中文摘要：

目的 建立SOX13抗体的放射配体检测法，初步探讨其对自身免疫糖尿病的诊断价值。方法 采用SOX13质粒，经体外转录与翻译，获得^35S标记SOX13。^35S-SOX13与血清在旋转孵育器中混匀过夜，用蛋白A琼脂糖沉淀抗原抗体复合物。沉淀复合物经TBST缓冲液洗涤后，置液体闪烁计数仪上计数，结果以国际标准化的抗体指数表示。检测162例急性起病、328例隐匿起病糖尿病患者以及120例正常人血清中SOX13抗体指数。结果 （1）方法的批内CV3．9％～9．2％，批间CV5．2％～12．0％，28例标本重复检测3次，结果判断一致；（2）120例正常人的SOX13抗体指数呈偏态分布，取97．5％的百分位点，阳性阈值为0．10；（3）检测急性起病患者162例，阳性15例，阳性率9．3％；隐匿起病患者328例，阳性34例，阳性率10．4％，均显著高于正常组（P〈0．05）。结论 （1）建立的SOX13抗体放射配体检测法灵敏度和重复性好，可应用于临床；（2）SOX13抗体对自身免疫性糖尿病（特别是GAD-Ab、IA-2Ab、CPH-Ab阴性者）具有独特的诊断价值。

英文摘要：

Objective To establish a radioligand assay for SOX13 antibody （SOX13-Ab） ,and to explore its diagnostic role in autoimmune diabetes. Methods ^35S labelled recombinant human SOX13 antigen was obtained by in vitro transcription and translation, and then was mixed with serum samples in rotating incubator overnight. The immune complexes were precipitated with protein A-sepharose, then washed with TBST buffer. The radioactivity was counted on a liquid scintillation counter. The results were expressed by international standardized antibody index. Sera from 162 diabetic patients with acute-onset, 328 patients with slow-onset and 120 healthy controls were tested for SOX13-Ab. Results The intra-assay coefficient of variation（CV） was 3.9 % - 9.2%, inter-assay CV 5.2%- 12.0%. The upper limit of the normal range was defined as the 97.5 percentile of the SOX13-Ab indexes measured in the sera of 120 healthy controls. The cut-off value thus obtained was 0. 1. The prevalence of SOX13-Ab was 2.5% （3/120） in healthy controls, 9.3% （15/162） in acute-onset diabetes and 10.4% （34/328） in slow-onset diabetes. The frequencies of positivity for SOX13-Ab were higher in acute-onset, slow-onset diabetic patients than that in healthy controls （P〈0.05）. Conclusions The established SOX13-Ab radioligand assay has a high sensitivity and reproducibility, which can be used in clinical practice. The higher frequencies of positivity in acute-onset and slow-onset diabetic patients suggest the unique diagnostic role of SOX13 antibody in autoimmune diabetes.