Prevalence of patients eligible for anti-IL-5 treatment in a cohort of adult-onset asthma

Publication date: Available online 9 June 2018
Source:The Journal of Allergy and Clinical Immunology: In Practice
Author(s): Pinja Ilmarinen, Leena E. Tuomisto, Onni Niemelä, Hannu Kankaanranta
BackgroundAntibodies against IL-5 pathway have been developed for treatment of late-onset eosinophilic steroid-resistant asthma. However, the prevalence of severe asthma and the proportion of patients who could benefit from such treatment among general population of asthmatics remains unknown.ObjectiveTo evaluate the prevalence and characteristics of patients eligible to anti-IL-5 treatment and severe asthma in an unselected cohort of adult-onset asthma.MethodsSeinäjoki Adult Asthma Study (SAAS) is a 12-year follow-up study of patients with new-onset adult asthma (n=203). Prevalence was estimated based on information collected at 12-year follow-up visit. Healthcare use was collected from the whole 12-year follow-up period.ResultsPrevalence of anti-IL-5-treatable patients was 2%, when the following criteria were used: daily use of medium-to-high ICS dose and LABA, ≥2 exacerbations/previous year and blood eosinophil count ≥300 cells/μl or FeNO≥50ppb. Prevalence of severe asthma, as defined according to ERS/ATS, was 5.9% and only one patient met criteria for both groups. When compared to anti-IL-5-eligible patients, severe asthmatics were more often current smokers at diagnosis, obese, used higher ICS dose and had higher blood neutrophils 12 years after diagnosis. Both groups differed from non-severe asthma by higher number of all and unplanned respiratory-related visits to healthcare. Severe asthmatics showed the highest number of hospitalizations.ConclusionsIn a cohort of unselected consecutive patients with adult-onset asthma, 5.9% fulfilled criteria for severe asthma and 2% qualified for anti-IL-5 treatment. Both groups represent a high burden to healthcare and specifically targeted treatment could lead to lower use of healthcare at long-term.