[Respiratory pathogen spectrum in pulmonary exacerbation of bronchiectasis in adults and its association with disease severity].

Objective: To determine the pattern of respiratory pathogens at bronchiectasis exacerbation and its associations with disease severity. Methods: A total of 119 steady-state bronchiectasis patients [42 males, 77 females, age range 19 to 74 years, mean age (45±14)years], diagnosed by a compatible history combined with evidence of bronchial dilatation on high-resolution computed tomography (HRCT), were recruited prospectively from out-patient clinics in the First Affiliated Hospital of Guangzhou Medical University between September 2012 and March 2013. A comprehensive history taking, radiologic appearance, spirometry, sputum bacterial culture and 16 respiratory viruses in nasopharyngeal swabs and sputum samples by PCR assays were collected at steady-state bronchiectasis. All bronchiectasis patients were followed up one year and assessed for bacteriology, virology and systemic inflammatory indices [including white blood cell, C-reactive protein (CRP), interleukin-6, 8 and tumor necrosis factor-α] during bronchiectasis exacerbation. Results: Fifty-eight bronchiectasis patients [20 males, 38 females, age range 19 to 74 years, mean age (44±14) years] reported 100 exacerbations (1 to 5 exacerbation events per patient) during one year follow-up. Respiratory viruses were found more frequently in sputum and nasal swab during exacerbation [35.0% (35/100) and 39% (39/100)] than those during steady-state in bronchiectasis [sputum: 13.8% (8/58), nasal swab: 8.6% (5/58)] (χ(2)=8.33,χ(2)=13.51; respectively, all P<0.05). The rate of bacterial detection during exacerbation in sputum was 56% (56/100), which was not significantly different compared with those at steady-state (35/58, 60.3%;χ(2)=0.284, P=0.59). Of these respiratory infections, viral-bacterial co-infection accounted for 30% exacerbation events. The most common bacteria and viruses during exacerbation in mild bronchiectasis (n=18, with 25 exacerbation events) were Haemophilus parainfluenzae (4 cases) in sputum and influenza A in nasal swab or sputum (4 cases), respectively. In patients with moderate (n=17, with 29 exacerbation events)-severe bronchiectasis (n=23, with 46 exacerbation events), pseudomonas aeruginosa was the most common bacteria in sputum (35 cases), and the most common respiratory viruses were rhinovirus in nasal swab or sputum (11 cases). In these 100 exacerbation events, patients with bacterial and viral co-infection, pure bacteria infection, pure virus infection, no bacteria and virus infection accounted for 30, 29, 16 and 25 exacerbation events, respectively. And patients with co-infection had higher serum CRP (45±23) mg/L and IL-8 [9.0 (4.4-15.5) ng/L] (F=23.32, F=9.81,respectively; all P<0.05), and increased risk of hospitalization (30% vs. 0] compared with those in non-infectious group(χ(2)=9.0, P=0.003). Conclusions: Pseudomonas aeruginosa, rhinovirus and influenza A were common causative agents of exacerbation in bronchiectasis.In patients with moderate-severe bronchiectasis, pseudomonas aeruginosa was the most common bacterium in sputum, and the most common respiratory virus was rhinovirus in nasal swab or sputum, compared to Haemophilus parainfluenzae in sputum and influenza A in nasal swab or sputum in mild bronchiectasis. Patients with co-infection had more severe systemic inflammatory response and higher risk of hospitalization during exacerbation.目的： 探讨成人支气管扩张症（支扩症）急性加重期呼吸道病原谱与病情严重程度的关系。 方法： 2012年9月至2013年3月在广州医科大学附属第一医院前瞻性募集稳定期支扩症患者119例，男42例，女77例，年龄19~74岁，平均（45±14）岁。收集病史、胸部影像学、肺功能及痰细菌培养结果，用荧光定量PCR方法检测鼻拭子及痰液中16种常见呼吸道病毒。对119例患者进行1年随访并在急性加重期再次行痰细菌培养、PCR病毒检测及其他实验室检查（包括血白细胞、C反应蛋白、IL-6、IL-8和肿瘤坏死因子-α）。 结果： 在为期1年的随访过程中，119例支扩症患者中58例出现急性加重，其中男20例，女38例，年龄19~74岁，平均（44±14）岁，58例患者共报告100例次急性加重事件（最多5次/例）。支扩症急性加重期痰液和鼻拭子病毒检出率分别为35.0%（35/100）和39.0%（39/100），明显高于稳定期病毒检出率[痰液：13.8%（8/58），鼻拭子8.6%（5/58）]，差异有统计学学意义（χ(2)值分别为8.33和13.51，均P<0.05）。100例急性加重事件中痰液标本细菌（包括铜绿假单胞菌、流感嗜血杆菌、副流感嗜血杆菌、肺炎链球菌、肺炎克雷伯杆菌、大肠埃希菌和卡他莫拉菌）的总分离率为56%（56/100），与稳定期的分离率（35/58，60.3%）相比差异无统计学意义（χ(2)=0.284，P=0.59），其中30次急性加重事件为细菌和病毒混合感染。轻度支扩症患者（18例，发生了25次急性加重）痰液中分离出的主要细菌是副流感嗜血杆菌（4次），鼻拭子和（或）痰液中分离的病毒为甲型流感病毒（4次）；中度（17例，发生了29次急性加重）和重度（23例，发生了46次急性加重）支扩症患者痰液中最常分离出的细菌为铜绿假单胞菌（35次），鼻拭子和（或）痰液中分离的病毒为鼻病毒（11次）。在100次急性加重事件中，细菌和病毒同时阳性、单纯细菌阳性、单纯病毒阳性、无细菌和病毒分离分别为30、26、19和25次，细菌和病毒同时阳性患者的血清C反应蛋白[（45±23）mg/L]和IL-8[9.0（4.4~15.5）ng/L]水平高于无细菌和病毒分离者，差异有统计学意义（F值分别为23.32和9.81，均P<0.05）；且细菌和病毒同时阳性者需要住院的比例较无细菌和病毒分离者高（30%和0），差异有统计学意义（χ(2)=9.0，P=0.003）。 结论： 铜绿假单胞菌、鼻病毒和流感病毒是支扩症急性加重期常见的病原微生物。中度和重度支扩症患者痰液中主要分离的细菌为铜绿假单胞菌，鼻拭子和（或）痰液中分离的病毒类型为鼻病毒；轻度支扩症患者痰液中主要分离的细菌是副流感嗜血杆菌，鼻拭子和（或）痰液中分离的病毒类型为甲型流感病毒。细菌和病毒混合感染患者全身炎症反应更重，住院率更高。.