P355 Exceeding treatment expectations in Crohn's disease: transmural healing and a new definition of deep remission

Castiglione, F.(1);Imperatore, N.(1);Testa, A.(1);de Sire, R.(1);Nardone, O.M.(1);Ricciolino, S.(1);Di Luna, I.(1);Patturelli, M.(1);Villani, G.D.(1);Olmo, O.(1);Rispo, A.(1);

(1)University Federico II of Naples, Clinical Medicine and Surgery, Naples, Italy;


While mucosal (MH) and transmural healing (TH) predict relevant clinical outcomes in Crohn's disease (CD), little is known about the real significance and clinical impact of deep remission (DR). The aim of this study was to better explore the concept of DR, towards a direct correlation between MH, TH and biomarkers.


A real-world observational longitudinal study was performed to evaluate the rate of clinical remission (CR), MH and TH, and the fecal calprotectin (FC)/C-reactive protein (CRP) levels in all consecutive patients with CD undergoing maintenance treatment with biologics. A ROC curve was constructed to define the best FC and CRP cut-offs associated with MH and TH. Finally, CD patients achieving CR, MH and TH, in association with the target FC and CRP values, were considered in DR.


Among 118 CD patients, CR, MH and TH were achieved in 74 (62.7%), 52 (44.1%) and 38 patients (32.2%), respectively. After 2 years, the mean FC levels decreased from 494 ± 515.4 μg/gr to 260 ± 354.9 μg/gr (p<0.01). Using the ROC curve analysis, a FC cut-off value of 94 μg/gr was associated with both MH (sensitivity 94.2%, specificity 84.8%, PPV 83.05%, NPV 94.92%, AUC 0.95) and TH (sensitivity 92.1%, specificity 70%, PPV 64.4%, NPV 94.9%, AUC 0.88). The MH/FC and TH/FC k of agreement was 0.81 (p<0.01) and 0.58 (p<0.01), respectively. CRP < 5 mg/L was associated with both MH (sensitivity 96.1%, specificity 62.1%, PPV 66.7%, NPV 95.35%, AUC 0.85) and TH (sensitivity 97.4%, specificity 52.5%, PPV 52%, NPV 95.35%, AUC 0.78). When considering CD patients with concomitant CR, MH and TH associated with a FC level < 94 μg/gr and CRP < 5 mg/L, DR was identified in 33 patients (27.9%).


A FC cut-off of 94 μg/gr and a normal CRP could be included in the definition of DR in association with CR, MH and TH. Thus, DR can be achieved in approximately 30% of CD patients during maintenance treatment with biologics.