Chronic insulitis after partial islet damage by passive insulin antibody transfer

The effect of passive insulin antibody transfer into recipient mice was reevaluated. Mice of inbred strains BALB/c, C57Bl/6 and DBA/2 received 10 injections of hyperimmune guinea pig insulin antiserum within 2 weeks. Ten days later the animals were sacrificed. It was found that up to 40% of animals had developed chronic lymphocytic infiltrations of pancreatic islets (insulitis) without showing diabetic symptoms. It is concluded that repeated damaging of islet tissue by passive insulin antibody transfer may result in chronic, possibly autoimmune insulitis. Our observation supports the concept that partial damage of pancreatic islets by environmental factors may trigger an organ-specific progressive islet cell destruction process mediated by immune cells.