Background and objective

Airway remodeling, as many other factors, may lead to lung function decline and irreversible airflow obstruction (IRAO) in asthma. This study was undertaken in order to highlight predictors of incomplete reversibility of airflow obstruction in adult asthmatics to identify patients with poorer prognosis and improve their care, and decrease morbidity.

Methods

A retrospective study was conducted in 973 asthmatics recruited from the University Asthma Clinic of Liege. Patients with IRAO (post-BD FEV₁/FVC<0.7 & FEV₁<80% predicted) were compared to patients with reversible airway obstruction (RAO) (post-BD FEV₁/FVC≥0.7 & FEV₁≥80% predicted). TGF-β was measured in sputum supernatant of 85 patients.

Results

Seventeen percent of asthmatics presented with IRAO. These patients were significantly older, more smokers, with a lower proportion of female, a longer disease duration, were more poorly controlled with a lower quality of life. This sub-population of asthmatics also showed more often elevated blood and sputum eosinophils and neutrophils, and higher exacerbation and hospitalisation rates in the previous year. The multivariable analysis revealed male gender, longer disease duration, cigarette smoking, ACQ score, sputum eosinophils and neutrophils, ICS dose and OCS maintenance, BMI, and asthma onset as variables independently linked to IRAO. Total TGF-β levels appeared higher in patients with IRAO (n = 38) compared to patients with RAO (n = 47).

Conclusion

These data show that risk factors for IRAO are male gender, smoking, a longer disease duration, uncontrolled asthma, eosinophilic or neutrophilic airway inflammation, lower BMI, and later asthma onset. Moreover, TGF-β levels are higher in IRAO.

中文翻译：

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与成人哮喘不可逆气道阻塞相关的临床和生物学因素

背景和目的

气道重塑与许多其他因素一样，可能导致哮喘患者的肺功能下降和不可逆气流阻塞 (IRAO)。本研究旨在强调成人哮喘患者气流阻塞不完全可逆性的预测因素，以识别预后较差的患者并改善他们的护理并降低发病率。

方法

对从列日大学哮喘诊所招募的 973 名哮喘患者进行了一项回顾性研究。将 IRAO 患者（BD FEV ₁ /FVC<0.7 & FEV ₁ <80% 预测值）与可逆性气道阻塞 (RAO) 患者（BD FEV _{1 /} FVC ≥0.7 & FEV ₁ ≥80% 预测值）进行比较. 在 85 名患者的痰上清液中测量了 TGF-β。

结果

17% 的哮喘患者出现 IRAO。这些患者年龄显着更大，吸烟者更多，女性比例更低，病程更长，控制更差，生活质量更低。这一哮喘患者亚群的血液和痰嗜酸性粒细胞和中性粒细胞也更频繁地升高，并且在前一年出现更高的恶化率和住院率。多变量分析显示，男性、更长的病程、吸烟、ACQ 评分、痰嗜酸性粒细胞和中性粒细胞、ICS 剂量和 OCS 维持、BMI 和哮喘发作是与 IRAO 独立相关的变量。与 RAO 患者（n = 47）相比，IRAO 患者（n = 38）的总 TGF-β 水平似乎更高。

结论

这些数据表明 IRAO 的危险因素是男性、吸烟、病程较长、哮喘不受控制、嗜酸性或中性粒细胞气道炎症、较低的 BMI 和较晚的哮喘发作。此外，IRAO 中的 TGF-β 水平较高。