P509 Risk score for Crohn's Disease activity using red cell distribution width, platelet count, erythrocyte sedimentation rate and C-reactive protein
S. Galea*, G. Balzan, P. Ellul, N. Azzopardi
Mater dei Hospital, Gastroenterology, Tal Qroqq, Malta
Recent evidence has shown that Red Cell Distribution Width (RDW) is associated with active inflammatory bowel disease.  RDW is cheap and easily available and may be used as a rapid, non-invasive tool in diagnosing disease activity. C-Reactive Protein (CRP) and Erythrocyte Sedimentation rate (ESR) have low sensitivities (54% and 55%) and specificities (71% and 90%) in detecting Crohn's disease (CD) activity.  In this study, we have analysed the usefulness of a risk score based on RDW, platelet count, ESR and CRP in assessing disease activity in CD.
Serum CRP, ESR, platelet count and RDW in CD patients were assessed on the day of colonoscopy and compared with CD activity. A total of 308 endoscopic procedures on 161 CD patients were performed over a 48 month period. 89 patients were male with a median age of 40.2 years (9-85 years). Disease activity was determined according to endoscopic and histologic findings at colonoscopy. A risk score for disease activity was then created by giving 1 point to each elevated marker (CRP, ESR, platelet count >400,000 and RDW > 14.9%).
Histological and endoscopic confirmation of disease activity was present in 191 colonoscopies (62%). RDW, platelet counts, ESR and CRP were all significantly elevated in patients with active CD (independent samples t test p <0.005) when compared with patients with quiescent disease. RDW, platelet counts, ESR and CRP had low sensitivities (43%, 21%, 68% and 44%) and specificities (73%, 93%, 40% and 64%) in detecting disease activity in CD patients.
90% of patients with a score of 4 (n=10) and 89% of patients with a score of 3 (n=37) had histologically active disease at endoscopy. Meanwhile 66.6% of patients with a score of 2 (n=72), 53% of patients with a score of 1 (n=91) and 54% of patients with a score of 0 had active disease at endoscopy. There was a statistically significant difference (p <0.0001) between the mean risk score in histologically quiescent disease (mean 0.9145, n=117) and the mean risk score in histologically active disease (mean 1.461, n=191).
Biomarkers have low sensitivities in detecting active CD. However, a score of 3 or more based on RDW, CRP, ESR and platelet count should raise the suspicion of ongoing inflammation.
 Song CS, Park DI, Yoon MY, et al., (2012), Association between red cell distribution width and disease activity in patients with inflammatory bowel disease. , Dig Dis Sci., 1033-8, 57
 Azzopardi N, (2013), Non-invasive monitoring in inflammatory bowel disease: time to use newer tools? , MMJ, 36-40, 25