Relevance of TSH-receptor antibody levels in predicting disease course in Graves’ orbitopathy: comparison of the third-generation TBII assay and Mc4-TSI bioassay

Abstract

Aims To investigate if TSH-receptor antibody (TRAb) levels measured in early Graves' orbitopathy (GO) stages are predictive of clinical disease course beyond 1 year after initial GO diagnosis and to compare performance of two newly developed TRAb assays (third-generation thyrotropin-binding inhibitor immunoglobulin (TBII) assay vs Mc4-thyroid-stimulating immunoglobulin (TSI) bioassay) in predicting disease course. Methods Newly diagnosed, untreated GO patients whose duration of ocular symptoms was less than 6 months were included. One year after initial diagnosis, all patients were classified as presenting either a mild (Group 1) or severe course (Group 2) according to their clinical manifestations. The measurements of two TRAb assays at initial GO diagnosis were used for analysis. Results Data from 112 patients were available for analysis. Seventy-three patients (65.2%) were designated as Group 1, and 39 patients (34.8%) as Group 2. Patients with higher initial TRAb levels demonstrated a higher risk of severe disease course upon multiple regression analysis (Po0.01). The cutoff values for the prediction of severe course of the third-generation TBII and Mc4-TSI assays were 10.67 IU/l and 555.10%, respectively, with assay specificities of 84.9 and 89.0%. The TBII assay predictive power

Expression and clinical significance of connective tissue growth factor (CTGF) in Graves' ophthalmopathy

“…In the present study, we also found that CTGF expression in the GO fibroblasts correlated with the serum levels of TSH-receptor antibodies in patients with GO. The levels of serum TSH-receptor antibodies have been reported to be correlated with disease activity and severity of GO,40 41 and the clinical outcome of GO therapy,41 as well as to predict disease course in early GO 43. Woo et al 44 reported that TSH-receptor levels generally remained high in patients with complicated GO or chronic inactive stage of GO, which may be related to aberrant tissue remodelling and fibrosis caused by CTGF 17 45.…”

Measuring TSH receptor antibody to influence treatment choices in Graves’ disease

“…These assays have undergone refinement over the years with the third‐generation assay employing a luciferase reporter to detect increased cAMP production . A study comparing the third‐generation TRAb assay with a thyroid‐stimulating immunoglobulin (TSI) assay to predict progression of Graves’ ophthalmopathy (GO) showed comparable results with both assays . It may be useful to test for TSI in patients with euthyroid GO …”

An update on thyroid-associated ophthalmopathy in children and adolescents

“…TSHreceptor antibodies (which are common in Graves' disease) can be responsible for pathological changes in the orbit. Therefore for assessing activity of TSH-receptor antibodies measurements of thyroid-stimulating immunoglobulin (TSI) and thyroid-binding inhibitory immunoglobulins (TBIIs) are performed [39]. In adults, Graves' disease TSI level can be a useful marker of ophthalmopathy activity and can facilitate the decision regarding treatment [40].…”