Differentiating Clostridium difficile Colitis from Clostridium difficile Colonization in Ulcerative Colitis: A Role for Procalcitonin

Digestion. 2017 Nov;96(4):207-212. doi: 10.1159/000481133. Epub 2017 Oct 14.


Background/aims: Clostridium difficile infection (CDI) frequently complicates ulcerative colitis (UC) and can mimic disease flare. Differentiating UC flare from CDI remains a clinical challenge, particularly due to C. difficile colonization. Procalcitonin (PCT) is a serum biomarker for bacterial infections. We hypothesized that PCT would differentiate acute CDI from UC flare and C. difficile colonization.

Methods: A single-center prospective cohort study was conducted from 2013 to 2016. All UC patients with a stool sample for C. difficile testing were eligible. A total of 117 patients were enrolled, while 20 were excluded. Chart review was performed.

Results: Among 27 patients with CDI, median PCT was 60.7 (range 26-560.6) pg/mL, while among 90 patients without CDI, median PCT was 56.7 (range 25.1-2,252) pg/mL (p = 0.9). It was found that 14 patients with CDI responded completely to C. difficile treatment (CDI-R), while 8 patients did not and were diagnosed with UC flare (CDI-NR). For CDI-R, median PCT was 104.5 (range 26.3-560.6), compared to 40.3 (range 26.0-116.3) for CDI-NR (p = 0.036).

Conclusions: In UC patients presenting with diarrhea, serum PCT was not significantly higher in UC patients with positive C. difficile testing. However, PCT was significantly elevated in CDI-R versus CDI-NR, suggesting that PCT may have utility in making this discrimination.

Keywords: Clostridium difficile; Diagnosis; Procalcitonin; Ulcerative colitis.

Publication types

  • Clinical Trial

MeSH terms

  • Adult
  • Antibodies / therapeutic use
  • Biomarkers / blood
  • Clostridioides difficile*
  • Colitis, Ulcerative / blood*
  • Colitis, Ulcerative / microbiology
  • Diagnosis, Differential
  • Diarrhea / diagnosis*
  • Diarrhea / drug therapy
  • Diarrhea / microbiology
  • Enterocolitis, Pseudomembranous / diagnosis*
  • Enterocolitis, Pseudomembranous / drug therapy
  • Enterocolitis, Pseudomembranous / microbiology
  • Female
  • Humans
  • Male
  • Middle Aged
  • Procalcitonin / blood*
  • Prospective Studies
  • Symptom Flare Up


  • Antibodies
  • Biomarkers
  • Procalcitonin