Incidence of iodine deficiency in patients presenting with goitre--discrepancy between clinical and ultrasonographic evaluation of the thyroid: comparison of patients with and without autoimmune thyroiditis--clinical, hormonal and urinary iodine excretion studies

Clinical, biochemical, and radiological follow-up results of children and adolescents with Hashimoto's thyroiditis: a single-center experience

OBJECTIVES

Hashimoto's thyroiditis (HT) is the most common cause of goiter and acquired hypothyroidism in children and adolescents, especially in areas without endemic iodine deficiency. We aimed to evaluate the follow-up results of children and adolescents diagnosed with HT, including clinical, biochemical, and radiological findings and treatment approaches.

METHODS

HT patients, who were diagnosed between 2012 and 2018 years in a single-center, were assessed retrospectively.

RESULTS

Two hundred and twenty-four cases were included in the study, 75.9% of whom were girls (female/male ratio: 3.1) and 66.5% were pubertal. The median age of the cases at first admission was 12.5 (9.2-15) years. The median follow-up period of 196 patients, who continued their follow-up regularly, was 2.1 (0.7-4.8) years. When autoantibody levels were analyzed according to gender, mean anti-Tg levels were higher in girls (p=0.028), whereas anti-TPO levels were similar (p=0.372). A nodule was detected in the ultrasonographic follow-up of 29 (13%) patients. Papillary thyroid carcinoma was observed in 10.3% (n=3) of those with nodules. When the last ultrasonography findings of 188 patients with available radiological follow-up data were compared with their initial evaluation, the rate of heterogeneous parenchymal echogenicity increased significantly (p=0.008). The need for l-thyroxine dosage augmented over time.

CONCLUSIONS

Although HT is more common in adolescent girls, it can be encountered in both genders and at all ages in childhood. The incidence of malignancy was not higher in patients with nodules associated with HT than the reported incidences of malignancy in nodules not associated with HT.

Enhanced iodine supplementation alters the immune process in a transgenic mouse model for autoimmune thyroiditis

BACKGROUND

The impact of excessive iodine intake on the development of autoimmune thyroiditis (AIT) is still under debate. Transgenic, antibody-devoid TAZ10 mice spontaneously develop AIT due to autoreactive thyroperoxidase-specific T cells. In this model, development of AIT is determined by a T cell infiltration of the thyroid gland leading to an elevation of serum thyrotropin (TSH) levels and significant weight gain. In the present study we investigated the impact of moderate and high iodine supplementation on the course of disease in these mice, which are immunologically prone to AIT.

METHODS

In addition to normal nutrition, mice were supplemented for 20 weeks with 2.5 μg versus 5 μg iodine per milliliter drinking water, which corresponds to a human daily iodine supplementation of 150 μg, 315 μg, and 615 μg iodine. AIT-defining parameters (weight gain, elevation of serum TSH levels, cellular infiltration of the thyroid) and immunologic effects were analyzed.

RESULTS

No significant differences were displayed when comparing weight and serum TSH levels in the iodine-supplemented versus control groups. Increased thyroid infiltrates with CD8⁺ T cells were detected by fluorescein-activated cell sorter (FACS) and immunofluorescence staining in mice supplemented with elevated iodine amounts (315 μg and 615 μg iodine per day, respectively). Immunologic monitoring revealed selective changes in immune cell frequencies (CD8⁺ and regulatory T cells, natural killer [NK] cells) and cytokine production (interferon-γ, interleukin-1α, and interleukin-17), however, without affecting the overall immune balance.

CONCLUSION

Our results demonstrate that elevated iodine supplementation has no physical impact on the course of disease in transgenic, antibody-devoid TAZ10 mice, which are immunologically prone to AIT.

The incidence and evolution of thyroid dysfunction during interferon-alpha therapy in children with chronic hepatitis B infection

AIM

To assess the effect of interferon-alpha (IFN-alpha) therapy on thyroid functions in children with chronic hepatitis B infection (CHB).

METHODS

Sixty-eight children (7.8 +/- 3.6 years) were treated with 5 (n = 37, group I) or 10 MU/m2 (n = 31, group II) IFN for 6 months. Thyroid hormones, thyrotropin, thyrotropin-releasing hormone stimulation test, thyroid peroxidase and thyroglobulin autoantibodies were evaluated.

RESULTS

Baseline features were not different in the two groups. After therapy, thyroid dysfunction was 27% and 41.9% in groups I and II (n.s.). Subclinical hypothyroidism was 17.9%/ 29%, subclinical hyperthyroidism 5.4%/12.9%, hypothyroidism 2.7%/-, and thyroid antibody positivity 2.7%/- in groups I and II (n.s.). Thyroid dysfunction was 33.8% in the whole group (p = 0.001). Predictors of IFN induced-thyroid dysfunction were female sex and age < 6 years. Thyroid dysfunction resolved within median 6 months in all but three children.

CONCLUSION

Although IFN-induced thyroid dysfunction is mostly subclinical and reversible, this side effect should be kept in mind.