title: Procalcitonin levels associate with severity of Clostridium difficile infection.
abstract: OBJECTIVE
  Clostridium difficile infection (CDI) is a major cause of morbidity and biomarkers that predict severity of illness are needed. Procalcitonin (PCT), a serum biomarker with specificity for bacterial infections, has been little studied in CDI. We hypothesized that PCT associated with CDI severity.
  
  
  METHODS
  Serum PCT levels were measured for 69 cases of CDI. Chart review was performed to evaluate the presence of severity markers and concurrent acute bacterial infection (CABI). We defined the binary variables clinical score as having fever (T >38°C), acute organ dysfunction (AOD), and/or WBC >15,000 cells/mm(3) and expanded score, which included the clinical score plus the following: ICU admission, no response to therapy, colectomy, and/or death.
  
  
  RESULTS
  In univariate analysis log10 PCT associated with clinical score (OR 3.13, 95% CI 1.69-5.81, P<.001) and expanded score (OR 3.33, 95% CI 1.77-6.23, P<.001). In a multivariable model including the covariates log10 PCT, enzyme immunoassay for toxin A/B, ribotype 027, age, weighted Charlson-Deyo comorbidity index, CABI, and extended care facility residence, log10 PCT associated with clinical score (OR 3.09, 95% CI 1.5-6.35, P = .002) and expanded score (OR 3.06, 95% CI 1.49-6.26, P = .002). PCT >0.2 ng/mL was 81% sensitive/73% specific for a positive clinical score and had a negative predictive value of 90%.
  
  
  CONCLUSIONS
  An elevated PCT level associated with the presence of CDI severity markers and CDI was unlikely to be severe with a serum PCT level below 0.2 ng/mL. The extent to which PCT changes during CDI therapy or predicts recurrent CDI remains to be quantified.
authors.affiliation: Department of Internal Medicine, University of Michigan Health System, Ann Arbor, Michigan, United States of America.
authors.forename: Krishna
authors.initials: K
authors.lastname: Rao
authors.forename: Seth T
authors.initials: ST
authors.lastname: Walk
authors.forename: Dejan
authors.initials: D
authors.lastname: Micic
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Chenoweth
authors.forename: Lili
authors.initials: L
authors.lastname: Deng
authors.forename: Andrzej T
authors.initials: AT
authors.lastname: Galecki
authors.forename: Ruchika
authors.initials: R
authors.lastname: Jain
authors.forename: Itishree
authors.initials: I
authors.lastname: Trivedi
authors.forename: Marie
authors.initials: M
authors.lastname: Yu
authors.forename: Kavitha
authors.initials: K
authors.lastname: Santhosh
authors.forename: Cathrin
authors.initials: C
authors.lastname: Ring
authors.forename: Vincent B
authors.initials: VB
authors.lastname: Young
authors.forename: Gary B
authors.initials: GB
authors.lastname: Huffnagle
authors.forename: David M
authors.initials: DM
authors.lastname: Aronoff
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000097:blood; D002116:Calcitonin / Q000097:blood*; D015740:Calcitonin Gene-Related Peptide; D016360:Clostridioides difficile / Q000302:isolation & purification; D004761:Enterocolitis, Pseudomembranous / Q000097:blood*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D011379:Prognosis; D011498:Protein Precursors / Q000097:blood*; D012372:ROC Curve; D012008:Recurrence; D012189:Retrospective Studies; D012720:Severity of Illness Index; D055815:Young Adult
chemical_list: D015415:Biomarkers; C000606589:CALCA protein, human; D011498:Protein Precursors; D002116:Calcitonin; D015740:Calcitonin Gene-Related Peptide