Evaluation of the structure, autoimmunity, and functions of the thyroid gland in familial Mediterranean fever patients

ABSTRACT Objective Familial Mediterranean fever (FMF) is an autosomal recessive autoinflammatory disorder that is frequently seen in the eastern Mediterranean region. The thyroid gland can be affected in FMF patients through autoimmunity or amyloidosis. Here, we aimed to evaluate the structure and functions of the thyroid gland in addition to possible autoimmunity in FMF patients. Subjects and methods The study was conducted by the Endocrinology and Metabolism and Internal Medicine Departments. Thirty FMF patients and 30 age and gender-matched healthy controls were enrolled in the study. Free thyroxin (fT4), free triiodothyronine (fT3), thyroid-stimulating hormone (TSH), and anti-thyroid peroxidase (anti-TPO) autoantibodies were investigated. Detailed thyroid grayscale and Doppler Ultrasonography examinations and shear-wave elastosonography (SWE) were performed in the patient and control groups. Results Anti-TPO was detected in 24% (n = 7) of the patients. On the grayscale US, mean thyroid volumes were similar between the FMF and the control groups (p > 0.05). By Doppler US, thyroid vascularity observed was detected in 10.3% (n = 3) of the patients. SWE revealed that the mean velocity value of right vs. left lobe in the patient group was 1.77 ± 0.45 m/s and 1.95 ± 0.51 m/s, respectively. Compared to the control group, the mean velocity values were significantly higher in the right (p = 0.004) and left (p = 0.01) lobes of the patient group. The mean stiffness value in the patient group was also significantly higher in the right and left lobes [10.13 ± 5.65 kPa (p = 0.005) and 12.24 ± 6.17 kPa (p = 0.02), respectively]. Conclusion Recognizing the complications of FMF early in the course of the disease is as important as the early diagnosis of the disorder. Based on this, thyroid functions and changes in its structure should be evaluated carefully for early diagnosis of a possible coexisting thyroid disorder. Arch Endocrinol Metab. 2020;64(1):66-70

摘要
目的 家族性地中海热（Familial Mediterranean fever, FMF）是一种常染色体隐性遗传性自身炎症性疾病，在地中海东部地区高发。FMF患者可通过自身免疫或淀粉样变累及甲状腺。本研究旨在评估FMF患者的甲状腺结构与功能，并探究其潜在的自身免疫异常。
对象与方法 本研究由内分泌与代谢科及内科开展。共纳入30例FMF患者，以及30例年龄、性别匹配的健康对照者。检测指标包括游离甲状腺素（free thyroxin, fT4）、游离三碘甲状腺原氨酸（free triiodothyronine, fT3）、促甲状腺激素（thyroid-stimulating hormone, TSH）与抗甲状腺过氧化物酶（anti-thyroid peroxidase, anti-TPO）自身抗体。对两组受试者均实施详细的甲状腺灰阶超声、多普勒超声检查，以及剪切波弹性成像（shear-wave elastosonography, SWE）。
结果 抗甲状腺过氧化物酶抗体在24%（n=7）的患者中呈阳性。灰阶超声结果显示，FMF患者组与对照组的甲状腺平均体积无显著统计学差异（p>0.05）。多普勒超声检测发现，10.3%（n=3）的患者存在甲状腺血管异常。剪切波弹性成像结果显示，患者组右侧甲状腺叶与左侧甲状腺叶的平均速度值分别为1.77±0.45 m/s与1.95±0.51 m/s。与对照组相比，患者组右侧（p=0.004）与左侧（p=0.01）甲状腺叶的平均速度值均显著升高。患者组右侧与左侧甲状腺叶的平均硬度值同样显著升高[分别为10.13±5.65 kPa（p=0.005）与12.24±6.17 kPa（p=0.02）]。
结论 在疾病进程中早期识别FMF的并发症，与该疾病的早期诊断同等重要。基于此，应仔细评估甲状腺功能及其结构变化，以早期诊断可能合并存在的甲状腺疾病。
Arch Endocrinol Metab. 2020;64(1):66-70