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Abstract
Objective To determine whether environmental control using nocturnal temperature controlled laminar airflow (TLA) treatment could improve the quality of life of patients with persistent atopic asthma.
Design Randomised, double-blind, placebo-controlled, parallel-group trial.
Setting Nineteen European asthma clinics.
Participants 312 patients aged 7–70 with inadequately controlled persistent atopic asthma.
Main outcome measure Proportion of patients with an increase of ≥0.5 points in asthma quality of life score after 1 year of treatment.
Results TLA devices were successfully installed in the bedrooms of 282 (90%) patients included in the primary efficacy analysis. There was a difference in treatment response rate between active (143 of 189, 76%) and placebo (56 of 92, 61%) groups, difference 14.8% (95% CI 3.1 to 26.5, p=0.02).3 In patients aged ≥12, on whom the study was powered, the difference in response rate was similar-active 106 of 143 (74%), placebo 42 of 70 (60%), difference 14.1% (0.6 to 27.7, p=0.059). There was a difference between groups in fractional exhaled nitric oxide change of −7.1 ppb (−13.6 to −0.7, p=0.03). Active treatment was associated with less increase in cat-specific IgE than placebo. There was no difference in adverse event rates between treatment groups.
Conclusion Inhalant exposure reduction with TLA improves quality of life, airway inflammation and systemic allergy in patients with persistent atopic asthma. TLA may be a treatment option for patients with inadequately controlled persistent atopic asthma.
Trial registration number Clinical Trials NCT00986323.
- Asthma
- exposure control
- temperature controlled laminar air flow
- protexo
- quality of life
- allergic lung disease
- paediatric physician
- paediatric asthma
- asthma pharmacology
- aspergillus lung disease
- copd mechanisms
- eosinophil biology
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Footnotes
Trial Steering Committee Professor Olof Zetterström (Chair), University Hospital of Linköping, Sweden; Professor Leif Bjermer, Lund University Hospital, Sweden; Professor Ronald Dahl, Aarhus University Hospital, Denmark; Professor Erkka Valovirta, Terveystalo Turku, Finland; Dr Andrea Von Berg, Marien Hospital, Germany; Professor John Warner, Imperial College London, UK; Professor Magnus Wickman, Sachs' Children's Hospital, Stockholm, Sweden.
Data and Safety Monitoring Committee Professor Jan Lötvall (Chair), Göteborg University, Sweden; Professor Stephen Durham, National Heart and Lung Institute, Imperial College London, UK; Fredrik Hansson, Commitum AB.
↵* 4A Study Group Members Robert Boyle, NIHR Biomedical Research Centre, Imperial College Healthcare NHS Trust and Imperial College London, UK; Christophe Pedroletti, Päivi Söderman and Björn Nordlund, Karolinska University Hospital Solna, Sweden; Per Tunqvist and Magnus Wickman, Sach's Children's Hospital, Sweden; Victoria Strand and Pär Gyllfors, Capio St Görans Hospital, Sweden; Janne Björkander, County Hospital Ryhov, Sweden; Leif Bjermer and Stefan Willers, Lund University Hospital, Sweden; Ann Hammarlund, Hospital of Ängelholm, Sweden; Bill Hesselmar and Nils Åberg, The Queen Silvia Children's Hospital, Sweden; Erkka Valovirta and and Heikki Valkama, Terveystalo Turku, Finland; Kai-Håkon Carlsen, Karin Lødrup Carlsen and Egil Bakkeheim, Ullevål University Hospital, Norway; Malcolm Sue-Chu, Trondheim University Hospital, Norway; Ronald Dahl, Aarhus University Hospital, Denmark; Vibecke Backer and Lotte Harmsen, Bispebjerg Hospital, Denmark; Claudia Gore, and Heather Hanna, Imperial College London, UK; Christian Virchow and Peter Julius, University of Rostock, Germany; Erika Von Mutius and Caroline von Ehrenstein, University of Munich, Germany; Andrea Von Berg and Christina Beckman, Marien-Hospital Wesel, Germany; Per Olof Wernersson, Allergimottagningen Karlstad, Sweden; Uwe Schauer, St Josef-Hospital Bochum, Germany; Olof Zetterström and Ulla Nyström Kronander, University Hospital of Linköping, Sweden; John Warner, NIHR Biomedical Research Centre, Imperial College Healthcare NHS Trust, and Imperial College London, UK.
Funding The study was funded by Airsonett AB. Robert Boyle was supported by a National Institute for Health Research Clinical Lectureship. John Warner is supported by a National Institute for Health Research Senior Fellowship. Robert Boyle and John Warner are supported by a National Institute for Health Research Biomedical Research Centre, and by the MRC and Asthma UK Centre in Allergic Mechanisms of Asthma.
Competing interests None.
Ethics approval Ethics approval was provided by responsible institutional review boards at each site in this multicentre international trial.
Provenance and peer review Not commissioned; externally peer reviewed.
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