慢性阻塞性肺病及支氣管擴張症的肺微生物菌叢基因體研究

Abstract

背景：慢性阻塞性肺病（COPD）和支氣管擴張症（Bronchiectasis, BE）都是異質性肺病，具有複雜的臨床和病理特徵。這些特徵的共存會加劇臨床症狀、強化炎症，並導致疾病惡化及較差的預後。當支氣管擴張症患者合併固定氣流阻塞（fixed airflow obstruction, FAO）時，通常同時滿足阻塞性肺功能測試標準及支氣管擴張症的影像結構性診斷。這表明這群患者符合近期所提出的「慢性阻塞性肺病-支氣管擴張症關聯症」（COPD-BE association）這一新的診斷群體。然而，肺微生物菌叢基因體(lung microbiome)在COPD-BE關聯症中的作用仍然不明確。本研究旨在利用支氣管肺泡灌洗液(Bronchoalveolar lavage, BAL)樣本，探討肺微生物菌叢基因體在慢性阻塞性肺病、支氣管擴張症及同時符合這兩種診斷的患者中的角色。此外，我們通過基於ROSE（放射學Radiology、阻塞Obstruction、肺功能測試Spirometry和暴露Exposure）標準對支氣管擴張症患者進行分類，以評估氣道炎症標誌物的臨床意義及其相關的臨床預後。 方法：我們在台灣進行了一項前瞻性觀察研究，招募患有支氣管擴張症或慢性阻塞性肺病的患者。我們分析了這些患者的肺微生物菌叢基因體，並評估其氣道發炎的生物標誌物。同時，我們收集了支氣管肺泡灌洗樣本，進行16S 核糖體核糖核酸基因定序分析。此外，我們還通過收集兩個支氣管擴張症世代研究來驗證ROSE標準在支氣管擴張症患者中的應用，包括一個前瞻性單中心世代和一個回顧性多中心世代，以評估COPD-BE關聯症的臨床意義和預後，並與其他有或沒有固定氣流阻塞（FAO）的支氣管擴張患者進行比較。 結果：在觀察性世代研究中，我們收入了181名患者，其中包括86名慢性阻塞性肺病患者、46名支氣管擴張症患者和49名經肺功能檢查確認的支氣管擴張症合併固定氣流阻塞(BE-FAO)患者。我們發現無論有無合併氣流阻塞，支氣管擴張症患者的微生物群特徵相似，表現為α多樣性降低和變形菌門（Proteobacteria）占主導地位，與展現更多厚壁菌門（Firmicutes）、更大多樣性和更多共生類群的慢性阻塞性肺病患者顯著不同。此外，與無固定氣流阻塞的COPD和BE相比，患有固定氣流阻塞的支氣管擴張症(BE-FAO)患者顯示出更嚴重的疾病和更高的惡化風險。我們發現綠膿桿菌（Pseudomonas aeruginosa）的存在與氣道嗜中性球發炎症的增加顯著相關，包括白介素（IL）-1β、IL-8和腫瘤壞死因子α（TNF-α），以及更高的支氣管擴張症嚴重程度，這可能導致惡化風險的增加。此外，在患有固定氣流阻塞的支氣管擴張症(BE-FAO)患者中，根據吸菸史的有無，使用ROSE標準將個體分類為ROSE（+）或ROSE（-）。這一分類突顯了ROSE（-）和ROSE（+）患者之間在臨床特徵、炎症特徵和微生物群細微變化上的差異，暗示在合併有氣流阻塞的支氣管擴張症(BE-FAO)患者群體中存在多樣的內表型(Endotypes)。 我們又在台灣人群中進行了一項世代分析，將147名參與者的前瞻性世代與574名參與者的多中心回顧性世代結合。使用ROSE標準，我們發現約有16.5%的參與者具有COPD-BE關聯症(前瞻性世代族群中為22.4%，回顧性世代族群中為14.9%），主要集中在年長的男性患者中。這些患者與無氣流阻塞的支氣管擴張症患者相比，他們的呼吸困難指數上升，臨床上合併有慢性阻塞性肺病診斷率較高，使用吸入治療的比例也增加。值得注意的是，儘管具有COPD-BE關聯患者和無吸菸的支氣管擴張症合併固定氣流阻塞(nonsmoking BE-FAO)患者在臨床症狀、肺功能和疾病嚴重性上表現相似，但在氣道的微生物學上略有不同。此外，具有COPD-BE關聯的患者在調整干擾因素後，仍顯示出其有顯著較高的急性惡化和住院的風險，強調COPD-BE關聯症的患者臨床預後較其他群體更差。 結論：根據ROSE標準進行定義，患有支氣管擴張症合併固定氣流阻塞（BE-FAO）的患者可能表現出兩種不同的內表型。這些內表型的特徵為疾病嚴重程度更高，其肺微生物菌叢基因體更接近於沒有固定氣流阻塞的支氣管擴張症患者，而不是慢性阻塞性肺患者。綠膿桿菌定殖(colonization)與氣道嗜中性球發炎症增加之間的顯著相關性以及疾病嚴重程度，突顯了氣道微生物菌叢的臨床意義。此外，我們發現使用ROSE標準可以有效地找出東亞人群中的具有COPD-BE關聯症患者，顯示出相較於其他支氣管擴張症群體，其未來急性惡化的風險顯著的增加。這一發現強調了這些肺微生物菌叢基因體在支氣管擴張症合併固定氣流阻塞的疾病進展與其在急性惡化中的潛在作用。未來的研究亟需深入了解支氣管擴張症的進展，特別是在合併固定氣流阻塞的族群。

Background: Chronic obstructive pulmonary disease (COPD) and bronchiectasis (BE) are both heterogeneous lung diseases characterized by complex clinical and pathological features. The coexistence of these features exacerbates symptoms, intensifies inflammation, and worsens prognosis compared to either condition alone. Patients with bronchiectasis and fixed airflow obstruction (FAO) meet both the obstructive spirometry criteria for COPD and the structural diagnosis of bronchiectasis, reflecting the recently proposed COPD-BE association. However, the role of the lung microbiome in the COPD-BE association remains unclear. This study aimed to investigate the role of the lung microbiome in patients with COPD, bronchiectasis, and those who meet both diagnoses, using bronchoalveolar lavage (BAL) samples. Additionally, we sought to evaluate airway inflammatory markers, their clinical significance, and outcomes by categorizing bronchiectasis patients based on the ROSE (Radiology, Obstruction, Spirometry, and Exposure) criteria. Methods: We conducted a prospective observational study in Taiwan, enrolling patients with either bronchiectasis or COPD. To analyze the lung microbiome and assess inflammatory markers, BAL samples were collected for 16S rRNA gene sequencing. Additionally, we validated the ROSE criteria in two bronchiectasis cohorts—a prospective single-center cohort and a retrospective multicenter cohort in Taiwan—to assess the clinical implications and clinical outcomes of the COPD-BE association compared to other groups with or without FAO. Results: The study cohort comprised 181 patients: 86 with COPD, 46 with bronchiectasis, and 49 with bronchiectasis and FAO, confirmed by spirometry. Patients with bronchiectasis, regardless of FAO, had similar microbiome profiles characterized by reduced alpha diversity and a predominance of Proteobacteria, which were distinctly different from COPD patients who exhibited more Firmicutes, greater diversity, and more commensal taxa. Furthermore, compared to COPD and BE without FAO, BE with FAO showed more severe disease and a higher risk of exacerbations. A significant correlation was found between the presence of Pseudomonas aeruginosa and increased airway neutrophilic inflammation, including Interleukin (IL)-1β, IL-8, and tumor necrosis factor-alpha (TNF)-α, as well as higher bronchiectasis severity, which may contribute to an increased risk of exacerbations. In BE patients with FAO, the ROSE criteria were employed to classify individuals as either ROSE (+) or ROSE (-) based on smoking history. This classification highlighted differences in clinical features, inflammatory profiles, and slight microbiome variations between ROSE (-) and ROSE (+) patients, suggesting diverse endotypes within the BE with FAO group. An integrated cohort analysis was conducted within a Taiwanese demographic, combining a prospective cohort of 147 participants with a multicenter retrospective cohort of 574 participants. Using the ROSE criteria, we found that 16.5% of participants had a COPD-BE association (22.4% in the prospective cohort and 14.9% in the retrospective cohort), predominantly among older male patients. These patients had escalated dyspnea scores, higher COPD diagnosis rates, and increased use of inhalation therapies compared to those without FAO. Notably, patients with a COPD-BE association and nonsmoking BE with FAO displayed similar clinical symptoms, pulmonary function, and disease severity but differed slightly in airway microbiology. Furthermore, patients with a COPD-BE association had significantly higher risks of exacerbations and hospitalizations, even after adjusting for confounding factors, highlighting poorer clinical outcomes compared to other groups. Conclusion: Patients with bronchiectasis and FAO may exhibit two distinct endotypes, as defined by the ROSE criteria. These endotypes are characterized by greater disease severity and a lung microbiome that is more similar to that of bronchiectasis patients without FAO than to those with COPD. The significant correlation between Pseudomonas aeruginosa colonization and increased airway neutrophilic inflammation, along with disease severity, underscores the clinical relevance of microbial patterns. Additionally, we found that the ROSE criteria effectively identify the COPD-BE association in East Asian populations, highlighting a significantly higher risk of future exacerbations compared to other bronchiectasis groups. This finding reinforces the potential role of this lung microbiome in the progression and exacerbations of bronchiectasis with FAO. Future research is warranted to better understand the progression of bronchiectasis, particularly in subgroups with FAO.