title: Procalcitonin levels are lower in intensive care unit patients with H1N1 influenza A virus pneumonia than in those with community-acquired bacterial pneumonia. A pilot study.
abstract: OBJECTIVE
  The purpose of the study was to know the kinetics of procalcitonin (PCT), C-reactive protein (CRP), and white blood cell (WBC) in critically ill patients with H1N1 influenza A virus pneumonia and to compare levels of these inflammatory mediators with patients with acute community-acquired bacterial pneumonia.
  
  
  METHODS
  An observational study in a mixed intensive care unit (ICU) at a general university hospital was performed. All consecutive patients admitted to the ICU with a diagnosis of severe acute community-acquired pneumonia from September 2009 to December 2009 were included. Viral (H1N1 influenza A) and bacterial microbiological diagnoses were done in every patient. At admission, demographics, comorbidities, Simplified Acute Physiology Score, Sequential Organ Failure Assessment, Lung Injury Score, and Pao(2)/Fio(2) were recorded. At admission and after 24, 48, and 120 hours, WBC, CRP, and PCT levels were obtained. Finally, hospital and ICU length of stay and mortality were recorded.
  
  
  RESULTS
  No differences in CRP or WBC were found between H1N1-positive patients and H1N1-negative patients (patients with acute community-acquired bacterial pneumonia). Procalcitonin levels at admission were lower in H1N1-positive patients (PCT = 0.4 [0.1-6.1] ng/mL) than in the H1N1-negative patients (24.8 [13.1-34.5] ng/mL). Procalcitonin significantly decreased with time but remained lower in the H1N1-positive group at all measurements (P < .05 for all comparisons).
  
  
  CONCLUSIONS
  Among patients admitted to the ICU with pneumonia, the PCT level could help identify H1N1 influenza A virus pneumonia and thus enable earlier antiviral therapy.
authors.affiliation: Doctorando UAB, Intensive Care Unit, Hospital Universitario Mútua de Terrassa, Terrassa 08221, Spain. enpiache@yahoo.com.ar
authors.forename: Enrique
authors.initials: E
authors.lastname: Piacentini
authors.forename: Baltasar
authors.initials: B
authors.lastname: Sánchez
authors.forename: Vanessa
authors.initials: V
authors.lastname: Arauzo
authors.forename: Esther
authors.initials: E
authors.lastname: Calbo
authors.forename: Eva
authors.initials: E
authors.lastname: Cuchi
authors.forename: Juan Manuel
authors.initials: JM
authors.lastname: Nava
mesh_terms: D000328:Adult; D000368:Aged; D015415:Biomarkers; D002097:C-Reactive Protein / Q000032:analysis; D002116:Calcitonin / Q000097:blood*; D015740:Calcitonin Gene-Related Peptide; D017714:Community-Acquired Infections / Q000097:blood; D016638:Critical Illness; D005260:Female; D006785:Hospitals, University; D006801:Humans; D053118:Influenza A Virus, H1N1 Subtype; D007251:Influenza, Human / Q000097:blood*; D007362:Intensive Care Units; D007902:Length of Stay; D007958:Leukocyte Count; D008297:Male; D008875:Middle Aged; D010865:Pilot Projects; D018410:Pneumonia, Bacterial / Q000097:blood*; D011024:Pneumonia, Viral / Q000097:blood*; D011446:Prospective Studies; D011498:Protein Precursors / Q000097:blood*
chemical_list: D015415:Biomarkers; C000606589:CALCA protein, human; D011498:Protein Precursors; D002116:Calcitonin; D002097:C-Reactive Protein; D015740:Calcitonin Gene-Related Peptide