Postoperative Change of Mucosal Inflammation at Strictureplasty Segment in Crohn's Disease: Cytokine Production and Endoscopic and Histologic Findings

Abstract

This study was designed to examine postoperative change of mucosal inflammation at strictureplasty segment in Crohn's disease mainly by cytokine measurements. Patients who underwent strictureplasty for Crohn's disease in the terminal ileum were investigated. Mucosal samples at the strictureplasty site were obtained during operation. At 3, 6, and 12 months after operation, biopsy specimens were taken from the strictureplasty site and macroscopically normal ileum at endoscopy. Mucosal cytokine concentrations were measured by enzyme-linked immunosorbent assay. The mucosal concentrations of proinflammatory cytokines (interleukin-1beta, interleukin-6, interleukin-8, and tumor necrosis factor-alpha) and anti-inflammatory mediator (interleukin-1 receptor antagonist) at the strictureplasty segment greatly increased at the time of operation. Interleukin-1beta, interleukin-1 receptor antagonist, interleukin-6, interleukin-8, and tumor necrosis factor-alpha concentrations at the strictureplasty segment decreased during a 12-month period after operation. Twelve months after operation there was no significant difference in each cytokine concentration between the strictureplasty and macroscopically normal segments. The mucosal interleukin-1 receptor antagonist/interleukin-1beta ratio at the strictureplasty segment increased during a 12-month period after operation. Twelve months after operation there was no significant difference in the ratio between the strictureplasty and macroscopically normal segments. The endoscopic and histologic severities of mucosal inflammation at the strictureplasty site also decreased; however, their findings were not normalized during the study. During one year after strictureplasty for Crohn's disease, cytokine production at the strictureplasty segment was decreased to the level of the macroscopically normal ileum and an imbalance between proinflammatory and antiinflammatory cytokines was corrected.