Page 94 - ADULT-ONSET ASTHMA PREDICTORS OF CLINICAL COURSE AND SEVERITY

ADULT-ONSET ASTHMA – PREDICTORS OF CLINICAL COURSE AND SEVERITY
Numerous studies have evaluated the ability of FeNO and blood eosinophils to detect speci c asthma phenotypes. Iden ca on of asthma pa ents with eosinophilic airway in amma on is clinically valuable, as this subgroup of pa ents is more likely to respond to cor costeroid treatment 19. However, in a recent systema c review, the diagnos c accuracy of FeNO and blood eosinophils for detec ng airway eosinophilia turned out to be only moderate 14. Interes ngly, one recent study in 336 asthma pa ents compared the accuracy of these two biomarkers in detec ng airway eosinophilia between never-smokers and former- or current- smokers, and no signi cant di erences were observed between these groups of pa ents 15.
The role of FeNO and blood eosinophils in selec ng pa ents for speci c treatment strategies could be more promising. Asthma is a heterogeneous disease, and the response to treatment is highly variable 20. This is especially true for smoking or ex-smoking asthma pa ents, in whom the type of airway in amma on is altered due to smoking e ects 2. Markers that are able to iden fy who will respond to a speci c treatment can therefore be of great clinical value. Although controversial and inconclusive, evidence suggests that FeNO and blood eosinophils may have such value, not only for selec ng responders to tradi onal cor costeroid treatment, but also to novel targeted therapeu cs 11, 21, 22. Whether this equally applies to smoking and non-smoking pa ents remains to be inves gated in future clinical trials.
In conclusion, the study by Giovannelli and colleagues shows that in the general popula on, FeNO and blood eosinophils are associated with allergic asthma, yet only in non-smokers. These ndings do not necessarily ques on the clinical value of these biomarkers in smoking asthma pa ents, but suggest that their poten al value in these pa ents may be di erent. In an era where clinical prac ce focuses more and more towards personalized medicine, phenotyping and subphenotyping pa ents has become increasingly important in the clinical workup of asthma pa ents; smoking status seems to be an important determinant in this di eren a on.
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