ABSTRACT
Purpose: Antibodies against collagen XIII have previously been identified in patients with active thyroid-associated ophthalmopathy (TAO). Although collagen XIII expression has been described in extraocular muscles and orbital fat, its detailed localization in extraocular and thyroid tissues and the connection to autoimmunity for collagen XIII remain unclear. Our objective was to map the potential targets for these antibodies in the tissues of the orbit and thyroid. Methods: We evaluated the expression of collagen XIII in human patient and mouse orbital and thyroid tissues with immunostainings and RT-qPCR using Col13a1-/- mice as negative controls. COL13A1 expression in Graves' disease and goiter thyroid samples was compared with TGF-ß1 and TNF, and these were also studied in human thyroid epithelial cells and fibroblasts. Results: Collagen XIII expression was found in the neuromuscular and myotendinous junctions of extraocular muscles, blood vessels of orbital connective tissue and fat and the thyroid, and in the thyroid epithelium. Thyroid expression was also seen in germinal centers in Graves' disease and in neoplastic epithelium. The expression of COL13A1 in goiter samples correlated with levels of TGF-B1. Upregulation of COL13A1 was reproduced in thyroid epithelial cells treated with TGF-ß1. Conclusions: We mapped the expression of collagen XIII to various locations in the orbit, demonstrated its expression in the pathologies of the Graves' disease thyroid and confirmed the relationship between collagen XIII and TGF-ß1. Altogether, these data add to our understanding of the targets of anti-collagen XIII autoantibodies in TAO.
Subject(s)
Goiter , Graves Disease , Graves Ophthalmopathy , Humans , Animals , Mice , Graves Ophthalmopathy/genetics , Orbit , Transforming Growth Factor beta1 , Collagen , AntibodiesABSTRACT
The knowledge of parathyroid and thyroid anatomy helps a surgeon to localize important details and lessen complications, especially laryngeal palsy and hypoparathyroidism. The ligament of Berry and tuberculum Zuckerkandl cover the recurrent laryngeal nerve in the upper part of the thyroid lobes. The recurrent laryngeal nerve or its branches are exposed during the mobilization of these structures during total thyreoidectomy. The upper parathyroid gland can be found on the upper part of the tuberculum Zuckerkandl behind the recurrent laryngeal nerve, whereas the lower parathyroid gland can be found in front of the nerve on the under surface of the thyroid lobe or in the thymus below. The tertiary branches of blood vessels are cut preserving the function of the parathyroid glands. If the parathyroid has lost its blood circulation, it is made into pieces and transplanted into the pockets of sternocleidomastoideus muscle. Exposing the recurrent laryngeal nerve during operation seems to decrease permanent recurrent laryngeal nerve injury. The role of neuromonitoring is during parathyroid and thyroid surgery still controversial.
