₂-agonists through GWAS.

Bronchodilator response (BDR) is an important asthma phenotype that measures reversibility of airway obstruction by comparing lung function before and after the administration of short-acting β₂-agonists, common medications used for asthma treatment. We performed a genome-wide association study of BDR with 1,644 white asthmatic subjects from six drug clinical trials and attempted to replicate these findings in 1,051 white subjects from two independent cohorts. The most significant associated variant was near the SPATS2L gene. We knocked down SPATS2L mRNA in human airway smooth muscle cells and found that β₂-adrenergic receptor levels increased, suggesting that SPATS2L may be a regulator of BDR. Our results highlight the promise of pursuing GWAS results that do not necessarily reach genome-wide significance and are an example of how results from pharmacogenetic GWAS can be studied functionally.

Obesity, Nutrition, and Asthma in Children

Obesity rates have increased dramatically among children in many parts of the world, especially in North America and several other English-speaking countries. The impact of obesity on pediatric health has become a major prevention initiative by the Obama administration and several public health organizations. Children with obesity are at increased risk for developing asthma, which is already one of the most common chronic diseases among children. The cause underlying obesity's impact on asthma risk is unknown. Commonly cited potential etiologies include airway smooth muscle dysfunction from thoracic restriction, obesity-related circulating inflammation priming the lung, and obesity-related comorbidities mediating asthma symptom development. Each of these theories does not fit precisely with all of the data that have accumulated over the last decade. In this review, I will explore other possible causes including: (1) dietary characteristics common in Westernized countries that might lead to both obesity and asthma; (2) reductions in physical activity; and (3) genetic alterations that increase the propensity to both obesity and asthma together. Next, I will review the current data on how obesity affects common characteristics of asthma such as airway inflammation, lung function, risk of exacerbation, atopy, and response to treatment. Obesity in children with asthma appears to be associated with greater airflow obstruction and a mildly diminished response to inhaled corticosteroids. Little objective evidence in children suggests that obesity significantly heightens the risk of exacerbation or worsens disease stability in children. Lastly, I will discuss the current literature that suggests that obese children with asthma generally should receive the same guidelines-based management as lean children. However, interventions that encourage daily physical activity, weight-loss, normalization of nutrient levels, and monitoring of common obesity-related sequelae should be considered by healthcare providers managing obese children with difficult-to-control asthma.

Anti-leukotriene agents compared to inhaled corticosteroids in the management of recurrent and/or chronic asthma in adults and children

BACKGROUND

Anti-leukotrienes (5-lipoxygenase inhibitors and leukotriene receptors antagonists) serve as alternative monotherapy to inhaled corticosteroids (ICS) in the management of recurrent and/or chronic asthma in adults and children.

OBJECTIVES

To determine the safety and efficacy of anti-leukotrienes compared to inhaled corticosteroids as monotherapy in adults and children with asthma and to provide better insight into the influence of patient and treatment characteristics on the magnitude of effects.

SEARCH METHODS

We searched MEDLINE (1966 to Dec 2010), EMBASE (1980 to Dec 2010), CINAHL (1982 to Dec 2010), the Cochrane Airways Group trials register, and the Cochrane Central Register of Controlled Trials (Dec 2010), abstract books, and reference lists of review articles and trials. We contacted colleagues and the international headquarters of anti-leukotrienes producers.

SELECTION CRITERIA

We included randomised trials that compared anti-leukotrienes with inhaled corticosteroids as monotherapy for a minimum period of four weeks in patients with asthma aged two years and older.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed the methodological quality of trials and extracted data. The primary outcome was the number of patients with at least one exacerbation requiring systemic corticosteroids. Secondary outcomes included patients with at least one exacerbation requiring hospital admission, lung function tests, indices of chronic asthma control, adverse effects, withdrawal rates and biological inflammatory markers.

MAIN RESULTS

Sixty-five trials met the inclusion criteria for this review. Fifty-six trials (19 paediatric trials) contributed data (representing total of 10,005 adults and 3,333 children); 21 trials were of high methodological quality; 44 were published in full-text. All trials pertained to patients with mild or moderate persistent asthma. Trial durations varied from four to 52 weeks. The median dose of inhaled corticosteroids was quite homogeneous at 200 µg/day of microfine hydrofluoroalkane-propelled beclomethasone or equivalent (HFA-BDP eq). Patients treated with anti-leukotrienes were more likely to suffer an exacerbation requiring systemic corticosteroids (N = 6077 participants; risk ratio (RR) 1.51, 95% confidence interval (CI) 1.17, 1.96). For every 28 (95% CI 15 to 82) patients treated with anti-leukotrienes instead of inhaled corticosteroids, there was one additional patient with an exacerbation requiring rescue systemic corticosteroids. The magnitude of effect was significantly greater in patients with moderate compared with those with mild airway obstruction (RR 2.03, 95% CI 1.41, 2.91 versus RR 1.25, 95% CI 0.97, 1.61), but was not significantly influenced by age group (children representing 23% of the weight versus adults), anti-leukotriene used, duration of intervention, methodological quality, and funding source. Significant group differences favouring inhaled corticosteroids were noted in most secondary outcomes including patients with at least one exacerbation requiring hospital admission (N = 2715 participants; RR 3.33; 95% CI 1.02 to 10.94), the change from baseline FEV(1) (N = 7128 participants; mean group difference (MD) 110 mL, 95% CI 140 to 80) as well as other lung function parameters, asthma symptoms, nocturnal awakenings, rescue medication use, symptom-free days, the quality of life, parents' and physicians' satisfaction. Anti-leukotriene therapy was associated with increased risk of withdrawals due to poor asthma control (N = 7669 participants; RR 2.56; 95% CI 2.01 to 3.27). For every thirty one (95% CI 22 to 47) patients treated with anti-leukotrienes instead of inhaled corticosteroids, there was one additional withdrawal due to poor control. Risk of side effects was not significantly different between both groups.

AUTHORS' CONCLUSIONS

As monotherapy, inhaled corticosteroids display superior efficacy to anti-leukotrienes in adults and children with persistent asthma; the superiority is particularly marked in patients with moderate airway obstruction. On the basis of efficacy, the results support the current guidelines' recommendation that inhaled corticosteroids remain the preferred monotherapy. 

Impact of omalizumab on emergency-department visits, hospitalizations, and corticosteroid use among patients with uncontrolled asthma

BACKGROUND

Omalizumab is a monoclonal antibody indicated for moderate to severe allergic asthma patients with inadequately controlled symptoms.

OBJECTIVE

To evaluate the impact of omalizumab on emergency department (ED) visits, hospitalizations, and corticosteroid use among patients with uncontrolled asthma using high-dose inhaled corticosteroids (ICS) and long-acting beta2-agonists (LABA).

METHODS

Health insurance claims from the MarketScan database (2002Q1-2009Q1) were analyzed. Patients with 12 months or more of continuous insurance coverage before and after the first omalizumab dispensing, 8 or more weeks of high-dose ICS use, 8 or more weeks of LABA use, and uncontrolled asthma at baseline were included. A retrospective analysis was conducted to quantify the impact of omalizumab on resource use by comparing ED visits, hospitalizations, and corticosteroid use 1 year before and after omalizumab initiation. A 1-year period was chosen to cover any potential seasonality impacts.

RESULTS

In total, 644 patients (mean age, 49.9; female, 59.2%) formed the study population. Omalizumab was associated with a 48.6% reduction in the proportion of patients with 1 or more asthma-related ED visits (pre vs post-omalizumab period: 21.4% vs 11.0%; P < .001) and a 40.8% reduction in asthma-related hospitalizations (25.0% vs 14.8%, respectively, P < .001). Compared with the pre-omalizumab period, the use of ICS decreased significantly after omalizumab initiation (7.8 vs 6.5 dispensings, P < .001; 41.9% of patients had a reduction in ICS use). A similar reduction in oral corticosteroid use was observed (5.0 vs 3.6 dispensings, P < .001; 53.3% of patients had a reduction in oral corticosteroid use).

CONCLUSION

The current analysis showed that omalizumab treatment initiation was associated with significant reductions in ED visits, hospitalizations, and corticosteroid use.

Asthma outcomes: exacerbations

BACKGROUND

The goals of asthma treatment include preventing recurrent exacerbations. Yet there is no consensus about the terminology for describing or defining "exacerbation" or about how to characterize an episode's severity.

OBJECTIVE

National Institutes of Health institutes and other federal agencies convened an expert group to propose how asthma exacerbation should be assessed as a standardized asthma outcome in future asthma clinical research studies.

METHODS

We used comprehensive literature reviews and expert opinion to compile a list of asthma exacerbation outcomes and classified them as either core (required in future studies), supplemental (used according to study aims and standardized), or emerging (requiring validation and standardization). This work was discussed at a National Institutes of Health-organized workshop in March 2010 and finalized in September 2011.

RESULTS

No dominant definition of "exacerbation" was found. The most widely used definitions included 3 components, all related to treatment, rather than symptoms: (1) systemic use of corticosteroids, (2) asthma-specific emergency department visits or hospitalizations, and (3) use of short-acting β-agonists as quick-relief (sometimes referred to as "rescue" or "reliever") medications.

CONCLUSIONS

The working group participants propose that the definition of "asthma exacerbation" be "a worsening of asthma requiring the use of systemic corticosteroids to prevent a serious outcome." As core outcomes, they propose inclusion and separate reporting of several essential variables of an exacerbation. Furthermore, they propose the development of a standardized, component-based definition of "exacerbation" with clear thresholds of severity for each component.