Abstract：
BACKGROUND: Clinical course and need for long-term L-thyroxine (LT4) therapy of congenital hypothyroidism (CH) with gland in situ (GIS) remain unclear.
OBJECTIVE: To describe the clinical history of CH with GIS and evaluate the proportion of patients who can suspend therapy during follow-up.
METHODS: Retrospective evaluation of patients followed at referral regional center for CH of Pisa.
METHODS: 77 patients with confirmed primary CH and GIS after positive neonatal screening were included. All children started LT4 at CH confirm.
METHODS: At 3 years of age, 55 children underwent a clinical re-evaluation after withdrawal of therapy with hormonal examinations, imaging of the thyroid gland with ultrasonography and 123-iodine with perchlorate discharge test. Subsequent periodic controls of thyroid function were executed and, when possible, a new attempt to stop LT4 was performed. Adequate follow-up data (at least 6 months after treatment suspension trial) were available for 49 patients.
RESULTS: Among the 55 patients who were reassessed, 18 (32.7%) were euthyroid. Considering subsequent follow-up, 49% of patients were no longer treated and 51% were taking therapy. No differences in neonatal parameters were observed between the two groups; LT4 dose before the last trial off medication was higher in permanent CH (p 0.016).
CONCLUSIONS: Monitoring of thyroid function in children with CH and GIS is necessary to evaluate the need for substitution and avoid overtreatment. Even if therapy can be suspended, patients need to be monitored because apparently normal thyroid function may decline several months after withdrawal of LT4.
OBJECTIVE: To describe the clinical history of CH with GIS and evaluate the proportion of patients who can suspend therapy during follow-up.
METHODS: Retrospective evaluation of patients followed at referral regional center for CH of Pisa.
METHODS: 77 patients with confirmed primary CH and GIS after positive neonatal screening were included. All children started LT4 at CH confirm.
METHODS: At 3 years of age, 55 children underwent a clinical re-evaluation after withdrawal of therapy with hormonal examinations, imaging of the thyroid gland with ultrasonography and 123-iodine with perchlorate discharge test. Subsequent periodic controls of thyroid function were executed and, when possible, a new attempt to stop LT4 was performed. Adequate follow-up data (at least 6 months after treatment suspension trial) were available for 49 patients.
RESULTS: Among the 55 patients who were reassessed, 18 (32.7%) were euthyroid. Considering subsequent follow-up, 49% of patients were no longer treated and 51% were taking therapy. No differences in neonatal parameters were observed between the two groups; LT4 dose before the last trial off medication was higher in permanent CH (p 0.016).
CONCLUSIONS: Monitoring of thyroid function in children with CH and GIS is necessary to evaluate the need for substitution and avoid overtreatment. Even if therapy can be suspended, patients need to be monitored because apparently normal thyroid function may decline several months after withdrawal of LT4.
摘要：
背景：先天性甲状腺功能减退症（CH）伴原位腺体（GIS）的长期L-甲状腺素（LT4）治疗的临床过程和需求仍不清楚。
目的：使用GIS描述CH的临床病史，并评估在随访期间可以暂停治疗的患者比例。
方法：回顾性评估在比萨地区CH转诊中心随访的患者。
方法：77例新生儿筛查阳性后确诊为原发性CH和GIS的患者。所有儿童在CH开始LT4确认。
方法：3岁时，55名儿童在停止激素检查治疗后接受了临床重新评估，超声检查甲状腺成像和高氯酸盐放电试验123碘。随后对甲状腺功能进行定期控制，如果可能,再次尝试停止LT4.49例患者获得了足够的随访数据（治疗暂停试验后至少6个月）。
结果：在重新评估的55名患者中，18例（32.7%）甲状腺功能正常。考虑到随后的后续行动，49%的患者不再接受治疗，51%的患者正在接受治疗。两组之间未观察到新生儿参数的差异；在永久性CH中，末次试验停药前的LT4剂量较高（p0.016）。
结论：监测CH和GIS患儿的甲状腺功能对于评估替代的需要和避免过度治疗是必要的。即使可以暂停治疗，患者需要接受监测,因为明显正常的甲状腺功能可能在停药LT4后几个月下降.
目的：使用GIS描述CH的临床病史，并评估在随访期间可以暂停治疗的患者比例。
方法：回顾性评估在比萨地区CH转诊中心随访的患者。
方法：77例新生儿筛查阳性后确诊为原发性CH和GIS的患者。所有儿童在CH开始LT4确认。
方法：3岁时，55名儿童在停止激素检查治疗后接受了临床重新评估，超声检查甲状腺成像和高氯酸盐放电试验123碘。随后对甲状腺功能进行定期控制，如果可能,再次尝试停止LT4.49例患者获得了足够的随访数据（治疗暂停试验后至少6个月）。
结果：在重新评估的55名患者中，18例（32.7%）甲状腺功能正常。考虑到随后的后续行动，49%的患者不再接受治疗，51%的患者正在接受治疗。两组之间未观察到新生儿参数的差异；在永久性CH中，末次试验停药前的LT4剂量较高（p0.016）。
结论：监测CH和GIS患儿的甲状腺功能对于评估替代的需要和避免过度治疗是必要的。即使可以暂停治疗，患者需要接受监测,因为明显正常的甲状腺功能可能在停药LT4后几个月下降.
