Khoo D H, Eng P H, Ho S C, Fok A C
Thyroid Unit, Department of Endocrinology, Singapore General Hospital, Singapore.
Clin Endocrinol (Oxf). 1999 Jul;51(1):73-9. doi: 10.1046/j.1365-2265.1999.00740.x.
The aims were to study the prevalence of TSH binding inhibitor immunoglobulins (TBII) in newly diagnosed patients with autoimmune hypo-thyroidism, to determine if clinical and biochemical parameters in these patients differed, and to study the course of these antibodies after 12 months of L-thyroxine (LT4) therapy.
In a prospective study, 111 consecutive patients with newly diagnosed auto-immune hypothyroidism were enrolled. Patients were divided into groups according to the presence or absence of a goitre and TBII levels. Clinical and biochemical differences in these patients were analysed. Patients were then treated with L-thyroxine (LT4) for 12 months and changes in their TBII monitored.
Free T4 and TSH levels were measured at baseline and then 6-weekly during the titration of LT4 doses. Once TSH levels had normalized, these measurements were performed 3 monthly. TBII levels were measured in patients at baseline and 12 months. Thyroid stimulating blocking antibody (TSBAb) levels were measured 12-18 months after initiation of LT4 therapy.
Twenty patients were TBII-positive, 10 goitrous and 10 agoitrous. Agoitrous TBII-positive patients were found to have similar characteristics: these included TBII levels > 100 U/l, potent thyroid stimulating blocking antibody (TSBAb) activity and a tendency for TBII levels to remain unchanged or to rise after LT4 therapy. The degree of hypothyroidism seen in these cases was significantly greater than in all other groups. In contrast, goitrous TBII-positive patients were heterogenous, most did not have significant TSBAb activity and TBII disappeared in 5 out of 10 cases after a year of LT4 treatment. While TBII disappeared in 6 of the 20 patients after a year, remission of hypothyroidism occurred in only 3 cases.
The degree of hypothyroidism in agoitrous TSH-binding inhibitor immunoglobulins-positive patients appears to be more severe than that seen in other forms of AIT. The differences in thyroid stimulating blocking antiboby activity and response to LT4 therapy in agoitrous and goitrous autoimmune thyroiditis suggest that the TSH-binding inhibitor immunoglobulins in these patients are fundamentally different. The disappearance of TSH-binding inhibitor immunoglobulins in hypothyroid patients was not accompanied by the reversal of hypothyroidism in 50% of patients.
本研究旨在探讨新诊断的自身免疫性甲状腺功能减退症患者中促甲状腺激素结合抑制性免疫球蛋白（TBII）的患病率，确定这些患者的临床和生化参数是否存在差异，并研究左甲状腺素（LT4）治疗12个月后这些抗体的变化情况。
在一项前瞻性研究中，纳入了111例新诊断的自身免疫性甲状腺功能减退症患者。根据是否存在甲状腺肿及TBII水平将患者分组。分析这些患者的临床和生化差异。然后患者接受左甲状腺素（LT4）治疗12个月，并监测其TBII的变化。
在基线时测量游离T4和TSH水平，在LT4剂量滴定期间每6周测量一次。一旦TSH水平恢复正常，每3个月进行一次测量。在基线和12个月时测量患者的TBII水平。在LT4治疗开始后12 - 18个月测量甲状腺刺激阻断抗体（TSBAb）水平。
20例患者TBII阳性，其中10例有甲状腺肿，10例无甲状腺肿。无甲状腺肿的TBII阳性患者具有相似的特征：包括TBII水平>100 U/l、强效甲状腺刺激阻断抗体（TSBAb）活性以及LT4治疗后TBII水平倾向于保持不变或升高。这些病例中甲状腺功能减退的程度明显大于所有其他组。相比之下，有甲状腺肿的TBII阳性患者具有异质性，大多数没有显著的TSBAb活性，10例中有5例在LT4治疗一年后TBII消失。虽然20例患者中有6例在一年后TBII消失，但只有3例甲状腺功能减退症得到缓解。
无甲状腺肿的促甲状腺激素结合抑制性免疫球蛋白阳性患者的甲状腺功能减退程度似乎比其他形式的自身免疫性甲状腺炎更严重。无甲状腺肿和有甲状腺肿的自身免疫性甲状腺炎在甲状腺刺激阻断抗体活性和对LT4治疗反应方面的差异表明，这些患者中的促甲状腺激素结合抑制性免疫球蛋白存在根本差异。甲状腺功能减退患者中促甲状腺激素结合抑制性免疫球蛋白的消失并未伴随50%患者甲状腺功能减退的逆转。
