Correlation between thrombin generation and endoscopic activity in Crohn's disease

Abstract

Introduction: thrombosis is associated with high morbidity and mortality, with an impact on the individual's quality of life. Immediately after the thrombotic event, mortality is high, especially in pulmonary embolism (PE), remaining increased over the next 30 years. Deep vein thrombosis (DVT) affects 127-314/100,000 patients with Crohn's disease per year, while pulmonary thromboembolism occurs in 105-110/100,000 patients per year, which corresponds to a risk of thrombosis 2 to 3 times higher compared to the general population. The incidence of venous thromboembolism ranges from 1-10% reaching up to 40% in postmortem studies in patients with CD. Probably, this high incidence of necropsy diagnosis reflects the low clinical suspicion index, because of the difficulty in differentiating Crohn's disease activity from mesenteric thrombosis, as for many times, thrombosis episodes are asymptomatic. Despite the breakthrough in the treatment of Crohn's disease in recent years, about 50% of patients in clinical remission still remain with endoscopic activity, which could be associated with increased risk of thrombosis in these patients. Thus, identifying out patients with sub-clinical inflammatory activity with an increased risk of thrombosis may justify the optimization of the treatment of Crohn's disease in order to control the inflammation, regardless of symptoms, as a preventive measure in the long term reduction risk of thrombosis in this specific population. Therefore, the aim of this study is to compare the potential of thrombin generation, which reflects the balance between the three phases of coagulation in outpatients with Crohn's disease in clinical remission, with and without endoscopic activity. Patients and methods: patients with Crohn's disease with clinical indication for colonoscopy, in clinical remission defined by the Crohn's Disease Activity Index below 150 and Harvey-Bradshaw Index below 5, with or without endoscopic activity defined by Crohn's Disease endoscopic Index of severity and simplified endoscopic activity score for Crohn's disease will be included in this study. Thrombin generation will be performed at HCFMUSP through automatically calibrated Thrombogram (CAT- Calibrated Automated Thrombogram®, Maastricht, The Netherlands), with and without thrombomodulin. Fifty patients regardless of the clinical activity of CD will be initially included, to test the correlation between disease activity and thrombin generation followed by addition of 150 patients in clinical remission, with and without endoscopic activity (75 patients in each group). The study will be performed in multiple centers specializing in the treatment of inflammatory bowel diseases in Brazil; data collection will be held in a systematic way through the Internet with the help of the RedCap software (AU)