Professional
Technical
In the Industry Vocabulary Test
thyroid-stimulating immunoglobulin
Also written as: TSI — thyroid-stimulating immunoglobulin
Antibodies that mimic TSH action, causing thyroid stimulation and hyperthyroidism.
Full Definition
Autoantibodies that bind to and activate TSH receptors on thyroid follicular cells, leading to excessive thyroid hormone production and gland enlargement. TSI is the pathognomonic marker for Graves' disease and helps distinguish it from other causes of hyperthyroidism. In surgical planning, persistently elevated TSI levels may predict higher risk of complications and influence decisions about extent of thyroidectomy. These antibodies can remain elevated even after thyroidectomy.
Usage
Usage note: Specify as TSI in most contexts; distinguish from broader TSH receptor antibody category.
In Context
- "Elevated thyroid-stimulating immunoglobulin confirmed the diagnosis of Graves' disease." — Laboratory results interpretation
- "Persistent thyroid-stimulating immunoglobulin elevation may predict continued eye disease activity." — Endocrinology consultation
Also known as
TSI
TSIG
Contrasted with
TSH receptor blocking antibodies
Don't confuse with
TSH receptor antibodies
thyroid peroxidase antibodies