Circulating Protectin D1 and Neutrophils Extracellular Traps in the Diagnosis and Progression of Acute Pancreatitis.

Purpose: Protectin D1 (PD1), a biologically active molecule derived from docosahexaenoic acid (DHA), plays a major role in the body's endogenous lipid-mediated inflammatory response. The study aims to explore the relationship between PD1, inflammatory response and the severity of acute pancreatitis (AP).

Patients and methods: Sixty consecutive AP patients within 72h of disease onset were enrolled as the study group, a further thirty healthy people were enrolled as the control group. General demographics collected at the time of enrollment. Serum PD1, Citrullinated Histone 3 (CitH3), myeloperoxidase-Deoxyribonucleic acid (MPO-DNA), tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) level were measured in AP patients on enrollment day 0, day 1, day 3 and day 7. Meanwhile, the Acute Physiology and Chronic Health evaluation II (APACHE II) scores, Sequential Organ Failure Assessment (SOFA) scores were also evaluated on day 0, day 1, day 3 and day 7.

Results: AP was severe in 29 patients (48.3%), moderately severe acute pancreatitis (MSAP) was found in 9 patients (15%), and mild acute pancreatitis (MAP) was found in 22 patients (36.7%). The level of PD1, CitH3 and MPO-DNA were statistically significantly higher in AP patients than in the healthy population. Serum PD1, CitH3 and MPO-DNA concentration increased with AP severity. In AP patients, PD1 has a strong linear association with TNF-α, CitH3 and MPO-DNA. The AUC for SAP predicted by PD1 was 0.938. The calculated cut-off point for prognosis SAP is 7.94 pg/mL. The AUC for infected pancreatic necrosis (IPN) predicted by PD1 was 0.836 and the cut-off point was 8.65 pg/mL. The AUC for organ failure (OF) predicted by PD1 was 0.719 and the cut-off point was 7.94 pg/mL.

Conclusion: PD1 is associated with both the presence of AP and the severity of pancreatitis.