AUTOANTIBODIES TO GASTRIN IN PATIENTS WITH PERNICIOUS-ANEMIA - A NOVEL ANTIBODY

Autoantibodies arise when there is a breakdown in immunological tolera nce. Autoantibodies to parietal cells and intrinsic factor are found i n autoimmune atrophic gastritis (AAG) and are associated with elevated plasma gastrin. Endogenous gastrin autoantibodies have not been descr ibed to date. The aim of this study was to investigate the occurrence of autoantibodies to gastrin. Plasma from 50 000 patients, including m ore than 2000 with AAG, was tested. Gastrin was measured by radioimmun oassay (RIA) in whole plasma and the presence of autoantibody determin ed by using a control which omitted assay antibody. The quantity and a ffinity of gastrin autoantibodies was assessed. Three patients had aut oantibodies to gastrin. All three had AAG and pernicious anaemia (PA). The antibodies were of low titre and relatively high affinity. Free c irculating plasma gastrin levels were within the normal range, but tot al gastrin levels were elevated. This is the first description of auto antibodies to endogenous gastrin. The incidence of antibodies to gastr in is low, they are found in association with PA, and they may lead to falsely low measurements of plasma gastrin.