Increase in blood eosinophils during follow-up is associated with lung function decline in adult asthma

Abstract

A B S T R A C TBackground: Asthma is associated with accelerated rate of lung function (FEV 1 ) decline. Objective: To determine predictive factors associated with FEV 1 decline in adult asthma. Methods: A retrospective study was conducted in 229 asthmatics recruited from the University Asthma Clinic of Liege. Subjects had at least two visits with post-bronchodilation (post-BD) FEV 1 and minimum one year between them. A multivariable linear regression analysis was conducted in order to come up with factors associated with lung function decline. Results: Post-BD FEV 1 decline in % predicted. y −1 was 0.2 (95%CI -2.0 to 2.8) in the overall population. Our population was made up of mild to moderate asthmatics [1] for 58%, aged 50 (41-60) years old, 62% were female and 59% were atopic. Median ICS dose was 1000 μg beclomethasone equivalent (CFC)/day with 81% treated at baseline. Time between visits was 46.8 ± 32.1 months. The univariate linear regression analysis revealed a negative association between % predicted FEV 1 decline and baseline ACQ (p < 0.0001) and blood eosinophils (% and/mm 3 ) (p < 0.0001 and p < 0.0001). A positive association was found between % predicted FEV 1 decline and baseline pre-BD FEV1 (mL) values (p = 0.001), blood neutrophils (%) (p = 0.02), change in blood eosinophils (%) (p < 0.0001), time between visits (months) (p < 0.0001). The predictive variables for accelerated decline highlighted by the multivariable analysis (r 2 = 0.39) were change in blood eosinophils (%) over time (p = 0.002) and time between visits (months) (p < 0.0001). Conclusion: These findings highlight a new value for blood eosinophil counts as their increase over time predicts greater lung function decline in asthma. Methods Study design, setting and participants

Persistence of both reversible airway obstruction and higher blood eosinophils may predict lung function decline in severe asthma

“…Therefore, lung function decline requires the association of a marked airway narrowing and eosinophilic inflammation. Studies have recently found an association between higher blood/ sputum eosinophil counts and lung function decline among asthmatics, [8][9][10][11][12][13] which, according to our results, may affect approximately 23% of patients receiving a step-5 treatment associated with omalizumab. It is not clear how eosinophilic inflammation affects lung function decline.…”

“…[3][4][5][6] Furthermore, other researches assert that failing to reduce eosinophilic inflammation (BE and/or FENO) significantly influences asthma control and lung function improvement. 10,16,17 Hence, the reversibility test may be a marker of reduced response because it may reflect a persistent eosinophilic airway inflammation suggesting possible different treatments as anti-eosinophilic therapies. RAO+ subjects showed a lower post-treatment FEV 1 , confirming what observed by other studies.…”

“…Furthermore, some studies confirm that higher blood/sputum eosinophils and an elevated FENO level are associated not only with a greater airflow obstruction, but also with an enhanced lung function decline. [8][9][10][11][12][13] Actually, some asthmatics present an accelerated lung function decline. Such decline is probably a functional reflection of airway remodelling, a consequence of inflammation induced structural and functional changes in the airways due to injury and repair processes of the airway tissue.…”

“…14 As already said, some studies have shown a correlation between a greater FEV 1 decline and the elevated levels of inflammatory cells (sputum or blood eosinophils and neutrophils, bronchial CD8+ T cells) and cytokines (serum periostin, IL5 and IFN γ). [8][9][10][11][12][13] The reversible airflow obstruction (RAO) prevalence and its relationship with asthma control are not well known in severe asthmatics under maximal step-5 treatment. It is also unclear whether RAO persistence might be linked with a constantly higher BE counts and whether both conditions can be also associated to an accelerated lung function decline in treated severe asthmatics.…”

Sanfu herbal patch applied at acupoints in patients with bronchial asthma: study protocol for a randomized controlled trial

“…The high incidence and high recurrence rate of BA not only bring a heavy economic burden to patients but also seriously affect their quality of life. If symptoms persist, patients may have asthma exacerbations [5,6], lung function decline [7], and pathological bronchial wall narrowing [8], which may cause psychological depression [9] and eventually lead to limited daily activities and even death [10].…”