Serum interleukin 17 as an early prognostic biomarker of severe acute pancreatitis receiving continuous blood purification

Background: Severe acute pancreatitis (SAP) is associated with systemic inflammation, immunoparalysis, and sepsis, and may lead to vital organ failure and death. We evaluated the efficacy of serum interleukin 17 (IL-17) concentration for predicting eventual SAP severity and the clinical benefits of removing IL-17 by continuous venovenous hemofiltration (CVVH). Methods: Patients were divided into 2 groups according to severity: Grade 1 (n = 18, SAP without organ dysfunction) and Grade 2 (n = 18, SAP with organ dysfunction). 20 healthy volunteers served as controls. All patients underwent 24-h CVVH and blood samples were taken at 0, 6, 12, and 24 h for measurement of bacterial load and serum IL-17, IL-6, and endotoxin. Clinical condition was graded by the sequential organ failure assessment (SOFA) score. Results: Baseline IL-17, IL-6, endotoxin, and bacterial load were higher in Grade 2 patients. SOFA scores improved significantly, and serum IL-17, IL-6, endotoxin, and bacterial load decreased significantly in all patients after CVVH. Serum IL-17 was significantly and positively correlated with IL-6, bacterial load, and endotoxin during CVVH treatment. In addition, post-CVVH serum IL-17 was directly correlated with SOFA scores on days 1 and 7, and with duration of hospital stay. Non-survivors showed both higher SOFA scores on day 1 and higher baseline IL-17 than survivors. Conclusions: Earlier and higher serum IL-17 elevation predicted prolonged hospitalization, organ failure, and death, possibly by disrupting gut barrier function. CVVH can remove inflammatory cytokines from serum, including IL-17 and IL-6, thereby attenuating the inflammatory response and diminishing associated systemic complications.