title: Lymphopenia as a novel marker of Clostridium difficile infection recurrence.
abstract: BACKGROUND
  Treatment of Clostridium difficile infection (CDI) is often limited by recurrence in 25% of cases. The objective of this study was to determine risk factors of CDI recurrence during a provincial endemic.
  
  
  METHODS
  Data was prospectively collected for 1 year in a Montréal hospital. Inclusion criteria were: age ≥ 18 years; admission for ≥ 72 h; CDI diagnosis during current admission; no CDI diagnosis in the previous 3 months.
  
  
  RESULTS
  A total of 121 patients were included, of which 42% were female. Mean age was 77 years, with a median Charlson comorbidity index of 5. Forty patients (33%) had recurrent disease within 2 months of initial CDI treatment. There were 20 deaths (17%) within the 2-month follow-up period. Higher risk of CDI recurrence was independently associated with older age (HR=2.26 for each decade), female gender (HR=1.56), and lymphopenia at completion of CDI treatment (HR=2.18), while a positive C. difficile antitoxin serology was protective (HR=0.17). CDI recurrence was not associated with either lymphopenia at time of diagnosis, underlying comorbidities, severity or treatment of the initial CDI episode, or re-exposure to antibiotics during the follow-up period.
  
  
  CONCLUSIONS
  Lymphopenia at the end of CDI treatment appears to be a strong marker for CDI recurrence. This available and inexpensive test may identify patients who are at higher risk of CDI recurrence.
authors.affiliation: Département de Microbiologie Médicale et Infectiologie, Hôpital du Sacré-Coeur de Montréal, 5400, boulevard Gouin Ouest, Montréal, Québec H4J 1C5, Canada. valerylavergne@gmail.com
authors.forename: Valéry
authors.initials: V
authors.lastname: Lavergne
authors.forename: Yannick
authors.initials: Y
authors.lastname: Beauséjour
authors.forename: Gilbert
authors.initials: G
authors.lastname: Pichette
authors.forename: Marc
authors.initials: M
authors.lastname: Ghannoum
authors.forename: Shih Hann
authors.initials: SH
authors.lastname: Su
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D015415:Biomarkers; D016360:Clostridioides difficile; D004761:Enterocolitis, Pseudomembranous / Q000175:diagnosis / Q000188:drug therapy / Q000453:epidemiology*; D005260:Female; D006801:Humans; D015994:Incidence; D008231:Lymphopenia; D008297:Male; D011379:Prognosis; D011446:Prospective Studies; D012008:Recurrence; D012307:Risk Factors
chemical_list: D000900:Anti-Bacterial Agents; D015415:Biomarkers