Vibeke Backer

Sequence variants affecting eosinophil numbers associate with asthma and myocardial infarction

Eosinophils are pleiotropic multifunctional leukocytes involved in initiation and propagation of inflammatory responses and thus have important roles in the pathogenesis of inflammatory diseases. Here we describe a genome-wide association scan for sequence variants affecting eosinophil counts in blood of 9,392 Icelanders. The most significant SNPs were studied further in 12,118 Europeans and 5,212 East Asians. SNPs at 2q12 (rs1420101), 2q13 (rs12619285), 3q21 (rs4857855), 5q31 (rs4143832) and 12q24 (rs3184504) reached genome-wide significance (P = 5.3 × 10−14, 5.4 × 10−10, 8.6 × 10−17, 1.2 × 10−10 and 6.5 × 10−19, respectively). A SNP at IL1RL1 associated with asthma (P = 5.5 × 10−12) in a collection of ten different populations (7,996 cases and 44,890 controls). SNPs at WDR36, IL33 and MYB that showed suggestive association with eosinophil counts were also associated with atopic asthma (P = 4.2 × 10−6, 2.2 × 10−5 and 2.4 × 10−4, respectively). We also found that a nonsynonymous SNP at 12q24, in SH2B3, associated significantly (P = 8.6 × 10−8) with myocardial infarction in six different populations (6,650 cases and 40,621 controls).

Preoperative Staging of Lung Cancer with Combined PET–CT

BACKGROUND Fast and accurate staging is essential for choosing treatment for non-small-cell lung cancer (NSCLC). The purpose of this randomized study was to evaluate the clinical effect of combined positron-emission tomography and computed tomography (PET-CT) on preoperative staging of NSCLC. METHODS We randomly assigned patients who were referred for preoperative staging of NSCLC to either conventional staging plus PET-CT or conventional staging alone. Patients were followed until death or for at least 12 months. The primary end point was the number of futile thoracotomies, defined as any one of the following: a thoracotomy with the finding of pathologically confirmed mediastinal lymph-node involvement (stage IIIA [N2]), stage IIIB or stage IV disease, or a benign lung lesion; an exploratory thoracotomy; or a thoracotomy in a patient who had recurrent disease or death from any cause within 1 year after randomization. RESULTS From January 2002 through February 2007, we randomly assigned 98 patients to the PET-CT group and 91 to the conventional-staging group. Mediastinoscopy was performed in 94% of the patients. After PET-CT, 38 patients were classified as having inoperable NSCLC, and after conventional staging, 18 patients were classified thus. Sixty patients in the PET-CT group and 73 in the conventional-staging group underwent thoracotomy (P=0.004). Among these thoracotomies, 21 in the PET-CT group and 38 in the conventional-staging group were futile (P=0.05). The number of justified thoracotomies and survival were similar in the two groups. CONCLUSIONS The use of PET-CT for preoperative staging of NSCLC reduced both the total number of thoracotomies and the number of futile thoracotomies but did not affect overall mortality. (ClinicalTrials.gov number, NCT00867412.)

A daily SMS reminder increases adherence to asthma treatment: A three-month follow-up study

BACKGROUND Poor adherence to asthma treatment is a well-recognised challenge and is associated with increased morbidity, mortality and consumption of health care resources. This study examined the impact of receiving a daily text message reminder on ones cell phone on adherence to asthma treatment. METHODS A total of 26 subjects aged 18-45 years, with a clinical history of asthma and a positive methacholine challenge test (PD(20)<or=4micromol) were randomised to receive, or to not receive, a daily short message service (SMS) reminder on their cell phone to take their anti-asthmatic medication. Inhaled corticosteroids to last for eight weeks and a prescription for four additional weeks were given to the subjects. The primary outcome was adherence to asthma treatment. Secondary outcomes were reimbursement of asthma medication, and change in exhaled nitric oxide levels, lung function, and airway responsiveness. RESULTS The absolute difference in mean adherence rate between the two groups after 12 weeks was 17.8%, 95% CI (3.2-32.3%), p=0.019. No significant differences were observed between the two randomisation groups for the secondary outcomes. CONCLUSION Daily text message reminders are already after a short period of observation associated with increased adherence to anti-asthmatic medication.

Adherence to inhaled therapies, health outcomes and costs in patients with asthma and COPD.

Suboptimal adherence to pharmacological treatment of asthma and chronic obstructive pulmonary disease (COPD) has adverse effects on disease control and treatment costs. The reasons behind non-adherence revolve around patient knowledge/education, inhaler device convenience and satisfaction, age, adverse effects and medication costs. Age is of particular concern given the increasing prevalence of asthma in the young and increased rates of non-adherence in adolescents compared with children and adults. The correlation between adherence to inhaled pharmacological therapies for asthma and COPD and clinical efficacy is positive, with improved symptom control and lung function shown in most studies of adults, adolescents and children. Satisfaction with inhaler devices is also positively correlated with improved adherence and clinical outcomes, and reduced costs. Reductions in healthcare utilisation are consistently observed with good adherence; however, costs associated with general healthcare and lost productivity tend to be offset only in more adherent patients with severe disease, versus those with milder forms of asthma or COPD. Non-adherence is associated with higher healthcare utilisation and costs, and reductions in health-related quality of life, and remains problematic on an individual, societal and economic level. Further development of measures to improve adherence is needed to fully address these issues.

Asthma and the elite athlete: Summary of the International Olympic Committee's Consensus Conference, Lausanne, Switzerland, january 22-24, 2008

Respiratory symptoms cannot be relied on to make a diagnosis of asthma and/or airways hyperresponsiveness (AHR) in elite athletes. For this reason, the diagnosis should be confirmed with bronchial provocation tests. Asthma management in elite athletes should follow established treatment guidelines (eg, Global Initiative for Asthma) and should include education, an individually tailored treatment plan, minimization of aggravating environmental factors, and appropriate drug therapy that must meet the requirements of the World Anti-Doping Agency. Asthma control can usually be achieved with inhaled corticosteroids and inhaled beta(2)-agonists to minimize exercise-induced bronchoconstriction and to treat intermittent symptoms. The rapid development of tachyphylaxis to beta(2)-agonists after regular daily use poses a dilemma for athletes. Long-term intense endurance training, particularly in unfavorable environmental conditions, appears to be associated with an increased risk of developing asthma and AHR in elite athletes. Globally, the prevalence of asthma, exercise-induced bronchoconstriction, and AHR in Olympic athletes reflects the known prevalence of asthma symptoms in each country. The policy of requiring Olympic athletes to demonstrate the presence of asthma, exercise-induced bronchoconstriction, or AHR to be approved to inhale beta(2)-agonists will continue.

Differences between allergic and nonallergic rhinitis in a large sample of adolescents and adults

Background:  The aim of this study was to describe differences between allergic rhinitis (AR) and nonallergic rhinitis (NAR) in a large community‐based sample of Danish adolescents and adults.

Efficacy of a House Dust Mite Sublingual Allergen Immunotherapy Tablet in Adults With Allergic Asthma: A Randomized Clinical Trial

IMPORTANCE The house dust mite (HDM) sublingual allergen immunotherapy (SLIT) tablet is a potential novel treatment option for HDM allergy-related asthma. OBJECTIVES To evaluate the efficacy and adverse events of the HDM SLIT tablet vs placebo for asthma exacerbations during an inhaled corticosteroid (ICS) reduction period. DESIGN, SETTINGS, AND PARTICIPANTS Double-blind, randomized, placebo-controlled trial conducted between August 2011 and April 2013 in 109 European trial sites. The trial included 834 adults with HDM allergy-related asthma not well controlled by ICS or combination products, and with HDM allergy-related rhinitis. Key exclusion criteria were FEV1 less than 70% of predicted value or hospitalization due to asthma within 3 months before randomization. Efficacy was assessed during the last 6 months of the trial when ICS was reduced by 50% for 3 months and then completely withdrawn for 3 months. INTERVENTIONS 1:1:1 randomization to once-daily treatment with placebo (n = 277) or HDM SLIT tablet (dosage groups: 6 SQ-HDM [n = 275] or 12 SQ-HDM [n = 282]) in addition to ICS and the short-acting β2-agonist salbutamol. MAIN OUTCOMES AND MEASURES Primary outcome was time to first moderate or severe asthma exacerbation during the ICS reduction period. Secondary outcomes were deterioration in asthma symptoms, change in allergen-specific immunoglobulin G4 (IgG4), change in asthma control or asthma quality-of-life questionnaires, and adverse events. RESULTS Among 834 randomized patients (mean age, 33 years [range, 17-83]; women, 48%), 693 completed the study. The 6 SQ-HDM and 12 SQ-HDM doses both significantly reduced the risk of a moderate or severe asthma exacerbation compared with placebo (hazard ratio [HR]: 0.72 [95% CI, 0.52-0.99] for the 6 SQ-HDM group, P = .045, and 0.69 [95% CI, 0.50-0.96] for the 12 SQ-HDM group, P = .03). The absolute risk differences based on the observed data (full analysis set) in the active groups vs the placebo group were 0.09 (95% CI, 0.01-0.15) for the 6 SQ-HDM group and 0.10 (95% CI, 0.02-0.16) for the 12 SQ-HDM group. There was no significant difference between the 2 active groups. Compared with placebo, there was a reduced risk of an exacerbation with deterioration in asthma symptoms (HR, 0.72 [95% CI, 0.49-1.02] for the 6 SQ-HDM group, P = .11, and 0.64 [95% CI, 0.42-0.96] for the 12 SQ-HDM group, P = .03) and a significant increase in allergen-specific IgG4. However, there was no significant difference for change in asthma control questionnaire or asthma quality-of-life questionnaire for either dose. There were no reports of severe systemic allergic reactions. The most frequent adverse events were mild to moderate oral pruritus (13% for the 6 SQ-HDM group, 20% for the 12 SQ-HDM group, and 3% for the placebo group), mouth edema, and throat irritation. CONCLUSIONS AND RELEVANCE Among adults with HDM allergy-related asthma not well controlled by ICS, the addition of HDM SLIT to maintenance medications improved time to first moderate or severe asthma exacerbation during ICS reduction, with an estimated absolute reduction at 6 months of 9 to 10 percentage points; the reduction was primarily due to an effect on moderate exacerbations. Treatment-related adverse events were common at both active doses. Further studies are needed to assess long-term efficacy and safety. TRIAL REGISTRATION clinicaltrialsregister.eu Identifier: 2010-018621-19.

The causal direction in the association between respiratory syncytial virus hospitalization and asthma.

BACKGROUND Earlier studies have reported an increased risk of asthma after respiratory syncytial virus (RSV) hospitalization. Other studies found that asthmatic disposition and propensity to wheeze increase the risk of RSV hospitalization. OBJECTIVE The current study examined the causal direction of the associations between RSV hospitalization and asthma in a population-based cohort of twins. METHODS We conducted a prospective cohort study examining the associations between RSV hospitalization and asthma by using registry information on RSV hospitalization and asthma among 18,614 Danish twins born 1994 to 2003. The associations between RSV and asthma were examined in both directions: we examined the risk of asthma after RSV hospitalization, and the risk of RSV hospitalization in children with asthma in the same population-based cohort. RESULTS Asthma hospitalization after RSV hospitalization was increased as much as 6-fold to 8-fold during the first 2 months after RSV hospitalization but was no longer increased 1 year later. Asthma increased the risk of RSV hospitalization by 3-fold, and the risk was not time-dependent. Analyzing these associations on the basis of asthma defined from use of inhaled corticosteroid did not materially change the risk estimates. CONCLUSION There is a bidirectional association between severe RSV infection and asthma. Severe RSV infection is associated with a short-term increase in the risk of subsequent asthma, suggesting that RSV induce bronchial hyperresponsiveness; and asthma is associated with a long-term increased susceptibility for severe RSV disease, suggesting a host factor being responsible for the severe response to RSV infection. This suggests that severe RSV infection and asthma may share a common genetic predisposition and/or environmental exposure.

Relationship between airway responsiveness to mannitol and to methacholine and markers of airway inflammation, peak flow variability and quality of life in asthma patients

Background Airway hyperresponsiveness (AHR) to stimuli that cause bronchial smooth muscle (BSM) contraction indirectly through the release of endogenous mediators is thought to reflect airway inflammation more closely compared with AHR measured by stimuli that act directly on BSM.

Inflammatory Subtypes in Asthma are Related to Airway Hyperresponsiveness to Mannitol and Exhaled NO

Asthma may be defined as eosinophilic or non-eosinophilic based on the presence of eosinophils in sputum. Recently a further classification into four inflammatory subtypes has been suggested. The aim of the present study was to describe the association between these inflammatory subtypes and markers of airway inflammation and hyperresponsiveness. In 62 adult non-smoking asthmatics, (18–65 yr) not taking inhaled steroids, sputum induction, bronchial challenge with mannitol and measurement of exhaled NO (eNO) were performed. Based on the eosinophil and neutrophil proportions in sputum, subjects were categorised into four inflammatory subtypes: Eosinophilic asthma: i.e., sputum eosinophils > 1.0%. Neutrophilic asthma: i.e., sputum neutrophils > 61%. Mixed granulocytic asthma: both increased eosinophils and neutrophils. Paucigranulocytic asthma: i.e., normal levels of both eosinophils and neutrophils. Among subjects with non-eosinophilic asthma, neutrophilic asthma was associated with low levels of eNO (Median (IQR): 12 ppb (8–27 ppb), whereas subjects with non-eosinophilic asthma of the paucigranulocytic subtype had levels of eNO (48 ppb (29–65 ppb)) that were comparable to subjects with eosinophilic asthma of the mixed granulocytic type (47 ppb (33–112 ppb). Purely eosinophilic asthma was associated with higher levels of eNO (77 ppb (37–122 ppb)). Furthermore, a low degree of airway hyperresponsiveness to mannitol was observed in neutrophilic asthma (PD15: (Median (IQR) 512 mg (291–610 mg))), whereas it was moderate in paucigranulocytic asthma (238 mg (77–467 mg)) and comparable to eosinophilic asthma of the mixed granulocytic subtype (186 mg (35–355 mg)). The highest degree of AHR to mannitol was observed in purely eosinophilic asthma (107 mg (68–245 mg)). In conclusion, further subclassification of eosinophilic and non-eosinophilic asthma showed significant differences in airway hyperresponsiveness to mannitol and exhaled NO levels among the four inflammatory subtypes.