P586 Influence of HLA-DQA1∗05 on the loss of response to anti-TNF treatment in inflammatory bowel disease. Spanish cohort of real clinical practice

Abstract

Abstract Background The presence of the HLA-DQA1*05 allele has been related to a loss of early secondary response, which could have clinical implications when choosing the first-line biological drug. Although its usefulness as a response predictor variant is not yet clearly established, the determination of polymorphism is common in clinical practice. Methods The objective of this study is to determine if there is an association between the presence of HLA-DQA1*05 and the loss of response in the short-medium term in the clinical practice of a real cohort. A retrospective cohort study has been carried out including adult patients with Crohn's Disease (CD), ulcerative colitis (UC) and indeterminate colitis (IC) who have received anti-TNF treatment with Infliximab (IFX) and Adalimumab (ADA) with a period of follow-up from 6 to 48 months. Results A total of 102 patients were included (73.52% CD- 75; 25.5% UC- 26; 0.98% IC- 1), of which 54.9% were men (56) and 45.1% were women (46), with a median age of 45 years (IQR 18-83). No statistically significant differences were observed between the HLA carrier and non-HLA carrier groups in age, sex, tobacco consumption, or type of inflammatory bowel disease. No differences were also observed between the location or severity of the disease. From the group of patients treated with Infliximab: • IFX at 6 months: a total of 52 patients were analyzed. Treatment was suspended in 6 patients (11.54%). • IFX at 18 months: a total of 35 patients were analyzed.Treatment was suspended in 4 patients (11.43%). • IFX at 48 months: a total of 26 patients were analyzed. Treatment was suspended in 7 patients (26.92%). From the group of patients treated with Adalimumab: • ADA at 6 months: a total of 50 patients were analyzed. Treatment was suspended in 6 patients (12%). • ADA at 18 months: a total of 31 patients were analyzed. Treatment was suspended in 1 patient (3.22%). • ADA at 48 months: a total of 22 patients were analyzed. Treatment was suspended in 3 patients (13.64%). Therefore, no statistically significant differences were observed in the loss of anti-TNF response between the HLA-DQA1*05 carrier and non-carrier groups for IFX and ADA at 6, 18 or 48 months. Nor were any differences found in the loss of response depending on the type of inflammatory bowel disease that the patients suffered from (CD or UC). Conclusion In this Spanish cohort from real clinical practice, the presence of the HLA-DQA1*05 allele in patients with inflammatory bowel disease does not influence the loss of response to anti-TNF treatment in the first 48 months of follow-up. However, more studies with larger samples are necessary to determine the usefulness of the polymorphism in clinical practice and establish its possible predictive implication.