Selenium supplementation in thyroid associated ophthalmopathy: an update

·The therapeutic effect of selenium(Se)has already been proven in thyroid disease and thyroid associated ophthalmopathy(TAO).In spite of clear scientific proof of its benefits in TAO,there appears to be no clear agreement among the clinicians regarding its optimum dose,duration of the treatment,efficacy and safety to date.In this review,the author summarises the findings of 135 English language articles published on this subject over the past four decades from 1973 to 2013.The regulation and metabolism of thyroid hormones require a steady supply of Se and recent studies have revealed several possible mechanisms by which Se improves the severity of thyroid disease and TAO.These mechanisms include 1)inhibitory effect of HLA-DR molecule expression on thyrocytes;2)profound reductions of thyroid stimulating hormone(TSH)receptor antibodies(TSHR-Ab)and TPO antibodies(TPO-Ab);3)prevention of dysregulation of cell-mediated immunity and B cell function;4)neutralising reactive oxygen species(ROS)and inhibition of redox control processes required for the activation,differentiation and action of lymphocytes,macrophages,neutrophils,natural killer cells involved in both acute and chronic orbital inflammation in TAO;5)inhibition of expression of proinflammatory cytokines and 6)inhibition of prostaglandin and leukotriene synthesis.An increased oxidative stress has been observed in both acute and chronic phases of thyroid disease with raised tissue concentrations of ROS.The benefits of Se supplementation in individuals with TAO appear to be proportionate to the degree of systemic activity of the thyroid disease.The maximal benefit of Se supplementation is therefore seen in thesubjects who are hyperthyroid.Restoration of euthyroidism is one of the main goals in the management of TAO and when anti-thyroid drugs are combined with Se,the patients with Graves’disease(GD)and autoimmune thyroiditis(AIT)achieved euthyroidism faster than those treated with anti-thyroid drugs alone.Se status of normal adult humans can vary widely and Se supplementation may confer benefit only if serum Se levels are insufficient.The author recommends that serum Se levels of patients with TAO to be assessed prior to and during Se supplementation at regular intervals to avoid potential iatrogenic chronic Se overdose.

Biomarker identification of thyroid associated ophthalmopathy using microarray data

AIM： To uncover the underlying pathogenesis of thyroid associated ophthalmopathy（TAO） and explore potential biomarkers of this disease.METHODS： The expression profile GSE9340, which was downloaded from Gene Expression Omnibus database, included 18 specimens from 10 TAO patients and 8 hyperthyroidism patients without ophthalmopathy. The platform was HumanRef-8 v2 Expression BeadChip. Raw data were normalized using preprocess. Core package and the differentially expressed genes（DEGs） were identified based on t-test with limma package of R. Functional enrichment analyses were performed recruiting the DAVID tool. Based on STRING database, a protein-protein interaction（PPI） network was constructed, from which a module was extracted. The functional enrichment for genes in the module was performed by the BinGO plugin.RESULTS： In total, 861 DEGs（433 up-regulated and 428 down-regulated） between TAO patients and hyperthyroidism patients without ophthalmopathy were identified. Crucial nodes in the PPI network included TPX2, CDCA5, PRC1, KIF23 and MKI67, which were also remarkable in the module and all enriched in cell cycle process. Additionally, MKI67 was highly correlated with TAO. Besides, the DEGs of GTF2 F1, SMC3, USF1 and ZNF263 were predicted as transcription factors（TFs）. CONCLUSION： Several crucial genes are identified such as TPX2, CDCA5, PRC1 and KIF23, which all might play significant roles in TAO via the regulation of cell cycle process. Regulatory relationships between TPX2 and CDCA5 as well as between PRC1 and KIF23 may exist.Additionally, MKI67 may be a potent biomarker of TAO, and SMC3 and ZNF263 may exert their roles as TFs in TAO progression.

Unilateral Periorbital Oedema with Hypothyroidism and Multinodular Goiter

Thyroid associated ophthalmopathy is an autoimmune disorder which involves orbital and periorbital tissue. The immune-mediated inflammation of the orbital tissues can involve extraocular muscles, orbital connective tissue or orbital fat and periocular soft tissues. Bilateral involvement of thyroid associated orbitopathy is usually asymmetric, but unilateral thyroid associated orbitopathy has been less reported. Periorbital oedema as the only sign with hypothyroidism is uncommon and if present, it is more frequent bilaterally present and no cases are evidenced as unilateral. Pitting oedema in hypothyroidism is rare and can be due to increased capillary permeability, decreased adrenergic tone and increase in serotonin metabolism. Unilateral periorbital and eyelid oedema can associate with various clinical entities, multidisciplinary team is necessary to exclude the concomitant disease, so the patient can immediately be treated with proper therapy. We represent the case of unusually unilateral recurrent periorbital oedema in the period of time for 3 years with stabilized primary hypothyroidism and multinodular goitre.