三种胰岛自身抗体联合检测对1型糖尿病早期诊断的意义

目的:评价联合检测谷氨酸脱羧酶抗体(GADA)、胰岛细胞抗体(ICA)和胰岛素自身抗体(IAA)对1型糖尿病的早期诊断价值。方法:采用酶联免疫吸附法(ELISA)检测GADA、ICA和IAA;电化学发光法检测患者空腹和餐后2h血清C肽。结果:1型糖尿病患者GADA、ICA和IAA阳性率明显高于2型患者和正常组,P<0.001。GADA在1型糖尿病中的阳性检出率明显高于ICA和IAA组,P<0.01。青少年患者组ICA阳性率高于GADA和IAA组,P<0.001,成年组及老年组患者中GADA阳性明显高于ICA和IAA组,P<0.05。GADA/ICA、GADA/IAA及三种抗体联合检测的阳性率,敏感性和诊断符合率均高于单一抗体检测的阳性率,P<0.05。抗体阳性患者的空腹和餐后C肽水平明显低于抗体阴性患者,P<0.01。结论:自身抗体阳性患者的胰岛功能明显低于阴性患者,表明抗体阳性患者胰岛功能有明显损伤。GADA、ICA和IAA联合检测可以提高诊断敏感性和诊断符合率,对1型糖尿病早期诊断具有重要价值,且青少年期GADA和ICA的联合检测显得尤为重要。

Significance of combined determination of three autoantibodies in early diagnosis of type 1 diabetes mellitus

Objective: To evaluate the significance of combined determination of glutamic acid decarboxylase antibodies(GADA), islet cell antibodies(ICA) and insulin autoantibodies(IAA) in precaution of type 1 diabetes mellitus. Methods: GADA, ICA and IAA were determined by enzyme-linked immunosorbent assay, and C peptide was delermined by electric chemical irradiated assay. Results: Compared with patients with type 2 diabetes mellitus and normal subjects, the positive rate of GADA, ICA and IAA was significantly elevated in patients with type 1 diabetes mellitus (P < 0.001), and the positive rate of GADA was higher than that of ICA and IAA(P < 0.01). In juvenile patients with diabetes, the positive rate of ICA was higher than that of GADA and IAA(P < 0.001), while in adult patients with diabetes, the positive rate of GADA was higher than that of ICA and IAA(P < 0.05). Fasting and postprandial C peptide levels of antibody positive diabetes were significantly lower than those of antibody negative diabetes(P < 0.01). Conclusion: The islet function of diabetic with positive antibodies is significantly lower than that of those with negative antibodies, suggesting that in the former islet functionis is markedly damaged. Combined determination of three autoantibodies may enhance the sensitivity and accuracy of diagnosis,with an important significance for early diagnosis of type 1 diabetes mellitus, and combined determination of GADA and ICA appears more important for juvenile patients with diabetes.