Effect of Tofacitinib on Coagulation and Platelet Function, and Its Role in Thromboembolic Events

Post-authorization, prospective and unicenter clinical trial, in which patients with UC will be included. The treatment with anti-TNFα (infliximab, adalimumab or golimumab) or JAK-inhibitors (tofacitinib) will be initiated by clinical practice and the choice will be made at the discretion of the investigator at the center where the patients will be recruited (Hospital Universitario de La Princesa). In the case of the group of patients treated with tofacitinib, the selection will be made following the action protocol implemented in our center, in which this drug is usually reserved for those cases refractory to anti-TNFα and/or vedolizumab. There will be no random assignment of treatment. The drugs will be used in the approved indications and conditions of use.

Inclusion Criteria: EX VIVO STUDY IN PATIENTS WITH UC PATIENTS WITH UC: * Over 18 years old. * Diagnosis of UC according to the criteria of the European Crohn's and Colitis Organisation (ECCO). * Previous treatments are allowed, provided they have remained stable for the past 3 months. * In the case of patients with active UC, they should have endoscopic activity within 1 month of starting the treatment (Mayo endoscopic sub-index of ≥ 2). * Women of childbearing age using contraceptive methods with an error rate \