Diagnostic accuracy of Immulite® TSI immunoassay for thyroid-associated orbitopathy in patients with recently diagnosed Graves’ hyperthyroidism

Abstract

Purpose The ImmuliteÒ thyroid stimulating immunoglobulin (TSI) immunoassay is a relatively new commercial assay that has shown good diagnostic accuracy in Graves' hyperthyroidism (GH). However, its clinical utility in thyroid-associated orbitopathy (TAO) is less clear. The purpose of this study was to assess the diagnostic accuracy of the ImmuliteÒ TSI immunoassay for TAO and investigate the associations between TSI and other clinical measures. Methods One hundred and forty patients that had been diagnosed with GH within the previous 12 months were recruited. Identification and grading of TAO were performed at enrolment and serum samples were analysed using the ImmuliteÒ TSI immunoassay. Results Of the 140 participants recruited, 75 (53.6%) had TAO. Age, sex and time since GH diagnosis were similar between those with and without TAO (p C 0.300). TSI level tended to decrease with increasing time from GH diagnosis (Spearman's q -0.28, 95% CI -0.43, -0.12). TSI levels were higher among those with than those without TAO (median 4.0 vs. 2.7 IU/L, respectively, p = 0.037). There was no correlation between TSI level and inflammatory index score (q = 0.14, 95% CI -0.03, 0.30) or clinical severity (p = 0.527) among those with TAO. TSI level showed poor diagnostic accuracy for TAO (area under the receiver operating characteristic curve 0.60, 95% CI 0.51, 0.70).Conclusions Although ImmuliteÒ TSI level was higher in the presence of TAO, it showed poor diagnostic accuracy and no correlation with clinical markers of TAO severity or activity.

Thyroid stimulating immunoglobulin concentration is associated with disease activity and predicts response to treatment with intravenous methylprednisolone in patients with Graves’ orbitopathy

“…Interestingly, although the bridge-based assay presumably detects TSI more specifically than TBII assays, studies found that TBII assays correlate equally or even stronger with disease activity than the bridge-based assay ( 26 , 30 ). Furthermore, our study did not find any correlation between bridge-based TSI levels and the severity of the disease, which is consistent with some previous reports ( 26 , 28 ), but differing from another ( 27 ).…”

“…Research herein has primarily focused on the use of different assays as a biomarker for disease activity and severity, showing that TSI bioassays, outperform TBII assays (4,5,7,(13)(14)(15)(16)(17)(18)(19)(20)(21)(22)(23)(24)(25). So far, only a limited number of studies investigated the applicability of the bridge-based TSI binding assay as a biomarker for disease activity and severity in GO, with conflicting results (26)(27)(28)(29)(30). Although identifying patients with active disease is important, it may be even more relevant to identify patients who will not respond to intravenous methylprednisolone (IVMP).…”

Comparison Between Thyroid Stimulating Immunoglobulin and TSH-Receptor Antibodies in the Management of Graves’ Orbitopathy

“…Our results are in line with a newly published study from Australia [34], in which 140 participants recruited of which 75 (53.6%) had GO. Although Immulite TSI level was higher in the presence of GO, it showed poor diagnostic accuracy and no correlation with clinical markers of GO severity or activity.…”

To Investigate the Effect of Magnetic Resonance Imaging (MRI) and Diffusion Tensor Imaging (DTI) in the Diagnosis of Mild Craniocerebral Injury

“…The changes of Fa value of MS lesions in different periods have their own characteristics. The accumulation of inflammatory cells and myelin disintegration products potentially limits the diffusion of water molecules, forming a diffusion barrier without directional water molecules, resulting in the decrease of FA value [ 12 ]. Giordano et al found that DTI imaging technology has characteristics of brain endoplasmic injury in toxic encephalopathy.…”