Clinical relevance of autoimmune-related pancreatitis.

Recently, a concept of 'autoimmune pancreatitis' (AIP) was proposed. Computed tomography, magnetic resonance imaging or ultrasonography show a diffusely enlarged pancreas with a so-called 'sausage-like' appearance. Hypergammaglobulinaemia, increased serum levels of total IgG or IgG4, positive autoantibodies such as antinuclear antibody, anti-lactoferrin antibody, anti-CA-II antibody, rheumatoid factor and anti-smooth muscle antibody, were often observed in patients with AIP. Microscopic findings showed fibrotic changes with infiltration of lymphocytes, plasmacytes and sometimes eosinophils in the pancreas. Major subgroups of lymphocytes infiltrating areas around pancreatic ducts were CD4(+) T-cells producing IFN-gamma. HLA-DR was expressed on pancreatic duct cells as well as CD4(+) cells. The diagnosis is made by a combination of clinical, laboratory and morphological findings. Laboratory data, pancreas images and diabetes mellitus in most patients do respond to steroid treatment. In conclusion, autoimmune-related pancreatitis appears to be a unique clinical entity. However, its importance in clinical practice needs further characterization.