Autoimmune thyroid disease in ankylosing spondylitis.

Area of Science:

• Rheumatology
• Endocrinology
• Immunology

Background:

• Autoimmune thyroid disease (AITD) is linked to primary Sjögren's syndrome (SjS) and other autoimmune conditions.
• The association between AITD and ankylosing spondylitis (AS) requires further investigation.

Purpose of the Study:

• To determine the frequency of AITD in patients diagnosed with AS.
• To compare AITD prevalence in AS patients versus healthy controls.

Main Methods:

• Cross-sectional study involving 80 AS patients, 80 age/sex-matched healthy controls, and 62 primary SjS patients.
• Thyroid ultrasonography (USG), thyroid function tests, and thyroid autoantibodies were assessed.
• Hashimoto's thyroiditis (HT) diagnosed based on autoantibody positivity and clinical/USG findings.

Main Results:

• AS patients showed significantly higher frequencies of USG parenchymal heterogeneity (30% vs 11.3%), thyroid autoantibody positivity (13.8% vs 2.5%), and HT diagnosis (10% vs 1.3%) compared to controls.
• Subclinical hypothyroidism was rare among AS patients with HT.

Conclusions:

• The prevalence of autoimmune thyroid disease is significantly elevated in individuals with ankylosing spondylitis compared to the general population.
• Further prospective research is warranted to understand the clinical implications and long-term outcomes of this association.