Chinedu Nwokoro

Intermittent montelukast in children aged 10 months to 5 years with wheeze (WAIT trial): a multicentre, randomised, placebo-controlled trial

Summary Background The effectiveness of intermittent montelukast for wheeze in young children is unclear. We aimed to assess whether intermittent montelukast is better than placebo for treatment of wheeze in this age group. Because copy numbers of the Sp1-binding motif in the arachidonate 5-lipoxygenase (ALOX5) gene promoter (either 5/5, 5/x, or x/x, where x does not equal 5) modifies response to montelukast in adults, we stratified by this genotype. Methods We did this multicentre, parallel-group, randomised, placebo-controlled trial between Oct 1, 2010, and Dec 20, 2013, at 21 primary care sites and 41 secondary care sites in England and Scotland. Children aged 10 months to 5 years with two or more wheeze episodes were allocated to either a 5/5 or 5/x+x/x ALOX5 promoter genotype stratum, then randomly assigned (1:1) via a permuted block schedule (size ten), to receive intermittent montelukast or placebo given by parents at each wheeze episode over a 12 month period. Clinical investigators and parents were masked to treatment group and genotype strata. The primary outcome was number of unscheduled medical attendances for wheezing episodes. Analysis was by intention to treat. This trial is registered with ClinicalTrials.gov, number NCT01142505. Findings We randomly assigned 1358 children to receive montelukast (n=669) or placebo (n=677). Consent was withdrawn for 12 (1%) children. Primary outcome data were available for 1308 (96%) children. There was no difference in unscheduled medical attendances for wheezing episodes between children in the montelukast and placebo groups (mean 2·0 [SD 2·6] vs 2·3 [2·7]; incidence rate ratio [IRR] 0·88, 95% CI: 0·77–1·01; p=0·06). Compared with placebo, unscheduled medical attendances for wheezing episodes were reduced in children given montelukast in the 5/5 stratum (2·0 [2·7] vs 2·4 [3·0]; IRR 0·80, 95% CI 0·68–0·95; p=0·01), but not in those in the 5/x+x/x stratum (2·0 [2·5] vs 2·0 [2·3]; 1·03, 0·83–1·29; p=0·79, pinteraction=0·08). We recorded one serious adverse event, which was a skin reaction in a child allocated to placebo. Interpretation Our findings show no clear benefit of intermittent montelukast in young children with wheeze. However, the 5/5 ALOX5 promoter genotype might identify a montelukast-responsive subgroup. Funding Medical Research Council (UK) and National Institute for Health Research.

Cycling to work in London and inhaled dose of black carbon

Modelling studies suggest that urban cycling is associated with an increased inhaled dose of fossil fuel-derived black carbon (BC). Using the amount of black material in airway macrophages as a marker of long-term inhaled BC, we sought to compare inhaled BC dose in London (UK) cyclists and non-cyclists. Airway macrophage carbon was assessed in 28 (58%) out of 48 healthy adults (14 cyclists and 14 non-cyclists) who attended for induced sputum. Short-term (24 h) exposure to BC was assessed on a representative working day in 27 out of 28 subjects. Serum interleukin (IL)-1&bgr;, IL-2, IL-6, IL-8, granulocyte-macrophage colony-stimulating factor and tumour necrosis factor (TNF)-&agr; were assessed in 26 out of the 28 subjects. Cyclists were found to have increased airway macrophage carbon when compared with non-cyclists (mean±se 1.81±0.21 versus 1.11±0.07 μm2; p<0.01). Short-term monitoring showed no difference in 24 h BC exposure between the two groups. However, cyclists were exposed to higher concentrations of BC during commuting (p<0.01). Airway macrophage carbon was associated with monitored commute BC (n=28; r=0.47, p<0.05). TNF-&agr; was found to be increased in cyclists (p<0.05), but no other cytokines were increased. Commuting to work by bicycle in London is associated with increased long-term inhaled dose of BC. Whether cycling per se increases inhaled BC dose remains unclear.

Recruiting ethnic minority participants to a clinical trial: a qualitative study

Objectives To compare the motives and experiences of different ethnic groups participating in a randomised double blind placebo-controlled trial of montelukast in preschool wheeze, and to assess parents’ or guardians’ understanding of trial procedures and their implications, including the collection of genetic material. Design Qualitative interviews with parents or guardians. Setting Interviews occurred in the homes of London children recruited to a national multicentre clinical trial following primary and secondary care attendance with wheeze. Participants 42 parents (20 of Bangladeshi origin, 10 white UK, 12 other ethnicities) of preschool children enrolled in a clinical trial. Results Bangladeshi families were relatively reluctant to participate in the qualitative study, despite strong engagement with the parent study. Anxiety related to wheezing was a common primary motive for trial enrolment. Parents viewed the trial as a route to improved treatment. Verbal delivery of trial information appeared more effective than study literature, especially for Bangladeshi families, with low parental literacy and high levels of trust in medical professionals potential contributors to this effect. All ethnic groups expressed a low understanding and/or retention of essential study concepts such as randomisation and genetic testing. Conclusions Bangladeshi families are particularly motivated to participate in clinical trials despite variable comprehension of study concepts. This motivation is more strongly contingent on strong researcher-subject rapport than on the quality of study literature. Trial teams seeking to recruit from South Asian populations should emphasise face-to-face verbal explanation of trial concepts and procedures and consider modified trial literature.

Alveolar macrophages carbon load: a marker of exposure?

To the Editor: In the editorial accompanying our article reporting higher alveolar macrophage carbon in adults who cycled to work in London, Ackermann-Liebrich 1 speculated that “very short, high peaks of exposure contribute more to total load of inhaled pollutants and, thus, we ought to control not only the mean pollutant levels but avoid higher peaks.” In our initial analyses, we found no …

Urinary prostanoids in preschool wheeze

Acute episodes of wheeze in children of preschool age are frequently triggered by viral upper respiratory tract infections and result in a significant burden to health services [1]. However, to date, the inflammatory mechanisms underlying preschool wheeze remain unclear. Mediators that have not been studied in preschool wheeze, but are implicated in the pathogenesis of wheeze in adults with asthma, include the pro-inflammatory prostanoid prostaglandin D2 (PGD2) [2] and the anti-inflammatory prostanoid PGE2 [3, 4]. In this study, we sought evidence for either increased PGD2 biosynthesis or reduced PGE2 biosynthesis, or a combination of both in children with preschool wheeze. To achieve this, we measured the major metabolites of PGD2 and PGE2 in the urine: 9α-hydroxy-11,15-dioxo-2,3,4,5-tetranor-prostan-1,20-dioic acid (tetranor-PGDM) and 9,15-dioxo-11α-hydroxy-13,14-dihydro-2,3,4,5-tetranor-prostan-1,20-dioic acid (tetranor-PGEM), respectively [5, 6]. Tetranor PGDM, a urinary metabolite of prostaglandin D2, is increased in children with preschool wheeze http://ow.ly/Ynjy305ZY9L

Preschool wheeze, genes and treatment

Preschool wheeze is a common but poorly understood cause of respiratory morbidity that is both distinct from and overlaps with infantile bronchiolitis and school age asthma. Attempts at classification by epidemiology, pathophysiology, therapeutic response and clinical phenotype are imperfect and yet fundamental to both treatment choice and research design. The four main therapeutic classes for preschool wheeze, namely beta2 agonists, anticholinergics, corticosteroids and leukotriene modifiers are employed with variable and often scanty evidence base, with evidence for a genetic influence on response variations. The article will discuss the pharmacogenetics of the various options, summarise current treatment recommendations, and explore future research directions.

Upper respiratory tract infections

• Tonsillitis is an infection of the tonsils, which are located in the pharynx. A viral infection, rather than a bacterial infection, is the more common cause of tonsillitis. The tonsils can be removed surgically if the infections are frequent and breathing is impaired. In the past, many children had their tonsils removed as a precaution, but this surgery is no longer as common. The tonsils help to prevent bacteria and other foreign pathogens from entering the body, so removing them can increase the number of infections later in life.

G158 Recruiting Ethnic Minority Participants to a Clinical Trial: Qualitative Study

Objectives To compare the motives and experiences of different ethnic groups participating in a randomised double blind placebo-controlled trial of montelukast in preschool wheeze, and to assess parents’ or guardians’ understanding of trial procedures and their implications, including the collection of genetic material. Design qualitative interviews with parents or guardians. Setting Parents of children recruited following medical attendance with wheeze were interviewed in their homes. Participants 42 parents, (20 of Bangladeshi origin, 10 white UK, 12 other ethnicities). Results Anxiety related to wheezing was a common primary motive for trial enrolment. Parents viewed the trial as a route to improved treatment. Verbal delivery of trial information was more effective than study literature, especially for Bangladeshi families, with low parental literacy and high levels of trust in medical professionals contributing to this effect. All ethnic groups expressed a low understanding and/or retention of essential study concepts such as randomisation and genetic testing. Conclusions Bangladeshi families are particularly motivated to participate in clinical trials despite variable comprehension of study concepts. This motivation is more strongly contingent on strong researcher-subject rapport than on the quality of study literature. Trial teams seeking to recruit from South Asian populations should emphasise face-to-face verbal explanation of trial concepts and procedures and consider modified trial literature.