D'Aurizio Federica, Biasotto Alessia, Cipri Claudia, Grimaldi Franco, Zucco Jessica, Marzinotto Stefania, Curcio Francesco, Benvenga Salvatore
Department of Laboratory Medicine, Institute of Clinical Pathology, University Hospital of Udine, Udine, Italy.
Department of Medicine, University of Udine, Udine, Italy.
Eur Thyroid J. 2022 May 24;11(3):e210088. doi: 10.1530/ETJ-21-0088.
Thyroid function tests (TFT) are extensively used in daily clinical practice. Here, we described a case of incongruent TFT both in a pregnant woman and in her newborn.
A 32-year-old woman, diagnosed with autoimmune thyroiditis during her first pregnancy, was monitored during her second gestation. At week 5 + 2 days, thyroid-stimulating hormone (TSH) and free thyroxine (FT4) values (Dimension VISTA 1500, Siemens Healthineers) were within normal limits. At week 19 + 5 days, TSH remained normal while FT4 increased approximately by three-fold. FT4 inconsistency was with both TSH and the clinical status since she continued to be clinically euthyroid. On the same serum sample, thyroid autoantibodies were negative. At week 25 + 4 days, the patient complained of palpitations and dyspnea, with tachycardia. Even though TSH was normal, high levels of both FT4 and free triiodothyronine (FT3) were interpreted as evidence of thyroid overactivity and methimazole was started. TFT of the pregnant woman continued to be monitored throughout gestation. Postpartum FT4 and FT3 gradually returned to normal. TFT, performed on the daughter's serum, 3 days after birth, showed the same inconsistency as her mother but without clinical signs of congenital hyperthyroidism. Based on the clinical and laboratory setting, the presence of circulating autoantibodies against T3 and T4 (THAb) was suspected and demonstrated by radioimmunoprecipitation.
Analytical interferences should be supposed when TFT do not fit with the clinical picture and despite their infrequency, THAb must also be considered. To our knowledge, this is the first case describing the passage of THAb to the newborn.
甲状腺功能检查（TFT）在日常临床实践中被广泛应用。在此，我们描述了一例孕妇及其新生儿甲状腺功能检查结果不一致的病例。
一名32岁女性，在首次怀孕时被诊断为自身免疫性甲状腺炎，第二次妊娠期间接受监测。在孕5 + 2天时，促甲状腺激素（TSH）和游离甲状腺素（FT4）值（西门子医疗的Dimension VISTA 1500检测系统）在正常范围内。在孕19 + 5天时，TSH仍正常，而FT4大约增加了三倍。FT4的这种变化与TSH以及临床状况不一致，因为她临床上仍处于甲状腺功能正常状态。同一血清样本的甲状腺自身抗体为阴性。在孕25 + 4天时，患者主诉心悸和呼吸困难，伴有心动过速。尽管TSH正常，但FT4和游离三碘甲状腺原氨酸（FT3）水平升高被解释为甲状腺功能亢进的证据，于是开始使用甲巯咪唑。整个孕期持续监测该孕妇的甲状腺功能检查。产后FT4和FT3逐渐恢复正常。在其女儿出生3天后采集的血清进行的甲状腺功能检查显示出与她母亲相同的不一致情况，但没有先天性甲状腺功能亢进的临床体征。基于临床和实验室检查结果，怀疑存在针对T3和T4的循环自身抗体（THAb），并通过放射免疫沉淀法得到证实。
当甲状腺功能检查结果与临床情况不符时，应考虑分析干扰因素，并且尽管罕见，但也必须考虑THAb。据我们所知，这是第一例描述THAb传递给新生儿的病例。
