Patient profiles

The small airways are not a “quiet zone”, but actively contribute to asthma pathogenesis.¹ As a result, therapies that are able to enter and treat the small airways, such as Alvesco^®, may improve asthma control in a wide range of asthma patients:

 

Mild asthma
A 10-fold higher resistance in the small airways has been observed in mild asthma patients compared to normal subjects, even though their lung function measurements are within normal limits.^2,3 Although having a limited effect on pulmonary function, this increase in small airway resistance may contribute to increased airway responsiveness in asthma.³

Allergic asthma
Small size aeroallergens (Table 1) are fine enough to reach the smallest parts of the airways and trigger asthma at these sites.^4,5 Therefore, treating the small airways of patients with allergic asthma may help to tackle inflammation in this region.

Table 1: Allergen sources^6-8

Severe asthma
An increased closing volume (CV) or closing capacity (CC), detected by the single-breath nitrogen washout test, is indicative of small airway disease. In severe asthma, these increases are associated with recurrent asthma exacerbations.⁹ (Figure1)

TLC: total lung capacity; FEV₁: forced expiratory volume in one second; FRC: functional residual capcity; RV: residual volume: CV: closing volume; dN₂: phase III slope of the nitrogen washout curve; VC: vital capacity; CC: closing capacity

Figure 1: In patients with difficult-to-control asthma, increases in CV and CC have been observed⁹

Nocturnal asthma
Increased alveolar tissue inflammation observed at night is indicative of small airway inflammation and has been observed in patients with nocturnal asthma.^10,11 (Figure 2)

 

*: p<0.05 between the groups at 4pm; **: p<0.05 between the groups at 4am; Rp: peripheral resistance

Figure 2: Peripheral resistance is increased in asthma patients with nocturnal asthma¹¹

 

Exercise-induced asthma
The small airways of patients with exercise-induced asthma are responsive to cool, dry air, which suggests that the small airways play an important role in asthma in this patient population.¹²

See the next section for instructions on how to use the Alvesco^® inhaler correctly.
For further information on choosing the right inhaler for your patients, see here.

 

References

1. Contoli M, Bousquet J, Fabbri LM, et al. The small airways and distal lung compartment in asthma and COPD: a time for reappraisal. Allergy 2010;65:141-151.
2. Hyde DM, Hamid Q, Irvin CG. Anatomy, pathology, and physiology of the tracheobronchial tree: emphasis on the distal airways. J Allergy Clin Immunol 2009;124:S72-7.
3. Wagner EM, Liu MC, Weinmann GG, et al. Peripheral lung resistance in normal and asthmatic subjects. Am Rev Respir Dis 1990;141:584-8.
4. D’Amato G, Liccardi G, D’Amato M, et al. Outdoor air pollution, climatic changes and allergic bronchial asthma. Eur Respir J 2002;20:763-776.
5. Zeidler MR, Goldin JG, Kleerup EC, et al. Small airways response to naturalistic cat allergen exposure in subjects with asthma. J Allergy Clin Immunol 2006;118:1075-1081.
6. Zeldin DC, Eggleston P, Chapman M, et al. How exposures to biologics influence the induction and incidence of asthma. Environ Health Perspect 2006;114:620-6.
7. Bacsi A, Choudhury BK, Dharajiya N, et al. Subpollen particles: carriers of allergenic proteins and oxidases. J Allergy Clin Immunol 2006;118:844-50.
8. Erwin EA, Woodfolk JA, Custis N, et al. Animal danders. Immunol Allergy Clin North Am 2003;23:469-481.
9. in 't Veen JC, Beekman AJ, Bel EH, et al. Recurrent exacerbations in severe asthma are associated with enhanced airway closure during stable episodes. Am J Respir Crit Care Med 2000;161:1902-6.
10. Kraft M, Djukanovic R, Wilson S, et al. Alveolar tissue inflammation in asthma. Am J Respir Crit Care Med 1996;154:1505-10.
11. Kraft M, Pak J, Martin RJ, et al. Distal lung dysfunction at night in nocturnal asthma. Am J Respir Crit Care Med 2001;163:1551-6.
12. Kaminsky DA, Irvin CG, Gurka DA, et al. Peripheral airways responsiveness to cool, dry air in normal and asthmatic individuals. Am J Respir Crit Care Med 1995;152:1784-90.