Airway Disease, National Heart and Lung Institute, Imperial College London, & Biomedical Research Unit, Royal Brompton & Harefield NHS Trust, London SW3, UK.
Respir Res. 2014 Jun 27;15(1):72. doi: 10.1186/1465-9921-15-72.
Bacteria are frequently cultured from sputum samples of severe asthma patients suggesting a defect in bacterial clearance from the airway. We measured the capacity of macrophages from patients with asthma to phagocytose bacteria.
Phagocytosis of fluorescently-labelled polystyrene beads, Haemophilus influenzae or Staphylococcus aureus by broncholaveolar lavage alveolar macrophages (AM) and by monocyte-derived macrophages (MDM) from non-asthmatics, mild-moderate and severe asthmatic patients was assessed using fluorimetry.
There were no differences in phagocytosis of polystyrene beads by AMs or MDMs from any of the subject groups. There was reduced phagocytosis of Haemophilus influenzae and Staphylococcus aureus in MDMs from patients with severe asthma compared to non-severe asthma (p < 0.05 and p < 0.01, respectively) and healthy subjects (p < 0.01and p < 0.001, respectively). Phagocytosis of Haemophilus influenzae and Staphylococcus aureus by AM was also reduced in severe asthma compared to normal subjects (p < 0.05). Dexamethasone and formoterol did not suppress phagocytosis of bacteria by MDMs from any of the groups.
Persistence of bacteria in the lower airways may result partly from a reduced phagocytic capacity of macrophages for bacteria. This may contribute to increased exacerbations, airway colonization and persistence of inflammation.
从严重哮喘患者的痰标本中经常培养出细菌，这表明气道中细菌清除存在缺陷。我们测量了哮喘患者的巨噬细胞吞噬细菌的能力。
使用荧光标记的聚苯乙烯珠、流感嗜血杆菌或金黄色葡萄球菌，通过支气管肺泡灌洗肺泡巨噬细胞（AM）和非哮喘、轻度至中度和重度哮喘患者的单核细胞衍生的巨噬细胞（MDM），通过荧光法评估吞噬作用。
来自任何实验组的 AMs 或 MDMs 对聚苯乙烯珠的吞噬作用均无差异。与非重症哮喘（p<0.05 和 p<0.01）和健康受试者（p<0.01 和 p<0.001）相比，重症哮喘患者的 MDM 对流感嗜血杆菌和金黄色葡萄球菌的吞噬作用降低（分别为 p<0.05 和 p<0.01）。与正常受试者相比，严重哮喘患者的 AM 对流感嗜血杆菌和金黄色葡萄球菌的吞噬作用也降低（p<0.05）。地塞米松和福莫特罗均不能抑制任何实验组 MDM 对细菌的吞噬作用。
下呼吸道细菌的持续存在可能部分归因于巨噬细胞对细菌的吞噬能力降低。这可能导致加重、气道定植和炎症持续存在。
