S57 Impact of the HLA-DQA1*05 Allele on Ustekinumab Loss of Response, Anti-drug Antibodies, and Concentration in Patients With Inflammatory Bowel Disease. (December 2022) - Colombel, Jean-Frederic; Martín-Arranz, María D; Brinkman, Brigitta; Gasink, Christopher; Guan, Meijian; Hart, Amy; Ahmad, Tariq