Combined EUS and Pancreatic Juice IL-8 Concentration Are Highly Predictive to Diagnose Chronic Pancreatitis

Background: The diagnosis of chronic pancreatitis (CP) remains challenging. EUS seems to be highly sensitive, but not specific enough. Pancreatic juice (PJ) IL-8 concentration has been proposed as a marker for pancreatic diseases. In this study, we aim to compare the accuracy of PJ IL-8 concentration and EUS to diagnose CP.

Methods: 79 patients presenting at our pancreas clinic with abdominal pain suspicious for CP were prospectively enrolled from Jan 2003 to Dec 2004. The diagnosis of CP by EUS was established when ≥4 of the previously established criteria were present. After IV secretin (0.2µg/kg), PJ emptied into the duodenum was collected and immediately frozen in liquid nitrogen until IL-8 concentration was measured by ELISA. The diagnosis of CP was made when PJ IL-8 concentration was ≥20 pg/mL. Final diagnosis of CP was made by the referring gastroenterologist using the composite gold standard: ERCP, histology, CT or MRI, and clinical follow-up (mean 18 months).

Results: 38 patients were diagnosed with CP, whereas 41 controls were found to have no pancreatic disease. No differences were demonstrated in demographics. The accuracy of EUS to diagnose CP was 80% with sensitivity and specificity of 71% and 88%. The accuracy of PJ IL-8 concentration was 71% with sensitivity and specificity of 47% and 93%. EUS was more sensitive, but equally accurate and specific compared to PJ IL-8 concentration. Combining the findings of EUS and PJ IL-8 concentration, the sensitivity and specificity increased to 82% and 100%.

Conclusions: Both EUS and PJ IL-8 concentration are accurate diagnostic modalities for CP. PJ collection can be performed at the time of EUS. EUS and PJ IL-8 concentration are complementary with higher sensitivity and specificity when used together. If confirmed in larger series, the combination of EUS with PJ IL-8 concentration will be highly predictive of CP.