title: Prognostic value of serum angiotensin-converting enzyme activity for outcome of community-acquired pneumonia.
abstract: BACKGROUND
  In a previous study, a relation between decreased serum angiotensin-converting enzyme (ACE) activity and physiological parameters was observed in patients with community-acquired pneumonia. The present study aims to further assess the prognostic value of serum ACE activity for outcome of community-acquired pneumonia.
  
  
  METHODS
  This was a prospective observational study including two cohorts of patients with community-acquired pneumonia (2004-2006; n=157 and 2007-2010; n=138). Serum ACE activity was measured at time of hospital admission. Based on reference values in healthy persons, patients were divided into subgroups of serum ACE activity: normal, low and extremely low. Physiological parameters, clinical outcomes and etiology were compared between the subgroups.
  
  
  RESULTS
  A total of 265 patients were enrolled in this study. Mean age was 60±19 years. In patients with low serum ACE activity (<20 U/L, n=53), compared to patients with normal serum ACE activity (≥20 U/L, n=212), C-reactive protein (CRP) was significantly increased, systolic blood pressure was significantly lower and there was a trend for higher heart rate and leukocyte counts. Furthermore, Streptococcus pneumoniae was significantly more identified in patients with low serum ACE activity. Serum ACE activity <24 U/L was independently associated with bacteremia (adjusted OR 3.93 [95% CI 1.57-9.87]). Low serum ACE activity was not prognostic for length of hospital stay nor mortality.
  
  
  CONCLUSIONS
  This study did not show prognostic value for serum ACE activity regarding clinical outcome in patients with community-acquired pneumonia. Serum ACE activity <24 U/L at time of hospitalization appeared an independent indicator for the presence of bacteremia. Further research should elucidate the role of ACE in systemic infection and sepsis during pneumonia.
authors.affiliation: Department of Internal Medicine, St. Antonius Hospital, Nieuwegein, The Netherlands. s.meijvis@antonius.net
authors.forename: Sabine C A
authors.initials: SC
authors.lastname: Meijvis
authors.forename: Marie Claire A
authors.initials: MC
authors.lastname: Cornips
authors.forename: Henrik
authors.initials: H
authors.lastname: Endeman
authors.forename: Henk J T
authors.initials: HJ
authors.lastname: Ruven
authors.forename: A H Jan
authors.initials: AH
authors.lastname: Danser
authors.forename: Douwe H
authors.initials: DH
authors.lastname: Biesma
authors.forename: Hubert G M
authors.initials: HG
authors.lastname: Leufkens
authors.forename: Willem Jan W
authors.initials: WJ
authors.lastname: Bos
authors.forename: Ewoudt M W
authors.initials: EM
authors.lastname: van de Garde
mesh_terms: D016470:Bacteremia / Q000097:blood / Q000175:diagnosis; D015415:Biomarkers / Q000097:blood; D015331:Cohort Studies; D017714:Community-Acquired Infections / Q000097:blood* / Q000175:diagnosis*; D005260:Female; D006760:Hospitalization; D006801:Humans; D008297:Male; D008875:Middle Aged; D007703:Peptidyl-Dipeptidase A / Q000097:blood*; D011014:Pneumonia / Q000097:blood* / Q000175:diagnosis*; D011379:Prognosis; D011446:Prospective Studies
chemical_list: D015415:Biomarkers; D007703:Peptidyl-Dipeptidase A