DOP055 Development of a new immunoassay for the accurate determination of anti-infliximab antibodies in inflammatory bowel disease

Abstract

patients, 28.5% progressed to B2 phenotype, 23.5% to B3 and 49.0% required surgery. Fifty percent of the patients started azathioprine prior to phenotype change and 13.9% started antiTNF alfa prior to phenotype change. Patients on monotherapy with azathioprine prior to phenotype change had disease progression (B1 to B2 or B3) later on the course of the disease than the ones that were not on azathioprine (median: 361 months, 95%CI: [306.3; 415.7] vs 71 months [47.6; 94.4], p < 0.001). Similar results were achieved on patients on combination therapy with azathioprine and antiTNF alfa prior to phenotype change (p < 0.001). The hazard ratio (HR) for disease progression was lower either for monotherapy with azathioprine (HR 0.28, p < 0.001) or combination therapy with antiTNF alfa (HR 0.33, p < 0.001). Conclusions: Monotherapy with azathioprine and combination therapy of azathioprine and antiTNF alfa prior to behaviour change modifies the phenotype progression of CD.