Increased soluble interleukin 2 receptor levels in autoimmune thyroid disease

Area of Science:

• Immunology
• Endocrinology
• Thyroidology

Background:

• Autoimmune thyroid diseases (AITD) involve complex immune dysregulation.
• T-cell activation markers, such as soluble interleukin-2 receptor (sIL-2R), may reflect immune status in AITD.

Purpose of the Study:

• To investigate sIL-2R levels in patients with Graves' disease and Hashimoto's thyroiditis.
• To explore the relationship between sIL-2R levels, thyroid hormone status, and autoimmune markers in AITD.

Main Methods:

• Measurement of serum sIL-2R (Tac protein p55) in patients with untreated Graves' disease, Hashimoto's thyroiditis, toxic multinodular goitre, and healthy controls.
• Correlation analysis of sIL-2R levels with thyroxine, TSH-inhibitory immunoglobulins, and thyroid autoantibodies.
• Assessment of sIL-2R levels following triiodothyronine (T3) administration in subjects in remission and controls.

Main Results:

• Significantly higher sIL-2R levels were observed in untreated Graves' disease and Hashimoto's thyroiditis patients compared to controls.
• sIL-2R levels correlated positively with thyroxine levels in untreated Graves' disease.
• No correlation was found between sIL-2R and specific thyroid autoantibodies or TSH-inhibitory immunoglobulins.
• T3 administration led to a significant increase in sIL-2R levels.
• Elevated sIL-2R levels were also found in patients with toxic multinodular goitre.

Conclusions:

• Serum sIL-2R levels are elevated in various thyroidal conditions associated with increased thyroid hormone levels.
• The findings suggest that thyroid hormone status, in addition to immunological factors, influences sIL-2R levels.
• sIL-2R may serve as a marker reflecting both immune activation and thyroid hormone levels in thyroid diseases.