title: The role of procalcitonin and IL-6 in discriminating between septic and non-septic causes of ALI/ARDS: a prospective observational study.
abstract: BACKGROUND
  The aim was to evaluate the clinical usefulness of a single plasma and bronchoalveolar lavage fluid (BALF) PCT and IL-6 measurement in discriminating septic from non-septic causes of acute respiratory distress syndrome (ARDS) and forecasting clinical outcomes.
  
  
  METHODS
  One hundred patients were enrolled within 48 h of ALI/ARDS recognition. Demographic, clinical data, severity indices were recorded and PCT and IL-6 concentrations were measured in plasma and BALF.
  
  
  RESULTS
  Plasma PCT and IL-6 values were significantly higher in septic compared to non-septic individuals (p=0.001 and 0.0005, respectively), while there were no differences in their respective BALF values. As far as identification of septic vs. non-septic ARDS is concerned, the comparison of the areas under the curves favored PCT vs. IL-6 [0.88, (95% CI 0.81-0.95) vs. 0.71, (95% CI 0.60-0.81); χ(2)=9.04, p=0.003]. A plasma PCT level of 0.815 ng/mL was associated with 74.1% sensitivity and 97.6% specificity in identifying septic ARDS cases; this corresponded to a diagnostic odds ratio value of 116. Linear regression multivariable analysis disclosed a significant relation of plasma PCT with SOFA score in septic ARDS patients (p<0.001), while neither BALF PCT nor IL-6 levels were associated with clinical outcome.
  
  
  CONCLUSIONS
  Early plasma - but not BALF - PCT concentrations can discriminate between septic and non-septic ARDS causes and are associated with the severity of multiple organ dysfunction syndrome in septic ARDS patients. However, neither plasma or BALF IL-6 levels nor BALF PCT levels carry any prognostic potential. A single plasma PCT value higher than 0.815 ng/mL makes a non-septic cause of ARDS highly unlikely.
authors: Laboratory of Haematology and Blood Bank Unit, ‘Attiko’ University General Hospital, Medical School, National and Kapodistrian University of Athens, 1 Rimini Street, Athens 12462, Greece. atsantes@yahoo.com
authors: Argirios
authors: A
authors: Tsantes
authors: Iraklis
authors: I
authors: Tsangaris
authors: Petros
authors: P
authors: Kopterides
authors: Violetta
authors: V
authors: Kapsimali
authors: Georgios
authors: G
authors: Antonakos
authors: Aikaterini
authors: A
authors: Zerva
authors: Eleni
authors: E
authors: Kalamara
authors: Stefanos
authors: S
authors: Bonovas
authors: George
authors: G
authors: Tsaknis
authors: Eleni
authors: E
authors: Vrigou
authors: Nikolaos
authors: N
authors: Maniatis
authors: Kleanthi
authors: K
authors: Dima
authors: Apostolos
authors: A
authors: Armaganidis
mesh_terms: D000328:Adult; D000368:Aged; D001992:Bronchoalveolar Lavage Fluid / Q000737:chemistry; D002116:Calcitonin / Q000097:blood*; D015740:Calcitonin Gene-Related Peptide; D042241:Early Diagnosis; D005260:Female; D006801:Humans; D015850:Interleukin-6 / Q000097:blood*; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D011379:Prognosis; D011446:Prospective Studies; D011498:Protein Precursors / Q000097:blood*; D012128:Respiratory Distress Syndrome / Q000097:blood / Q000150:complications / Q000175:diagnosis* / Q000473:pathology; D012680:Sensitivity and Specificity; D018805:Sepsis / Q000097:blood / Q000150:complications / Q000175:diagnosis* / Q000473:pathology
chemical_list: C000606589:CALCA protein, human; C508600:IL6 protein, human; D015850:Interleukin-6; D011498:Protein Precursors; D002116:Calcitonin; D015740:Calcitonin Gene-Related Peptide