免疫印迹和放射免疫沉淀法检测胰岛自身抗体的比较

Comparison of immunoblotting with radioimmunoprecipitation in detecting islet autoantibodies

目的探讨免疫印迹法(IB)和放射免疫沉淀法(RIP)在胰岛自身抗体检测中的差异。方法 IB和RIP分别测定本院55例和外院218例1型糖尿病(T1DM)患者的谷氨酸脱羧酶抗体(GADA)、蛋白酪氨酸磷酸酶抗体(IA-2A)和胰岛素自身抗体(IAA)水平;再从218例外院患者中随机抽取24例,用IB和RIP分别检测血清中GADA和IA-2A,评价两种方法的敏感性。结果 IB和RIP检测IA-2A阳性率无明显差异(P>0.05),而GADA、IAA总阳性率的差异均有统计学意义(P<0.05)。两种方法联合检测GADA和IA-2A的抗体总阳性率为91.7%,高于单一方法的检测结果。结论 IB检测GADA和IAA的敏感性明显低于RIP,且两种方法联合检测的抗体检出率明显高于单一方法。

Objective To study the differences of immunoblotting（IB） and radioimmuno-precipitation（RIP） used for detecting islet autoantibodies.Methods The glutamic acid dearboxylase antibody（GADA）,protein tyrosine phosphatase IA2 antibody（IA-2A） and insulin autoantibody（IAA） of 58 patients in our hospital and 218 patients in the other hospitals with type 1 diabetes（T1DM） were detected by IB and RIP respectively.Then the GADA and IA-2A of 24 patients randomly chosen from the 218 patients were measured by IB and RIP.The sensitivities of two assays were evaluated and compared.Results There was no significant difference between IB and RIP in the detection of IA-2A（P0.05）,but the difference was obvious in the positive rates of GADA and IAA（P0.05）.The positive rate reported by IB combined with RIP was 91.7%,which was higher than that by single assay.Conclusion The positive rates of GADA and IAA detected by IB were obviously lower than those by RIP,and the combination of the two assays could significantly raise the positive rate of autoantibody detection.