Abstract: This study explored the prognosis correlation analysis and degree of illness of modified CT severity index (MCTSI), peripheral blood free DNA/neutrophil extracellular traps (cf-DNA/NETs), D-dimer and the severity and prognosis of acute pancreatitis (AP). 175 AP patients were selected as the research objects, and they were divided into mild AP group (75 cases), moderate-severe AP group (56 cases), and severe AP group (44 cases) according to the extent of disease. And they also divided into survival group (163 cases) and death group (12 cases) based on patient survival within 3 months. Compared the levels of MCTSI, cf-DNA/NETs and D-dimer of patients with different severity and prognosis, and analyzed the prognostic value of MCTSI, cf-DNA/NETs and D-dimer. The results showed that the levels of MCTSI, cf-DNA/NETs, and D-dimer in the severe AP group were higher than those in the moderate-severe AP group, and the moderate-severe AP group was higher than the mild AP group, and the differences were statistically significant (P<0.05). The difference was statistically significant at the levels of MCTSI, cf-DNA/NETs and D-dimer in the death group were higher than those in the survival group (P<0.05). ROC curve analysis showed that the AUCs of MCTSI, cf-DNA/NETs and D-dimer in predicting the prognosis of AP patients were 0.950, 0.997, and 0.974, respectively. Z test was used to compare the AUCs of each index, and there was no statistical significance (P>0.05). With the aggravation of AP, MCTSI, cf-DNA/NETs and D-dimer tend to increase, and MCTSI, cf-DNA/NETs and D-dimer were closely related to the prognosis and death of patients, which could be used to evaluate the prognosis a reference indicator of death.

Key words: modified CT severity index, free DNA/neutrophil extracellular trap, D-dimer, acute pancreatitis, extent of disease, prognosis