Thyroiditis and SARS-CoV-2 pandemic: a review

The world is dealing with the Covid-19 pandemic due to the coronavirus SARS-CoV-2. Amongst the extra-pulmonary manifestations presented by Covid-19 patients, thyroiditis form part of the spectrum of visceral involvement linked to SARS-CoV-2. In this review, we will describe the various documented clinical forms of thyroiditis (inflammatory thyroiditis, subacute or de Quervain's thyroiditis, chronic lymphocytic thyroiditis or Hashimoto's disease, painless (silent) postpartum thyroiditis) to facilitate their diagnosis in more or less symptomatic Covid-19 patients and to provide guidance for patient treatment.

Lenvatinib-induced thyroid abnormalities in unresectable hepatocellular carcinoma

Lenvatinib has anti-tumor activity against advanced hepatocellular carcinoma (HCC). Hypothyroidism is also a frequent complication in patients treated with lenvatinib. However, studies on lenvatinib-induced thyroid toxicity and destructive thyroiditis are limited. Therefore, this study aimed to clarify the frequency and timing of thyroid abnormalities in lenvatinib for unresectable HCC. This retrospective study enrolled 50 patients with advanced HCC treated with lenvatinib. Patients were classified to have euthyroid, subclinical hypothyroidism, overt hypothyroidism, and thyrotoxicosis. The timing of thyroid dysfunction was assessed, and risk factors for incident hypothyroidism or thyrotoxicosis were evaluated using multivariate models. Subclinical hypothyroidism, overt hypothyroidism, and thyrotoxicosis occurred in 7 (14.0%), 26 (52.0%), and 5 (10.0%) patients, respectively. In the 33 patients with hypothyroidism, 27 (84.4%) developed the condition within 2 weeks of starting lenvatinib treatment. Of the 5 patients with thyrotoxicosis, 3 developed the condition within 8 weeks of starting lenvatinib administration. One patient developed thyrotoxicosis in only 1 week of the initiation of treatment. No correlation between the presence of antibodies and the incidence and severity of thyroid dysfunction due to the autoimmune mechanism was observed. The progression-free survival was significantly better in the hypothyroidism group. Lenvatinib treatment for unresectable HCC not only causes hypothyroidism, but also thyrotoxicosis. Moreover, these thyroid conditions develop within the early period of treatment at a higher prevalence. Patients with thyroid dysfunction had better prognosis. Based on these results, in patients administered with lenvatinib, there is need for careful assessment for the possibility of thyroid dysfunction from the onset of treatment.

Plasma Beta-Glucuronidase Activity: A Novel Tool to Distinguish Type 1 from Type 2 Amiodarone-Induced Thyrotoxicosis?

BACKGROUND

Amiodarone-induced thyrotoxicosis (AIT) is a common and deleterious side effect of amiodarone use. There are two types of AIT, characterized by distinct pathogenic mechanisms and, hence, different treatments. Discriminating between type 1 (AIT1) and type 2 (AIT2) AIT is often very challenging. Beta-glucuronidase (β-G) is a lysosomal enzyme released into the extracellular fluid during inflammation.

OBJECTIVES

To examine whether the determination of the plasma activity of β-G is useful in distinguishing AIT1 from AIT2.

METHODS

The study included 67 subjects: 9 with AIT1, 9 with AIT2, 14 with hyperthyroidism due to Grave's disease or toxic multinodular goiter, 14 with subacute thyroiditis, and 21 euthyroid controls. Thyroid function tests and plasma β-G activity were determined in all participants, while thyrotoxic patients also underwent thyroid ultrasound/scintigraphy and urine iodine excretion assessment.

RESULTS

Plasma β-G activity (expressed as mean ± SD in nmol 4-methylumbelliferone [4-MU]/mL plasma/h) in AIT2 was higher compared to AIT1 (2,263.6 ± 771 vs. 1,101.8 ± 201.9, p < 0.05) and similar to subacute thyroiditis (2,263.6 ± 771 vs. 2,083.2 ± 987.5, p = ns). β-G activity did not differ significantly between AIT1 and controls (1,101.8 ± 201.9 vs. 954.6 ± 248.6, p = ns). ROC curve analysis revealed that β-G activity had a high predictive value for destructive processes, namely AIT2 and subacute thyroiditis (AUC 0.846, 95% CI 0.748-0.943) and a cut-off value of 1,480.5 nmol 4-MU/mL plasma/h was able to discriminate between destructive and non-destructive thyroid conditions with 74% sensitivity and 82% specificity.

CONCLUSION

In our study, plasma β-G activity performed well in distinguishing AIT1 from AIT2. Further studies are warranted to establish its usefulness as a discriminator between the two AIT types.

2018 European Thyroid Association (ETA) Guidelines for the Management of Amiodarone-Associated Thyroid Dysfunction

Treatment with amiodarone is associated with changes in thyroid function tests, but also with thyroid dysfunction (amiodarone-induced hypothyroidism, AIH, and amiodarone-induced thyrotoxicosis, AIT). Both AIH and AIT may develop in apparently normal thyroid glands or in the presence of underlying thyroid abnormalities. AIH does not require amiodarone withdrawal, and is treated with levothyroxine replacement if overt, whereas subclinical forms may be followed without treatment. Two main types of AIT are recognized: type 1 AIT (AIT 1), a form of iodine-induced hyperthyroidism occurring in nodular goitres or latent Graves disease, and type 2 AIT (AIT 2), resulting from destructive thyroiditis in a normal thyroid gland. Mixed/indefinite forms exist due to both pathogenic mechanisms. AIT 1 is best treated with thionamides that may be combined for a few weeks with sodium perchlorate to make the thyroid gland more sensitive to thionamides. AIT 2 is treated with oral glucocorticoids. Once euthyroidism has been restored, AIT 2 patients are followed up without treatment, whereas AIT 1 patients should be treated with thyroidectomy or radioiodine. Mixed/indefinite forms of AIT are treated with thionamides. Oral glucocorticoids can be added from the beginning if a precise diagnosis is uncertain, or after a few weeks if response to thionamides alone is poor. The decision to continue or to stop amiodarone in AIT should be individualized in relation to cardiovascular risk stratification and taken jointly by specialist cardiologists and endocrinologists. In the presence of rapidly deteriorating cardiac conditions, emergency thyroidectomy may be required for all forms of AIT.

Isolated Adrenocorticotropic Hormone Deficiency and Severe Hypercalcemia After Destructive Thyroiditis in a Patient on Nivolumab Therapy With a Malignant Melanoma

We describe a 58-year-old man with a malignant melanoma metastasis to the liver. After initiation of nivolumab therapy, he developed destructive thyroiditis and subsequently simultaneous isolated adrenocorticotropic hormone (ACTH) deficiency and severe hypercalcemia. Although isolated ACTH deficiency and hypercalcemia due to nivolumab therapy are both rare occurrences, these conditions can often cause a severe clinical course accompanied by a disturbance of consciousness. Therefore, clinicians should pay attention to these possible side effects of nivolumab if the patients have clinical symptoms, such as fatigue and a disturbance of consciousness.

Comparative frequency of four different types of pregnancy-associated thyrotoxicosis in a single thyroid centre

Background

Pregnancy and delivery markedly influence thyroid function. However, the comparative prevalence of gestational thyrotoxicosis (GT), new onset of Graves’ disease during pregnancy (GD during pregnancy), postpartum destructive thyrotoxicosis (PPT), and postpartum Graves’ thyrotoxicosis (PPGD) has not yet been determined.

Methods

We prospectively registered and performed a review of 4127 consecutive non treated female patients with thyrotoxicosis, seen between August 2008 and December 2013 in our outpatient clinic of Kuma Hospital. 187 out of the 4127 women had new diagnosis of thyrotoxicosis during pregnancy or in the postpartum period. We investigated the prevalence of new diagnosis of GT, GD during pregnancy, PPT and PPGD and compared the characteristics of these types of thyrotoxicosis. The postpartum period is defined as twelve months after delivery.

Results

Out of 187 pregnant or postpartum women, we identified 30 (16.0%) with GT, 13 (7.0%) with GD during pregnancy, 42 (22.5%) with PPT, and 102 (54.5%) with PPGD. The onset time of thyrotoxicosis during pregnancy, i.e., both GT and GD during pregnancy, was delayed by a couple of weeks when hCG peaked at 10 gestational weeks. Seventy-six percent of patients with PPT developed thyrotoxicosis between delivery and 4 months postpartum; on the other hand, 83.3% of patients with PPGD developed thyrotoxicosis at 6 months postpartum or later.

Conclusions

We named gestational thyrotoxicosis, new onset of Graves’ disease during pregnancy, postpartum destructive thyrotoxicosis, and postpartum Graves’ thyrotoxicosis as pregnancy-associated thyrotoxicosis. A clinically significant number of women developed Graves’ disease in the postpartum period in a single thyroid centre.