Eosinophilia Associated With Chronic Pancreatitis

Objectives: Eosinophilia (>0.5 x 10(9)/L eosinophils [EOSs] in the peripheral blood) has been overlooked in the study of chronic pancreatitis (CP). The purpose of this study was to investigate the clinical significance and causes of eosinophilia by analyzing the features of CP cases with eosinophilia. Methods: We retrospectively analyzed the clinical features of CP patients with eosinophilia and compared them with CP patients without eosinophilia. Results: There were 28 cases (15.6%) of CP with eosinophilia among 180 CP patients. The ratio of male to female patients was 8.3:1. The mean patient age at the time of diagnosis was 49.0 (+/- 16.2) years. The peak value of EOSs in the patients' peripheral blood was 0.935 (+/- 0.600) x 10(9)/L. The incidence of eosinophilia in autoimmune pancreatitis was significantly higher than in non-autoimmune pancreatitis CP cases. The incidence of pancreatic ascites, pancreatic enlargement, or jaundice in CP cases with eosinophilia was significantly higher than in those without eosinophilia. There was no obvious infiltration of EOSs in the pancreatic tissues of 16 pathology or cytology specimens. Conclusions: The occurrence of eosinophilia during the course of CP is not unusual. This may be related to autoimmune mechanisms, serous membrane response, or the progression of pancreatic inflammation and fibrosis.