Abstract
Background
The platelet-to-lymphocyte ratio (PLR) index has been a recent focus of investigation as a reliable marker of inflammation. This score was recently shown to have a good accuracy upon predicting endoscopic remission in patients with colonic Crohn’s Disease (CD). We aimed to assess the discriminative power of PLR index in patients with isolated small bowel CD.
Methods
Single center study of consecutive patients with isolated small bowel CD (L1 ± L4 disease according to Montreal classification) who underwent small bowel capsule endoscopy (SBCE) for assessment of endoscopic activity between January 2019 and December 2020. Only complete SBCEs were considered. CD endoscopic activity was classified according to the Lewis score (LS) value. Complete blood count, C-reactive protein and fecal calprotectin values were collected within 1 month of SBCE.
Results
Final sample included 49 patients, 35 (71.4%) of them females, with a mean age of 35.1±11.8 years. SBCE reported mucosal healing (LS<135) in 30.6% of the patients; mild activity (135≤LS<790) in 42.9% and moderate-to-severe activity (LS≥790) in 26.5% of the patients.
PLR index positive correlation with LS was significant and moderate (k=0.597; p<0.001). This correlation was stronger than the one seen between fecal calprotectin (k=0.525; p=0.001) or C-reactive protein (k=0.321; p=0.029) and the LS score.
In particular, PLR index presented an excellent accuracy for predicting patients with a moderate-to-severe endoscopic activity (AUC=0.908; 95%CI=0.816–0.999; p<0.001), with an optimal cut-off of PLR above 157 (sensitivity 92.3%; specificity 82.9%). The accuracy for prediction of mucosal healing was good (AUC=0.743; 95%CI=0.600–0.887; p=0.007), with an optimal cut-off of PLR below 126 (sensitivity 66.7%; specificity 80.0%).
Conclusion
PLR index demonstrated an excellent acuity for predicting patients with moderate to severe disease in small bowel CD. Moreover, it also demonstrated good acuity for predicting mucosal healing on this set of patients. These results come from a significant correlation of PLR index with endoscopic activity in small bowel CD. Our findings establish this index as a promising and easy-to-apply tool for non-invasive and regular follow-up of patients with small bowel CD.
Optimal Cutoff Level of Fecal Calprotectin for Detecting Small Bowel Inflammation in Crohn's Disease
