胰岛自身抗体对Ⅰ型糖尿病诊断效率的研究

目的 探讨免疫指标谷氨酸脱羧酶抗体（ＧＡＤ６５－Ａｂ）与胰岛细胞抗体（ＩＣＡ）对Ⅰ型糖尿病的诊断价值。方法 Ⅰ型糖尿病１０４例,正常对照１０２例,用放射配体分析法检测ＧＡＤ６５－Ａｂ,ＥＬＩＳＡ法检测ＩＣＡ;用受试者运筹特性（ＲＯＣ）曲线及曲线下面积比较二者的诊断效率。结果 （１）ＧＡＤ６５－Ａｂ最佳界值０．３０,ＩＣＡ最佳界值０．４５。ＧＡＤ６５－Ａｂ、ＩＣＡ、ＲＯＣ曲线下面积分别为０．８３５、

Diagnostic efficacy of glutamic acid decarboxylase antibody and islet cell antibody in type I diabetes mellitus

OBJECTIVE: To investigate the diagnostic efficacy of glutamic acid decarboxylase antibody (GAD65-Ab) and islet cell antibody (ICA) in type I diabetes mellitus. METHODS: 104 cases of type I diabetes mellitus and 102 normal controls were recruited, GAD65-Ab was determined with radioligand assay and ICA with ELISA. The diagnostic efficacy of GAD65-Ab and ICA was analysed by receiver-operating characteristic (ROC) curve with sensitivity, specificity and curve area. RESULTS: (1) The optimal cut-off point of GAD65-Ab was at 0.30, while that of ICA was at 0.45. The area under the curve of GAD65-Ab and ICA were 0.835 and 0.715 respectively. Compared with 0.5, the area under curve of GAD65-Ab and ICA was higher (P < 0.0001). The area under curve of GAD65-Ab was higher than that of ICA(P < 0.01). (2) In type I diabetes mellitus patients, the positivity of GAD65-Ab was not correlated to the age of onset and duration of the disease, while the positivity of ICA was correlated to the age of onset and duration. CONCLUSION: Type I diabetes mellitus can be diagnosed with GAD65-Ab and ICA. The diagnostic efficacy of GAD65-Ab is higher than that of ICA. In patients of type I diabetes mellitus with adult-onset and duration more than one year, the diagnostic efficacy of GAD65-Ab is higher than that of ICA, while in patients of type I diabetes mellitus with adolescent-onset and duration less than one year, the diagnostic efficacy of ICA is higher than that of GAD65-Ab.