title: [Diagnostic values of procalcitonin, interleukin-6, C reactive protein and serum amyloid A in sepsis].
abstract: OBJECTIVE
  To evaluate the diagnostic values of procalcitonin (PCT), C reactive protein (CRP), interleukin-6 (IL-6), serum amyloid A (SAA) in septic patients.
  
  
  METHODS
  This study totally enrolled 390 patients who were admitted to West China Hospital, Sichuan University from March to November 2011 with septic manifestation. The patients were divided into sepsis group (n = 203) and non-sepsis group (n = 187) according to clinical infectious disease standard. PCT and IL-6 were measured by automatic electrochemiluminescence (ECL) analyser. CRP was measured by rate immunonephelometric analyser, SAA was measured by fixed time nephelometric method. The diagnostic powers of these four biomakers were constructed by receiver operating characteristics (ROC) curves.
  
  
  RESULTS
  There were statistically significant differences on the values of PCT, CRP, IL-6, SAA between sepsis group and non-sepsis group. PCT had an AUC value of 0. 919 (P < 0.05) which was higher than that of CRP, IL-6, and SAA (P < 0.05). CRP performed with an AUC of 0.755 (P < 0.05), IL-6 with an AUC of 0.786 (P < 0.05), and SAA with the lowest AUC of 0.645 (P < 0.05). The combination AUC was 0.892 (P < 0.05) and there was no statistically significant difference when compared to PCT. As an early diagnostic indicator of sepsis, the cut-off value of PCT was 1.18 ng/mL, with sensitivity of 84.7%, specific of 83.4%, while Youden index was 0.681, positive predict value was 64.1%, negative predict value was 75.8%, positive likelihood ratio was 5.10, negative likelihood ratio was 0.18, respectively. A statistically significant difference was available on the value of PCT in septic patients between ICU and non-ICU.
  
  
  CONCLUSIONS
  PCT as an early independent biomarker for sepsis is superior to immune inflammatory biomarkers (CRP, IL-6, SAA), also is better than the combination of these four biomarkers for economic effect.
authors.affiliation: Department of Immunology Laboratory, West China Hospital, Sichuan University, Chengdu 610041, China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Fu
authors.forename: Jie
authors.initials: J
authors.lastname: Chen
authors.forename: Bei
authors.initials: B
authors.lastname: Cai
authors.forename: Jun-Long
authors.initials: JL
authors.lastname: Zhang
authors.forename: Li-Xin
authors.initials: LX
authors.lastname: Li
authors.forename: Lan-Lan
authors.initials: LL
authors.lastname: Wang
mesh_terms: D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000097:blood*; D002097:C-Reactive Protein / Q000378:metabolism; D002116:Calcitonin / Q000097:blood*; D015740:Calcitonin Gene-Related Peptide; D005260:Female; D006801:Humans; D015850:Interleukin-6 / Q000097:blood; D008297:Male; D008875:Middle Aged; D011498:Protein Precursors / Q000097:blood*; D018805:Sepsis / Q000097:blood / Q000175:diagnosis*; D000685:Serum Amyloid A Protein / Q000378:metabolism
chemical_list: D015415:Biomarkers; C000606589:CALCA protein, human; D015850:Interleukin-6; D011498:Protein Precursors; D000685:Serum Amyloid A Protein; D002116:Calcitonin; D002097:C-Reactive Protein; D015740:Calcitonin Gene-Related Peptide