title: Serial monitoring of faecal calprotectin for the assessment of endoscopic recurrence in asymptomatic patients after ileocolonic resection for Crohn's disease: a long-term prospective study.
abstract: BACKGROUND
  It is recommended that ileocolonoscopy is performed within 1 year after resection for Crohn's disease (CD). Nevertheless, optimal monitoring strategies for recurrence after the ileocolonoscopy remain to be elucidated. This prospective study was to evaluate the value of serial monitoring of faecal calprotectin (FC) after ileocolonoscopy for the assessment of endoscopic recurrence in asymptomatic patients.
  
  
  METHODS
  Patients in clinical remission who had no endoscopic recurrence at ileocolonoscopy 6-12 months after ileocolonic resection were studied. FC levels were measured every 2 months up to 24 months after the ileocolonoscopy. When the FC level was elevated (⩾140 µg/g), a second ileocolonoscopy was immediately undertaken. In contrast, patients who maintained low FC levels (<140 µg/g) during the 24-month follow up underwent a second ileocolonoscopy at the end of the study. Endoscopic recurrence was defined as a Rutgeerts score ⩾i2.
  
  
  RESULTS
  A total of 30 patients were studied. In eight patients, the FC level was raised during the 24-month follow up. Six of the eight patients (75%) had endoscopic recurrence. Of 22 patients who maintained low FC levels, 20 (91%) had no endoscopic recurrence, whereas two showed endoscopic recurrence at the end of the follow up. The incidence of endoscopic recurrence was significantly higher in patients with elevation of FC levels versus those with maintained low FC levels (75% versus 9%). A cut-off value of 140 µg/g for FC had a sensitivity of 75%, a specificity of 91%, a positive predictive value of 75%, a negative predictive value of 91% and a diagnostic accuracy of 87% to detect endoscopic recurrence.
  
  
  CONCLUSIONS
  Consecutive monitoring of FC is useful for the assessment of endoscopic recurrence after the initial ileocolonoscopy. Increased FC levels indicate a need for repeat ileocolonoscopy, while sustained low FC levels predict a low risk of endoscopic recurrence. In patients maintaining low FC levels, unnecessary invasive endoscopic examinations can be avoided.
authors: Inflammatory Bowel Disease Centre, Yokkaichi Hazu Medical Centre, 10-8 Hazuyamacho, Yokkaichi, Mie 510-0016, Japan.
authors: Takayuki
authors: T
authors: Yamamoto
authors: Inflammatory Bowel Disease Centre, Yokkaichi Hazu Medical Centre, Yokkaichi, Mie, Japan.
authors: Takahiro
authors: T
authors: Shimoyama
authors: Inflammatory Bowel Disease Centre, Yokkaichi Hazu Medical Centre, Yokkaichi, Mie, Japan.
authors: Satoru
authors: S
authors: Umegae
authors: Inflammatory Bowel Disease Centre, Yokkaichi Hazu Medical Centre, Yokkaichi, Mie, Japan.
authors: Koichi
authors: K
authors: Matsumoto
keywords: Crohn’s disease; endoscopic recurrence; faecal calprotectin; ileocolonoscopy; postoperative recurrence