Lewis Score: a useful clinical tool for patients with suspected Crohn's Disease submitted to capsule endoscopy

Background/aims: The Lewis Score (LS) can assess inflammatory activity on small bowel capsule endoscopy (SBCE). We aimed to evaluate the LS usefulness in the setting of suspected Crohn's Disease (CD).

Methods: Retrospective single-center study including 56 patients undergoing SBCE for suspected CD. Patients were divided into three groups, according to clinical presentation: Group 1 (28 patients): suspected CD not supported by the International Conference on Capsule Endoscopy (ICCE) criteria; Group 2 (19 patients): suspected CD based on two ICCE criteria; Group 3 (9 patients): patients fulfilling three or more criteria. Inflammatory activity was assessed with the LS. The diagnosis of CD required a minimum follow-up of 6 months after SBCE, basing on clinical evaluation, endoscopic, histological, radiological, and/or biochemical investigations.

Results: SBCE detected significant inflammatory activity (LS≥135) in 23 patients (41.1%), being 5 patients from Group 1 (17.8%), 11 from Group 2 (57.9%) and 7 from Group 3 (77.8%) (p<0.05). CD was diagnosed in 23 patients (41.1%): six patients from Group 1 (21.4%), 10 from Group 2 (52.6%) and 7 from Group 3 (77.8%) (p<0.05). CD was diagnosed in 82.6% of patients with significant inflammatory activity on CE (LS≥135), but in only 12.1% of those having a LS<135 (p<0.05). The LS Positive Predictive Value, Negative Predictive Value, Sensitivity and Specificity were 82.6%, 87.9%, 82.6% and 87.9%, respectively.

Conclusions: The LS may be a valuable diagnostic tool in the setting of suspected CD. Patients not fulfilling the ICCE criteria have lower LS and fewer are diagnosed with CD during follow-up.