Acute thyrotoxicosis secondary to destructive thyroiditis associated with cardiac catheterization contrast dye

Eosinophil/Monocyte Ratio Combined With Serum Thyroid Hormone for Distinguishing Graves' Disease and Subacute Thyroiditis

Background: Thyrotoxicosis is commonly classified into several entities according to different etiologies. Identifying the causes of thyroid dysfunction is critical for the subsequent selection of treatment. The free triiodothyronine to free thyroxine ratio (fT₃/fT₄) is widely used but is still a controversial diagnostic measurement. Methods: A total of 290 patients including 141 healthy control subjects, 86 patients with untreated Graves' disease (GD,) and 63 patients with subacute thyroiditis (SAT) were enrolled in the study. The main aim was to evaluate the diagnostic value of different indexes from serum testing including fT₃, fT₄, eosinophils (Eo) and monocytes (Mo). The diagnostic performance of multiple indexes was evaluated separately using receiver operating characteristic curve analysis. Results: Sensitivities and specificities of fT₄/fT₃, Mo/Eo ratios and Mo/Eo ratio + fT₄/fT₃ for diagnosing GD were 80.23 and 88.89, 82.56 and 60.32, and 74.4 and 87.3 with cut-off values of ≤ 2.841, ≤ 8.813 and >0.644, respectively. An equation of combined indicators including Mo, Eo, fT₃, and fT₄ data was developed to calculate a probability value and among all indexes studied the indicator combination formula gave the best diagnostic value, reaching sensitivity and specificity of 89.53 and 90.48%, respectively, with an optimum cut-off value at 0.561 for GD diagnosis. Conclusion: Compared to regular indexes (fT_4/fT₃ and Mo/Eo), a newly developed indicator combination formula provided a higher prediction probability and may serve as a simple, cost-effective tool for differentiating GD from SAT patients, especially in undeveloped regions of China.

Thyrotoxicosis in a 13-year-old girl following pituitary adenectomy for Cushing's disease

Our objective is to report a case of thyrotoxicosis following pituitary adenectomy for Cushing′s disease, the only pediatric case to our knowledge. No thyroid antibodies were detected, and the thyrotoxicosis was successfully treated for 3 months with no relapse after 5 years of follow‐up. The cause of thyrotoxicosis remains unknown.

Lugol's solution-induced painless thyroiditis

Lugol’s solution is usually employed for a limited period for thyroidectomy preparation in patients with Graves’ disease and for the control of severe thyrotoxicosis and thyroid storm. We describe a rare case of Lugol’s solution-induced painless thyroiditis. In November 2014, a 59-year-old woman was prescribed Lugol’s solution four drops per day for the alleviation of menopausal symptoms. She was referred to our clinic in June 2015 for fatigue, hair loss, and a 20-lb weight loss without thyroid pain or discomfort. Physical examination revealed a normal thyroid gland. On 7 May 2015, laboratory tests revealed a suppressed thyroid-stimulating hormone (TSH) 0.01 U/L with elevated free T4 3.31 ng/dL (42.54 pmol/L). Repeat testing on 25 May 2015 showed spontaneous normalization of the free thyroid hormone levels with persistently low TSH 0.10 U/L. Following these results, a family physician prescribed methimazole 10 mg PO TID and very soon after, the TSH concentration rose to >100 U/L along with subnormal free T4 and T3 levels. Methimazole was promptly discontinued, namely within 18 days of its initiation. Over the course of the next few months, the patient spontaneously achieved clinical and biochemical euthyroidism. To our knowledge, this is a unique case of painless thyroiditis induced by Lugol’s solution, which has not been reported before. Lugol’s solution is a short-term medication given for the preparation of thyroidectomy in patients with Graves’ disease and for the control of severe thyrotoxicosis. Iodine excess can cause both hyperthyroidism and hypothyroidism. Rarely, Lugol’s solution can cause acute painless thyroiditis.

Transient hypercortisolism and symptomatic hyperthyroidism associated to primary hyperparathyroidism in an elderly patient: case report and literature review

BACKGROUND

Primary hyperparathyroidism (PHPT) is often found on routine blood tests, at a relatively asymptomatic stage. However many studies suggest different systemic effects related to PHPT, which could be enhanced by an abnormal cortisol release due to chronic stress of hyperparathyroidism. Being PHPT frequently found in the 6(th) to 7(th) decade of life, a careful and multifaceted approach should be taken.

CASE PRESENTATION

We report the case of an elderly patient with symptomatic PHPT and incidental pulmonary embolism. He was treated with hydration, zoledronic acid, cinacalcet and high-dose unfractionated heparin. Parathyroid surgery was successfully performed, but patient's conditions suddenly worsened because of a transient thyrotoxicosis, probably induced by a previous exposure to iodine load and/or thyroid surgical manipulation. A short-term treatment with beta-blockers was introduced for symptomatic relief. The patient also presented a transient hypercortisolism with elevated ACTH, likely due to stress related not only to aging and hospitalization but also to PHPT, resolved only four months after parathyroid surgery.

CONCLUSION

Chronic hyperparathyroidism has been linked with increased all-cause mortality. A functional chronic hypercortisolism could be established, enhancing PHPT related disorders. Only parathyroid surgery has been demonstrated to cure PHPT and complications related, showing similar outcome between older and younger patients. However, the management of post-operative period should be more careful in fragile patients. In particular, the early diagnosis and treatment of a transient post-operative thyrotoxicosis could improve recovery. Due to the increase in prevalence and the evidence of many related complications even in asymptomatic PHPT, expert opinion-based guidelines for surgical treatment of PHPT should be developed especially for elderly patients.

Identification of iopanoic acid as substrate of type 1 deiodinase by a novel nonradioactive iodide-release assay

Enzymatic 5'- and 5-deiodination are key reactions for local and systemic activation and inactivation of iodothyronines and thyronamines. Expression of the three deiodinase (DIO) isoenzymes is regulated by a number of parameters, including thyroid status, genotype, micronutrient availability, and disease-related signaling. In addition, DIO are potential targets of pharmacological as well as environmentally derived substances, which might affect their enzymatic activity (endocrine disruptors). With the classical DIO activity assay, testing depends on the availability of radioactively labeled substrates (e.g. (125)I-rT(3)) to monitor the release of radioactive iodide. Recently, liquid chromatography-tandem mass spectrometry was described as an alternative method apparently resolving this limitation. However, it has a high demand in technical equipment and analytical routine and is limited in sample number by considerable measuring time. We therefore combined the classical deiodination assay with an easily accessible photometric method taking advantage of the Sandell-Kolthoff reaction for measuring iodide release. In brief, iodine works as a catalyst within this redox reaction between Ce(4+) and As(3+) leading to an acceleration of destaining. Furthermore, the protocol was adapted to minimize handling effort and time consumption. Because this method is not dependent on radioactivity, it expands the substrate spectrum of the classical method. Suitability of this assay was tested with tissue samples from animal experiments (hepatic Dio1 activity in hypo- and hyperthyroid mice) and established DIO inhibitors. As a new but not unexpected finding, the alleged inhibitor iopanoic acid turned out to be a DIO substrate. This finding was confirmed by liquid chromatography-tandem mass spectrometry, and its potential clinical impact requires further studies.

Thyrotoxicosis

Hyperthyroidism describes the sustained increase in thyroid hormone biosynthesis and secretion by a thyroid gland with increased metabolism. Although the use of radioiodine scanning serves as a useful surrogate that may help characterize the cause of thyrotoxicosis, it only indirectly addresses the underlying physiologic mechanism driving the increase in serum thyroid hormones. In this article, thyrotoxic states are divided into increased or decreased thyroid metabolic function. In addition to the diagnosis, clinical presentation, and treatment of the various causes of hyperthyroidism, a section on functional imaging and appropriate laboratory testing is included.

Subacute, silent, and postpartum thyroiditis

Subacute, silent, and postpartum thyroiditis are temporary forms of thyroid dysfunction caused by thyroid gland inflammation. They classically present with a triphasic course: a brief period of thyrotoxicosis due to release of preformed thyroid hormone that lasts for 1 to 3 months, followed by a more prolonged hypothyroid phase lasting up to 6 months, and eventual return to a euthyroid state. However, the types and degree of thyroid dysfunction are variable in these disorders, and individual patients may present with mild or more severe cases of thyrotoxicosis alone, hypothyroidism alone, or both types of thyroid dysfunction.