title: Increased T cell activation in BALF from children with Mycoplasma pneumoniae pneumonia.
abstract: OBJECTIVE
  The mechanisms of Mycoplasma pneumoniae induced lung inflammation are not clearly understood yet. This study investigated whether activated T cells in the airway contributed to the pulmonary inflammation in patients with severe Mycoplasma pneumoniae pneumonia (MPP).
  
  
  METHODS
  BALF were collected in all 45 patients with MPP (MPP, n = 45), including mild (Mild, n = 20) and severe (Severe, n = 25) group. BALF in 20 of all 25 severe cases with MPP at the recovery stage (Rec-severe, n = 20) were collected again. The control group consisted of 20 patients with airway foreign body aspiration (Con., n = 20). CD3+ T cells, CD69+, HLA-DR+, CD25+ on CD3+ T cells in BALF were determined by flow cytometry. Levels of IL-6, IL-10 in BALF were determined by ELISA, and percentage of neutrophils was counted.
  
  
  RESULTS
  A significant increased percentage of neutrophils and levels of IL-6 and IL-10, decreased percentage of CD3+ T cells, increased expressions of CD69+, HLA-DR+ or CD25+ on CD3+ T cells were observed in children with MPP compared with the control group (P < 0.05 or 0.01). Compared to mild group, the percentage of neutrophils, CD3+ CD25+, IL-6, and IL-10 were increased in children with severe MPP (P < 0.01 or 0.05). Compared to acute stage, an increased percentage of CD3+ T cells, decreased percentage of neutrophils and IL-6 level, and expressions of CD3+ CD69+ or CD3+ CD25+ were observed at the recovery stage in children with severe MPP (P < 0.01 or 0.05).
  
  
  CONCLUSIONS
  Increased activation of T cell in BALF may play an important role in the inflammatory response of acute and severe MPP. IL-6 may predict the severity and prognosis and provide a better assessment for patient care. However, the underlying mechanism awaits further detailed investigations.
authors.affiliation: Department of Rheumatology Immunology & Allergy, Children's Hospital, Zhejiang University School of Medicine, Hangzhou, 310003, China.
authors.forename: Li
authors.initials: L
authors.lastname: Guo
authors.affiliation: Department of Respiratory, Children's Hospital, Zhejiang University School of Medicine, Hangzhou, 310003, China.|Taizhou Nursing School, 100 Chennan Huaxi Rd, Linhai, 317000, Zhejiang, China.
authors.forename: Fang
authors.initials: F
authors.lastname: Liu
authors.affiliation: Department of Rheumatology Immunology & Allergy, Children's Hospital, Zhejiang University School of Medicine, Hangzhou, 310003, China.|Department of Respiratory, Children's Hospital, Zhejiang University School of Medicine, Hangzhou, 310003, China.
authors.forename: Mei-Ping
authors.initials: MP
authors.lastname: Lu
authors.affiliation: Department of Rheumatology Immunology & Allergy, Children's Hospital, Zhejiang University School of Medicine, Hangzhou, 310003, China.
authors.forename: Qi
authors.initials: Q
authors.lastname: Zheng
authors.affiliation: Department of Respiratory, Children's Hospital, Zhejiang University School of Medicine, Hangzhou, 310003, China.
authors.forename: Zhi-Min
authors.initials: ZM
authors.lastname: Chen
mesh_terms: D000293:Adolescent; D001992:Bronchoalveolar Lavage Fluid / Q000166:cytology*; D017252:CD3 Complex / Q000378:metabolism; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D016753:Interleukin-10 / Q000378:metabolism; D015850:Interleukin-6 / Q000378:metabolism; D008213:Lymphocyte Activation; D008297:Male; D009504:Neutrophils / Q000378:metabolism; D011019:Pneumonia, Mycoplasma / Q000378:metabolism*; D013601:T-Lymphocytes / Q000378:metabolism*
chemical_list: D017252:CD3 Complex; D015850:Interleukin-6; D016753:Interleukin-10
keywords: Mycoplasma pneumoniae; activated T cells; bronchoalveolar lavage; children; cytokine