ICA were first described in patients with type 1 diabetes and multiple endocrine deficiencies associated with organ-specific autoimmunity,[3] and were subsequently identified in new-onset cases and in individuals at high risk of developing diabetes. ICA are measured by immunofluorescent techniques which identify any antibody that binds to human islet tissue in a non-specific manner. They were difficult to standardise because the assay is operator-dependent, varies according to the quality of the human pancreatic tissue used as a substrate, and recognises heterogeneous antibodies which vary between individuals. A series of workshop meetings resulted in reasonable standardisation of ICA and quantification in Juvenile Diabetes Foundation Units, but ICA testing has since been superseded by testing for specific autoantibodies against biochemically defined islet antigens.