Anti-thyroid Antibodies in Bipolar Disorder

Abstract

Background: Dysfunction of the hypothalamus-pituitary-thyroid axis has been shown to play a role in the pathophysiology of bipolar disorder. Autoimmune thyroiditis is the most common cause of thyroid function alteration. Thus, auto-immune thyroiditis is likely associated with bipolar disorder. It might influence its course, prognosis and/or management. Objective: To study the prevalence of positive anti-thyroid antibodies in patients with bipolar disorder and to examine the prognostic and the therapeutic implications of their presence. Methods: Literature was reviewed using the Medline database and the following keywords: 'bipolar disorder" 'antithyroid antibodies" 'thyroiditis". Results: PubMed research returned 12 results. After manual inspection, 10 articles were retained and examined. The prevalence of positive antithyroperoxydase antibodies (anti-TPO Abs) is higher in bipolar patients than in healthy controls, reaching 27%. The presence of positive anti-TPO Abs has been associated with rapidcycling, with a higher risk of lithium-induced hypothyroidism as well as with poor prognosis. Auto-immune thyroiditis appears to be related not only to bipolar disorder itself but also to the genetic vulnerability to develop the disorder. Conclusion: The presence of anti-TPO Abs is a possible endophenotype for bipolar disorder. Anti-TPO Abs should be obtained in many patients with bipolar disorder, especially in those on lithium.

Quetiapine‐Induced Thyroid Dysfunction: A Systematic Review

“…46,47 These findings suggest that thyroid autoantibodies, especially anti-TPOs) could have potential utility as a biomarker for hypothyroidism in patients taking quetiapine and may even affect prognosis. 7 Another plausible mechanism for the decrease of thyroid hormones during quetiapine treatment is competitive metabolism of thyroid hormones and quetiapine by uridine 5 -diphosphoglucurosyltransferase. 33 Nonetheless, direct action of quetiapine on the hypothalamopituitary axis cannot also be excluded, although TSH levels have been reported to remain unaffected in context of decrease in thyroid hormones in some studies (Table 2).…”

“…These factors may include the nature of the mental illness, sex, age group, duration of treatment, positive antithyroperoxidase antibodies (anti-TPOs) and whether quetiapine was used as monotherapy or in combination with other drugs. [5][6][7] It is also important to highlight that the drug manufacturer reported that quetiapine was associated with a dose-related decrease in TT4 and FT4. However, the underlying mechanism was not mentioned.…”