Intestinal inflammatory biomarkers and outcome in pediatric Clostridium difficile infections

Abstract

Objectives: To identify specific fecal biomarkers for symptomatic Clostridium difficile infection and predictors of poor outcomes.

Study design: We enrolled 65 children with positive C difficile testing (cases) and 37 symptomatic controls. We also analyzed stool samples from colonized and non-colonized asymptomatic children. We performed enzyme immunoassays to determine fecal interleukin (IL)-8, lactoferrin, and phosphorylated-p38 protein concentrations, and quantitative polymerase chain reaction to determine IL-8 and chemokine ligand (CXCL)-5 RNA relative transcript abundances, and C difficile bacterial burden.

Results: Of 68 asymptomatic controls, 16 were colonized with C difficile. Phosphorylated-p38 was specific for C difficile infection but lacked sensitivity. Fecal cytokines were elevated in samples from symptomatic children, whether cases or controls. In children with C difficile infection, fecal CXCL-5 and IL-8 messenger RNA abundances at diagnosis correlated with persistent diarrhea after 5 days of C difficile infection therapy and with treatment with vancomycin. When children with concomitant viral gastroenteritis were excluded, these correlations persisted. Time-to-diarrhea resolution was significantly longer in patients with elevated fecal cytokines at diagnosis. A logistic regression model identified high CXCL-5 messenger RNA abundance as the only predictor of persistent diarrhea. Conversely, fecal C difficile bacterial burden was not different in symptomatic and asymptomatic children and did not correlate with any clinical outcome measure.

Conclusions: Fecal inflammatory cytokines may be useful in distinguishing C difficile colonization from disease and identifying children with C difficile infection likely to have prolonged diarrhea.

Keywords: CT; CXCL; Chemokine ligand; Cycle threshold; Difference of CT between cytokines and internal control, representing cytokine relative abundance; EIA; Enzyme immunoassay; HR; Hazard ratio; IBD; IL; Inflammatory bowel disease; Interleukin; MD; Median difference; Messenger RNA; PCR; Phosphorylated-p38; Polymerase chain reaction; RR; RT; Relative risk; Reverse-transcription; SLCH; St. Louis Children's Hospital; WBC; White blood cell; mRNA; pp38; ΔCT.