Open AccessEvaluation of analytic and clinical performance of two immunoassays for detecting thyroid‐stimulating receptor antibody in the diagnosis of Graves’ disease
Author(s) -
Hu Yao,
Ni Jiajin,
Cen Yi,
Zhang Buyue,
Wu Wenqing,
Cheng Wei,
Huang Mingying,
Guan Ming
Publication year - 2021
Publication title -
journal of clinical laboratory analysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.536
H-Index - 50
eISSN - 1098-2825
pISSN - 0887-8013
DOI - 10.1002/jcla.23950
Subject(s) - repeatability , receiver operating characteristic , medicine , graves' disease , medical diagnosis , coefficient of variation , immunoassay , predictive value , correlation coefficient , thyroid , diagnostic accuracy , antibody , gastroenterology , pathology , chromatography , immunology , chemistry , mathematics , statistics
Objective To evaluate the analytical and clinical performance of two immunoassays for diagnosis of Graves’ disease (GD), the Immulite thyroid‐stimulating immunoglobulin (TSI), and Elecsys Anti‐TSH receptor (TSHR) assay. Methods Precision and analytical measurement range were assessed using pooled samples of patients. The comparison between the two methods was evaluated using 579 clinical samples, and receiver operating characteristic (ROC) curves were drawn using the final diagnosis as reference. Clinical sensitivity and specificity, accuracy, positive predictive value (PPV), and negative predictive value (NPV) were calculated for the two tests. Results The repeatability and intermediate imprecision coefficient of variation (CV%) of the TSI assay were 3.8% and 4.1% at 0.95 IU/L, and 3.5% and3.6% at 19.5 IU/L, respectively. The assays were linear over a range 0.27–38.5 IU/L. There was a high correlation between the quantitative results of the two methods (correlation coefficient r = 0.930). The cut‐off value obtained by ROC analysis for TSI assay was 0.7 IU/L with sensitivity of 93.7% and specificity of 85.1%. An overall qualitative agreement of 91.5% between two methods was observed. Among 44 patients with discordant qualitative results, the TSI assay provided more satisfactory results consistent with clinical diagnoses. Conclusion The TSI assay showed excellent analytical performance and provided a high PPV for GD.