Background

Chronic cough frequently occurs in patients with diffuse interstitial lung diseases (ILDs), and can have negative effects on quality-of-life. While there are multiple possible contributors to cough in this setting, the contribution and consequences of airway inflammation have not been previously measured. We aimed to estimate the prevalence of airway cellular inflammation in patients with chronic cough and ILD, and examine the interaction between airway inflammation and changes in lung function.

Methods

We examined all patients with physician-diagnosed ILD and chronic cough who had sputum quantitative cytometry ordered between 2004 and 2018. The prevalence of airway inflammation was estimated by applying previously established criteria for bronchitis. FEV₁ and FVC were compared between individuals based on the presence of airway inflammation. The changes in FEV₁ and FVC were compared between individuals who had their treatment tailored to their sputum result, and those who did not.

Results

Airway inflammation was present in 50% of patients (n = 173), and was associated with lower FEV₁ (1.87 vs 2.05 L, p = 0.043) and FVC (2.39 vs 2.71, p = 0.024). Sputum-guided management of airway eosinophilia was associated with improvements in FEV₁ (+120 vs −205mL, p < 0.0001) and stability of FVC (+13 vs −284mL, p = 0.003).

Conclusions

Airway inflammation is common in patients with chronic cough and ILD, and its presence may negatively affect lung function. Further research is required to understand if there is a role for quantitative sputum cytometry in this population, particularly if sputum-guided management of airway inflammation could lead to improvements in cough and other ILD outcomes.

中文翻译：

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间质性肺疾病和慢性咳嗽患者的痰液定量细胞计数。

背景

慢性咳嗽经常发生在弥漫性间质性肺病（ILD）患者中，并且可能对生活质量产生负面影响。尽管在这种情况下有多种可能的咳嗽病因，但先前并未测量气道炎症的病因和后果。我们旨在评估慢性咳嗽和ILD患者气道细胞炎症的患病率，并研究气道炎症与肺功能变化之间的相互作用。

方法

我们检查了所有在2004年至2018年间订购了痰液定量细胞仪的，经医生诊断为ILD和慢性咳嗽的患者。通过应用先前建立的支气管炎标准评估气道炎症的发生率。根据气道炎症的存在，比较个体之间的FEV ₁和FVC。比较了针对痰液结果进行了个性化治疗的患者与未进行痰液治疗的个体之间的FEV ₁和FVC的变化。

结果

50％的患者存在气道炎症（n = 173），并伴有较低的FEV ₁（1.87 vs 2.05 L，p = 0.043）和FVC（2.39 vs 2.71，p = 0.024）。痰引导的气道嗜酸性粒细胞增多的处理与FEV _1的改善（+120 vs -205mL，p <0.0001）和FVC的稳定性（+13 vs -284mL，p = 0.003）相关。

结论

气道炎症在慢性咳嗽和ILD患者中很常见，并且它的存在可能会对肺功能产生负面影响。需要进行进一步的研究以了解该人群中定量痰细胞计数法是否有作用，特别是如果以痰为指导的气道炎症处理可以改善咳嗽和其他ILD结果。