Iodine, thymus, and immunity

Frontiers in immunology, 2017

Iodine is an essential element required for the function of all organ systems. Although the importance of iodine in thyroid hormone synthesis and reproduction is well known, its direct effects on the immune system are elusive. Human leukocytes expressed mRNA of iodide transporters (NIS and PENDRIN) and thyroid-related proteins [thyroglobulin (TG) and thyroid peroxidase (TPO)]. The mRNA levels of PENDRIN and TPO were increased whereas TG transcripts were decreased post leukocyte activation. Flow cytometric analysis revealed that both PENDRIN and NIS were expressed on the surface of leukocyte subsets with the highest expression occurring on monocytes and granulocytes. Treatment of leukocytes with sodium iodide (NaI) resulted in significant changes in immunity-related transcriptome with an emphasis on increased chemokine expression as probed with targeted RNASeq. Similarly, treatment of leukocytes with NaI or Lugol's iodine induced increased protein production of both pro- and anti...

Toxicology mechanisms and methods, 2018

Altered lymphocytic activity and its subset ratio found responsible for initiating abnormal autoimmune responses in mans and animals after excess iodine exposure. Study objective is to reveal excess iodine induced impairment of peripheral blood lymphocytes (PBL), its functional status, antioxidant balance, DNA damage, proliferation assay and serum cytokine levels (IL6 and TNF α)in adult male rats to understand the onset of autoimmune alterations if any indirectly that is unexplored. Experimental animals were grouped depending on doses of iodine (KI) treatment with moderately excess-7mg/kg bw (100EI) and excessively excess-35mg/kg bw (500EI)for 30 days to analyze IL6 and TNF α, haematological indices, oxidative stress, lymphocytic DNA damage and proliferation status. Significant impairment in superoxide dismutase, catalase, GPx activities including elevated NO, LPO in lymphocytes of treated group, with increased IL6 and TNF α level, lymphocyte proliferation and DNA damage depending o...

British Journal of Nutrition, 2011

Little information is available as to whether doses of iodide similar to those recommended in clinical practice for the prevention of iodine deficiency in pregnant women affect thyroid function. The aim of the present study was to analyse whether doses of iodide can affect thyroid function in adults, and evaluate its effect on plasma markers of oxidative stress, inflammation and acute-phase proteins. A total of thirty healthy volunteers (ten men and twenty women) with normal thyroid function were randomly assigned to three groups (n 10). Each group received a daily dose of 100, 200 or 300 μg of iodide in the form of KI for 6 months. Free tetraiodothyronine (FT4) levels at day 60 of the study were higher in the groups treated with 200 and 300 μg (P = 0·01), and correlated with the increase in urinary iodine (r 0·50, P = 0·007). This correlation lost its significance after adjustment for the baseline FT4. The baseline urinary iodine and FT4 correlated positively with the baseline glut...

Autoimmunity Reviews, 2002

Like most autoimmune diseases of humans, chronic lymphocytic (Hashimoto's) thyroiditis results from the combination of a genetic predisposition and an environmental trigger. A body of clinical and epidemiologic evidence points to excessive ingestion of iodine as an environmental agent. In genetically determined thyroiditis in animals, iodine enrichment has been shown to increase the incidence and severity of disease. Its mechanism of action is still uncertain. Using a new animal model of autoimmune thyroiditis, the NOD.H2 mouse, we have h4 been able to show that iodine enhances disease in a dose-dependent manner. Immunochemical studies suggest that iodine incorporation in the thyroglobulin may augment the antigenicity of this molecule by increasing the affinity of its determinants for the T-cell receptor or the MHC-presenting molecule either altering antigen processing or by affecting antigen presentation. ᮊ

Critical Reviews in Food Science and Nutrition, 2020

Adequate iodine nutrition is crucial for all mammals by playing his starring role as a component of thyroid hormones, which are key regulators of cellular processes for life such as differentiation, growth, function, and metabolism. Deficiency or excess of iodine in the diet are worldwide highly frequent conditions that are responsible of health problems like hypothyroidism, hypothyroxinemia, goiter, thyroiditis, hyperthyroidism, and autoimmune thyroid diseases among others. The incorporation of iodine in salt or other nutrients resolved the consequences of severe iodine deficiency like goiter, cretinism. However, this strategy in several countries led to other ailments like Hashimoto autoimmune thyroiditis, hyperthyroidism, and hypothyroidism. The goal of this review is to analyze and discuss the different aspects of iodine nutrition for human health comprising its biological role through thyroid hormones, pathogen control, and the regulation of the intestinal microbiota.

Journal of Endocrinological Investigation, 1980

A 62-year-old female who had received prolonged iodine therapy for asthma presented with severe thyrotoxicosis and severe' asthma. Her history, elevated serum thyroxine and triiodothyronine, low 131 1 uptake, and elevated intrathyroidal iodine content by fluorescent scan were most consistent with a diagnosis of iodine-induced thyrotoxicosis (liTT). The clinical course 01 her thyrotoxicosis was protracted, and in spite of its etiologic role in the precipitation of thyrotoxicosis, iodine was therapeutically efficacious, although combined treatment with methimazole was required to ultimately restore euthyroidism. Therapy with lithium was also employed but appeared to be only transiently effective and contributed no additional decrement in serum T than that seen with iodine alone. The case exemplifies the heterogeneity of what is considered"iodine-induced" thyrotoxicosis, the complexities inherent in establishing a diagnosis of liTT, and the usa of other rapid acting pharmacologic agents in liTT when ß blockade is contraindicated by asthma. 1 The opinions or assertions contained herein are the private views of the authors and are not to be construed as ollicial or reflecting the views of the Departmenl of the Army or the Depertment of Defense.

The Journal of clinical endocrinology and metabolism, 2016

An inverse relationship between thyroglobulin (Tg) and urinary iodine concentration (UIC) has been found in children potentially making Tg a viable blood marker of iodine status. The application of Tg in adults is unknown. To determine the efficacy of Tg to assess iodine status in adults. A randomized, double-blind, placebo-controlled, clinical trial. Dunedin, New Zealand. Mildly iodine deficient (n=112) adults aged 18-40 years. Participants were supplemented with 150 μ g of iodine as potassium iodate (KIO3) or placebo daily for 24 wk. At baseline and 24 wk, participants provided five casual urine samples for UIC determination; serum TSH and FT4 was also measured. Tg was determined at baseline and 8, 16 and 24 wk. A change in Tg concentration between the iodine-supplemented and placebo groups at 24 wk. At baseline, the overall median UIC was 65 μ g/L confirming that participants were mildly iodine deficient (i.e. median UIC between 50-99 μ g/L). The overall median Tg was 16.6 μ g/L;...

Nutrients

The thyroid gland requires iodine to synthesize thyroid hormones, and iodine deficiency results in the inadequate production of thyroxine and related thyroid, metabolic, developmental, and reproductive disorders. Iodine requirements are higher in infants, children, and during pregnancy and lactation than in adult men and non-pregnant women. Iodine is available in a wide range of foods and water and is susceptible to almost complete gastric and duodenal absorption as an iodide ion. A healthy diet usually provides a daily iodine consumption not exceeding 50% of the recommended intake. Iodine supplementation is usually necessary to prevent iodine deficiency disorders (IDDs), especially in endemic areas. The community-based strategy of iodine fortification in salt has eradicated IDDs, such as endemic goiter and cretinism, in countries providing adequate measures of iodine prophylaxis over several decades in the 20th century. Iodized salt is the cornerstone of iodine prophylaxis in endem...

Journal of Endocrinological Investigation, 1994

The aim of this study was to determine the incidence rate of thyrotoxicosis (TT) before and during dietary-iodine supplementation in an iodinesufficient area. Population: the study was carried out in Vigo, South Galicia (northwest of Spain), from January 1977 to December 1989. The mean population throughout the study period was 267,330 inhabitants (47% males and 53% females). From January 1985, a mandatory consumption of iodinized salt on the whole population started in Galicia. This region was considered as an iodine-deficient area but Vigo is an iodine-sufficient area. Measurements: all newly diagnosed TT cases in Vigo city within the study period were included in this study. Diagnosis of TT was based on the clinical manifestations, an elevated level of T4 and suppressed TSH values. The difference between diffuse and nodular forms of goiter was assessed by scintigraphy. The average in-1This work was supported by Grant FISss 89/127 from Spanish Ministry of Health and "Valgrande" Foundation.

IECN 2022

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