P264 Impact of the HLA-DQ1*05 alelle on the initial response to infliximab in patients with Inflammatory Bowel Disease

Abstract

Abstract Background HLA-DQA1*05 Carriage is associated with development of anti-drug antibodies to infliximab in patients With Crohn’s Disease (Sazonovs et al. Gastroenterology 2019). Our group has shown that the presence of this allele is also an independent predictor of secondary loss of response to infliximab (Guardiola J, ECCO 2019) and adalimumab (Guardiola J ECCO 2020). However, the impact of the HLA-DQA1 * 05 allele on the initial response and persistence of IFX in the first months of treatment is unknown. Methods This is a retrospective cohort study from a prospectively maintained data base at the Hospital Universitari de Bellvitge (third level teaching hospital) Patients with Crohn’s Disease (CD) or Ulcerative Colitis (UC) who initiated IFX to induce remission and who had been followed up for failure or a minimum of 6 months were included. Failure at IFX was defined as the need of escalation or change treatment, surgery, or hospitalization for the first 6 months. Results 99 patients (65 MC, 34 CU) were included. In 63 (63.63%) IFX failed. 39 (39%) were carriers of the HLA-DQA1 * 05 allele. In multivariate analysis, HLA-DQA1*05 carriage (HR 1.9, 95% CI 1.14–3.31 p=0.015), the use of immunomodulators (HR 0.38, 95% CI 0, 23–0.66 p = 0.001) and suffering a CU vs. MC (HR 1.72, 95% CI 1.02–2.89 p = 0.041) were independent predictors of IFX failure. HLA-DQA1 * 05 was also associated with non-persistence of treatment (HR 2,4,95% CI1.45–3.99 p = 0.001). Figure A Conclusion HLA-DQA1*05 carriage is common in patients with IBD and it’s associated with a marked increase in the risk of loss of response to infliximab. Testing for HLA-DQA1*05 would allow treatment to be tailored according to the risk of loss of response.