[Specific immune response to pancreas antigen (PA3) in chronic pancreatitis and Sjögren syndrome].

The pancreas antigen (PA3) was prepared by an interspecies cross-reactive monoclonal antibody (SP3-1, IgM), which reacts with duct cells of multiple exocrine organs. Cell-mediated immunity to PA3 was examined using a lymphocyte proliferation test, and serum antibody to PA3 was measured by radioimmunoassay. Lymphocyte sensitization and serum antibody to PA3 were demonstrated in patients with idiopathic chronic pancreatitis (CP) and Sjögren syndrome with high rate and high titer. In normal controls and patients with alcoholic CP, stone related CP, PBC, SLE and chronic thyroiditis, they were rarely detected. The antigen detected by serum antibodies in patients with idiopathic CP and Sjögren syndrome was 60 kDa on Western immunoblot. These results revealed a possibility that PA3 was the target antigen for immune response in the pathogenesis of idiopathic CP and/or Sjögren syndrome.