Predictive value of postoperative CRP levels for endoscopic recurrence in patients with Crohn's disease undergoing ileocolic resection.

Background and aims: Patients with Crohn's disease (CD) undergoing ileocolic resection (ICR) develop higher postoperative C-reactive protein (CRP) levels compared to colorectal cancer (CRC) patients, suggesting an increased postoperative inflammatory response. This study investigates whether postoperative C-reactive protein (CRP) levels are associated with endoscopic recurrence (ER) after ICR.

Methods: All CD patients who underwent ICR between 2007 and 2022 at two referral centers were identified from prospectively maintained databases. Those with endoscopic follow-up within 12 months postoperatively were included. ER was defined as modified Rutgeerts score (mRs) ≥i2b. The primary outcome was the association between postoperative CRP levels and ER. Secondary outcomes were the added prognostic value of postoperative CRP levels for predicting ER, adjusted for traditional risk factors.

Results: Among 542 patients, 36% had penetrating disease, 24% were active smokers, and 11% received prophylactic advanced therapies. ER was observed in 243/542 (45%). Patients with ER had higher CRP levels on postoperative day (POD) 2-5, with a significant difference on POD 4 (median CRP, 122 mg/L vs 97 mg/L; adjusted mean difference, 16% [1 to 26%]). After adjusting for traditional risk factors, CRP levels on POD 4 remained an independent predictor of ER (p = 0.022) and improved the AUC of a model with traditional risk factors by 0.04 (95% CI, 0.02-0.09; p = 0.0005).

Conclusion: Elevated CRP levels on POD 4 in CD patients undergoing ICR were associated with an increased risk of ER within 12 months. In combination with other known risk factors, CRP could serve as a marker to identify patients benefitting from closer postoperative monitoring.