S89 Does Autoimmune Pancreatitis Pose a Greater Risk of Deep Vein Thrombosis Compared to Acute Pancreatitis? A 10-Year, Single Center Experience

Introduction: Autoimmune pancreatitis (AIP) is a rare pathology that is often mistaken for pancreatic cancer. Three aspects of this pathology can promote thrombus formation: chronic pancreatitis, acute pancreatitis (AP), and systemic autoimmune disease. Despite this, no studies exist describing deep vein thrombosis (DVT) and pulmonary embolism (PE) prevalence in AIP. We hypothesize that DVT and PE rates are higher in this population, given the combined prothrombotic risk from these 3 mechanisms. Methods: We conducted a 10-year single-center retrospective study. Patients were confirmed to have AIP using ICDC criteria. AP was confirmed with 2/3 revised Atlanta criteria. All patients had radiographically confirmed DVT or PE within 3 months of initial AP or AIP diagnosis. Patients with malignancy, surgery unrelated to pancreatitis, pro-coagulant disorders, pregnancy, or estrogen therapy were excluded. Propensity score matching (1:3 nearest-neighbor) was used to control for age, sex, race, and smoking status. Statistical analysis included Fisher’s exact and t-tests. Results: Fourteen patients with AIP were matched to 42 patients with AP using propensity score matching. No significant differences were observed in baseline demographic characteristics, including age, sex, race, and smoking status. No statistically significant differences were noted in the prevalence of common medical comorbidities between the 2 groups. Throughout the 10-year study period, no AIP patients were documented to have developed either DVT or PE. In the AP group, 3 patients (7.1%) developed DVT and 1 (2.4%) developed PE. These differences were not statistically significant (DVT: P = 0.565; PE: P = 1.000). Conclusion: There was no statistically significant difference in the prevalence of DVT or PE between patients with AIP and those with AP. This finding suggests that AIP is not associated with an increased risk of thrombosis, despite the 3 known prothrombotic risk factors: systemic autoimmune inflammation, AP, and chronic pancreatitis. Further, across the 10-year study period, no AIP patient developed DVT or PE. This study was limited by a small sample size. To our knowledge, it is the first to specifically evaluate thromboembolic events in AIP and may provide valuable initial insight into its thrombotic risk profile.