L-carnitine treatment in a seriously ill cancer patient with severe hyperthyroidism

The protective role of nutritional antioxidants against oxidative stress in thyroid disorders

An imbalance between pro-oxidative and antioxidative cellular mechanisms is oxidative stress (OxS) which may be systemic or organ-specific. Although OxS is a consequence of normal body and organ physiology, severely impaired oxidative homeostasis results in DNA hydroxylation, protein denaturation, lipid peroxidation, and apoptosis, ultimately compromising cells' function and viability. The thyroid gland is an organ that exhibits both oxidative and antioxidative processes. In terms of OxS severity, the thyroid gland's response could be physiological (i.e. hormone production and secretion) or pathological (i.e. development of diseases, such as goitre, thyroid cancer, or thyroiditis). Protective nutritional antioxidants may benefit defensive antioxidative systems in resolving pro-oxidative dominance and redox imbalance, preventing or delaying chronic thyroid diseases. This review provides information on nutritional antioxidants and their protective roles against impaired redox homeostasis in various thyroid pathologies. We also review novel findings related to the connection between the thyroid gland and gut microbiome and analyze the effects of probiotics with antioxidant properties on thyroid diseases.

The metabolomics approach revealed a distinctive metabolomics pattern associated with hyperthyroidism treatment

BACKGROUND

Hyperthyroidism is characterized by increased thyroid hormone production, which impacts various processes, including metabolism and energy expenditure. Yet, the underlying mechanism and subsequent influence of these changes are unknown. Metabolomics is a broad analytical method that enables qualitative and quantitative examination of metabolite level changes in biological systems in response to various stimuli, pathologies, or treatments.

OBJECTIVES

This study uses untargeted metabolomics to explore the potential pathways and metabolic patterns associated with hyperthyroidism treatment.

METHODS

The study consisted of 20 patients newly diagnosed with hyperthyroidism who were assessed at baseline and followed up after starting antithyroid treatment. Two blood samples were taken from each patient, pre (hyperthyroid state) and post-treatment (euthyroid state). Hyperthyroid and euthyroid states were identified based on thyroxine and thyroid-stimulating hormone levels. The metabolic alteration associated with antithyroid therapy was investigated using liquid chromatography- high-resolution mass spectrometry. The untargeted metabolomics data was analyzed using both univariate and multivariate analyses using MetaboAnalyst v5.0. The significant metabolic pattern was identified using the lab standard pipeline, which included molecular annotation in the Human Metabolome Database, LipidMap, LipidBlast, and METLIN. The identified metabolites were examined using pathway and network analyses and linked to cellular metabolism.

RESULTS

The results revealed a strong group separation between the pre- and post-hyperthyroidism treatment (Q2 = 0.573, R2 = 0.995), indicating significant differences in the plasma metabolome after treatment. Eighty-three mass ions were significantly dysregulated, of which 53 and 30 characteristics were up and down-regulated in the post-treatment compared to the pre-treatment group, respectively. The medium-chain acylcarnitines, octanoylcarnitine, and decanoylcarnitine, previously found to rise in hyperthyroid patients, were among the down-regulated metabolites, suggesting that their reduction could be a possible biomarker for monitoring euthyroid restoration. Kynurenine is a downregulated tryptophan metabolite, indicating that the enzyme kynurenine 3-hydroxylase, inhibited in hyperthyroidism, is back functioning. L-cystine, a cysteine dimer produced from cysteine oxidation, was among the down-regulated metabolites, and its accumulation is considered a sign of oxidative stress, which was reported to accompany hyperthyroidism; L-cystine levels dropped, this suggests that the plasma level of L-cystine can be used to monitor the progress of euthyroid state restoration.

CONCLUSION

The plasma metabolome of patients with hyperthyroidism before and after treatments revealed differences in the abundance of several small metabolites. Our findings add to our understanding of hyperthyroidism's altered metabolome and associated metabolic processes and shed light on acylcarnitines as a new biomarker for treatment monitoring in conjunction with thyroxine and thyroid-stimulating hormone.

Nutraceutical Supplements in the Thyroid Setting: Health Benefits beyond Basic Nutrition

In recent years, there has been a growing interest in nutraceuticals, which may be considered as an efficient, preventive, and therapeutic tool in facing different pathological conditions, including thyroid diseases. Although iodine remains the major nutrient required for the functioning of the thyroid gland, other dietary components play important roles in clinical thyroidology—these include selenium, l-carnitine, myo-inositol, melatonin, and resveratrol—some of which have antioxidant properties. The main concern regarding the appropriate and effective use of nutraceuticals in prevention and treatment is due to the lack of clinical data supporting their efficacy. Another limitation is the discrepancy between the concentration claimed by the label and the real concentration. This paper provides a detailed critical review on the health benefits, beyond basic nutrition, of some popular nutraceutical supplements, with a special focus on their effects on thyroid pathophysiology and aims to distinguish between the truths and myths surrounding the clinical use of such nutraceuticals.

The protective effect of myo-inositol on human thyrocytes

Patients affected by autoimmune thyroiditis reached positive effects on indices of thyroid autoimmunity and/or thyroidal function, after following a treatment with selenomethionine (Se) alone, or Se in combination with Myo-inositol (Myo-Ins). Our purpose was to investigate if Myo-Ins alone, or a combination of Se + Myo-Ins, is effective in protecting thyroid cells from the effects given by cytokines, or hydrogen peroxide (H₂O₂). We assessed the interferon (IFN)-γ-inducible protein 10 (IP-10/CXCL10) secretion by stimulating primary thyrocytes (obtained from Hashimoto's thyroiditis or from control patients) with cytokines in presence/absence of H₂O_2. Our results confirm: 1) the toxic effect of H₂O₂ in primary thyrocytes that leads to an increase of the apoptosis, to a decrease of the proliferation, and to a slight reduction of cytokines-induced CXCL10 secretion; 2) the secretion of CXCL10 chemokine induced by IFN-γ + tumor necrosis factor alpha (TNF)-α has been decreased by Myo + Ins, both in presence or absence of H₂O₂; 3) no effect has been shown by the treatment with Se. Therefore, a protective effect of Myo-Ins on thyroid cells has been suggested by our data, which exact mechanisms are at the basis of this effect need to be furtherly investigated.

Thyroid dysfunctions secondary to cancer immunotherapy

BACKGROUND

Immunotherapy is a firmly established pillar in the treatment of cancer, alongside the traditional approaches of surgery, radiotherapy, and chemotherapy. Like every treatment, also cancer immunotherapy causes a diverse spectrum of side effects, collectively referred to as immune-related adverse events.

OBJECTIVE

This review will examine the main forms of immunotherapy, the proposed mechanism(s) of action, and the incidence of thyroid dysfunctions.

METHODS

A comprehensive MEDLINE search was performed for articles published up to March 30, 2017.

RESULTS

Following the pioneering efforts with administration of cytokines such as IL-2 and IFN-g, which caused a broad spectrum of thyroid dysfunctions (ranging in incidence from 1 to 50%), current cancer immunotherapy strategies comprise immune checkpoint inhibitors, oncolytic viruses, adoptive T-cell transfer, and cancer vaccines. Oncolytic viruses, adoptive T-cell transfer, and cancer vaccines cause thyroid dysfunctions only rarely. In contrast, immune checkpoint blockers (such as anti-CTLA-4, anti-PD-1, anti-PD-L1) are associated with a high risk of thyroid autoimmunity. This risk is highest for anti-PD-1 and increases further when a combination of checkpoint inhibitors is used.

CONCLUSIONS

Cancer patients treated with monoclonal antibodies that block immune checkpoint inhibitors are at risk of developing thyroid dysfunctions. Their thyroid status should be assessed at baseline and periodically after initiation of the immunotherapy.