高感度測定法による自己抗体の早期検出と栄養指導への応用-インスリン自己抗体の場合-

概要

論文の詳細を見る
INTRODUCTIONGlucose intolerance and insulin resistance are major components of diabetes mellitus(DM). Insulin autoantibody (IAA), which specifically influences glucose intolerance, wasfound to be positive in patients of type 2 DM. Controlling blood glucose level is importantfor diabetic patients for the optimal outcome and treatment. As IAA is implicated in glucoseintolerance, we developed the highly sensitive enzyme immunoassay, ICT-EIA, for theearly detection of IAA in pre-DM subjects for inclusion in a nutritional and exercise educationprogram for the control of the blood glucose level.SUBJECTSSerum was obtained from patients with type 1 DM (n=4), type 2 DM (n=23), and hyperinsulinemia(n=9), as well as from non-DM subjects (n=53).RESULTSAfter serum samples from patients of type 1 DM were serially diluted with standard serumfrom healthy subjects, ICT-EIA for IAA was found to be 100-fold more sensitive than conventionalELISA. Specificity of ICT-EIA for IAA was confirmed by the 99% inhibition of fluorescenceintensity (FI) of IAA following the addition of insulin to the diluted samples.Without DC treatment, recovery of insulin antibody with treatment of acid at pH 2.5 orpH 3.5 was 5%. With DC treatment, recovery of the insulin antibody without the treatmentof acid was 15%. With DC treatment, recovery of insulin antibody with the treatment ofacid at pH 3.5 and pH 2.5 was 35% and 60%, respectively. However, after correcting for the90% insulin antibody reduction by acid treatment at pH 2.5, the recalculated recovery withthe treatment of both DC and acid at pH 2.5 was 70%. Optimal volume of the serum sampleto assay by DC treatment was 16.7 ml/tube.Using ICT-EIA without DC treatment and with streptavidin-coated polystyrene beads,IAA were found in 2/4 patients with type 1 DM, 1/8 patients with insulin-treated type 2DM, 2/15 patients with insulin-untreated type 2 DM, and 1/9 patients with hyperinsulinemia.Only one non-DM subject exhibited an FI level higher than the cutoff value of 1.7(mean ± 2 standard deviations of non-DM subjects). These samples were confirmed to beIAA positive by addition of excess insulin. Using ICT-EIA with DC treatment and streptavidin-coated polystyrene beads, wedetected IAA in 2/4 patients with type 1 DM, 1/8 patients with insulin-treated type 2 DM,2/15 patients with insulin-untreated type 2 DM, and 1/9 patients with hyperinsulinemia.With the cutoff value for non-DM subjects being 8.7, nobody of non-DM subjects was positiveto IAA.Using ICT-EIA with DC treatment and anti-human immunoglobulin IgG-coated polystyrenebeads, we detected IAA in 4/4 patients with type 1 DM, 3/8 patients with insulintreatedtype 2 DM, 1/13 patients with insulin-untreated type 2 DM, 2/9 patients withhyperinsulinemia. With the cutoff value for non-DM subjects being 4.7, nobody of non-DMsubject was positive to IAA.CONCLSIONSWe developed a highly sensitive enzyme immunoassay (ICT-EIA) that was combined withDC treatment to detect IAA in all (4/4) patients with type 1 DM and in 2/15 patients withinsulin-untreated type 2 DM.Therefore, the detection of IAA may be able to predict the risk of developing DM andcan help prevent disease onset with the implementation of nutritional education and exerciseguidance.

高感度測定法による自己抗体の早期検出と栄養指導への応用-インスリン自己抗体の場合-

スポンサーリンク

概要

著者

関連論文

スポンサーリンク