Combined evaluation of biomarkers as predictor of maintained remission in Crohn's disease

The individual performances and the complementarity of Crohn's disease (CD) activity index (CDAI), C-reactive protein (CRP) and faecal calprotectin (Fcal) to monitor patients with CD remain poorly investigated in the era of "tight control" and "treat to target" strategies. To assess CDAI, CRP and Fcal variation, alone or combined, after 12 wk (W12) of anti-tumor necrosis factor (TNF) therapy to predict corticosteroids-free remission (CFREM = CDAI < 150, CRP < 2.9 mg/L and Fcal < 250 μg/g with no therapeutic intensification and no surgery) at W52. CD adult patients needing anti-TNF therapy with CDAI > 150 and either CRP > 2.9 mg/L or Fcal > 250 μg/g were prospectively enrolled. Among the 40 included patients, 13 patients (32.5%) achieved CFREM at W52. In univariable analysis, CDAI < 150 at W12 ( = 0.012), CRP level < 2.9 mg/L at W12 ( = 0.001) and Fcal improvement at W12 (Fcal < 300 μg/g; or, for patients with initial Fcal < 300 μg/g, at least 50% decrease of Fcal or normalization of Fcal (< 100 μg/g) ( = 0.001) were predictive of CFREM at W52. Combined endpoint (CDAI < 150 and CRP ≤ 2.9 mg/L and FCal improvement) at W12 was the best predictor of CFREM at W52 with positive predictive value = 100.0% (100.0-100.0) and negative predictive value = 87.1% (75.3-98.9). In multivariable analysis, Fcal improvement at W12 [odd ratio (OR) = 45.1 (2.96-687.9); = 0.03] was a better predictor of CFREM at W52 than CDAI < 150 [OR = 9.3 (0.36-237.1); = 0.145] and CRP < 2.9 mg/L (0.77-278.0; = 0.073). The combined monitoring of CDAI, CRP and Fcal after anti-TNF induction therapy is able to predict favorable outcome within one year in patients with CD.