Thyroid function in pediatric patients with juvenile idiopathic arthritis

Abstract

Purpose: Juvenile Idiopathic Arthritis (JIA) is a chronic inflammatory disease characterized by chronic synovitis, sometimes associated with fever, rash, pericarditis and uveitis. Limited data are available concerning autoimmune diseases associated with JIA in childhood.

The aims of our study were: (a) evaluating the thyroid function in a group of Italian children affected by JIA; (b) identifying which Autoimmune Thyroid Diseases (ATDs) are related to JIA in this population.

Methods: A population of 51 patients with JIA was investigated. Each patient enrolled was evaluated clinically (family history for Autoimmune Diseases (ADs), personal history and physical examination). In the sample were evaluated thyroid function, inflammation's index and anti-thyroid antibodies.

Results: The 68.6% (35) of our patients had the oligoarticular form, 27.5% (14) had the polyarticular one, 2% (1) had systemic onset and 2% (1) had undifferentiated arthritis. We focused our attention on the differences between the first two forms. We did not find any difference on the gender prevalence (p > 0.05). A higher presence of anti-TPO antibodies was found in the polyarticular form, with a significant difference with the oligoarticular one (p = 0.032). We researched the anti-hTG antibodies (p > 0.05) and ANA for each group (p > 0.05). We found a significant prevalence of family history for ADs in the polyarticular form (p < 0.05).

Conclusion: Our findings show the necessity to focus on thyroid function in patients with JIA. Although the oligoarticular form is the most frequent, the polyarticular form shows a higher frequency of thyroid function's alteration. This suggests the need for specific attention in polyarticular form.

Keywords: Autoimmune Thyroiditis; Autoimmune diseases; Autoimmunity; JIA; Thyroid function.