Tehran University Medical Journal

The presence of the antibodies against the main thyroid antigens, which include thyroid peroxidase (TPO) or microsomal antigen, thyroglobulin (Tg) as well as thyrotropin receptor or Thyroid Stimulating Hormone Receptor (TSH-R), is a hallmark and symbol of the autoimmune thyroid diseases (AITDs) as one of the most common autoimmune diseases (AD) around the world. The prevalence of the thyroid peroxidase antibodies (anti-TPO antibody) and the thyroglobulin antibodies (anti-Tg antibody) is considerably higher in patients suffering from Graves’ disease (GD) and Hashimoto's thyroiditis (HT, chronic autoimmune thyroiditis, autoimmune hypothyroidism). While the TSH receptor antibodies (TRAbs) are common in the patients suffering from GD, they are relatively rare and infrequent in HT patients. This fact may indicate that TRAbs are more specific than other antibodies. In fact, TRAbs as one of the most important autoantibodies against the different thyroid antigens, are a set of the heterogeneous group of antibodies that based on the function, fall into three categories, including TSHR-stimulating antibodies (TSAbs), TSHR-blocking antibodies (TBAbs), and the neutral antibodies (no effect on receptor). TSAbs and TBAbs result in overproduction and reduction of intracellular cAMP respectively. Therefore the induction of the relevant signaling pathways can be the cause of different clinical symptoms in the form of hyperthyroidism or hypothyroidism consecutively. The extra-thyroidal effects of TRAbs as the extra-thyroid GD manifestations, such as ophthalmopathy and dermopathy, often have an effect on the eyes as well as the skin with the relatively well-known immunological mechanisms of the antibodies functions. Hashimoto encephalopathy is an extra-thyroidal effects of anti-TPO that provokes the central nervous system. On the other hand, anti-TPO like anti-Tg can affect the reproductive organs of women and lead to infertility by an unknown mechanism. Moreover, the circulating antibodies against the thyroid antigens can also be detected in other autoimmune diseases such as rheumatoid arthritis (RA), type I diabetes (T1DM) and celiac disease (CD). In this review article, the most important types of thyroid autoantibodies, their essential immunological processes in AITD as well as the main and important clinical extra-thyroidal manifestations of them have been discussed and reviewed.

Background: Fine needle aspiration biopsy (FNAB) is usually used to distinguish the malignant and benign nodules. Applying a biopsy needle evokes a sense of fear and pain in the patients. Although some studies refute the usefulness of local anesthesia (LA) prior to fine needle aspiration biopsy, it is still debatable. This prospective cross-sectional study intended to evaluate the effect of LA prior to fine needle aspiration biopsy on pain and anxiety considering nodule size.
Methods: Amongst the patients who were referred to Shiraz Shahid Fagihi Hospital for Thyroid fine needle aspiration biopsy from August 2017 to January 2018, 114 patients participated in this study. LA was performed for 41 patients, and 73 underwent the thyroid nodule fine needle aspiration biopsy without LA. Patients' pain and anxiety were scored using the visual-analog-score and Spielberger anxiety scale. The nodules were categorized into five groups. Pain and anxiety of patients were compared considering their nodule sizes to assess the effects of LA in the reduction of pain and anxiety considering the nodule size.

Results: The patients undergoing LA had a mean age of 44.69 years old and average body mass index (BMI) of 26.7, the patients who performed thyroid nodule fine needle aspiration biopsy without LA had a mean age of 48.17 years old with an average BMI of 26.0. The patients with the maximum nodule size of<10 mm, experienced more pain during the fine needle aspiration biopsy without LA, but there was no significant difference between the S/T-anxiety of these patients. There was no significant difference between the pain and anxiety scores of the patients with larger nodules. Conclusion: The more pain experienced by the patients with the smallest nodules can be attributed to the need for more needle manipulation due to the small nodule size and less precision while piercing the needle into the nodule. Thus, it can be suggested that in patients with a small nodule size, less than 10mm, usage of LA prior to fine needle aspiration biopsy can reduce the pain significantly.