Nagafuji Motomichi, Hitaka Daisuke, Iwabuchi Atsushi, Miyazono Yayoi, Takada Hidetoshi
Department of Pediatrics, University of Tsukuba Hospital, Tsukuba, Ibaraki, Japan.
Department of Child Health, Faculty of Medicine, University of Tsukuba, Tsukuba, Ibaraki, Japan.
Am J Case Rep. 2021 Dec 21;22:e934417. doi: 10.12659/AJCR.934417.
BACKGROUND The interference of biotin administration with thyroid function tests has been reported; however, it remains unclear in clinical practice. In this report, we present the case of a neonate with a diagnosis of pontocerebellar hypoplasia type 6 (PCH6) treated with biotin who developed biotin interference with laboratory thyroid function tests. CASE REPORT A 1-day-old male infant with hypothermia, tachypnea, and lactic acidosis had a suspected diagnosis of mitochondrial disease. Biotin and several vitamins were administered to improve his condition. On day 14, his laboratory tests revealed a free triiodothyronine level of 4.7 pg/mL, free thyroxine level of 3.7 ng/dL, thyroid-stimulating hormone level of 0.07 μIU/mL, and thyroid-stimulating hormone receptor antibody (TRAb) level of 37.6 IU/L, suggesting Graves' disease. No goiter or tachycardia developed. The maternal thyroid function was not measured during pregnancy, while the maternal TRAb was negative on the same day. After methimazole administration, the patient's thyroid function normalized, and methimazole was therefore discontinued. All thyroid function tests were conducted using immunoassay methods with avidin and biotin. Later, reduced oxygen consumption under aerobic conditions in skin fibroblasts and compound heterozygous variants of the mitochondrial arginine tRNA synthetase gene were identified, and the patient was diagnosed with PCH6. CONCLUSIONS In this case, the clinical symptoms and physical findings were incompatible with the thyroid function. These laboratory findings could have mimicked Graves' disease due to the biotin interference with immunoassays. Therefore, caution is required when evaluating similar cases.
背景 已有报道称生物素的使用会干扰甲状腺功能测试；然而，在临床实践中仍不清楚。在本报告中，我们介绍了一例诊断为6型脑桥小脑发育不全（PCH6）的新生儿，其接受生物素治疗后出现了生物素对实验室甲状腺功能测试的干扰。病例报告 一名1日龄男婴，有体温过低、呼吸急促和乳酸酸中毒症状，疑似诊断为线粒体疾病。给予生物素和多种维生素以改善其病情。在第14天，他的实验室检查显示游离三碘甲状腺原氨酸水平为4.7 pg/mL，游离甲状腺素水平为3.7 ng/dL，促甲状腺激素水平为0.07 μIU/mL，促甲状腺激素受体抗体（TRAb）水平为37.6 IU/L，提示格雷夫斯病。未出现甲状腺肿大或心动过速。孕期未检测母亲的甲状腺功能，而母亲的TRAb在同一天为阴性。给予甲巯咪唑后，患者的甲状腺功能恢复正常，因此停用了甲巯咪唑。所有甲状腺功能测试均采用含抗生物素蛋白和生物素的免疫测定方法。后来，在皮肤成纤维细胞中发现有氧条件下氧气消耗减少以及线粒体精氨酸tRNA合成酶基因的复合杂合变异，该患者被诊断为PCH6。结论 在本病例中，临床症状和体征与甲状腺功能不相符。由于生物素对免疫测定的干扰，这些实验室检查结果可能会误诊为格雷夫斯病。因此，在评估类似病例时需要谨慎。
