title: The detection of autoantibodies to pancreatic islet cells by immunoenzyme histochemistry.
abstract: Using horseradish peroxidase- or alkaline phosphatase-conjugated secondary antibodies, an immunohistochemical assay was established for the detection of islet cell cytoplasmic antibodies (ICA). Determination of end-point titers showed a significant correlation between the conventional immunofluorescence and either immunocytochemistry assay. The assays with the enzyme-conjugated antibodies were more sensitive than the indirect immunofluorescence assay. Because of its simplicity, specificity, and easy microscopic evaluation of the chromogenic reaction product at the site of ICA binding, the indirect immunoperoxidase technique proved to be most suitable. This technique detected frequencies of ICA positives among newly diagnosed insulin-dependent (IDDM), noninsulin-dependent, and at-risk subjects that were comparable with previous studies. Preabsorption of ICA-positive sera with either rat or porcine brain extracts, containing the glutamate decarboxylase antigen, differently blocked, reduced or did not affect ICA reactivity with human or porcine pancreas sections. Testing of sera on human, bovine, and porcine pancreas sections demonstrated heterogeneity in ICA-binding with a high proportion of ICA false-positives on bovine pancreas. The results demonstrated that immunohistochemical techniques for detecting ICA are, in several aspects, preferable to indirect immunofluorescence and that individual serum ICA identify various antigens on pancreas from different species. However, bovine or porcine pancreas could not substitute for human pancreas in the ICA assay.
authors.affiliation: Institute of Diabetes Gerhardt Katsch, University of Greifswald, Karlsburg, Germany.
authors.forename: K D
authors.initials: KD
authors.lastname: Kohnert
authors.forename: I
authors.initials: I
authors.lastname: Rjasanowski
authors.forename: B
authors.initials: B
authors.lastname: Hehmke
authors.forename: J
authors.initials: J
authors.lastname: Hamann
authors.forename: H
authors.initials: H
authors.lastname: Keilacker
authors.forename: D
authors.initials: D
authors.lastname: Michaelis
mesh_terms: D000293:Adolescent; D000328:Adult; D000818:Animals; D001323:Autoantibodies / Q000032:analysis* / Q000097:blood; D001921:Brain / Q000166:cytology / Q000276:immunology; D002417:Cattle; D002648:Child; D002675:Child, Preschool; D003922:Diabetes Mellitus, Type 1 / Q000097:blood / Q000235:genetics / Q000276:immunology*; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000235:genetics / Q000276:immunology*; D016640:Diabetes, Gestational / Q000097:blood / Q000276:immunology; D005189:False Positive Reactions; D005260:Female; D005455:Fluorescent Antibody Technique; D006801:Humans; D007124:Immunoenzyme Techniques; D007150:Immunohistochemistry / Q000379:methods; D007223:Infant; D007515:Islets of Langerhans / Q000166:cytology / Q000276:immunology*; D008875:Middle Aged; D009679:Nuclear Family; D011247:Pregnancy; D051381:Rats; D012016:Reference Values; D012044:Regression Analysis; D013045:Species Specificity; D013552:Swine
chemical_list: D001323:Autoantibodies; C024211:islet cell antibody