A novel microwell indirect immunofluorescence assay to detect antibodies against islet cell surface antigens in insulin-dependent diabetes mellitus.
End-point titers of islet cell surface antibodies (ICSA) were determined in 144 patients with newly diagnosed insulin-dependent diabetes mellitus (IDDM), 98 siblings to such patients, and 188 controls using a microwell indirect immunofluorescence assay with an insulin-producing cell line of Syrian hamster origin. The prevalence of ICSA of a titer equal to or greater than 1:4 was 33% (p less than 0.001) in IDDM patients and 15% (p less than 0.01) in siblings, compared to 5% among the controls. In patients under 15 years of age at clinical onset, the prevalence of ICSA was 43% (37/77), which was higher than the 30% (20/67) found in patients older than 15 years at onset (p less than 0.05). The ICSA titer at the time of diagnosis varied between 1:4 and 1:32; however, 43% (23/53) of ICSA positive IDDM patients had a titer equal to or greater than 1:8. Although gender did not affect ICSA prevalence, 56% (15/27) of the female IDDM patients had ICSA titers exceeding 1:8 which was higher than 30% (8/26) among male patients (p less than 0.05). These results confirm that IDDM patients have a high prevalence of ICSA and that this convenient, high capacity immunofluorescence assay allows studies of large numbers of serum samples. The cell-specific reaction following absorption should also allow the islet cell surface antigens to be characterized.
Matsuba
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Hagedorn Research Laboratory, Gentofte, Denmark.
Lernmark
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D000293:Adolescent; D000328:Adult; D000954:Antigens, Surface / Q000276:immunology*; D001323:Autoantibodies / Q000032:analysis*; D002648:Child; D002675:Child, Preschool; D003922:Diabetes Mellitus, Type 1 / Q000276:immunology*; D005260:Female; D005455:Fluorescent Antibody Technique; D006801:Humans; D007515:Islets of Langerhans / Q000276:immunology*; D008297:Male; D008875:Middle Aged
D000954:Antigens, Surface; D001323:Autoantibodies; C024211:islet cell antibody