[Effects of selenium supplementation on antibodies of autoimmune thyroiditis].

Abstract

OBJECTIVE:

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.

METHODS:

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.

RESULTS:

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).

CONCLUSION:

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.

• Authors: Lin Zhu, Xue Bai, Wei-ping Teng, Zhong-yan Shan, Wei-wei Wang, Chen-ling Fan, Hong Wang, Hong-mei Zhang
• Journal: Zhonghua yi xue za zhi (Zhonghua Yi Xue Za Zhi) Vol. 92 Issue 32 Pg. 2256-60 (Aug 28 2012) ISSN: 0376-2491 [Print] China
• PMID: 23158484 (Publication Type: English Abstract, Journal Article, Randomized Controlled Trial, Research Support, U.S. Gov't, Non-P.H.S.)

Chemical References

• Autoantibodies
• Iodide Peroxidase
• Selenium

Topics

• Adolescent
• Adult
• Aged
• Autoantibodies (blood, classification)
• Double-Blind Method
• Humans
• Iodide Peroxidase (immunology)
• Middle Aged
• Selenium (therapeutic use)
• Thyroiditis, Autoimmune (blood, drug therapy)
• Young Adult