Original Article
The preliminary clinical application of electrochemiluminescence assays for islet β cell autoantibodies
Qian Li, Zhu Yuxiao, Zou Jing, Chen Rourou, Liu Qing, He Rongbo, Peng Li, Yu Liping, Liu Yu
Published 2019-06-27
Cite as Chin J Diabetes Mellitus, 2019,11(6): 429-433. DOI: 10.3760/cma.j.issn.1674-5809.2019.06.011
Abstract
ObjectiveTo establish a new standard for measurement islet autoantibodies by electrochemiluminescence (ECL) assay and to discuss its applications for type 1 diabetes mellitus (T1DM) prediction and diagnosis.
MethodsECL assay was used to measure serum levels of glutamic acid decarboxylase antibody (GADA65), insulin autoantibody (IAA) and protein tyrosine phosphatase antibody (IA-2A) in 124 healthy volunteers, 180 T1DM patients, and 180 type 2 diabetes mellitus (T2DM) patients. Patients admitted in Sir Run Run Hospital, Nanjing Medical University from December 2016 to June 2018 with diagnosis of T1DM or T2DM were enrolled in the study. Healthy volunteers were recruited from students in Nanjing Medical University. The serum antibody level was represented as antibody index. The positive cut-off limit for each antibody was defined as 99% of the indicated antibody index from healthy volunteers. The chi-square test was used to analyze the positivity of GADA65, IAA, IA-2A of T1DM and T2DM patients detected by ECL method.
ResultsThe cut-off points for GADA65, IAA and IA-2A were 0.047, 0.009 and 0.0029 respectively by ECL methods. The intra-assay coefficients of variation (CV) for GADA65, IAA and IA-2A were 1.88%-8.30%, 1.39%-3.40%, 1.23%-3.17% respectively, and the inter-assay CV were 3.9%-7.3%, 2.7%-9.8%, 2.2%-7.4% respectively. The repeatability of the result was 99.8%. The positivity of GADA65, IAA,IA-2A were 52% (94/180), 45% (81/180), 21% (39/180) respectively in T1DM patients and were 2.2% (4/180), 2.2% (4/180), 2.2% (4/180) respectively in T2DM patients. There were statistic significances in positivity between T1DM and T2DM for all three antibodies (χ2=113.57,32.35,91.31, all P<0.001). The positive ratio of GADA65 and IA-2A detected by ECL or radio-binding assay shows no difference.
ConclusionThe ECL assay has high sensitivity, specificity and repeatability and could be used for the prediction and diagnosis of T1DM.
Key words:
Electrochemiluminescence; Diabetes mellitus; Glutamic acid decarboxylase antibody; Insulin autoantibody; Protein tyrosine phosphatase antibody
Contributor Information
Qian Li
The Department of Endocrinology, Sir Run Run Hospital, Nanjing Medical University, Nanjing 210000, China
Zhu Yuxiao
The Department of Endocrinology, Sir Run Run Hospital, Nanjing Medical University, Nanjing 210000, China
Zou Jing
The Department of Endocrinology, Sir Run Run Hospital, Nanjing Medical University, Nanjing 210000, China
Chen Rourou
The Department of Endocrinology, Sir Run Run Hospital, Nanjing Medical University, Nanjing 210000, China
Liu Qing
The Department of Endocrinology, Sir Run Run Hospital, Nanjing Medical University, Nanjing 210000, China
He Rongbo
The Department of Endocrinology, Sir Run Run Hospital, Nanjing Medical University, Nanjing 210000, China
Peng Li
The Department of Endocrinology, Sir Run Run Hospital, Nanjing Medical University, Nanjing 210000, China
Yu Liping
Barbara Davis Center for Childhood Diabetes, University of Colorado School of Medicine, Aurora 80045, China
Liu Yu
The Department of Endocrinology, Sir Run Run Hospital, Nanjing Medical University, Nanjing 210000, China
