title: Thin-section computed tomography detects long-term pulmonary sequelae 3 years after novel influenza A virus-associated pneumonia.
abstract: BACKGROUND
  The aim of this research was to evaluate long-term pulmonary sequelae on paired inspiration-expiration thin-section computed tomography (CT) scans 3 years after influenza A (H1N1) virus-associated pneumonia, and to analyze the affecting factors on pulmonary fibrosis.
  
  
  METHODS
  Twenty-four patients hospitalized with H1N1 virus-associated pneumonia at our hospital between September 2009 and January 2010 were included. The patients underwent thin-section CT 3 years after recovery. Abnormal pulmonary lesion patterns (ground-glass opacity, consolidation, parenchymal bands, air trapping, and reticulation) and evidence of fibrosis (architectural distortion, traction bronchiectasis, or honeycombing) were evaluated on follow-up thin-section CT. Patients were assigned to Group 1 (with CT evidence of fibrosis) and Group 2 (without CT evidence of fibrosis). Demographics, rate of mechanical ventilation therapy, rate of intensive care unit admission, cumulative prednisolone-equivalent dose, laboratory tests results (maximum levels of alanine aminotransferase, aspartate transaminase [AST], lactate dehydrogenase [LDH], and creatine kinase [CK]), and peak radiographic opacification of 24 patients during the course of their illness in the hospital were compared between two groups.
  
  
  RESULTS
  Parenchymal abnormality was present in 17 of 24 (70.8%) patients and fibrosis occurred in 10 of 24 (41.7%) patients. Patients in Group 1 (10/24; 41.7%) had a higher rate of mechanical ventilation therapy (Z = -2.340, P = 0.019), higher number of doses of cumulative prednisolone-equivalent (Z = -2.579, P = 0.010), higher maximum level of laboratory tests results (AST [Z = -2.140, P = 0.032], LDH [Z = -3.227, P = 0.001], and CK [Z = -3.345, P = 0.019]), and higher peak opacification on chest radiographs (Z = -2.743, P = 0.006) than patients in group 2 (14/24; 58.3%).
  
  
  CONCLUSIONS
  H1N1 virus-associated pneumonia frequently is followed by long-term pulmonary sequelae, including fibrotic changes, in lung parenchyma. Patients who need more steroid therapy, need more mechanical ventilation therapy, had higher laboratory tests results (maximum levels of AST, LDH, and CK), and had higher peak opacification on chest radiographs during treatment are more likely to develop lung fibrosis.
authors.forename: Zhi-Heng
authors.initials: ZH
authors.lastname: Xing
authors.forename: Xin
authors.initials: X
authors.lastname: Sun
authors.forename: Long
authors.initials: L
authors.lastname: Xu
authors.affiliation: Department of Respiratory, Tianjin Institute of Respiratory Diseases, Tianjin Haihe Hospital, Tianjin 300350, China.
authors.forename: Qi
authors.initials: Q
authors.lastname: Wu
authors.forename: Li
authors.initials: L
authors.lastname: Li
authors.forename: Xian-Jie
authors.initials: XJ
authors.lastname: Wu
authors.forename: Xu-Guang
authors.initials: XG
authors.lastname: Shao
authors.forename: Xin-Qian
authors.initials: XQ
authors.lastname: Zhao
authors.forename: Jing-Hua
authors.initials: JH
authors.lastname: Wang
authors.forename: Long-Yan
authors.initials: LY
authors.lastname: Ma
authors.forename: Kai
authors.initials: K
authors.lastname: Wang
mesh_terms: D000328:Adult; D005260:Female; D006801:Humans; D053118:Influenza A Virus, H1N1 Subtype / Q000472:pathogenicity*; D007251:Influenza, Human / Q000150:complications* / Q000821:virology*; D008168:Lung / Q000000981:diagnostic imaging* / Q000473:pathology* / Q000821:virology; D008297:Male; D008875:Middle Aged; D011014:Pneumonia / Q000150:complications* / Q000000981:diagnostic imaging / Q000382:microbiology*; D014057:Tomography, X-Ray Computed / Q000379:methods*
references.citation: Eur Radiol. 2001;11(12):2436-43
references.pmid: 11734936
references.citation: J Comput Assist Tomogr. 2002 May-Jun;26(3):323-9
references.pmid: 12016356
references.citation: Radiology. 2003 Aug;228(2):395-400
references.pmid: 12738877
references.citation: Radiology. 2003 Sep;228(3):810-5
references.pmid: 12805557
references.citation: Radiology. 2003 Dec;229(3):737-42
references.pmid: 14657310
references.citation: Chest. 1994 Jul;106(1):105-9
references.pmid: 8020254
references.citation: Radiology. 1994 Dec;193(3):789-93
references.pmid: 7972826
references.citation: AJR Am J Roentgenol. 2005 Mar;184(3):734-41
references.pmid: 15728590
references.citation: Radiology. 2005 Apr;235(1):168-75
references.pmid: 15703312
references.citation: Radiology. 2005 Sep;236(3):1067-75
references.pmid: 16055695
references.citation: AJR Am J Roentgenol. 2006 Jun;186(6):1707-14
references.pmid: 16714663
references.citation: Radiology. 2007 Aug;244(2):591-8
references.pmid: 17641377
references.citation: Radiology. 2008 Mar;246(3):697-722
references.pmid: 18195376
references.citation: N Engl J Med. 2009 Aug 13;361(7):680-9
references.pmid: 19564631
references.citation: AJR Am J Roentgenol. 2009 Dec;193(6):1488-93
references.pmid: 19933638
references.citation: AJR Am J Roentgenol. 2009 Dec;193(6):1494-9
references.pmid: 19933639
references.citation: N Engl J Med. 2009 Dec 24;361(26):2507-17
references.pmid: 20007555
references.citation: BMC Infect Dis. 2010;10:256
references.pmid: 20799934
references.citation: Intensive Care Med. 2010 Nov;36(11):1899-905
references.pmid: 20721530
references.citation: Korean J Intern Med. 2011 Jun;26(2):160-7
references.pmid: 21716592
references.citation: Eur J Radiol. 2011 Nov;80(2):573-5
references.pmid: 21035973
references.citation: AJR Am J Roentgenol. 2011 Dec;197(6):W970-7
references.pmid: 22109341
references.citation: Radiol Med. 2012 Mar;117(2):165-84
references.pmid: 22020427
references.citation: Radiol Med. 2012 Mar;117(2):185-200
references.pmid: 22020433
references.citation: Br J Radiol. 2012 Jun;85(1014):729-35
references.pmid: 22167502
references.citation: Intensive Care Med. 2012 Jul;38(7):1152-61
references.pmid: 22527080
references.citation: Chin Med J (Engl). 2013 Jun;126(12):2222-8
references.pmid: 23786929
references.citation: Radiographics. 2013 Nov-Dec;33(7):1951-75
references.pmid: 24224590