title: Distinct cytoplasmic islet cell antibodies with different risks for type 1 (insulin-dependent) diabetes mellitus.
abstract: The cytoplasmic islet cell antibody patterns of sera from islet cell antibody positive non-diabetic and diabetic endocrine autoimmune patients, and newly-diagnosed Type 1 (insulin-dependent) diabetic patients were characterised using four layer immunofluorescence with monoclonal anti-proinsulin or anti-glucagon antibodies. Two distinct islet cell antibody types were identified. One gave a diffuse cytoplasmic staining in both Beta and Alpha cells ('whole' islet pattern), and was not affected by pre-incubation with rat brain homogenate. The other had a granular appearance with staining restricted predominantly to Beta cells ('selective' islet pattern) and was completely inhibited by pre-incubation with rat brain homogenate. Some sera appeared to have a 'mixed' islet pattern, in which glucagon-positive cells gave a weaker cytoplasmic staining than proinsulin-positive cells. The granular 'selective' pattern was found in sera from 19 (79%) of 24 non-diabetic endocrine autoimmune patients, in two (22%) endocrine autoimmune patients who developed Type 1 diabetes (p less than 0.0001 vs non-diabetic endocrine autoimmune patients), and in none of 19 newly-diagnosed diabetic patients. The 'whole' islet pattern was found only in sera from patients who had, or who subsequently progressed to, Type 1 diabetes. This study has identified a novel islet cell antibody specificity and demonstrates that in islet cell antibody positive endocrine autoimmune patients, only islet cell antibodies which stain both Beta and Alpha cells are associated with progression to Type 1 diabetes.
authors.affiliation: Department of Immunology, London Hospital Medical College, UK.
authors.forename: S
authors.initials: S
authors.lastname: Genovese
authors.forename: E
authors.initials: E
authors.lastname: Bonifacio
authors.forename: J M
authors.initials: JM
authors.lastname: McNally
authors.forename: B M
authors.initials: BM
authors.lastname: Dean
authors.forename: R
authors.initials: R
authors.lastname: Wagner
authors.forename: E
authors.initials: E
authors.lastname: Bosi
authors.forename: E A
authors.initials: EA
authors.lastname: Gale
authors.forename: G F
authors.initials: GF
authors.lastname: Bottazzo
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000818:Animals; D000911:Antibodies, Monoclonal; D001323:Autoantibodies / Q000032:analysis*; D001327:Autoimmune Diseases / Q000276:immunology*; D001921:Brain / Q000276:immunology; D002648:Child; D003593:Cytoplasm / Q000276:immunology; D003922:Diabetes Mellitus, Type 1 / Q000276:immunology*; D005260:Female; D005455:Fluorescent Antibody Technique; D005934:Glucagon / Q000032:analysis; D006801:Humans; D007515:Islets of Langerhans / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D051381:Rats
chemical_list: D000911:Antibodies, Monoclonal; D001323:Autoantibodies; C024211:islet cell antibody; D005934:Glucagon