CRP ≥ 12 mg/L may predict severity of ulcerative colitis instead of ESR

The erythrocyte sedimentation rate [ESR] as a component of the Truelove and Witts Criteria [TWC] is the traditional inflammatory marker used for the assessment of ulcerative colitis [UC] activity. However, the C-reactive protein [CRP] is preferentially used in contemporary clinical practice. We aimed to determine the equivalent CRP cut-off for an ESR of >30 mm/h in patients presenting with acute severe UC.

Clinical and pathological data were prospectively collected from 163 presentations of severe UC. A CRP cut-off corresponding to an ESR of >30 mm/h was determined using confusion matrices. A validation cohort of 128 presentations was prospectively collected and analysed.

Results:

A CRP cut-off of ≥12 mg/L generated an 85% positive predictive value [PPV] with a sensitivity of 95% and an accuracy of 82% for having a paired ESR of >30 mm/h. There were no statistically significant differences between groups determined by the traditional ESR versus the new CRP-based criterion in the presenting faecal calprotectin, Mayo endoscopic subscore, or the rates of intravenous corticosteroid therapy failure and colectomy-by-discharge. Applying the CRP ≥12 mg/L criterion to a validation cohort of 128 presentations generated a PPV of 83% and a sensitivity of 94%.