Dr. Sami Ulus Obstetrics and Gynecology, Children's Health and Disease Training and Research Hospital, Clinic of Pediatric Endocrinology, Ankara, Turkey.
J Paediatr Child Health. 2022 Aug;58(8):1431-1438. doi: 10.1111/jpc.16025. Epub 2022 Jun 10.
The incidence of congenital hypothyroidism (CH) has increased world-wide. Lowering cut-off in screening programs has led to an increase in the rate of transient CH. We aimed to evaluate the rates of permanent and transient CH in cases referred from the screening program and to investigate the clinical and laboratory factors which predict transient CH.
In 109 cases referred from the neonatal screening program to our hospital, from September 2015 to April 2018, 52 primarily diagnosed CH cases were prospectively evaluated. Regularly followed up, 44 CH cases were included in the study at the end of 3 years.
38.2 ± 1.31 weeks (w) and mean birthweight 3021.3 ± 389.6 gram (g) in the transient CH group; both were significantly lower compared to permanent CH cases with 39.06 ± 1.33 w and 3375.3 ± 425.3 g (P = 0.025, P = 0.007) respectively. Transient CH rate was found to be 50% (all hypoplastic) in the dysgenesis group and 73.3% in groups with normal and hyperplasic thyroid gland. While fT , thyroid-stimulating hormone, and thyroglobulin levels at diagnosis do not predict transient/permanent CH, levothyroxine (LT-4) dosage was significantly lower in the transient CH group in all years. The optimal cut-off value with highest sensitivity and specificity for LT-4 dosage as a predictive marker to differentiate transient CH from permanent CH was 2.27 μg/kg/day (P = 0.004; sensitivity: 71%, specificity: 83%) at 1st year, 1.85 μg /kg/day (P = 0.013; sensitivity: 66%, specificity: 72%) at 2nd year and 1.69 μg /kg/day at 3rd year (P < 0.0001; sensitivity: 90%, specificity: 83%).
Transient CH is more frequent than expected. Our results suggest that LT-4 requirement may be a good marker for predicting transient CH, while thyroid hormone levels at the time of diagnosis do not significantly predict permanent and transient CH. Therefore, infants with CH requiring LT-4 doses <2.27 μg/kg/day at 1st year, <1.85 μg /kg/day at 2nd year may be re-evaluated earlier to discriminate transient CH rather than at 3 years of age.
先天性甲状腺功能减退症（CH）的发病率在全球范围内有所增加。筛查项目中降低截止值导致一过性 CH 发生率增加。我们旨在评估从筛查项目中转诊的病例中永久性和一过性 CH 的发生率，并探讨预测一过性 CH 的临床和实验室因素。
2015 年 9 月至 2018 年 4 月，从新生儿筛查项目中，我们前瞻性评估了 109 例转诊至我院的病例，共 52 例初诊 CH 病例。经过定期随访，3 年后，44 例 CH 病例纳入研究。
在一过性 CH 组中，中位发病周龄为 38.2±1.31 周（w），平均出生体重为 3021.3±389.6 克（g）；与永久性 CH 组相比，均显著较低，后者分别为 39.06±1.33w 和 3375.3±425.3g（P=0.025，P=0.007）。在发育不良组中，一过性 CH 发生率为 50%（均为发育不全），在正常和增生性甲状腺组中，发生率为 73.3%。虽然在诊断时的游离 T₃、促甲状腺激素和甲状腺球蛋白水平不能预测永久性或一过性 CH，但在所有年份中，一过性 CH 组的左甲状腺素（LT-4）剂量均显著较低。LT-4 剂量作为预测标志物，区分永久性和一过性 CH 的最佳截断值为 2.27μg/kg/天时，具有最高的敏感性和特异性（P=0.004；敏感性：71%，特异性：83%），在第 1 年；1.85μg/kg/天时，具有最高的敏感性和特异性（P=0.013；敏感性：66%，特异性：72%），在第 2 年；1.69μg/kg/天时，具有最高的敏感性和特异性（P<0.0001；敏感性：90%，特异性：83%），在第 3 年。
一过性 CH 比预期更为常见。我们的结果表明，LT-4 需求可能是预测一过性 CH 的良好标志物，而诊断时的甲状腺激素水平并不能显著预测永久性和一过性 CH。因此，需要 LT-4 剂量<2.27μg/kg/天的婴儿，在第 1 年，<1.85μg/kg/天的婴儿，在第 2 年，可能需要更早地重新评估，以区分一过性 CH，而不是在 3 岁时。
