Thyroid-Stimulating Immunoglobulin as a Potential Biomarker for Thyroid Eye Disease

Macro closeup of young woman face portrait in profile side with Grave's disease hyperthyroidism symptoms of ophthalmopathy bulging eyes proptosis edema
Macro closeup of young woman face portrait in profile side with Grave’s disease hyperthyroidism symptoms of ophthalmopathy bulging eyes proptosis edema
Study offers a cut-off TSI level that might be able to discriminate between active and inactive TED.

Serum thyroid-stimulating immunoglobulin (TSI) level is strongly associated with thyroid eye disease activity, according to research published in Eye (Lond). It may serve as a functional biomarker to identify patients with active disease in the clinic.

Researchers looked at 101 patients (mean age of 46 years, 70% women and 30% men). The investigators measured participants’ TSI level with a cell-based bioassay and evaluated the association between TSI and various demographic and clinical features of thyroid eye disease. They also determined a TSI cut-off value for discriminating active from inactive disease.

Researchers found a mean duration of ocular symptoms of 8 months (range, 1–60 months), and a mean TSI level of 402.7 SSR% (specimen-to-reference ratio percentage; range, 23–890). The prevalence of TSI-positive participants in this study with thyroid eye disease was 89%. 

The study found TSI levels are higher in men than in women (469.3 vs 374.6 SSR%; P =.023) and in smokers than nonsmokers (492.4 vs 369.9 SSR%; P =.004). They also note its inverse correlation with the duration of ocular symptoms (r=-0.295; P =.003), which is significantly different depending upon thyroid function (hyperthyroid, 439.5 SSR%; subclinical hyperthyroid, 397.8 SSR%; euthyroid, 251.3 SSR%; P =.003) and disease activity (active vs inactive, 488.3 vs 315.4 SSR%; P <.001) and severity (mild, 342.9 SSR%; moderate to severe, 446.6 SSR%; dysthyroid optic neuropathy, 566.6 SSR%; P <.001).

Using a multivariate regression analysis adjusting for other clinical characteristics, the investigators show that disease activity and thyroid function are significantly associated with TSI level (P =.010; P =.026, respectively). They also determined that the TSI cut-off value for predicting active disease is 406.7 SSR% (P <.001; area under the curve=0.847; sensitivity, 77.4%; specificity, 81.3%).

The primary limitations of the study included the retrospective, single-center design and the limited number of cases, especially patients with dysthyroid optic neuropathy.


Jeon H, Lee JY, Kim YJ, Lee MJ. Clinical relevance of thyroid-stimulating immunoglobulin as a biomarker of the activity of thyroid eye disease. Eye (Lond). Published online February 26, 2022. doi:10.1038/s41433-022-01981-z

This article originally appeared on Ophthalmology Advisor