Predicting response after infliximab salvage in acute severe ulcerative colitis

Background and Aim
Acute severe ulcerative colitis (ASUC) is a medical emergency requiring prompt therapeutic intervention. Although infliximab has been used as salvage therapy for over 15 years, clinical predictors of treatment success are lacking. We performed a retrospective analysis to identify factors that predict colectomy and may guide dose intensification.

Methods
Fifty‐four hospitalized patients received infliximab for ASUC at seven Australian centers (April 2014–May 2015). Follow‐up was over 12 months. The data were primarily analyzed for predictors of colectomy. Accelerated (AI) versus standard (SI) infliximab induction strategies were also compared.

Results
Of 54 patients identified, the overall colectomy rate was 15.38% (8/52) at 3 months and 26.92% (14/52) at 12 months. Two patients were lost to follow‐up. There was a numerically higher colectomy rate in those treated with AI compared with SI (P = 0.3); however, those treated with AI had more severe biochemical disease. A C‐reactive protein (CRP)/albumin ratio cut‐off of 0.37 post‐commencement of infliximab and before discharge was a significant predictor of colectomy with an area under receiver operating curve of 0.73. Pretreatment CRP and albumin levels were not predictive of colectomy. A Mayo Endoscopic Score of 2 had a 94% PPV for avoidance of colectomy following infliximab salvage.

Conclusions
The baseline Mayo Endoscopic Score and the CRP/albumin ratio following infliximab salvage are significant predictors of treatment response for ASUC and identify patients at high risk of colectomy. Whether this risk can be mitigated using infliximab dose intensification requires prospective evaluation before the CRP/albumin ratio can be integrated into ASUC management algorithms.