AIM: To study tissue factor (TF) in acute pancreatitis and evaluate the role of IF as a predictive marker of severity. METHODS: Forty-nine consecutive patients admitted to Lund University Hospital, fulfilling the criteria of predicted severe acute pancreatitis (AP), were recruited prospectively between 2002 and 2004. Blood samples for TF analyses were drawn at inclusion in the study and 12 h, 1 d and 3 d later. RESULTS: Twenty-seven patients developed mild AP, and 22 patients severe AR At inclusion in the study, the groups were comparable with respect to gender, aetiology, Acute Physiology and Chronic Health Evaluation II score, and duration of pain. At inclusion in the study and at 12 h, IF was higher in the severe AP group (P = 0.035 and P = 0.049, respectively). After 1 and 3 d, no differences in TF levels were noted. Interleukin (IL)-6 was significantly higher in the severe AP group at all of the studied time points. C-reactive protein (CRP) was significantly higher in the AP group at 1 and 3 d. In receiver operating characteristic-curves, the area under the curve (AUC) for TF was 0.679 (P = 0.035) at inclusion in the study, and a cut off level for IF of 40 pg/mL showed a sensitivity of 71% and a specificity of 67%, whereas corresponding AUC for IL-6 was 0.775, P = 0.001, and for CRP was 0.653. IL-6 showed better AUC-values than TF at all time points studied. CONCLUSION: IF-levels are raised early in severe AR TF as an early predictive marker of severe AP is superior to CRP, but inferior to IL-6. (C) 2010 Baishideng. All rights reserved.