What Is New In Small Airways Research
By Ves Dimov, MD
Allergist/Immunologist, Assistant Professor of Medicine and Pediatrics, University of Chicago
Web Editor, WAO Small Airways Working Group Website
Posted: 16 March 2012
Tailoring of asthma treatment based on FeNO levels was ineffective in improving outcomes in children and adults
The official ATS Clinical Practice Guideline suggests that measurement of fractional nitric oxide (NO) concentration in exhaled breath (FeNO) is a useful tool for assessing asthma during clinic visits (Am. J. Respir. Crit. Care Med. September 1, 2011 vol. 184 no. 5 pp 602-615). This review included 6 studies of patients with asthma utilising FeNO (2 in adults and 4 in children/adolescent) (last searches were in February 2009).
There was no significant difference in exacerbations between groups for FeNO compared with controls. The daily dose of inhaled corticosteroids at the end of the study was decreased in adults whose treatment was based on FeNO in comparison with the control group. However, children who had treatment adjusted according to FeNO had an increase in their mean daily dose of inhaled corticosteroids.
The authors concluded that tailoring of asthma treatment based on FeNO levels has not been shown to be effective in improving asthma outcomes in children and adults. They questioned the justification to advocate the routine use of either sputum analysis (due to technical expertise required) or FeNO in everyday clinical practice.
Although conventional tests such as FEV1 are only indirectly associated with airway inflammation, they assess the functional capacity of asthmatic patients and provide actionable information during clinic visits.
Source: A systematic review and meta-analysis: tailoring asthma treatment on eosinophilic markers (exhaled nitric oxide or sputum eosinophils). Thorax 2012; 67(3):199-208. (doi:10.1136/thx.2010.135574)
Image source: Wikipedia (http://en.wikipedia.org/wiki/Nitric_oxide)
High rates of persistent and uncontrolled asthma in the United States; almost half of patients do not use controller medications
The CHOICE survey included 1,000 patients with asthma (Comprehensive Survey of Healthcare Professionals and Asthma Patients Offering Insight on Current Treatment Gaps and Emerging Device Options, CHOICE). Asthma severity and control were categorized using the Expert Panel Report III (EPR 3).
Almost half of the patients (490 out of 1,000) were not using asthma controller medications. Most of those not using controllers (79%) had persistent asthma; 47% had either mild or moderate persistent asthma.
Of patients who were using asthma controllers, only 14% were well controlled.
As expected, acute care utilization was greater for patients with persistent and poorly controlled asthma.
The CHOICE survey demonstrates for the first time the current extent of poor asthma control in the United States, using EPR 3 methods. This situation falls far short of national asthma management targets and needs urgent improvement. Web-based interventions such as educational videos and social networking, and reminders such as text messaging, need to be explored in the quest to achieve asthma control targets.
Source: The CHOICE survey: high rates of persistent and uncontrolled asthma in the United States. Annals of Allergy, Asthma & Immunology, 2012; 108(3): 57-162.e1.
Asthma exacerbations in children are predicted by (simple) asthma control score and (complex) test of IL-5 in breath
This prospective one-year study evaluated the ability of non-invasive inflammatory markers in exhaled breath to predict exacerbations of childhood asthma and included 40 children (aged 6-16 years). Regular two-month visits at the outpatient clinic were performed. During the course of the study, 16 children developed exacerbations, of which 10 were moderate and 6 severe.
Significant predictors of an asthma exacerbation included:
- breath condensate acidity
- interleukin-5 (IL-5)
- asthma control score
The exacerbations were best predicted by the asthma control score and by the level of interleukin-5 in exhaled breath condensate. There was a 2-times reduced risk on exacerbations in children with the 10% most optimal values of IL-5 and asthma control score.
Both exhaled breath condensate interleukin-5 level and asthma control score were significant predictors of asthma exacerbations. These parameters can optimize the titration of asthma treatments.
Source: Prediction of asthma exacerbations in children: results of a one-year prospective study. Clinical & Experimental Allergy, 2012, accepted article, published online before print. (doi: 10.1111/j.1365-2222.2012.03992.x)
Posted: 16 March 2012