Purified immunoglobulin G (IgG) from the serum of patients with insulin- dependent diabetes mellitus (IDDM) of recent onset inhibits high-K(m) uptake of 3-O-methyl-β-D-glucose by rat pancreatic islets. To determine if the inhibition is the result of antibodies against GLUT-2, the high-K(m) glucose transporter of β cells, we incubated IDDM sera with rat islet cells and with AtT-20(ins) cells transfected to express GLUT-2. IDDM sera inhibited glucose uptake in islet cells and in GLUT-2-expressing AtT-20(ins) cells but not in AtT-20(ins) cells transfected to express the low-K(m) isoform, GLUT-1. In 24 of 30 (77%) patients with newly diagnosed IDDM, IgG binding as measured by immunofluorescence and flow cytometry of the cells transfected to express GLUT-2 was >2 standard deviations from the mean of the nondiabetic population; 29 of 31 (96%) of nondiabetic children were negative (P < 0.0001). Increased IgG binding could be removed by absorption with GLUT-2- expressing cells but not with GLUT-1-expressing cells. We conclude that most patients with IDDM of recent onset have autoantibodies to GLUT-2.
|Original language||English (US)|
|Number of pages||4|
|Journal||Proceedings of the National Academy of Sciences of the United States of America|
|State||Published - 1993|
- flow cytometry
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