Background: Recent studies have implied peripheral blood eosinophil (PBE) can be used as a biomarker in inflammatory bowel disease (IBD). However, the role of PBE in predicting postoperative surgical site infection (SSI) in patients of Crohn’s disease (CD) with gastrointestinal (GI) fistula remains unknown. The purpose of this study was to evaluate the predictive value of perioperative PBE in SSI in Crohn’s patients undergoing definitive bowel resection.
Methods: One hundred and twenty-two CD patients with GI fistula undergoing definitive bowel reconstruction were enrolled in this study. Leukocyte, neutrophil, C-reactive protein (CRP), procalcitonin (PCT), peripheral blood eosinophil (PBE) was evaluated preoperatively and postoperatively. SSI was an infection occurred at the surgical site within 30 days after operation, which was identified as purulent drainage from the surgical site, organism cultured from the fluid of surgical site, and/or incisional inflammation. Multivariate logistic regression analysis was used to identify independent risk factors of SSI and receiver operating characteristic curve (ROC) analysis was used to evaluate effectiveness of PBE. Kaplan-Meier curve was used to describe the length of hospital and postoperative stay days in patients with and without high-PBE.
Results: Overall, 37 patients (30.3%) developed surgical site infection (SSI). The level of PBE in SSI group was higher than NSSI group on POD (postoperative day) -1 (p=0.002), 3 (p=0.0001) and POD 5 (p=0.026). In multivariate logistic regression analysis, preoperative high-PBE was independently associated with SSI (P=0.032, OR=3.308, 95%CI: 2.002-5.750). ROC analysis showed that the ideal cutoff value of PBE in predicting SSI was 0.2007 × 109/L and 0.2082 × 109/L on POD -1 and 3 with area under the curve (AUC) was 0.74 and 0.71, respectively. Patients with high-PBE had a longer length of hospital stay (33 vs 23 days, p=0.01) and longer length of postoperative stay (16 vs 14 days, p=0.04) compared to patients without high-PBE.
Conclusion: Peripheral blood eosinophil (PBE) can be used as a novel marker to predict SSI in CD patients with GI fistula undergoing intestinal resection. Measurement of perioperative PBE is recommended in the routine assessment of CD with GI fistula undergoing bowel resection. Keywords: Peripheral blood eosinophil; Surgical site infection; Crohn’s disease; Fistula; Biomarker