Zhu Lin, Bai Xue, Teng Wei-ping, Shan Zhong-yan, Wang Wei-wei, Fan Chen-ling, Wang Hong, Zhang Hong-mei
Department of Endocrinology, First Affiliated Hospital of China Medical University, Shenyang, China.
Zhonghua Yi Xue Za Zhi. 2012 Aug 28;92(32):2256-60.
To evaluate the effects of selenium (Se) supplementation on concentrations of thyroid peroxidase antibodies (TPOAb) and TPOAb IgG subclasses in autoimmune thyroiditis (AIT) patients with different thyroid functional status.
A blind and placebo-controlled prospective study was performed for a total of 134 cases with AIT and thyroid peroxidase antibodies above 300 U/ml. Their mean age was 41 years (range: 15-70). All of them were recruited from Department of Endocrinology, First Affiliated Hospital of China Medical University from June 2008 to June 2009 and divided into 2 groups according to thyroid function: euthyroidism or subclinical hypothyroidism (n = 89) and hypothyroidism (n = 45). Then they were randomized into 2 groups: selenium-treated and placebo-treated. And 49 cases in subclinical autoimmune thyroiditis group and 28 cases in hypothyroidism group received 200 µg oral selenium yeast daily for 6 months while others placebo. Serum concentrations of TPOAb, TPOAb IgG subclasses, thyroid-stimulating hormone (TSH), free thyroxine (FT(4)) and Se were measured at baseline and after 3 and 6 months of follow-up.
The TPOAb levels showed an overall decrease of 4.3% at 3 months and of 12.6% at 6 months (both P < 0.05) post-supplementation in subclinical autoimmune thyroiditis patients. In overt hypothyroidism patients, the overall decrease of TPOAb concentrations was 21.9% at 3 months and 20.4% at 6 months (both P < 0.05) compared with those at pre-treatment. The predominant TPOAb IgG subclasses in sera from the AIT patients were IgG1, IgG3 and IgG4 and the positive percentages 72%, 41% and 72% respectively. The positive rate and concentrations of IgG3 in the patients with hypothyroidism were significantly higher than those of subclinical autoimmune thyroiditis (P < 0.05). Significant decreases in IgG1 and IgG3 levels were noted in subclinical autoimmune thyroiditis group at 6 months post-supplementation (P < 0.05). IgG1 levels in overt hypothyroidism decreased significantly compared with those at pre-supplementation (P < 0.05). In all patients with supplementation (n = 77), the TPOAb levels decreased in 52 at 6 months while increase or no change occurred in 25. The positive percentage and concentrations of IgG1 in patients whose TPOAb levels decreased at 6 months post-supplementation were markedly higher than those whose TPOAb levels increased (P < 0.05).
Se is effective in reducing TPOAb concentrations and the predominant decreasing TPOAb IgG subclasses are IgG1 and IgG3. And a high level of IgG1 subclass may explain the difficult decline of TPOAb.
评估补充硒（Se）对不同甲状腺功能状态的自身免疫性甲状腺炎（AIT）患者甲状腺过氧化物酶抗体（TPOAb）及TPOAb IgG亚类浓度的影响。
对134例AIT且甲状腺过氧化物酶抗体高于300 U/ml的患者进行一项盲法、安慰剂对照的前瞻性研究。他们的平均年龄为41岁（范围：15 - 70岁）。所有患者均于2008年6月至2009年6月从中国医科大学附属第一医院内分泌科招募，并根据甲状腺功能分为2组：甲状腺功能正常或亚临床甲状腺功能减退组（n = 89）和甲状腺功能减退组（n = 45）。然后将他们随机分为2组：硒治疗组和安慰剂治疗组。亚临床自身免疫性甲状腺炎组49例和甲状腺功能减退组28例患者每日口服200 μg硒酵母，持续6个月，其余患者服用安慰剂。在基线以及随访3个月和6个月后测定血清TPOAb、TPOAb IgG亚类、促甲状腺激素（TSH）、游离甲状腺素（FT4）和硒的浓度。
亚临床自身免疫性甲状腺炎患者补充硒后3个月时TPOAb水平总体下降4.3%，6个月时下降12.6%（均P < 0.05）。在显性甲状腺功能减退患者中，与治疗前相比，TPOAb浓度3个月时总体下降21.9%，6个月时下降20.4%（均P < 0.05）。AIT患者血清中主要的TPOAb IgG亚类为IgG1、IgG3和IgG4，阳性率分别为72%、41%和72%。甲状腺功能减退患者中IgG3的阳性率和浓度显著高于亚临床自身免疫性甲状腺炎患者（P < 0.05）。补充硒6个月后，亚临床自身免疫性甲状腺炎组IgG1和IgG3水平显著下降（P < 0.05）。显性甲状腺功能减退患者的IgG1水平与补充硒前相比显著下降（P < 0.05）。在所有补充硒的患者（n = 77）中，6个月时52例患者的TPOAb水平下降，25例患者升高或无变化。补充硒6个月后TPOAb水平下降的患者中IgG1的阳性率和浓度显著高于TPOAb水平升高的患者（P < 0.05）。
硒可有效降低TPOAb浓度，主要降低的TPOAb IgG亚类为IgG1和IgG3。高水平的IgG1亚类可能解释了TPOAb难以下降的原因。
