ERCP findings in idiopathic pancreatitis: patients who are cystic fibrosis gene positive and negative

Background: Our series of patients with idiopathic pancreatitis (IP) found a cystic fibrosis (CF) gene abnormality in 19% compared with 3.5% in patients without pancreatitis. Objective: The objective was to determine whether the CF gene predicts more severe ERP findings. Design: This was a retrospective case-control study. Setting and Patients: From July 1998 to August 2004, CF gene analysis was performed in 819 patients with IP via Genzyme Genetics. The panel tests for 70 to 87 alleles and has a detection rate of more than 90% of the cases. Sixty-nine patients (8.4%) who had at least one CF gene positive mutation were the study cohort. A total of 218 patients with IP and negative CF gene mutation were randomly selected from our database to be in the control group. Main Outcome Measurements: Pancreatograms were evaluated for chronic pancreatitis (CP) based on Cambridge criteria. The results of the gene analysis were not available at the time of pancreatogram interpretation. Results: Among patients positive for the CF gene, 42 (61%) were women. The mean age at intervention was 40 years (range 14-80 years), and 48 patients (70%) had cholecystectomy Among patients who were negative for the CF gene, 147 (67%) were women. The mean age at intervention was 41 years (range 9-89 years), and 125 patients (57%) had cholecystectomy. Compared with controls, cases had higher incidence of CP (62% vs. 48%, p = 0.05), grade III CP (35% vs. 18%, p = 0.004), pseudocysts (12% vs. 4%, p = 0.036) and pancreatic strictures (20% vs. 8%, p = 0.008). Limitations: The limitations of the study were (1) retrospective design and (2) the panel used tests only for 70 to 87 alleles (of approximately, 900 CF transmembrane conductance regulator genes known). Conclusions: The mean age at intervention in both groups was similar. CP, grade III CP, pseudocysts, and pancreatic strictures were more common among patients who were CF gene positive.