β型甲状腺激素抵抗综合征患者临床特点分析

Clinical Characteristics of Patients with Resistance to Thyroid Hormoneβ

背景β型甲状腺激素抵抗综合征(RTHβ)属于罕见内分泌疾病,临床极易误诊、误治。目的总结RTHβ患者的临床特点,为临床医师了解本病提供帮助。方法选取2013—2016年于中国医科大学附属第一医院内分泌与代谢病科诊断为RTHβ的患者6例。回顾性分析6例RTHβ患者的临床资料,包括性别、诊断年龄、发病年龄、家族史、主诉、心电图检查结果、甲状腺触诊结果、甲状腺超声检查结果、甲状腺核素静态显像结果、甲状腺功能指标〔游离三碘甲腺原氨酸(FT3)、游离甲状腺素(FT4)、促甲状腺激素(TSH)〕、促甲状腺素受体抗体(TRAb)、性激素结合蛋白(SHBG)、血清铁蛋白、脂代谢指标、骨代谢指标、骨密度、基因测序情况等。结果6例RTHβ患者的诊断年龄均高于发病年龄,患者在确诊RTHβ之前均被误诊为甲状腺功能亢进症,长期服用抗甲状腺药物治疗。患者主诉均存在心悸、多汗,3例伴心房颤动。6例患者甲状腺核素静态显像均显示甲状腺双叶摄取率增高。5例RTHβ患者甲状腺超声显示有甲状腺肿大,4例显示多发结节。6例RTHβ患者血清FT3、FT4水平升高,TSH水平在参考范围,且TRAb均为阴性;血清SHBG和血清铁蛋白均在参考范围;甲状腺激素受体(TR)β基因测序均存在点突变。结论RTHβ的临床表现存在高度异质性,临床诊断时需注意与甲状腺功能亢进症和甲状腺功能减退症区分,同时注意并非所有的RTHβ患者能检测出TRβ基因突变。对于高度怀疑为RTHβ的患者,可以采用促甲状腺素释放激素(TRH)兴奋试验、左旋-三碘甲腺原氨酸(L-T3)抑制试验或TRH兴奋试验联合L-T3抑制试验进行临床诊断。

Background Resistance to thyroid hormone β (RTHβ) is a rare endocrine disease that is easily misdiagnosed and mistreated clinically.Objective To summarize the clinical characteristics of patients with RTHβ,which will be helpful for clinicians to understand this disease.Methods We selected six patients diagnosed with RTHβ from Department of Endocrinology and Metabolism,the First Affiliated Hospital of China Medical University from 2013 to 2016.We retrospectively analyzed the clinical data of the patients,including gender,age of diagnosis,age of onset,family history,chief complaint,electrocardiogram,thyroid palpation observations,thyroid ultrasound,and static thyroid radionuclide imaging,quantification of thyroid function indicators 〔free triiodothyronine acid(FT3),free thyroxine(FT4),thyroid stimulating hormone(TSH)〕,thyrotropin receptor antibody(TRAb),sex hormone binding protein(SHBG),serum ferritin,lipid metabolism indices,bone metabolism indices,and bone density and gene sequences.Results The age of diagnosis was higher than the age of onset in all the patients.Before the diagnosis of RTHβ,the patients were misdiagnosed with hyperthyroidism and took antithyroid drugs for a long time.All patients complained of palpitations and hyperhidrosis,and three also had atrial fibrillation.Static thyroid radionuclide imaging showed an increase in the uptake rate of the thyroid double lobe in all six patients.Five patients showed thyroid enlargement on ultrasound,and four showed multiple nodules.All six patients showed elevated serum FT3 and FT4 levels,normal TSH,serum SHBG and ferritin levels,and were negative for TRAb.In gene sequencing,point mutations were observed in thyroid hormone receptor(TR) β in all patients.Conclusion The clinical manifestations of RTHβ are highly heterogeneous.Therefore,in clinical diagnosis,attention should be given to distinguish RTHβ from hyperthyroidism and hypothyroidism.It should be noted that not all RTHβ patients have TRβ gene mutations.For patients with high suspicion of RTHβ,the thyrotropin-releasing hormone stimulation test,L-triiodothyronine inhibition test,or the combination of these two tests can be used for diagnosis.