Update on Clinical Inflammometry for the Management of Airway Diseases
Can Respir J
Update on clinical inflammometry for the management of airway diseases
Parameswaran Nair FRCPC 0
0 Firestone Institute for Respiratory Health, St Joseph's Healthcare Hamilton and the Department of Medicine, McMaster University , Hamilton, Ontario Hamilton, Ontario L8N 4A6. Telephone 905-522-1155 ext 35044, fax 905-521-6183, e-mail
P nair. Update on clinical inflammometry for the management of airway diseases. Can respir J 2013;20(2):117-120. Airway inflammation is a central feature of many airway diseases such as asthma, chronic bronchitis, bronchiectasis and chronic cough; therefore, it is only logical that it is measured to optimize its treatment. However, most treatment recommendations, including the use of anti-inflammatory therapies such as corticosteroids, are based on assessments of only airflow and symptoms. Over the past 10 years, methods have been developed to assess airway inflammation relatively noninvasively. Quantitative cell counts in sputum and the fraction of exhaled nitric oxide are the most validated tests. Judicious use of currently available drugs, such as corticosteroids, bronchodilators and antibiotics, and other anti-inflammatory therapies guided by sputum eosinophil and neutrophil counts, have been demonstrated to decrease exacerbations of asthma and chronic obstructive pulmonary disease, ameliorate cough, improve quality of life in patients with these diseases and is cost effective compared with treatment strategies based on guidelines that do not incorporate these measurements. Thus, it is unfortunate that this is not used more widely in the management of airway diseases, particularly in patients with severe asthma and chronic obstructive pulmonary disease who experience frequent exacerbations.
Asthma; COPD; Cough; Exhaled nitric oxide; Inflammometry; Sputum
-
Apersistence of asthma (
1
) and other airway diseases such as
irway mucosal inflammation is fundamental to the etiology and
smoker’s bronchitis, emphysema, chronic cough and bronchiectasis. It
contributes to symptoms, variable airflow limitation and airway
hyperresponsiveness and the structural changes (ie, remodelling) associated
with asthma. The presence and type of airway inflammation can be
difficult to detect clinically, delaying the introduction of appropriate
treatment (
2
). However, until recently, its measurement was not considered
by national and international guidelines that recommended treatment
based only on symptoms and measurement of airflow. The Canadian
Thoracic Society pioneered the introduction of these measurements in
the management of chronic obstructive pulmonary disease (COPD) (
3
)
and asthma (
4
) in the most recent iteration of their guidelines. The
present review will summarize the methods that are currently under
evaluation for the measurement of airway inflammation in clinical
practice and discuss the practical implementation of quantitative sputum
cell counts in the management of asthma, COPD and chronic cough as
practiced at the Firestone Institute of Respiratory Health at St Joseph’s
Healthcare in Hamilton, Ontario, for the past 20 years. The present
update does not review indirect measures of airway inflammation such as
mannitol (Aridol, Pharmaxis, Australia) hyper-responsiveness.
Methods to assess airway inflaMMation
sputum
Sputum cell counts are a relatively noninvasive and reliable method
of identifying airway inflammation. The method of sputum collection
is well described and standardized (
5
). Hypertonic saline inhalation is
safe in patients with forced expiratory volume in 1 s (FEV1) as low as
0.9 L (
6
). Spontaneously expectorated sputum, when available, provides
Mise à jour sur l’inflammométrie clinique pour
prendre en charge les maladies des voies respiratoires
L’inflammation des voies respiratoires est un élément central de
nombreuses maladies des voies respiratoires comme l’asthme, la bronchite
chronique, la bronchiectasie et la toux chronique. Par conséquent, il est
logique de la mesurer pour en optimiser le traitement. Cependant, la
plupart des recommandations thérapeutiques, y compris le recours à des
traitements anti-inflammatoires comme les corticoïdes, se fondent sur des
évaluations limitées au débit respiratoire et aux symptômes. Depuis dix ans,
des méthodes ont été mises au point pour évaluer l’inflammation des voies
respiratoires de manière relativement non envahissante. Le dénombrement
cellulaire quantitatif dans les expectorations et la fraction de monoxyde
d’azote exhalé sont les tests les plus validés. Il est démontré qu’une
utilisation judicieuse des médicaments sur le marché, tels que les corticoïdes,
les bronchodilatateurs et les antibiotiques, et d’autres traitements
antiinflammatoires sélectionnés selon la numération des éosinophiles et des
neutrophiles dans les expectorations, réduit les exacerbations d’asthme et
de maladie pulmonaire obstructive chronique, limite la toux, améliore la
qualité de vie chez les patients atteint (...truncated)