Pharmacogenetics of anti-inflammatory treatment in children with asthma: rationale and design of the PACMAN cohort

ADRB2 haplotypes and asthma exacerbations in children and young adults: An individual participant data meta-analysis

BACKGROUND

The polymorphism Arg16 in β2 -adrenergic receptor (ADRB2) gene has been associated with an increased risk of exacerbations in asthmatic children treated with long-acting β2 -agonists (LABA). However, it remains unclear whether this increased risk is mainly attributed to this single variant or the combined effect of the haplotypes of polymorphisms at codons 16 and 27.

OBJECTIVE

We assessed whether the haplotype analysis could explain the association between the polymorphisms at codons 16 (Arg16Gly) and 27 (Gln27Glu) in ADRB2 and risk of asthma exacerbations in patients treated with inhaled corticosteroids (ICS) plus LABA.

METHODS

The study was undertaken using data from 10 independent studies (n = 5903) participating in the multi-ethnic Pharmacogenomics in Childhood Asthma (PiCA) consortium. Asthma exacerbations were defined as asthma-related use of oral corticosteroids or hospitalizations/emergency department visits in the past 6 or 12 months prior to the study visit/enrolment. The association between the haplotypes and the risk of asthma exacerbations was performed per study using haplo.stats package adjusted for age and sex. Results were meta-analysed using the inverse variance weighting method assuming random-effects.

RESULTS

In subjects treated with ICS and LABA (n = 832, age: 3-21 years), Arg16/Gln27 versus Gly16/Glu27 (OR: 1.40, 95% CI: 1.05-1.87, I2  = 0.0%) and Arg16/Gln27 versus Gly16/Gln27 (OR: 1.43, 95% CI: 1.05-1.94, I2  = 0.0%), but not Gly16/Gln27 versus Gly16/Glu27 (OR: 0.99, 95% CI: 0.71-1.39, I2  = 0.0%), were significantly associated with an increased risk of asthma exacerbations. The sensitivity analyses indicated no significant association between the ADRB2 haplotypes and asthma exacerbations in the other treatment categories, namely as-required short-acting β2 -agonists (n = 973), ICS monotherapy (n = 2623), ICS plus leukotriene receptor antagonists (LTRA; n = 338), or ICS plus LABA plus LTRA (n = 686).

CONCLUSION AND CLINICAL RELEVANCE

The ADRB2 Arg16 haplotype, presumably mainly driven by the Arg16, increased the risk of asthma exacerbations in patients treated with ICS plus LABA. This finding could be beneficial in ADRB2 genotype-guided treatment which might improve clinical outcomes in asthmatic patients.

Nonadherence to inhaled corticosteroids: A characteristic of the pediatric obese-asthma phenotype?

BACKGROUND

Children with excess weight and asthma tend to respond less well to inhaled corticosteroids (ICS) than children with normal weight, potentially resulting in nonadherence to ICS.

OBJECTIVES

To assess whether excess weight (body mass index ≥85th percentile) was associated with general, unintentional, and intentional nonadherence to ICS in children with asthma.

METHODS

We analyzed data from 566 children aged 4-13 years with asthma, who used ICS as maintenance therapy, from the cross-sectional Pharmacogenetics of Asthma medication in Children: Medication with Anti-inflammatory effects study. General nonadherence was measured objectively with the proportion of days covered (<50%) and subjectively with the parent-reported Medication Adherence Rating Scale (MARS <21) reflecting parent-reported nonadherent behavior. Unintentional and intentional nonadherence were defined as forgetting to take medication and deliberately changing or skipping doses, respectively, from specific items of the MARS. We performed logistic regression analyses, stratifying estimates by asthma severity and age group.

RESULTS

Excess weight was associated with a trend towards increased odds of parent-reported nonadherent behavior (odds ratio [OR]: 1.54; 95% confidence interval [CI]: 0.84-2.81) and objectively measured general nonadherence, but only in moderate-to-severe asthma (OR: 1.71; 95% CI: 0.84-3.48). The odds of intentional, but not unintentional, nonadherence seemed to be greater in children with excess weight than normal weight (OR: 1.94; 95% CI: 0.94-4.01), and the association appeared to be stronger in younger (OR: 2.17; 95% CI 1.00-4.73) versus older children (OR: 1.18; 95% CI: 0.36-3.94).

CONCLUSIONS

Excess weight was associated with general nonadherence to ICS, but only in children with moderate-to-severe asthma, and nonadherent behavior, which seemed to be intentional.

Pharmacogenomic Testing In Pediatrics: Navigating The Ethical, Social, And Legal Challenges

For the past several years, the implementation of pharmacogenetic (PGx) testing has become widespread in several centers and clinical practice settings. PGx testing may be ordered at the point-of-care when treatment is needed or in advance of treatment for future use. The potential benefits of PGx testing are not limited to adult patients, as children are increasingly using medications more often and at earlier ages. This review provides some background on the use of PGx testing in children as well as mothers (prenatally and post-natally) and discusses the challenges, benefits, and the ethical, legal, and social implications of providing PGx testing to children.

FCER2 T2206C variant associated with FENO levels in asthmatic children using inhaled corticosteroids: The PACMAN study

BACKGROUND

The FCER2 gene, via encoding of the CD23 receptor, plays an important role in the regulation of IgE responses. A genetic variant of the FCER2 gene (T2206C) was previously shown to be associated with IgE levels in asthmatic children. IgE sensitization has also been linked to increased levels of fractional exhaled nitric oxide (FENO).

OBJECTIVE

To investigate whether the FCER2 T2206C variant influences FENO levels in asthmatic children with a reported use of inhaled corticosteroids (ICS).

METHODS

This cross-sectional study involved 593 asthmatic children with a reported use of ICS, availability of FENO measurements and genotyping data on the FCER2 T2206C variant (rs28364072). An additive genetic model was assumed, and the association between the FCER2 T2206C variant and the log-transformed (ln) FENO levels was evaluated using linear regression analysis, adjusted for age, sex, adapted British Thoracic Society (BTS) treatment steps and atopy.

RESULTS

The mean age of the population was 9.1 ± 2.2 years, and the median of FENO levels was 13.0 ppb with an interquartile range (IQR) of (8.0-27.5 ppb). The minor allele (G) frequency of rs28364072 was 29.6%, and each extra copy of the G allele was significantly associated with a lower level of the geometric mean of FENO (log scale, β = -0.12, 95% CI: -0.23, -0.02).

CONCLUSION AND CLINICAL RELEVANCE

Our results showed that the FCER2 T2206C variant was significantly associated with lower FENO levels in carriers of the G allele. Nevertheless, this SNP contributed little to the variability in FENO levels in this patient population. Our findings contribute to the present knowledge on FENO in asthmatic children; however, future replication studies are required to establish the role of this gene in relation to FENO.

Patterns of topical corticosteroids prescriptions in children with asthma

OBJECTIVES

To study topical corticosteroid use in Dutch asthmatic children using pharmacy dispensing data and to assess whether Dutch physicians prescribe topical corticosteroids in this population according to clinical guidelines.

METHODS

Medication histories of children using asthma medication were extracted from the pharmacy dispensing system in 100 Dutch community pharmacies. The incidence rate and the potency of topical corticosteroid prescriptions per age were assessed. The topical corticosteroid incidence rates of the different age groups were compared using the Pearson chi-square test. Generalized linear models were used to study the prescription behavior of general practitioners and atopic dermatitis-related specialists regarding different classes of topical corticosteroids.

RESULTS

Thirty percent of the infants received a topical corticosteroid prescription, compared with 15%-18% of the children aged 4 and older. Similarly, the mean number of topical corticosteroid prescriptions in infants was 2.2 per year, compared with 1.6-1.9 in children aged 4 and older. In concordance with the clinical guidelines, we observed that atopic dermatitis-related specialists more often prescribed first prescriptions of potent and very potent topical corticosteroids than general practitioners (relative risk = 2.55, 95% confidence interval = 1.79-3.63). Statistically significant differences (P < .01) were found between potencies of prescribed topical corticosteroids.

CONCLUSION

Younger children receive more topical corticosteroid prescriptions than children aged 4 and older, and there is a statistically significantly higher prescription rate of topical corticosteroid for infants. Sometimes general practitioners do not follow guidelines and prescribe more-potent topical corticosteroids without a prior prescription of the same potency by a specialist.

Breastfeeding is associated with a decreased risk of childhood asthma exacerbations later in life

BACKGROUND

Breastfeeding has been suggested to influence the risk of asthma and asthma severity in children. However, the conclusions from epidemiologic studies are inconsistent.

METHODS

We used data from 960 children (aged 4-12 years) using regular asthma medication who participated in the PACMAN study. Breastfeeding exposure was based on questionnaire data and stratified into (i) ever vs never, and (ii) ≥6 vs <6 months duration of breastfeeding. Asthma severity was based on the occurrence of asthma exacerbations in the preceding year and/or poorly controlled asthma symptoms during the last week of study visit. Odds ratios (ORs) were derived from univariate and multivariable logistic regression analyses.

RESULTS

Breastfeeding was associated with a decreased risk of asthma exacerbations; adjusted (adj.) OR: 0.55 (95% confidence interval [CI]: 0.35-0.87). After stratification for duration of breastfeeding, the adj. ORs were 0.48 (95% CI: 0.27-0.84) for duration <6 months and 0.71 (95% CI: 0.43-1.20) for duration ≥6 months breastfeeding. When we stratified the analysis by family history of asthma, the association between breastfeeding and asthma exacerbations was strong and statistically significant only in children with a positive family history of asthma; adj. OR: 0.34 (95% CI: 0.18-0.66). There was no association between breastfeeding and risk of poor asthma control; adj. OR: 1.04 (95% CI: 0.76-1.41).

CONCLUSION

In a pediatric population with asthma, children who had been breastfed had a statistically significantly lower risk of asthma exacerbations later in life compared to asthmatic children who had not been breastfed.

Early life antibiotic use and the risk of asthma and asthma exacerbations in children

BACKGROUND

The use of antibiotic therapy early in life might influence the risk of developing asthma. Studies assessing the influence of early life antibiotic use on the risk of asthma exacerbations are limited, and the results are inconsistent. Therefore, the aim of this study was to assess the association between use of antibiotic during the first 3 years of life and the risk of developing childhood asthma and the occurrence of asthma exacerbations.

METHODS

Data from four large childhood cohorts were used; two population-based cohorts to study the risk of developing asthma: Generation R (n=7393, The Netherlands) and SEATON (n=891, Scotland, UK), and two asthma cohorts to assess the risk of asthma exacerbations: PACMAN (n=668, The Netherlands) and BREATHE (n=806, Scotland, UK). Odds ratios (ORs) were derived from logistic regression analysis within each database followed by pooling the results using a fixed- or random-effect model.

RESULTS

Antibiotic use in early life was associated with an increased risk of asthma in a meta-analysis of the Generation R and SEATON data (OR: 2.18, 95% CI: 1.04-4.60; I² : 76.3%). There was no association between antibiotic use in early life and risk of asthma exacerbations later in life in a meta-analysis of the PACMAN and BREATHE data (OR: 0.93, 95% CI: 0.65-1.32; I² : 0.0%).

CONCLUSION

Children treated with antibiotic in the first 3 years of life are more likely to develop asthma, but there is no evidence that the exposure to antibiotic is associated with increased risk of asthma exacerbations.

Rationale and design of the multiethnic Pharmacogenomics in Childhood Asthma consortium

AIM

International collaboration is needed to enable large-scale pharmacogenomics studies in childhood asthma. Here, we describe the design of the Pharmacogenomics in Childhood Asthma (PiCA) consortium.

MATERIALS & METHODS

Investigators of each study participating in PiCA provided data on the study characteristics by answering an online questionnaire.

RESULTS

A total of 21 studies, including 14,227 children/young persons (58% male), from 12 different countries are currently enrolled in the PiCA consortium. Fifty six percent of the patients are Caucasians. In total, 7619 were inhaled corticosteroid users. Among patients from 13 studies with available data on asthma exacerbations, a third reported exacerbations despite inhaled corticosteroid use. In the future pharmacogenomics studies within the consortium, the pharmacogenomics analyses will be performed separately in each center and the results will be meta-analyzed.

CONCLUSION

PiCA is a valuable platform to perform pharmacogenetics studies within a multiethnic pediatric asthma population.

Atopic dermatitis characteristics and medication-use patterns in school-age children with AD and asthma symptoms

BACKGROUND

Atopic dermatitis (AD) and asthma often coexist. Both diseases can have a major impact on the lives of children with AD and their caregivers.

AIM

To investigate the association of patient characteristics, comorbidities and impact of AD on children who have both asthma and AD.

METHODS

Children with AD (n = 140) were selected from a larger cohort of children with a reported use of asthma medication. The Children's Dermatology Life Quality Index (CDLQI) was used to assess Quality of Life (QoL), and the Self-Assessed Eczema Area and Severity Index (SA-EASI) was used to measure AD severity. Characteristics assessed included: age, sex, and the number and type of atopic comorbidities. Medication use for AD was defined using the total number of AD prescriptions, the number of different topical AD prescriptions and the highest potency topical corticosteroid (TCS) used. Determinants of AD severity and QoL were evaluated using Spearman rank tests.

RESULTS

The following factors were most strongly associated with a lower QoL: characteristics of AD lesions (Spearman R_s = 0.61-0.69, P < 0.01), a higher SA-EASI score (R_s = 0.54, P < 0.01) and a larger number of different topical AD prescriptions (R_s = 0.38, P < 0.01). The following factors were correlated with more severe AD: age (R_s = -0.36, P < 0.01), larger number of different TCS preparations used (R_s = 0.27, P < 0.05) and larger number of TCS prescriptions (R_s = 0.25, P < 0.05).

CONCLUSION

In children with asthma and AD, the number of TCS preparations used is associated with lower QoL and increased AD severity.

Childhood asthma exacerbations and the Arg16 β2-receptor polymorphism: A meta-analysis stratified by treatment

BACKGROUND

The Gly-to-Arg substitution at the 16 position (rs1042713) in the β2-adrenoceptor gene (ADRB2) is associated with enhanced downregulation and uncoupling of β2-receptors.

OBJECTIVES

We sought to undertake a meta-analysis to test the hypothesis that there is an interaction between the A allele of rs1042713 (Arg16 amino acid) and long-acting β-agonist (LABA) exposure for asthma exacerbations in children.

METHODS

Children with diagnosed asthma were recruited in 5 populations (BREATHE, Genes-Environments and Admixture in Latino Americans II, PACMAN, the Paediatric Asthma Gene Environment Study, and the Pharmacogenetics of Adrenal Suppression with Inhaled Steroid Study). A history of recent exacerbation and asthma treatment was determined from questionnaire data. DNA was extracted, and the Gly16Arg genotype was determined.

RESULTS

Data from 4226 children of white Northern European and Latino origin were analyzed, and the odds ratio for exacerbation increased by 1.52 (95% CI, 1.17-1.99; P = .0021) for each copy of the A allele among the 637 children treated with inhaled corticosteroids (ICSs) plus LABAs but not for treatment with ICSs alone (n = 1758) or ICSs plus leukotriene receptor antagonist (LTRAs; n = 354) or ICSs plus LABAs plus LTRAs (n = 569).

CONCLUSIONS

The use of a LABA but not an LTRA as an "add-on controller" is associated with increased risk of asthma exacerbation in children carrying 1 or 2 A alleles at rs1042713. Prospective genotype-stratified clinical trials are now required to explore the potential role of rs1042713 genotyping for personalized asthma therapy in children.

High incidence of oral corticosteroids prescriptions in children with asthma in early childhood

OBJECTIVE

Severe asthma exacerbations are often treated with short courses of oral corticosteroids (OCS). This study assessed the incidence of OCS being prescribed in asthmatic children of various age groups and calculated their chances of receiving subsequent OCS prescriptions.

METHODS

Longitudinal Dutch community pharmacy data of 2272 children who were regular users of asthma medication was analyzed retrospectively. Incidence rates for first, second and third prescriptions of OCS were calculated, stratified by age and sex. Probabilities of receiving first, second or third OCS prescriptions were assessed with Kaplan-Meier analysis.

RESULTS

Incidence rates for first OCS prescriptions were 4.5 for the 1(st) year of life per 100 person-years (100PY); 3.9 for the 2(nd); 4.6 for the 3(rd); 4.2 for the 4(th), and 4.7 for the 5(th) year of life per 100PY. This was relatively high compared to incidence rates for children between the ages of 6 and 11 (ranging between 2.2 per 100PY (age 9) and 3.7(age 11)). Incidence rates for second and third OCS prescriptions were very high: 78.2(95%CI: 45.0-123.7) and 241.2(95%CI: 81.2-583.4) per 100PY for infants, respectively. The chances of receiving a first OCS prescription was higher in males (P value < 0.01).

CONCLUSIONS

In the Netherlands, the incidence of OCS being prescribed to children being treated with asthma medication in early childhood is relatively high for first OCS prescriptions and extremely high for second and third OCS prescriptions compared to other ages. Furthermore, there is a high probability of receiving a further OCS prescription shortly after an OCS prescription.

ST13 polymorphisms and their effect on exacerbations in steroid-treated asthmatic children and young adults

BACKGROUND

The clinical response to inhaled corticosteroids (ICS) is associated with single nucleotide polymorphisms (SNPs) in various genes. This study aimed to relate variations in genes in the steroid pathway and asthma susceptibility genes to exacerbations in children and young adults treated with ICS.

METHODS

We performed a meta-analysis of three cohort studies: Pharmacogenetics of Asthma Medication in Children: Medication with Anti-Inflammatory effects (n = 357, age: 4-12 years, the Netherlands), BREATHE (n = 820, age: 3-22 years, UK) and Paediatric Asthma Gene Environment Study (n = 391, age: 2-16 years, UK). Seventeen genes were selected based on a role in the glucocorticoid signalling pathway or a reported association with asthma. Two outcome parameters were used to reflect exacerbations: hospital visits and oral corticosteroid (OCS) use in the previous year. The most significant associations were tested in three independent validation cohorts; the Childhood Asthma Management Programme (clinical trial, n = 172, age: 5-12 years, USA), the Genes- environment and Mixture in Latino Americans II- study (n = 745, age: 8-21, USA) and the Pharmacogenetics of adrenal suppression cohort (n = 391, age: 5-18, UK) to test the robustness of the findings. Finally, all results were meta-analysed.

RESULTS

Two SNPs in ST13 (rs138335 and rs138337), but not in the other genes, were associated at a nominal level with an increased risk of exacerbations in asthmatics using ICS in the three cohorts studied. In a meta-analysis of all six studies, ST13 rs138335 remained associated with an increased risk of asthma-related hospital visits and OCS use in the previous year; OR = 1.22 (P = 0.013) and OR = 1.22 (P = 0.0017), respectively.

CONCLUSION AND CLINICAL RELEVANCE

A novel susceptibility gene, ST13, coding for a cochaperone of the glucocorticoid receptor, is associated with exacerbations in asthmatic children and young adults despite their ICS use. Genetic variation in the glucocorticoid signalling pathway may contribute to the interindividual variability in clinical response to ICS treatment in children and young adults.

Characteristics and severity of asthma in children with and without atopic conditions: a cross-sectional study

Background

Childhood allergic diseases have a major impact on a child’s quality of life, as well as that of their parents. We studied the coexistence of reported allergies in children who use asthma medication. Additionally, we tested the hypothesis that asthma severity is greater among children with certain combinations of co-morbid allergic conditions.

Methods

For this cross-sectional study, 703 children (ages 4 to 12 years) from the PACMAN cohort study were selected. All of the children were regular users of asthma medication. The study population was divided into nine subgroups according to parental-reported allergies of the child (hay fever, eczema, food allergy or combinations of these). In order to assess whether these subgroups differed clinically, the groups were compared for child characteristics (age, gender, family history of asthma), asthma exacerbations in the past year (oral corticosteroids (OCS) use; asthma-related emergency department (ED) visits), asthma control, fractional exhaled nitric oxide level (FeNO), and antihistaminic usage.

Results

In our study, 79.0 % of the parents reported that their child suffered from at least one atopic condition (hay fever, food allergy and eczema), and one quarter of the parents (25.6 %) reported that their child suffered from all three atopic conditions. Having more than one atopic condition was associated with an increased risk of OCS use (OR = 3.3, 95 % CI = 1.6 – 6.6), ED visits (OR = 2.3, 95 % CI = 1.2 – 4.6) in the past year and inadequate short term asthma control (OR = 1.9, 95 % CI = 1.3 – 2.8).

Conclusions

Children who use asthma medication often also have other allergic conditions. Parental reported allergies were associated with a higher risk of more severe asthma (more asthma complaints and more asthma exacerbations).

Pharmacogenetic analysis of GLCCI1 in three north European pediatric asthma populations with a reported use of inhaled corticosteroids

BACKGROUND

GLCCI1 rs37972 has previously been associated with decreased lung function improvement upon treatment with inhaled corticosteroids (ICS) in asthmatics.

AIM

To assess whether variation in rs37972 is associated with altered ICS efficacy in north European asthmatic children and young adults with a reported use of ICS.

PATIENTS & METHODS

rs37972 was genotyped in three cohort studies of asthmatic children with a reported use of ICS. As an indicator for asthma exacerbations, asthma-related hospital visits and oral corticosteroid use were studied. Asthma control was assessed using a questionnaire.

RESULTS

rs37972 T allele was not significantly associated with an increased risk of oral corticosteroid use (summary odds ratio: 1.20; 95% CI: 0.99-1.45), an increased risk of asthma-related hospital visits (summary odds ratio: 1.07; 95% CI: 0.89-1.29), uncontrolled symptoms (summary odds ratio: 1.01; 95% CI: 0.75-1.36) or higher ICS dosages (summary β: 0.01, 95% CI: -0.06-0.08).

CONCLUSION

Variation in GLCCI1 rs37972 genotype does not seem to affect ICS efficacy in north European asthmatic children. Original submitted 26 November 2013; Revision submitted 13 February 2014.

Respiratory tract infections and asthma control in children

INTRODUCTION

Asthma control is considered the major goal of asthma management, while many determinants of control are difficult to modify. We studied the association between respiratory infection episodes (RTIs) of various types and asthma control.

METHODS

Cross-sectional data were used from children aged 4-18 years with physician-diagnosed asthma who participated in a web-based electronic portal for children with asthma, allergies or infections. Asthma control was measured using the Childhood Asthma Control Test (C-ACT) or the Asthma Control Test (ACT). Linear regression was used to analyse the association between categories of numbers of various types of RTIs sustained in the preceding 12 months (categorized) and asthma control, adjusted for potential confounders.

RESULTS

Asthma control was assessed in 654 children, and 68.5% were clinically well controlled (ACT ≥ 20). Higher total numbers of RTIs in the last 12 months were strongly associated with a lower level of asthma control (p(trend) < 0.001). Similarly strong statistically significant associations were found for subtypes of RTI: ≥4 vs. 0 otitis episodes: coefficient -1.7 (95% CI -3.3 to -0.2); ≥5 vs.0 colds: coefficient -2.3 (95% CI -3.0 to -1.6); ≥3 vs. 0 bronchitis episodes: coefficient -3.1 (95% CI -4.0 to -2.3), each with p(trend) < 0.05.

CONCLUSION

Higher numbers of reported respiratory tract infections are associated with lower level of asthma control. The different type of respiratory tract infections contribute equally to less controlled asthma.

Arg16 ADRB2 genotype increases the risk of asthma exacerbation in children with a reported use of long-acting β2-agonists: results of the pacman cohort

Background: Current evidence suggests that asthma patients with the ADRB2 Arg16 genotype have a poorer response to long-acting β2-agonists (LABA), but the results remain inconsistent. Aim: This study assessed the association between Arg16 variants and treatment outcome in children treated with inhaled corticosteroids (ICS) and LABA. Materials & methods: ADRB2 Arg16 was genotyped in 597 children (4–12 years of age) participating in the PACMAN cohort study. A questionnaire was used to assess asthma control, frequency of asthma-related emergency department visits and use of oral corticosteroids in the past year. Results: Arg/Arg carriers with a reported use of ICS and LABA had an increased risk of oral corticosteroid use (odds ratio: 14.9; 95% CI: 1.59–140.1) and emergency department visits in the past year (odds ratio: 11.9; 95% CI: 1.22–115.8) compared to Gly/Gly carriers. This effect was not observed in Arg/Arg genotype carriers reporting ICS use only. Conclusion: Children who are homozygous for ADRB2 Arg16 have an increased risk of exacerbations when treated with combined LABA and ICS.

Original submitted 4 September 2013; Revision submitted 27 September 2013

Inflammatory phenotypes underlying uncontrolled childhood asthma despite inhaled corticosteroid treatment: rationale and design of the PACMAN2 study

BACKGROUND

The diagnosis of childhood asthma covers a broad spectrum of pathological mechanisms that can lead to similarly presenting clinical symptoms, but may nonetheless require different treatment approaches. Distinct underlying inflammatory patterns are thought to influence responsiveness to standard asthma medication.

METHODS/DESIGN

The purpose of the PACMAN2 study is to identify inflammatory phenotypes that can discriminate uncontrolled childhood asthma from controlled childhood asthma by measures in peripheral blood and exhaled air. PACMAN2 is a nested, case-control follow-up study to the ongoing pharmacy-based "Pharmacogenetics of Asthma medication in Children: Medication with Anti-inflammatory effects" (PACMAN) study. The original PACMAN cohort consists of children aged 4-12 years with reported use of asthma medication. The PACMAN2 study will be conducted within the larger PACMAN cohort, and will focus on detailed phenotyping of a subset of the PACMAN children. The selected participants will be invited to a follow-up visit in a clinical setting at least six months after their baseline visit based on their adherence to usage of inhaled corticosteroids, their asthma symptoms in the past year, and their age (≥ 8 years). During the follow-up visit, current and long-term asthma symptoms, medication use, environmental factors, medication adherence and levels of exhaled nitric oxide will be reassessed. The following measures will also be examined: pulmonary function, exhaled volatile organic compounds, as well as inflammatory markers in peripheral blood and blood plasma. Comparative analysis and cluster-analyses will be used to identify markers that differentiate children with uncontrolled asthma despite their use of inhaled corticosteroids (ICS) (cases) from children whose asthma is controlled by the use of ICS (controls).

DISCUSSION

Asthmatic children with distinct inflammatory phenotypes may respond differently to anti-inflammatory therapy. Therefore, by identifying inflammatory phenotypes in children with the PACMAN2 study, we may greatly impact future personalised treatment strategies, uncover new leads for therapeutic targets and improve the design of future clinical studies in the assessment of the efficacy of novel therapeutics.

Technical report: Ethical and policy issues in genetic testing and screening of children

The genetic testing and genetic screening of children are commonplace. Decisions about whether to offer genetic testing and screening should be driven by the best interest of the child. The growing literature on the psychosocial and clinical effects of such testing and screening can help inform best practices. This technical report provides ethical justification and empirical data in support of the proposed policy recommendations regarding such practices in a myriad of settings.

Exhaled NO is a poor marker of asthma control in children with a reported use of asthma medication: a pharmacy-based study

BACKGROUND

A high fraction of nitric oxide in exhaled breath (FeNO) has been suggested to be a marker of ongoing airway inflammation and poorly controlled disease in asthma. The usefulness of FeNO to monitor asthma control is still debated today.

AIM

To assess the validity of FeNO as a marker of asthma control in children with reported use of asthma medication.

METHODS

Fraction of nitric oxide in exhaled breath was measured in 601 children (aged 4-12 yr) with reported use of asthma medication in the past 6 months and in 63 healthy non-asthmatic children (aged 5-12). Asthma control was assessed by the Asthma Control Questionnaire (ACQ). A receiver-operator characteristics (ROC) curve was generated to assess the accuracy of FeNO as a marker for asthma control. Logistic regression analysis was used to study whether clinical, healthcare, medication, and environmental factors are associated with high FeNO levels (>25 ppb).

RESULTS

Fraction of nitric oxide in exhaled breath had a poor accuracy to discriminate well-controlled from not well-controlled asthma [area under the ROC curve: 0.56 (95% CI: 0.52-0.61, p = 0.008)]. In addition, high FeNO (>25 ppb) was associated with lower medication adherence rates (OR: 0.4; 95% CI 0.3-0.6), fewer antibiotic courses in the past year (OR: 0.6; 95% CI: 0.4-0.9), fewer leukotriene antagonists use in the past year (OR: 0.4; 95% CI: 0.2-0.9), and fewer visits to a (pulmonary) pediatrician (OR: 0.6; 95% CI: 0.4-0.9). Children living in a non-urban environment had more often high FeNO levels (OR: 1.7; 95% CI: 1.1-2.6).

CONCLUSION

High FeNO is a poor marker of asthma control in children with reported use of asthma medication. Various other factors, including medication adherence and medication use, are associated with increased FeNO levels.

Limited agreement between current and long-term asthma control in children: the PACMAN cohort study

BACKGROUND

Several studies have shown that predictors of asthma treatment outcomes differ depending on the definition of the outcome chosen. This provides evidence that different outcomes studied may reflect distinct aspects of asthma control. To assess predictors of asthma control, we need firm outcome phenotypes. The aim of this study was to investigate the association between measurements of current and long-term asthma control.

METHODS

We included 527 children using inhaled corticosteroids participating in the Pharmacogenetics of Asthma medication in Children: Medication with ANti-inflammatory effects cohort. Current asthma control (previous week) was defined using the Asthma Control Questionnaire. Long-term asthma control was based on Global Initiative for Asthma guidelines. Not well-controlled asthma in a season was defined as ≥ 3 of the following items present in a season: (i) day-time or (ii) night-time symptoms, (iii) limitations in activities, and (iv) rescue medication use. Asthma control during (i) the previous season and (ii) the year preceding the pharmacy visit was used as long-term asthma control definitions. Current and long-term asthma control were compared to investigate agreement.

RESULTS

Long-term uncontrolled asthma rates were highest in autumn and winter (50%) and lowest in summer (32%) (p < 0.05). Overall agreement between current and long-term asthma control was limited (66% for previous season and 68% for previous year).

CONCLUSION

Congruence between current and long-term asthma control was limited. Furthermore, we showed significant seasonal differences. It is therefore important to calculate asthma control over a longer period of time, instead of using current asthma control as indicator.

FCER2 T2206C variant associated with chronic symptoms and exacerbations in steroid-treated asthmatic children

BACKGROUND

The T2206C FCER2 variant was found previously to be associated with IgE levels, exacerbation rates and decreased FCER2 expression in children on inhaled corticosteroids (ICS) participating in a clinical trial. This finding has not been replicated. We sought to replicate the association between the FCER2 gene and exacerbations in children with asthma. In addition, we tested the hypothesis that the T2206C variant may be associated with other markers of steroid resistance such as asthma symptom scores and asthma medication use.

METHODS

The influence of the T2206C variant on asthma exacerbations (emergency department visits or hospitalization), symptoms scores and medication use was explored using data from two populations of asthmatic children using ICS: Pharmacogenetics of Asthma medication in Children: Medication with ANti-inflammatory effects study (n = 386) and BREATHE study (n = 939).

RESULTS

The T2206C variant was associated with increased risk of asthma-related hospital visits in both cohorts (OR: 1.91, 95% CI: 1.08-3.40), and meta-analysis with previously published results was highly significant (OR: 2.38, 95% CI: 1.47-3.85, P = 0.0004). The FCER2 variant was also associated with increased risk of uncontrolled asthma measured by Asthma Control Questionnaire (OR: 2.64, 95% CI: 1.00-6.98) and was associated with increased daily steroid dose (OR: 2.46, 95% CI: 1.38-4.39).

CONCLUSION

The association between the FCER2 T2206C variant and asthma-related hospitalizations in steroid-treated asthma appears robust and may also be associated with other indicators of lack of ICS efficacy such as asthma symptoms and a requirement for higher daily doses of ICS. Our results suggest that the FCER2 T2206C variant might be a useful pharmacogenetic predictor of steroid refractory patients.

Inhaled corticosteroid adherence in paediatric patients: the PACMAN cohort study

AIMS

Poor adherence with inhaled corticosteroids (ICSs) has been reported frequently and may be associated with uncontrolled asthma. A better understanding of factors influencing adherence may help to achieve higher adherence rates for a larger part of the population, which will eventually lead to better asthma control. The aim of this study was to investigate factors associated with adherence in paediatric ICS users.

METHODS

We included 527 children using ICSs who participated in the Pharmacogenetics of Asthma Medication in Children: Medication with Anti-inflammatory Effects (PACMAN) cohort study. The outcome, a parent-reported adherence, was assessed by using the Medication Adherence Report Scale. Four categories of determinants were studied: child characteristics, family characteristics, medication use (parental beliefs towards medication; using Beliefs about Medicines Questionnaire) and environmental factors.

RESULTS

Good adherence was observed in 302 children (57%). Increased fractional exhaled nitric oxide values (indication for airway inflammation) were associated with a lower chance of good adherence (OR = 0.25, 95%CI = 0.15-0.41). Parental necessity beliefs about medication were associated with higher adherence (OR = 2.32, 95%CI = 1.59-3.39). Dutch origin was also associated with higher adherence rates (OR = 2.11, 95%CI = 1.09-4.07). Furthermore, younger age (< 6 years) was associated with better adherence (OR = 1.62, 95%CI = 1.02-2.59).

CONCLUSIONS

Increased airway inflammation was associated with lower ICS adherence, which underlines the need of good adherence to reach disease control. Our results suggest that by improving knowledge, especially in ethnic minorities, and by stimulating positive parental perception towards the nature of the disease, the characteristics of the prescribed drugs and the use of medications, better adherence and as a result better asthma control could be reached.

Asthma symptoms in pediatric patients: differences throughout the seasons

INTRODUCTION

Seasonal variation in asthma has been widely recognized. The aim of this study was to describe seasonal patterns of asthma symptoms and asthma medication use in a cohort of pediatric asthma medication users and to study determinants of seasonal childhood asthma.

METHODS

For this study, 602 children participating in the Pharmacogenetics of Asthma medication in Children: Medication with Anti-inflammatory effects) cohort were included. Parents were asked about their child's respiratory symptoms and quick-reliever medication use over the past year. Logistic regression analysis was used to study determinants of seasonality in asthma control (the level of disease control based on symptoms, limitations in activities, and rescue medication use).

RESULTS

There was a decline in asthma symptoms and asthma medication use during the summer period and a peak occurred from autumn to spring. The prevalence of wheeze ranged from 32% in summer to 56% in autumn. The prevalence of respiratory symptoms and medication use was significantly lower during summer (p < .0001). Oral steroids and antibiotics use and strong parental necessity beliefs were associated with uncontrolled asthma, regardless of seasonality. Allergic rhinitis was associated with an increased risk of uncontrolled asthma during spring [odds ratio (OR): 1.9; 95% confidence interval (CI): 1.3-2.8] and summer (OR: 1.9; 95% CI: 1.2-3.0). Eczema was associated with a higher risk of uncontrolled asthma during autumn (OR: 1.5; 95% CI: 1.0-2.2) and winter (OR: 1.3; 95% CI: 1.0-1.9).

CONCLUSION

We showed seasonal patterns in asthma symptoms and medication use. Associations were shown between allergic rhinitis and asthma control during spring/summer and eczema was associated with uncontrolled asthma during autumn/winter. Seasonality in asthma morbidity and health-care use is most likely associated with atopic constitution and viral infections, which are common during fall, winter, and spring.

Chronic obstructive pulmonary disease: towards pharmacogenetics

Chronic obstructive pulmonary disease (COPD) is a common problem worldwide, and it is recognized that the term encompasses overlapping sub-phenotypes of disease. The development of a sub-phenotype may be determined in part by an individual's genetics, which in turn may determine response to treatment. A growing understanding of the genetic factors that predispose to COPD and its sub-phenotypes and the pathophysiology of the condition is now leading to the suggestion of individualized therapy based on the patients' clinical phenotype and genotype. Pharmacogenetics is the study of variations in treatment response according to genotype and is perhaps the next direction for genetic research in COPD. Here, we consider how knowledge of the pathophysiology and genetic risk factors for COPD may inform future management strategies for affected individuals.

Recent Publications on Medications and Pharmacy

Hospital Pharmacy presents this feature to keep pharmacists abreast of new publications in the medical/pharmacy literature. Articles of interest regarding a broad scope of topics are abstracted monthly.

Conference Scene: Pharmacogenomics at the second PharmSciFair 2009: adverse drug reactions and clinical implementation

From 8th to 12th June 2009, the second PharmSciFair took place in Nice, France. Sessions were organized on different types of pharmaceutical research. Two pharmacogenomics sessions were organized by the European Federation for Pharmaceutical Sciences Network on Research in Pharmacogenetics/Pharmacogenomics. The topics of the sessions were adverse drug reactions and clinical implementation. Important conclusions of the presentations were that there has been much progress in the field of pharmacogenomics and that implementation in clinical practice is not as easy as it was once thought. Large prospective trials might be necessary to prove clinical relevance.