Autoimmune Thyroid Disease

The Association of UCP2-866 G/A Genotype with Autoimmune Hypothyroidism in the Southwestern Saudi Arabia Population

Introduction

Autoimmune hypothyroidism (AHT) is a widespread disease that disproportionately affects women over men. It is characterized by the presence of autoantibodies that lead to the dysfunction of the thyroid gland. The exact cause of this process is unknown; however, some factors, such as genetic factors, may be to blame. The uncoupling protein 2 (UCP2) gene encodes uncoupling protein 2, which has been linked to several pathogeneses; however, the link between UCP2-866 G/A polymorphism and AHT has yet to be investigated. Thus, we investigate the potential relationship between UCP2-866 G/A polymorphism and AHT.

Methods

A total of 158 subjects participated in this study, they were either control or AHT patient, and genotyping was performed using a polymerase chain reaction.

Results

The frequencies of UCP2-866 G/G, G/A, and A/A in the control subject were 34%, 51%, and 15%, respectively, whereas these frequencies in the AHT were 43%, 46%, and 10%.

Conclusion

The study concludes a significant relationship between UCP2-866 G/A polymorphism and AHT, with a carrier subject of the -866 A allele being 3 times more likely to suffer from AHT than wild-type carriers in the study population.

Postpartum thyroiditis and autoimmune thyroiditis in women of childbearing age: recent insights and consequences for antenatal and postnatal care

Postpartum thyroiditis is a syndrome of transient or permanent thyroid dysfunction occurring in the first year after delivery and based on an autoimmune inflammation of the thyroid. The prevalence ranges from 5-7%. We discuss the role of antibodies (especially thyroid peroxidase antibodies), complement, activated T cells, and apoptosis in the outbreak of postpartum thyroiditis. Postpartum thyroiditis is conceptualized as an acute phase of autoimmune thyroid destruction in the context of an existing and ongoing process of thyroid autosensitization. From pregnancy an enhanced state of immune tolerance ensues. A rebound reaction to this pregnancy-associated immune suppression after delivery explains the aggravation of autoimmune syndromes in the puerperal period, e.g., the occurrence of clinically overt postpartum thyroiditis. Low thyroid reserve due to autoimmune thyroiditis is increasingly recognized as a serious health problem. 1) Thyroid autoimmunity increases the probability of spontaneous fetal loss. 2) Thyroid failure due to autoimmune thyroiditis-often mild and subclinical-can lead to permanent and significant impairment in neuropsychological performance of the offspring. 3) Evidence is emerging that as women age subclinical hypothyroidism-as a sequel of postpartum thyroiditis-predisposes them to cardiovascular disease. Hence, postpartum thyroiditis is no longer considered a mild and transient disorder. Screening is considered.

Relationship between psychotropic drugs and thyroid function: a review

Some widely used psychoactive drugs, such as tricyclic antidepressants and antipsychotic phenothiazines exhibit iatrogenic effects on the thyroid. These side effects may arise from interactions at different steps of thyroid hormone biosynthesis. These drugs can induce a change in iodine capture by thyroid cells or can complex iodine, making it unavailable for thyroid hormone synthesis and thus decreasing thyroid hormone blood levels; they can also inhibit thyroid peroxidase activity and thus T3 and T4 synthesis or enhance deiodination of T4 to T3 or to Rt3 by stimulation of deiodinase activity. Moreover, tricyclic antidepressants interfere with the hypothalamic-pituitary-thyroid axis via the noradrenergic or serotonergic systems and might therefore decrease T4 or T3 blood levels, respectively. Phenothiazines can induce autoimmune hypothyroidism, as shown by an increase in the expression of the major histocompatibility complex antigen and by a production of antithyroglobulin or antithyroperoxidase antibodies. However, all these mechanisms are only speculative in humans, as they have only been demonstrated in vitro or in animal experiments. Clinically, thyroid function and affective disorders are closely linked. On one hand, the therapeutic response to antidepressants could be influenced by the thyroid status; on the other hand, the larger the thyroxin decrease induced by antidepressants, the better the therapeutic effect might be. Moreover, cotreatment with thyroid hormones and antidepressant drugs could allow either a decrease in the rate of treatment failure or a faster recovery from depression. As antipsychotic or antidepressant treatments are administered over long periods in humans, their thyroid toxic effects must be taken seriously.