title: Plasma procalcitonin and C-reactive protein in acute septic shock: clinical and biological correlates.
abstract: OBJECTIVE
  To determine the relationship between plasma procalcitonin (PCT) levels, C-reactive protein (CRP), white blood cell count (WBC), ionized calcium (Ca2+), and patient outcome; and to compare the diagnostic and prognostic information provided by PCT and by CRP.
  
  
  METHODS
  Prospective, observational study.
  
  
  METHODS
  Intensive care unit.
  
  
  METHODS
  Fifty-three patients with septic shock, consecutively diagnosed according to consensus guidelines.
  
  
  METHODS
  None.
  
  
  RESULTS
  Blood was sampled at diagnosis and 24 and 48 hrs later and in a subgroup (n = 23) after 120 hrs. PCT was measured with LUMItest and CRP with Vitros slides. Ca2+ was calculated according to McLean-Hastings from calcium and protein levels on Vitros. In all 53 patients, PCT and CRP were elevated (>0.5 ng/mL and >10 mg/L, respectively) within 24 hrs after diagnosis. Nonsurvivors (n = 25) were older (p <.001) and had higher Acute Physiology and Chronic Health Evaluation (APACHE) II scores (p =.02) at diagnosis but did not differ in sepsis etiology, medical history, sex ratio, levels of PCT, CRP, and Ca2+, or WBC count at any time point. Using logistic regression, initial PCT levels were correlated with CRP values (p =.001) and APACHE II score (p <.05), but not with age, gender, Ca2+ levels, survival, or type of pathogen. Within 48 hrs, however, PCT levels decreased more frequently from baseline in survivors than in nonsurvivors (80% vs. 41%, p <.05). Likewise, CRP levels decreased more often in survivors (100% vs. 64%, p <.05) but only at 120 hrs.
  
  
  CONCLUSIONS
  PCT levels were correlated with the severity of disease at onset (APACHE II) and inflammation (CRP) but not with Ca2+ levels. Inaugural PCT or CRP levels per se poorly predicted outcome but decreasing levels were associated with a higher probability of survival. In this respect, PCT was found to be an earlier marker than CRP.
authors.affiliation: Department of Clinical Chemistry, Vrije Universiteit Brussels, Brussels, Belgium.
authors.forename: Roxane
authors.initials: R
authors.lastname: Claeys
authors.forename: Stephanie
authors.initials: S
authors.lastname: Vinken
authors.forename: Herbert
authors.initials: H
authors.lastname: Spapen
authors.forename: Kristien
authors.initials: K
authors.lastname: ver Elst
authors.forename: Katelyn
authors.initials: K
authors.lastname: Decochez
authors.forename: Luc
authors.initials: L
authors.lastname: Huyghens
authors.forename: Frans K
authors.initials: FK
authors.lastname: Gorus
mesh_terms: D000208:Acute Disease; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000097:blood; D002097:C-Reactive Protein / Q000032:analysis*; D002116:Calcitonin / Q000097:blood*; D015740:Calcitonin Gene-Related Peptide; D002118:Calcium / Q000097:blood; D005260:Female; D006801:Humans; D007362:Intensive Care Units; D007958:Leukocyte Count; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D011446:Prospective Studies; D011498:Protein Precursors / Q000097:blood*; D012772:Shock, Septic / Q000097:blood* / Q000401:mortality
chemical_list: D015415:Biomarkers; C000606589:CALCA protein, human; D011498:Protein Precursors; D002116:Calcitonin; D002097:C-Reactive Protein; D015740:Calcitonin Gene-Related Peptide; D002118:Calcium