title: Role of the Mycoplasma pneumoniae/Interleukin-8/Neutrophil Axis in the Pathogenesis of Pneumonia.
abstract: Neutrophil infiltration is the characteristic pathological feature of M. pneumoniae pneumonia (MPP). This study aimed to explore the associations among neutrophil activity, clinical presentation, and role of the M. pneumoniae/interleukin-8 (IL-8)/neutrophil axis in the pathogenesis of MPP. A total of 42 patients with MPP were prospectively enrolled in the study. Neutrophil activity, including matrix metalloproteinase-9 (MMP-9), myeloperoxidase (MPO), and neutrophil elastase (NE), were measured. Clinical information was collected for all patients and control group. In vitro, IL-8 production was measured at different time points after M. pneumoniae infection of bronchial epithelial cells, and neutrophil activity was analyzed after IL-8 stimulation. The percentage of neutrophil in the bronchoalveolar lavage fluid was higher in the group of patients with high levels of M. pneumoniae DNA than in those with low levels of M. pneumoniae DNA (P < 0.05). IL-8, MMP-9, and NE in patients with MPP significantly increased compared with controls and decreased after treatment (P < 0.05). MPO and MMP-9 were associated with duration of fever (r = 0.332, P < 0.05) and length of stay (r = 0.342, P < 0.05), respectively. In vitro, M. pneumoniae induced IL-8 production by bronchial epithelial cells in a time dependent manner. MPO, MMP-9 and NE production by neutrophils significantly increased compared with medium controls after IL-8 stimulation. In summary, the M. pneumoniae/IL-8/neutrophil axis likely plays a vital role in the pathogenesis of MPP.
authors.affiliation: Department of Respiratory Disease, Children's Hospital of Soochow University, Soochow University, Suzhou, China.
authors.forename: Zhengrong
authors.initials: Z
authors.lastname: Chen
authors.affiliation: Department of Clinical Laboratory, Children's Hospital of Soochow University, Soochow University, Suzhou, China.
authors.forename: Xuejun
authors.initials: X
authors.lastname: Shao
authors.affiliation: Department of Ophthalmology and Otorhinolaryngology, Children's Hospital of Soochow University, Soochow University, Suzhou, China.
authors.forename: Xunwu
authors.initials: X
authors.lastname: Dou
authors.affiliation: Department of Respiratory Disease, Children's Hospital of Soochow University, Soochow University, Suzhou, China.
authors.forename: Xinxing
authors.initials: X
authors.lastname: Zhang
authors.affiliation: Department of Respiratory Disease, Children's Hospital of Soochow University, Soochow University, Suzhou, China.
authors.forename: Yuqing
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Department of Respiratory Disease, Children's Hospital of Soochow University, Soochow University, Suzhou, China.
authors.forename: Canhong
authors.initials: C
authors.lastname: Zhu
authors.affiliation: Department of Respiratory Disease, Children's Hospital of Soochow University, Soochow University, Suzhou, China.
authors.forename: Chuangli
authors.initials: C
authors.lastname: Hao
authors.affiliation: Department of Ophthalmology and Otorhinolaryngology, Children's Hospital of Soochow University, Soochow University, Suzhou, China.
authors.forename: Mingyue
authors.initials: M
authors.lastname: Fan
authors.affiliation: Department of Respiratory Disease, Children's Hospital of Soochow University, Soochow University, Suzhou, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Ji
authors.affiliation: Department of Respiratory Disease, Children's Hospital of Soochow University, Soochow University, Suzhou, China.
authors.forename: Yongdong
authors.initials: Y
authors.lastname: Yan
mesh_terms: D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D016209:Interleukin-8 / Q000235:genetics / Q000378:metabolism*; D019272:Leukocyte Elastase / Q000235:genetics / Q000378:metabolism; D008297:Male; D020780:Matrix Metalloproteinase 9 / Q000235:genetics / Q000378:metabolism; D009177:Mycoplasma pneumoniae / Q000472:pathogenicity*; D020556:Neutrophil Infiltration / Q000235:genetics / Q000502:physiology; D009195:Peroxidase / Q000235:genetics / Q000378:metabolism; D011019:Pneumonia, Mycoplasma / Q000378:metabolism / Q000382:microbiology*; D011446:Prospective Studies
chemical_list: C508606:CXCL8 protein, human; D016209:Interleukin-8; D009195:Peroxidase; D019272:Leukocyte Elastase; D020780:Matrix Metalloproteinase 9