Distinct Autoantibodies Against Exocrine Pancreatic Antigens in European Patients with Type 1 Diabetes Mellitus and Non-Alcoholic Chronic Pancreatitis

Context Histopathological analysis has demonstrated lymphocytic infiltration in both the endocrine and the exocrine pancreas in some patients with type 1 diabetes and nonalcoholic chronic pancreatitis, suggesting an immune-mediated mechanism which affects both diabetes mellitus and chronic pancreatitis. Objective The examination of exocrine pancreatic humoral markers in Caucasian patients with respect to the interactions between exocrine and endocrine pancreatic diseases. Patients One hundred and thirty-six European Caucasian subjects subdivided into three groups: type 1 diabetes (n=48); non-alcoholic chronic pancreatitis (n=48); controls (n=40). Main outcome measure Autoantibodies against carbonic anhydrase II (CAIIAb) and lactoferrin (LACAb) (both of which are exocrine pancreatic antigens) were analyzed by enzyme-linked immunosorbent assay. Results No positivity for CAIIAb and LACAb were found in the controls. Patients with type 1 diabetes had a significantly higher prevalence of CAIIAb (25.0%) than the controls while the prevalence of LACAb (8.3%) was not significantly higher than the controls. The prevalence of CAIIAb (12.5%) and LACAb (20.8%) in the patients with nonalcoholic chronic pancreatitis was significantly higher than that in the controls. A significantly higher prevalence of CAIIAb and/or LACAb was found in patients with type 1 diabetes (29.2%) and non-alcoholic chronic pancreatitis (22.9%) compared to that in the controls (0%). There was a significant association between CAIIAb and LACAb titers both in patients with type 1 diabetes (P=0.042) and in patients with non-alcoholic chronic pancreatitis (P<0.001). Conclusion We have clearly demonstrated that some European Caucasian patients with type 1 diabetes and non-alcoholic chronic pancreatitis have autoantibodies against the exocrine pancreatic antigens CAIIAb and LACAb.