title: [Clinical characteristics of late-onset severe pneumonia after allogeneic hematopoietic stem cell transplantation].
abstract: OBJECTIVE
  To analyze the clinical characteristics of the late-onset severe pneumonia after allogeneic hematopoietic stem cell transplantation (allo-HSCT).
  
  
  METHODS
  A retrospective study was conducted in patients diagnosed as late-onset severe pneumonia after allo-HSCT from March, 2009 to January, 2013 in People's Hospital of Peking University.
  
  
  RESULTS
  Of 1538 patients receiving allo-HSCT, 20 developed late-onset severe pneumonia with an incidence rate of 1.3%. Among the 20 patients, 17(85%) had human leukocyte antigen (HLA) identical donors. The other 3(15%) patients had received haplo-identical transplantation. Severe pneumonia occurred at a median time of 227(150-690) days after allo-HSCT. Blood gas tests showed that 14 patients (70%) had arterial oxygen lower than 60 mm Hg (1 mm Hg = 0.133 kPa). All patients had abnormal findings in chest X-ray or CT scan images, 18 (90%) of whom represented bilateral infiltrative lesions. None of the patients had evidence of active graft-versus-host disease before or during pneumonia. Eighteen patients did not respond to empiric antibiotics, neither did 8 patients to targeted medications who had positive pathogens by culture. Eleven patients died of respiratory failure and 9 survived. Six patients received donor lymphocyte infusion (DLI), 4 of whom obtained improvement of chest images and 3 survived till the end of follow-up.
  
  
  CONCLUSIONS
  The late-onset severe pneumonia after allo-HSCT represents an aggressive behavior with poor prognosis. DLI might be an effective way to improve its outcome.
authors.affiliation: Institute of Hematology and People's Hospital, Peking University, Beijing 100044, China.
authors.forename: Dai-hong
authors.initials: DH
authors.lastname: Liu
authors.affiliation: Institute of Hematology and People's Hospital, Peking University, Beijing 100044, China.
authors.forename: Su-shan
authors.initials: SS
authors.lastname: Chen
authors.affiliation: Institute of Hematology and People's Hospital, Peking University, Beijing 100044, China.
authors.forename: Yu-qian
authors.initials: YQ
authors.lastname: Sun
authors.affiliation: Institute of Hematology and People's Hospital, Peking University, Beijing 100044, China.
authors.forename: Jing-zhi
authors.initials: JZ
authors.lastname: Wang
authors.affiliation: Institute of Hematology and People's Hospital, Peking University, Beijing 100044, China.
authors.forename: Feng-rong
authors.initials: FR
authors.lastname: Wang
authors.affiliation: Institute of Hematology and People's Hospital, Peking University, Beijing 100044, China.
authors.forename: Xiao-hui
authors.initials: XH
authors.lastname: Zhang
authors.affiliation: Institute of Hematology and People's Hospital, Peking University, Beijing 100044, China.
authors.forename: Lan-ping
authors.initials: LP
authors.lastname: Xu
authors.affiliation: Institute of Hematology and People's Hospital, Peking University, Beijing 100044, China. Email:huangxiaojun@bjmu.edu.cn.
authors.forename: Xiao-Jun
authors.initials: XJ
authors.lastname: Huang
mesh_terms: D000293:Adolescent; D000328:Adult; D018380:Hematopoietic Stem Cell Transplantation / Q000009:adverse effects* / Q000379:methods; D006801:Humans; D008875:Middle Aged; D011014:Pneumonia / Q000453:epidemiology*; D012189:Retrospective Studies; D014184:Transplantation, Homologous; D055815:Young Adult