Endoscopic Ultrasound (EUS) and EUS-Acquired Pancreatic Juice (PJ) Cytokine Analysis: A Modern Method of Diagnosing Chronic Pancreatitis (CP)?

Background: EUS is increasingly used to diagnose CP, and can also allow simultaneous collection of PJ for molecular analysis. Recent data advocate lipase determination in PJ collected endoscopically. Little is known with regard to cytokines levels in PJ in CP. Aim: In patients with abdominal pain (AP) to evaluate EUS and PJ analysis for Lipase, Interleukin 8 (IL-8) and Intercellular Adhesion Molecule-1 (ICAM-1) after secretin stimulation to diagnose CP. Methods: From 1/03 to 11/03 all consecutive pts. seen in the pancreas clinic with chronic AP suggestive of pancreatic origin were asked to participate in the study. Pts. underwent upper endoscopy with conscious sedation. Secretin (0.2 micrograms/kg) was given IV prior to intubation. PJ collected from the duodenum was immediately frozen in liquid nitrogen until the assays were performed. EUS diagnosis of CP was made when >4 established criteria were present. ERCP (scored according to the Cambridge classification) was performed on a separate day and blindly reviewed by a radiologist. Titrametric and ELISA assays were used to determine lipase and IL-8 and ICAM-1, respectively. Fisher's exact test was used for statistical analysis. Results: There were 28 pts. (11/17 M/F), mean age 55 yrs. (range 32-79). Analysis of endoscopically (at EUS) acquired PJ for lipase and cytokines was successful in all 28 pts. No complications occurred. ERCP and EUS findings correlated poorly with cytokine and lipase levels. According to the ERCP scoring system, 14 pts. had normal pancreas (score 0-1), 14 had CP (3 pts: score=2; 5 pts: score=3; 6 pts: score=4). In this small, preliminary sample, we found no statistical significant differences between pts. with ERCP score 0-1 versus ERCP score 2-4, or between those with >4 or <4 EUS features with regard to concentrations of lipase, IL-8 and ICAM-1 in PJ. Two pts. (14%) in the control group and 6 pts. (43%) in the CP group had > 4 EUS criteria for CP (p<0.05) (Sens 75%, NPV 86%). Conclusions: This preliminary study indicates the feasibility and safety of EUS-acquired PJ collection and cytokine/function analysis. Cytokine and lipase levels were similar in pts. with abdominal pain regardless of EUS or ERCP findings. The high negative predictive value of EUS alone may obviate the need for ERCP testing in pts. with AP of suspected pancreatic origin. Further data is required to determine if cytokine analysis improved the diagnosis of CP.