Lewis score: a useful tool for diagnosis and prognosis in Crohn's disease.

Background: videocapsule endoscopy (VCE) is currently the most sensitive diagnostic tool to detect early small bowel inflammation. A Lewis score (LS) of ≥ 135 as the cutoff value for the presence of significant inflammatory activity in patients undergoing VCE for suspected Crohn's disease (CD) has been suggested as a useful tool for the diagnosis of CD. The aim of this study was to evaluate the diagnostic and prognostic accuracy of the LS in patients with suspected CD undergoing VCE.

Methods: a retrospective single-center study was performed that included patients who underwent VCE for suspected CD between January 2010 and December 2015. Inflammatory activity was assessed with the LS. Patients were grouped according to the criteria of the International Conference on Capsule Endoscopy (ICCE) for the definition of suspected CD; group 1: patients not fulfilling ICCE and group 2: patients with ≥ 2 ICCE criteria.

Results: one hundred and ninety-one patients were included, 61% were female and the mean age was 39 ± 14 years. VCE detected significant inflammatory activity (LS ≥ 135) in 81 patients (42%); 24 patients from group 1 (32%) and 57 patients from group 2 (50%) (p = 0.014). During a mean follow-up period of 41 ± 21 months (12-79), a CD diagnosis was determined in 60 patients (31%); 55 patients with LS ≥ 135 (92%) and five patients with LS < 135 (5%) (p < 0.001). The LS showed a good diagnostic accuracy with an AUROC of 0.93 (p < 0.001). During the first year after diagnosis, there was a significant association between a higher LS and the need for immunomodulatory therapy, biological therapy, bowel resection surgery or hospital admission due to a CD flare-up.

Conclusions: the LS (cutoff ≥ 135) is very useful in the diagnosis of CD in patients undergoing VCE. Moreover, higher values of this score was associated with prognostic variables.