Human Antigen Leucocyte (HLA)-G and HLA-E are differentially expressed in pancreatic disorders

Background: Little information is available regarding the expression of the immunomodulatory Human Leukocyte Antigen (HLA)-G and -E molecules in pancreatic disorders. Aim: To analyze HLA-G and -E expression in specimens of alcoholic chronic pancreatitis (ACP), idiopathic chronic pancreatitis (ICP), type 1 (T1D) and type 2 diabetes (T2D) and in histologically normal pancreas (HNP). Methods: HLA-G and -E expression (ACP = 30, ICP = 10, T1D = 10, T2D = 30 and HNP = 20) was evaluated by immunohistochemistry in three different areas (acini, islets and inflammatory infiltrate). Results: Acini and islets from HNP specimens exhibited higher HLA-G and -E expression compared to corresponding areas from all other patient groups. In inflammatory infiltrate, HLA-G and -E expression was observed only among the pancreatic disorders. We observed higher HLA-G and -E expression in acini from T2D compared to ACP, as well as higher HLA-G expression compared to ICP. Conclusion: The decreased expression of HLA-G and -E in islets and acini together with the expression of these molecules in the inflammatory infiltrating cells were shared features among chronic inflammatory and auto immune pancreatic disorders evaluated in this study, possibly reflecting tissue damage.