Background/Purpose: The inflammation of thyroid arteries (ThA) is not commonly considered and investigated in giant cell arteritis (GCA). We aimed to estimate the frequency of ThA involvement as detected by Colour Doppler Sonography (CDS).

Methods: We conducted a prospective single center study between 1 October 2013 and 30 March 2018. The CDS of superior and inferior ThA was performed in all newly diagnosed, treatment naive GCA patients, in addition to the routinely evaluated temporal, facial, occipital and large supra-aortic arteries. The superior and inferior ThA were identified at their respective anatomical locations in close proximity to the thyroid gland and examined using the standard Doppler settings for temporal arteries. Arteries were evaluated in two planes for the highly specific halo sign. Laboratory thyroid function tests consisted of TSH, T3 and T4 measurements at the time of GCA diagnosis (prior to any steroid therapy). Characteristics of GCA cases with inflamed ThA were explored and compared to the GCA group without ThA involvement.

Results: During the 54 months we performed the CDS of the multiple arteries in 153 consecutive GCA patients (median age 75.2 (IQR 66.5–80.0) years, 63% female). We observed the halo sign on either superior or inferior ThA in 16 (10.5%) cases. All patients but one (15/16) with ThA involvement also had CDS signs of temporal artery involvement and 2/16 patients (12.5%) had CDS signs of large supra-aortic artery involvement.

Constitutional symptoms were reported significantly more often by the patients with ThA involvement (100% vs. 73%, p=0.013); specifically, fever was significantly more frequent (44% vs. 19%, p=0.047). No significant correlation was found between ThA involvement and other clinical or demographic characteristics, including headache, jaw claudication and visual disturbances.

Local symptoms consistent with thyroid gland pathology were reported by 4/16 patients (25%) with ThA involvement. Laboratory signs of thyroid dysfunction were found in 3/16 patients (19%) with ThA involvement (2 latent hyperthyroidism, 1 latent hypothyroidism); none of these patients had any previous history of thyroid disease.

Previous history of thyroid disease was noted in 19 (12%) out of all GCA patients (13 hypothyroidism, 1 hyperthyroidism, 2 euthyrotic goiter; 3 patients had thyroid surgery because of either goiter or suspected malignancy). Two of those patients also had CDS signs of ThA involvement, yet their thyroid function tests were normal at the time of GCA diagnosis.

Conclusion: In our incipient GCA cohort, a tenth of all patients had ultrasonographic signs of ThA involvement. GCA patients with ThA involvement had a higher prevalence of constitutional symptoms than those without ThA inflammation.

ACR Meeting Abstracts - https://acrabstracts.org/abstract/thyroid-artery-involvement-detected-by-colour-doppler-ultrasonography-in-an-incipient-single-centre-giant-cell-arteritis-cohort/