title: Procalcitonin as a rapid diagnostic biomarker to differentiate between culture-negative bacterial sepsis and systemic inflammatory response syndrome: a prospective, observational, cohort study.
abstract: OBJECTIVE
  Differentiation between culture-negative sepsis and noninfectious systemic inflammatory response syndrome (SIRS) remains a diagnostic challenge for clinicians, both conditions having similar clinical presentations. Therefore, a swift accurate diagnostic tool, which helps differentiate these 2 conditions would immensely aid appropriate therapeutic continuum. This prospective study was conducted to evaluate the potential diagnostic role of biomarkers, procalcitonin (PCT) and interleukin 6 (IL-6), in culture-negative sepsis patients.
  
  
  METHODS
  Enrolled patients (208) included 46 noninfectious SIRS, 90 culture-negative sepsis, and 72 culture-positive sepsis. Culture, PCT, and IL-6 estimations were performed on day 1 of intensive care unit admission.
  
  
  RESULTS
  Procalcitonin and IL-6 levels were significantly higher (P < .001) in both culture-negative and culture-positive groups as compared with SIRS group. Procalcitonin was a better predictor of sepsis in both culture-negative (area under curves 0.892 vs 0.636) and culture-positive (area under curves 0.959 vs 0.784) groups as compared with IL-6. In culture-negative group, the best cutoff point for PCT was at 1.43 ng/mL (92% sensitivity; 83% negative predictive value), best cutoff point for IL-6 was at 219.85 pg/mL (47% sensitivity and 42% negative predictive value).
  
  
  CONCLUSIONS
  Procalcitonin can accurately differentiate culture-negative sepsis from noninfectious SIRS and thereby contribute to early diagnosis and effective management of these conditions.
authors.affiliation: Department of Biochemistry, Sir Ganga Ram Hospital, New Delhi, 110060, India.
authors.forename: Dimple
authors.initials: D
authors.lastname: Anand
authors.affiliation: Department of Biochemistry, Sir Ganga Ram Hospital, New Delhi, 110060, India.
authors.forename: Sabari
authors.initials: S
authors.lastname: Das
authors.affiliation: Department of Biochemistry, Sir Ganga Ram Hospital, New Delhi, 110060, India.
authors.forename: Seema
authors.initials: S
authors.lastname: Bhargava
authors.affiliation: Department of Biochemistry, Sir Ganga Ram Hospital, New Delhi, 110060, India.
authors.forename: Lalit Mohan
authors.initials: LM
authors.lastname: Srivastava
authors.affiliation: Department of Critical Care and Emergency Medicine, Sir Ganga Ram Hospital, New Delhi, 110060, India.
authors.forename: Ashish
authors.initials: A
authors.lastname: Garg
authors.affiliation: Department of Critical Care and Emergency Medicine, Sir Ganga Ram Hospital, New Delhi, 110060, India.
authors.forename: Niraj
authors.initials: N
authors.lastname: Tyagi
authors.affiliation: Department of Critical Care and Emergency Medicine, Sir Ganga Ram Hospital, New Delhi, 110060, India.
authors.forename: Saurabh
authors.initials: S
authors.lastname: Taneja
authors.affiliation: Department of Critical Care and Emergency Medicine, Sir Ganga Ram Hospital, New Delhi, 110060, India. Electronic address: drsray2014@gmail.com.
authors.forename: Sumit
authors.initials: S
authors.lastname: Ray
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019540:Area Under Curve; D016470:Bacteremia; D015415:Biomarkers / Q000097:blood; D002116:Calcitonin / Q000097:blood*; D015740:Calcitonin Gene-Related Peptide; D003937:Diagnosis, Differential; D042241:Early Diagnosis; D005260:Female; D006801:Humans; D007362:Intensive Care Units; D015850:Interleukin-6 / Q000097:blood*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011498:Protein Precursors / Q000097:blood*; D012680:Sensitivity and Specificity; D018805:Sepsis / Q000097:blood / Q000175:diagnosis* / Q000382:microbiology; D018746:Systemic Inflammatory Response Syndrome / Q000097:blood / Q000175:diagnosis*; D055815:Young Adult
chemical_list: D015415:Biomarkers; C000606589:CALCA protein, human; D015850:Interleukin-6; D011498:Protein Precursors; D002116:Calcitonin; D015740:Calcitonin Gene-Related Peptide
keywords: Culture negative; Interleukin 6 (IL-6); Negative predictive value (NPV); Procalcitonin (PCT); Sepsis; Systemic inflammatory response syndrome (SIRS)