Potential monitoring of patients with CD in clinical remission
| Question | Monitoring tool | Prediction (95% CI) |
|---|---|---|
| Has mucosal healing been achieved? | CRP ≤10 mg/l and faecal calprotectin ≤200 μg/g | CDEIS ≤3 with a sensitivity of 78% and specificity of 58%57 |
| What is the risk of relapse? | Increased CRP Increased faecal calprotectin Mucosal healing at ileocolonoscopy (SESCD=0) | Relative risk of relapse increasing to 3–58*70–72 Clinical relapse over 1 year with a sensitivity of 43–90% and a specificity of 43–88% (depending on the threshold for faecal calprotectin)*67–69 69% of remission without steroids over the next 2 years (compared with 38% if no mucosal healing)19 |
| What is the risk of abdominal surgery? | Mucosal healing at ileocolonoscopy (at least partial) | 14% requiring abdominal surgery (vs 38% if absence of healing)4 |
| What is the risk of relapse upon anti-TNF withdrawal? | CRP ≥5 mg/l Faecal calprotectin ≥300 μg/g Absence of mucosal healing at ileocolonoscopy (CDEIS >0) | HR for relapse 2.5 (1.4–4.4)21 HR for relapse 3.2 (1.7–6.2)21 HR for relapse 1.8 (1.0–3.3)21 |
| What is the risk of postoperative clinical recurrence? | Endoscopic Rutgeerts score within 6–12 months after surgical resection | i0–i1: 10% of relapse at 8 years22 i2: 40% of relapse at 8 years22 i3–i4: 90% of relapse at 8 years22 |
*Increase in CRP and faecal calprotectin occurs within the 4–6 months before relapse.73
CD, Crohn's disease; CDEIS, CD Endoscopic Index of Severity; CRP, C-reactive protein; SESCD, Simplified Endoscopic Score of CD; TNF, tumour necrosis factor.