title: Markers of intestinal inflammation, not bacterial burden, correlate with clinical outcomes in Clostridium difficile infection.
abstract: BACKGROUND
  Clostridium difficile is a leading hospital-acquired infection. Many patients remain symptomatic for several days on appropriate antibiotic therapy. To assess the contribution of ongoing infection vs persistent inflammation, we examined the correlation between fecal cytokine levels, fecal C. difficile burden, and disease outcomes in C. difficile infection (CDI).
  
  
  METHODS
  We conducted a prospective cohort study in Barnes Jewish Hospital between June 2011 and May 2012 of hospitalized adults with CDI. We determined fecal interleukin 8 (IL-8) and lactoferrin protein concentrations by enzyme immunoassay. We used real-time polymerase chain reaction (PCR) to measure relative fecal IL-8 and CXCL-5 RNA transcript abundances, and quantitative PCR to enumerate C. difficile burden.
  
  
  RESULTS
  Of 120 study subjects, 101 (84%) were started on metronidazole, and 33 of those (33%) were subsequently given vancomycin. Sixty-two (52%) patients had diarrhea persistent for 5 or more days after starting CDI therapy. Initial fecal CXCL-5 messenger RNA (mRNA), IL-8 mRNA, and IL-8 protein correlated with persistent diarrhea and use of vancomycin. Time to diarrhea resolution was longer in patients with elevated fecal cytokines at diagnosis. Fecal cytokines were more sensitive than clinical severity scores in identifying patients at risk of treatment failure. Clostridium difficile burden did not correlate with any measure of illness or outcome at any point, and decreased equally with metronidazole and vancomycin.
  
  
  CONCLUSIONS
  Persistent diarrhea in CDI correlates with intestinal inflammation and not fecal pathogen burden. These findings suggest that modulation of host response, rather than adjustments to antimicrobial regimens, might be a more effective approach to patients with unremitting disease.
authors.affiliation: Department of Pediatrics, Washington University School of Medicine, St Louis, MO 63110, USA.
authors.forename: Rana E
authors.initials: RE
authors.lastname: El Feghaly
authors.forename: Jennifer L
authors.initials: JL
authors.lastname: Stauber
authors.forename: Elena
authors.initials: E
authors.lastname: Deych
authors.forename: Carlos
authors.initials: C
authors.lastname: Gonzalez
authors.forename: Phillip I
authors.initials: PI
authors.lastname: Tarr
authors.forename: David B
authors.initials: DB
authors.lastname: Haslam
mesh_terms: D000368:Aged; D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D015415:Biomarkers / Q000032:analysis / Q000378:metabolism; D016360:Clostridioides difficile / Q000302:isolation & purification*; D016207:Cytokines / Q000235:genetics / Q000378:metabolism*; D004761:Enterocolitis, Pseudomembranous / Q000188:drug therapy / Q000378:metabolism* / Q000382:microbiology* / Q000473:pathology; D005243:Feces / Q000737:chemistry; D005260:Female; D006760:Hospitalization; D006801:Humans; D007249:Inflammation / Q000378:metabolism* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D008923:Missouri; D011446:Prospective Studies; D012333:RNA, Messenger / Q000378:metabolism; D016896:Treatment Outcome
chemical_list: D000900:Anti-Bacterial Agents; D015415:Biomarkers; D016207:Cytokines; D012333:RNA, Messenger
keywords: CXCL-5; Clostridium difficile; IL-8; cytokines; inflammation