Department of Microbiology, University of Massachusetts Amherst Massachusetts, Amherst, MA 01003, USA.
Pediatr Infect Dis J. 2010 Dec;29(12):1093-8. doi: 10.1097/inf.0b013e3181eaebdc.
Neutrophilic asthma is thought to be less responsive than eosinophilic asthma to anti-inflammatory therapies including corticosteroids. Chlamydia pneumoniae has been implicated in asthma, possibly by induction of interleukin (IL-8). We hypothesized that IL-8 is increased in the bronchoalveolar lavage (BAL) fluid from children with asthma and C. pneumoniae.
BAL fluid was analyzed for C. pneumoniae and IL-8 using polymerase chain reaction (PCR) and enzyme-linked immunosorbent assay from 2 asthma patient populations in the Bronx, NY and Massachusetts with an average age of 8 and 8.7 years old, respectively. For comparison, samples were also analyzed for C. trachomatis and Mycoplasma 16s DNA.
Of 18 Bronx samples analyzed, 6 (33%) were PCR-positive for C. pneumoniae, 10 (56%) for C. trachomatis, and 8 (44%) for Mycoplasma 16s DNA. IL-8 from C. pneumoniae-positive samples was 3.3-fold higher compared with negative samples (P = 0.003). There was no difference between patients tested for C. trachomatis or Mycoplasma. Of 84 Massachusetts samples analyzed, 42 (50%) were PCR-positive for C. pneumoniae, 42 (50%) for C. trachomatis, and 13 (16%) for Mycoplasma. IL-8 concentration from C. pneumoniae-positive samples was 10.49-fold higher compared with negative samples (P = 0.0001). As in the Bronx cohort, there were no differences between patients tested for C. trachomatis or Mycoplasma. Lastly, BAL neutrophilia predicted the presence of C. pneumoniae but not Mycoplasma or C. trachomatis.
Children with asthma who were PCR-positive for C. pneumoniae demonstrated elevated concentrations of IL-8 and neutrophils in BAL fluid compared with similar patients who were positive for C. trachomatis or Mycoplasma organisms, but PCR-negative for C. pneumoniae. Undiagnosed C. pneumoniae infection in children may therefore contribute to poorly controlled asthma via induction of IL-8.
嗜中性粒细胞性哮喘被认为对包括皮质类固醇在内的抗炎治疗的反应不如嗜酸性粒细胞性哮喘好。肺炎衣原体与哮喘有关，可能通过诱导白细胞介素（IL-8）。我们假设哮喘儿童的支气管肺泡灌洗液（BAL）中 IL-8 增加，并且肺炎衣原体阳性。
使用聚合酶链反应（PCR）和酶联免疫吸附试验（ELISA）分析来自纽约布朗克斯和马萨诸塞州的 2 个哮喘患者人群的 BAL 液，其平均年龄分别为 8 岁和 8.7 岁。为了比较，还分析了样品中的衣原体和支原体 16s DNA。
在 18 个分析的 Bronx 样本中，6 个（33％）PCR 阳性为肺炎衣原体，10 个（56％）PCR 阳性为衣原体，8 个（44％）PCR 阳性为支原体 16s DNA。肺炎衣原体阳性样本的 IL-8 是阴性样本的 3.3 倍（P = 0.003）。未发现衣原体或支原体检测患者之间存在差异。在分析的 84 个马萨诸塞州样本中，42 个（50％）PCR 阳性为肺炎衣原体，42 个（50％）PCR 阳性为衣原体，13 个（16％）PCR 阳性为支原体。肺炎衣原体阳性样本的 IL-8 浓度是阴性样本的 10.49 倍（P = 0.0001）。与 Bronx 队列一样，衣原体或支原体检测患者之间没有差异。最后，BAL 嗜中性粒细胞增多症预测肺炎衣原体的存在，但不能预测支原体或衣原体的存在。
PCR 阳性的肺炎衣原体患儿的 BAL 液中 IL-8 和嗜中性粒细胞浓度高于类似的衣原体或支原体阳性但肺炎衣原体阴性的患儿。因此，儿童未确诊的肺炎衣原体感染可能通过诱导 IL-8 导致哮喘控制不佳。
