Development of severe thyroid-associated ophthalmopathy in a patient with disseminated thyroid cancer treated with recombinant human thyrotropin/radioiodine and retinoic acid

Graves' ophthalmopathy: low-dose dexamethasone reduces retinoic acid receptor-alpha gene expression in orbital fibroblasts

OBJECTIVE

Graves' ophthalmopathy (GO) is an autoimmune disease that leads to ocular proptosis caused by fat accumulation and inflammation, and the main treatment is corticosteroid therapy. Retinoid acid receptor-alpha (RARα) seems to be associated with inflammation and adipocyte differentiation. This study aimed to assess the effect of glucocorticoid treatment on orbital fibroblasts of GO patient treated or not with different glucocorticoid doses.

MATERIALS AND METHODS

Orbital fibroblasts collected during orbital decompression of a female patient with moderately severe/severe GO were cultivated and treated with 10 nM and 100 nM dexamethasone (Dex). rRARα gene expression in the treated and untreated cells was then compared.

RESULTS

Fibroblast RARα expression was not affected by 100 nM Dex. On the other hand, RARα expression was 24% lower in cells treated with 10 nM Dex (p < 0.05).

CONCLUSIONS

Orbital fibroblasts from a GO patient expressed the RARα gene, which was unaffected by higher, but decreased with lower doses of glucocorticoid.

Time course of Graves' orbitopathy after total thyroidectomy and radioiodine therapy for thyroid cancer

The risk of cancer is relatively higher in Graves' patients presenting simultaneously with thyroid nodules. Radioiodine (RAI) therapy recommended in high-risk differentiated thyroid carcinoma may be associated with worsening of a pre-existing Graves' orbitopathy (GO) or developing a new onset. The impact of RAI therapy in patients with differentiated thyroid cancer on the course of a pre-exisiting GO has not been specifically investigated.The aim of this study is to assess the influence of RAI treatment administered for differentiated thyroid cancer on the course of a pre-existing GO.This is a retrospective multicenter study including 35 patients from the University Hospital of Clermont-Ferrand (7 patients) and Lyon-Est (6 patients) in France and from a literature review published as case reports or studies (22 patients).Seven patients exhibited a worsened pre-existing GO after total thyroidectomy followed by RAI treatment for thyroid cancer. Older men, those who initially presented with a lower clinical score of GO before RAI therapy, received higher doses of I especially when prepared with recombinant thyroid-stimulating hormone, and/or not prepared with glucocorticoids during RAI are at a higher risk to worsen their GO.This study is the first and complete study collection. We describe worsening of GO in 20% of patients after RAI treatment for thyroid cancer and determine a pool of predictive factors.

Development of Thyroid-Associated Ophthalmopathy in Patients Who Underwent Total Thyroidectomy

PURPOSE

To report clinical characteristics of thyroid-associated ophthalmopathy (TAO) in patients who previously underwent total thyroidectomy for thyroid cancer or a benign mass of the thyroid.

MATERIALS AND METHODS

Of the patients who were diagnosed with TAO from March 2008 to March 2012, we performed a retrospective chart review on those who had undergone total thyroidectomy for thyroid cancer or a benign mass of the thyroid before the occurrence of ophthalmopathy.

RESULTS

Of the 206 patients diagnosed with TAO, seven (3.4%) met the inclusion criteria. The mean age of the subjects was 47.4 years, and all were female. Six patients were diagnosed with papillary thyroid cancer, and one was diagnosed with a benign mass. The duration between total thyroidectomy and onset of TAO ranged from 3-120 months (median 48 months). Ophthalmic manifestations varied among cases. Except for the patient who was diagnosed with a benign mass, all patients showed hyperthyroid status and were under Synthroid hormone treatment at the time of TAO development. Five of these six patients had positive levels of thyroid-stimulating hormone (TSH) receptor autoantibodies.

CONCLUSION

TAO rarely develops after total thyroidectomy, and the mechanism of TAO occurrence is unclear. However, most patients showed abnormalities in thyroid function and TSH receptor autoantibodies.

The role of radioiodine therapy in benign nodular goitre

For treatment of benign nodular goitre the choice usually stands between surgery and (131)I therapy. (131)I therapy, used for 30 years for this condition, leads to a goitre volume reduction of 35-50% within 1-2 years. However, this treatment has limited efficacy if the thyroid (131)I uptake is low or if the goitre is large. Recombinant human TSH (rhTSH)-stimulated (131)I therapy significantly improves goitre reduction, as compared with conventional (131)I therapy without pre-stimulation, and adverse effects are few with rhTSH doses of 0.1 mg or lower. RhTSH-stimulated (131)I therapy reduces the need for additional therapy due to insufficient goitre reduction, but the price is a higher rate of hypothyroidism. Another approach with rhTSH-stimulation is to reduce the administered (131)I activity by a factor that equals the increase in the thyroid (131)I uptake. Using this approach, radiation exposure is considerably reduced while the goitre reduction is similar to that obtained with conventional (131)I therapy.

Radioiodine ablation of postsurgical thyroid remnants after treatment with recombinant human TSH (rhTSH) in patients with moderate-to-severe graves' orbitopathy (GO): a prospective, randomized, single-blind clinical trial

CONTEXT

Recent evidence suggests thyroidectomy (Tx) followed by radioiodine remnant ablation to be beneficial to Graves' orbitopathy (GO) patients.

OBJECTIVE

The aim of the study was to evaluate the effect of (131)I thyroid ablation after recombinant human TSH stimulation in patients with moderate-to-severe GO.

DESIGN, PATIENTS, AND INTERVENTIONS

The study was prospective, randomized, and single-blind, and it included 40 consecutive patients with moderate-to-severe GO randomized into: 1) a Tx-radioactive iodine (RAI) group (20 subjects who underwent total-Tx and (131)I ablation after recombinant human TSH stimulation); and 2) a Tx group (20 subjects who underwent total-Tx alone).

OUTCOME MEASURES

The overall GO outcome 12 months after Tx/radioiodine ablation was the main measure.

RESULTS

GO evaluation at the end of iv glucocorticoids showed eye disease to be improved in 65% of the Tx-RAI group and 60% of the Tx group patients. At 6 and 12 months, no further changes in the GO outcome could be observed in the Tx-RAI group. Conversely, five patients from the Tx group exhibited a deterioration in GO. At 12 months, GO was found to be improved in 70% of the Tx-RAI and 20% of the Tx group patients, the latter being found to be stable (55%) or worse (25%) than at baseline evaluation. At 12 months, GO was found to be inactive in a significantly higher percentage of patients in the Tx-RAI than in the Tx group (75 vs 30%; P < .01).

CONCLUSIONS

Postoperative radioiodine ablation proved more effective than Tx alone in inducing earlier and steadier GO improvement in patients with moderate-to-severe GO treated with iv glucocorticoids over a 24-month follow-up period.

Potential use of recombinant human thyrotropin in the treatment of distant metastases in patients with differentiated thyroid cancer

OBJECTIVE

In order to effectively treat differentiated thyroid cancer (DTC) with radioiodine (RAI) it is necessary to raise serum TSH levels either endogenously by thyroid hormone withdrawal (THW) or exogenously by administration of recombinant human TSH (rhTSH). The goal of this review is to present current data on the relative efficacy and side effects profile of rhTSH-aided versus THW-aided RAI therapy for the treatment of patients with distant metastases of DTC.

METHODS

We have searched the PubMed database for articles including the keywords "rhTSH", "thyroid cancer", and "distant metastases" published between January 1, 1996 and January 7, 2012. As references, we used clinical case series, case reports, review articles, and practical guidelines.

RESULTS

Exogenous stimulation of TSH is associated with better quality of life because it obviates signs and symptoms of hypothyroidism resulting from endogenous TSH stimulation. The rate of neurological complications after rhTSH and THW-aided RAI therapy for brain and spine metastases is similar. The rate of leukopenia, thrombocytopenia, xerostomia, and pulmonary fibrosis is similar after preparation for RAI treatment with rhTSH and THW. There is currently a controversy regarding RAI uptake in metastatic lesions after preparation with rhTSH versus THW, with some studies suggesting equal and some superior uptake after preparation with THW. Analysis of available retrospective studies comparing survival rates, progression free survival, and biochemical and structural response to a dosimetrically-determined dose of RAI shows similar efficacy after preparation for therapy with rhTSH and THW.

CONCLUSION

The rhTSH stimulation is not presently approved by the FDA as a method of preparation for adjunctive therapy with RAI in patients with metastatic DTC. Data on rhTSH compassionate use suggest that rhTSH stimulation is as equally effective as THW as a method of preparation for dosimetry-based RAI treatment in patients with RAI-avid metastatic DTC.

Radioiodine therapy in benign thyroid diseases: effects, side effects, and factors affecting therapeutic outcome

Radioiodine ((131)I) therapy of benign thyroid diseases was introduced 70 yr ago, and the patients treated since then are probably numbered in the millions. Fifty to 90% of hyperthyroid patients are cured within 1 yr after (131)I therapy. With longer follow-up, permanent hypothyroidism seems inevitable in Graves' disease, whereas this risk is much lower when treating toxic nodular goiter. The side effect causing most concern is the potential induction of ophthalmopathy in predisposed individuals. The response to (131)I therapy is to some extent related to the radiation dose. However, calculation of an exact thyroid dose is error-prone due to imprecise measurement of the (131)I biokinetics, and the importance of internal dosimetric factors, such as the thyroid follicle size, is probably underestimated. Besides these obstacles, several potential confounders interfere with the efficacy of (131)I therapy, and they may even interact mutually and counteract each other. Numerous studies have evaluated the effect of (131)I therapy, but results have been conflicting due to differences in design, sample size, patient selection, and dose calculation. It seems clear that no single factor reliably predicts the outcome from (131)I therapy. The individual radiosensitivity, still poorly defined and impossible to quantify, may be a major determinant of the outcome from (131)I therapy. Above all, the impact of (131)I therapy relies on the iodine-concentrating ability of the thyroid gland. The thyroid (131)I uptake (or retention) can be stimulated in several ways, including dietary iodine restriction and use of lithium. In particular, recombinant human thyrotropin has gained interest because this compound significantly amplifies the effect of (131)I therapy in patients with nontoxic nodular goiter.

Is Recombinant Human TSH a Trigger for Graves' Orbitopathy?

The pathogenesis of Graves' orbitopathy (GO) remains unknown. The hypothesis of a causal relationship between autoimmunity against the TSH receptor (TSHR) and GO is supported by clinical studies. Radioiodine treatment is associated with worsening or new onset of GO, possibly via antigen shedding or by inducing hypothyroidism. The coexistence of thyroid cancer with Graves' disease (GD) and GO is rare. Here we report 3 cases of reactivation of GO in patients who underwent treatment with recombinant human TSH (rhTSH) and radioiodine ablation. In each case, a thyroidectomy was performed to treat the GD, and an incidental thyroid cancer was discovered. In all 3 cases, reactivation of GO was observed 3-6 weeks after administration of rhTSH, despite maintaining euthyroidism, which was unaccompanied by a rise in serum TSHR antibodies after radioiodine and despite steroids in 1 of the 3 patients. These observations suggest that binding of either TSH or TSHR antibodies to the TSHR, independently of thyroid status, may be causally related to deterioration of GO. Clinicians should be aware of a possible association between rhTSH administration and reactivation of GO, which should be taken into account before prescribing rhTSH in patients with GO. Prophylactic steroids may need to be considered for patients at high risk of exacerbation of GO.

Thyroid-associated ophthalmopathy and TSH receptor autoantibodies in nonmetastatic thyroid cancer after total thyroidectomy

In a 58-year-old woman with nontoxic nodular goiter, a fine-needle aspiration biopsy showed the presence of papillary thyroid cancer, which was treated with total thyroidectomy in June 2000 and a subsequent ablative dose of 131-radioiodine. A posttherapy whole body scan showed the presence of residual tissue in the neck. On physical examination, she did not exhibit any signs or symptoms of thyroid-associated ophthalmopathy. A subsequent whole body scan and serum thyroglobulin determination were negative. In July 2004, she developed left retrobulbar pain, discomfort, palpebral retraction, and exophthalmos associated with the appearance of antithyrotropin receptor autoantibodies. Symptoms progressively worsened, paralleling the incremental increase in autoantibodies, and then spontaneously remitted as autoantibodies disappeared. The parallel trend of antithyrotropin receptor autoantibodies titres and thyroid-associated ophthalmopathy suggests a role of these autoantibodies in the pathogenesis of thyroid-associated ophthalmopathy.

Papillary Thyroid Carcinoma With Thyroid-associated Orbitopathy in a Euthyroid State

PURPOSE

Thyroid cancers with concurrent thyroid-associated orbitopathy (TAO) are extremely rare. The present study reports 5 unusual cases of papillary thyroid microcarcinoma in patients presenting with TAO in an euthyroid state.

METHODS

We retrospectively reviewed the records of 5 patients (4 female, 1 male) with no known history of thyroid disease, who initially presented with TAO and were subsequently found to have thyroid cancer. TAO was diagnosed by a combination of computed tomography and clinical symptoms and signs. All patients underwent routine serologic assessment of thyroid hormones and thyroid-related autoantibodies including thyrotropin-receptor antibodies, as well as imaging studies such as neck ultrasonography or thyroid scintiscan with I.

RESULTS

Patients presented with asymmetric proptosis (cases 1-3), ocular motility restriction (cases 1-3), and eyelid retraction (cases 1-5). None of the patients showed clinical signs of hyperthyroidism, and all returned normal thyroid function test data. Thyroid nodules were detected by neck imaging; subsequent fine-needle aspiration biopsies were performed with the cytologic result of papillary carcinoma. In no cases did ophthalmic symptoms resolve following cancer treatment (e.g., thyroidectomy and radioactive iodine therapy). All patients were positive for thyroid-binding inhibiting immunoglobulin in low titers.

CONCLUSIONS

Although coincident occurrence is rare, patients presenting with TAO should be carefully evaluated for the possible presence of papillary microcarcinoma, which can develop in a setting of systemic autoimmunity without inducing hyperthyroidism.

Dietary soy protein isolate modifies hepatic retinoic acid receptor-beta proteins and inhibits their DNA binding activity in rats

Retinoic acid receptors (RAR) belong to the same nuclear receptor superfamily as thyroid hormone receptors (TR) that were previously shown to be modulated by dietary soy protein isolate (SPI). This study has examined the effect of dietary SPI and isoflavones (ISF) on hepatic RAR gene expression and DNA binding activity. In Expt. 1, Sprague-Dawley rats were fed diets containing 20% casein or 20% alcohol-washed SPI in the absence or presence of increasing amounts of ISF (5-1250 mg/kg diet) for 70, 190, or 310 d. In Expt. 2, weanling Sprague-Dawley rats were fed diets containing 20% casein with or without supplemental ISF (50 mg/kg diet) or increasing amounts of alcohol-washed SPI (5, 10, and 20%) for 90 d. Intake of soy proteins significantly elevated hepatic RARbeta2 protein content dose-dependently compared with a casein diet, whereas supplemental ISF had no consistent effect. Neither RARbeta protein in the other tissues measured nor the other RAR (RARalpha and RARgamma) in the liver were affected by dietary SPI, indicating a tissue and isoform-specific effect of SPI. RARbeta2 mRNA abundances were not different between dietary groups except that its expression was markedly suppressed in male rats fed SPI for 310 d. DNA binding activity of nuclear RARbeta was significantly attenuated and the isoelectric points of RARbeta2 were shifted by dietary SPI. Overall, these results show for the first time, to our knowledge, that dietary soy proteins affect hepatic RARbeta2 protein content and RARbeta DNA binding activity, which may contribute to the suppression of retinoid-induced hypertriglyceridemia by SPI as reported.