Autoimmune thyroid disease-is high prolactin a risk factor?

Area of Science:

• Endocrinology
• Immunology
• Reproductive Medicine

Background:

• Prolactin (PRL) is known for lactation but also exhibits non-classic immune system effects.
• Hyperprolactinemia (HPRL) is a condition characterized by elevated PRL levels.
• Autoimmune thyroid disease (AITD) involves the immune system attacking the thyroid gland.

Purpose of the Study:

• To compare the prevalence of AITD, thyroid autoantibodies, and thyroid function tests (TFTs) in patients with HPRL versus healthy controls.
• To investigate the relationship between PRL levels and thyroid-related markers.

Main Methods:

• Retrospective case-control study at a single tertiary referral center.
• Measurement of anti-thyroglobulin (anti-Tg), anti-thyroid peroxidase (anti-TPO), TSH, and free T4 (fT4) levels.
• Ultrasonographic thyroid pattern assessment in patients with PRL ≥ 25 ng/ml and controls with PRL < 25 ng/ml.

Main Results:

• AITD prevalence was significantly higher in the HPRL group (33.5%) compared to controls (23.5%).
• Patients with HPRL showed significantly higher anti-TPO, anti-Tg, and TSH levels, and lower fT4 levels.
• A positive correlation was observed between PRL and TSH, anti-Tg, anti-TPO, and a negative correlation with fT4. ROC analysis indicated a PRL cut-off of 21.92 ng/mL for detecting thyroid autoantibodies.

Conclusions:

• HPRL is associated with an increased frequency of AITD and thyroid autoantibodies.
• Elevated PRL levels above a certain threshold appear to elevate the risk of thyroid autoimmunity.