Possible induction of Graves' disease and painless thyroiditis by gonadotropin-releasing hormone analogues

New onset of Graves' disease after controlled ovarian stimulation: A case report and brief literature review

De novo onset of Graves' disease (GD) after controlled ovarian stimulation (OS) is exceptional. Only one case of progression to GD after OS in a patient with pre-existing subclinical hyperthyroidism has been reported. We describe the case of a patient with neither previous thyroid disorders nor autoimmunity who developed GD after OS for primary infertility. A 40-year-old woman with primary infertility underwent four cycles of OS. Her thyroid function performed before the last cycle was unremarkable (thyroid stimulating hormone [TSH] 1.9 mU/L, fT4 1.3 ng/dL, fT3 2.4 pg/mL), and thyroid autoimmunity was negative (anti-thyroperoxidase antibodies and anti-thyroglobuline antibodies). Six weeks after the last cycle she developed overt thyrotoxicosis (TSH < 0.005 mU/L, fT4 4.79 ng/dL, fT3 15.6 pg/mL) with anti-thyrotropin receptor antibodies (TRAb) positivity (9.2 IU/L). She was diagnosed with GD and anti-thyroid therapy was instituted. After 1 year of treatment, thyroid function was still suboptimal (TSH 0.2 mU/L, fT4 1.04 ng/dL, fT3 2.2 pg/mL), and TRAb titer still elevated (8.75 IU/L). Despite her desire to achieve pregnancy, a further cycle of OS was postponed until complete remission of thyroid dysfunction and withdrawal of anti-thyroid therapy. Although TSH assay after OS is not recommended in euthyroid women without autoimmunity, in the presence of hyperthyroid symptoms throughout OS it is advisable to evaluate thyroid function and TRAb. It is advisable to carefully evaluate the course of GD before proceeding with further courses of OS that could lead to its exacerbation or recurrence. In cases where a strong desire for pregnancy persists, thyroidectomy may be proposed.

Is gonadotropin-releasing hormone agonist usage really leading to thyroid dysfunction?

Objectives

Gonadotropin-releasing hormone agonist (GnRHa) could influence the levels of sex hormones and thyroid hormones. The aim of this study was to investigate the effect of GnRHa on thyroid function.

Materials and methods

The data of the patients were collected from the registrations of July 2014–October 2014. A total of 41 women who underwent one-time IVF cyclus were evaluated in this cross-sectional study. The patients were categorized into two groups according to the serum T₃, T₄, and TSH levels before and 2 weeks’ after the administration of GnRHa.

Results

Mean basal TSH and mean TSH levels on hCG day were 1.98 ± 0.77 and 1.75 ± 0.70, respectively. The difference between the two groups was statistically significant (p < 0.05). GnRHa did not lead to statistically significant difference on serum-free T₃ and T₄ levels.

Conclusions

In conclusion, our results demonstrate that GnRHa led to a decrease on serum TSH level. Serum-free T₃ and T₄ levels were remained unchanged and this might be due to early measurement of the hormone levels (just 2 weeks later from GnRHa administration).

Effects of controlled ovarian stimulation on thyroid stimulating hormone in infertile women

OBJECTIVE

To study the effects of long-acting gonadotropin-releasing hormone agonist (GnRH-a) on thyroid function in euthyroid patients of in vitro fertilization (IVF)/ intracytoplasmic sperm injection of embryo transfer (ICSI-ET) and to investigate the timing and alteration of thyroid stimulating hormone (TSH) during controlled ovarian stimulation(COS).

MATERIALS AND METHODS

Euthyroid patients scheduled for IVF/ICSI were enrolled. Euthyroidism was defined as having no history of hypothyroidism with normal TSH before IVF. Long GnRH-a protocol was chosen as COS protocol. 207 patients were divided into two groups based on basal serum TSH level: group A with 0.35mIU/L＜TSH＜2.5mIU/L (n = 137) and group B with 2.5mIU/L ≤ TSH＜4.5mIU/L (n = 70). Serum TSH was tested on 6 time points: before COS (2-5days in menstrual cycle, before GnRH-a injection), Gn injection day 1, Gn injection day 5, human chorionic gonadotropin (HCG) day, 14 and 28 days after transplantation. The serum TSH, clinical pregnancy and abortion rate were investigated.

RESULT

The serum TSH value was significantly (P < 0.05) increased after injection of long-acting GnRH-a in all patients. Both groups had significant (P < 0.05) increases in serum TSH level after long-acting GnRH-a injection. The TSH level was increased in 131(63.3%) patients after GnRH-a injection, of which twenty (9.7%) had subclinical hypothyroidism with TSH level over 4.5 mIU/L. The other 76 (36.7%) patients had decreased TSH. In group A, 79 (57.7%) patients showed an increase of TSH, including three patients (2.2%) with simultaneous rise of TPOAb and four (2.9%) diagnosed of subclinical hypothyroidism with TSH level over 4.5 mIU/L, and the rest fifty-eight (42.3%) patients had decreased TSH with one patient with elevated TPOAb who was diagnosed with subclinical hyperthyroidism. In group B, fifty-two (74.3%) patients showed an increase of TSH, including thirteen (18.6%) patients with elevated TPOAb and sixteen (22.9%) patients diagnosed of subclinical hypothyroidism with TSH level over 4.5 mIU/L, and the rest eighteen (25.7%) patients had decreased TSH with one patient diagnosed with subclinical hyperthyroidism. Group B had a significant higher proportion of patients with elevated serum TSH than group A (P ＜ 0.05). Compared to the baseline level, serum TSH ascended distinctly and reached peak level on HCG day in all patients. Group A and B had similar trends of alteration. Patients in group A had significantly (P＜0.05) higher clinical pregnancy rate than in group B. No significant (P＞0.05) difference in abortion rate were observed between the two groups.

CONCLUSION

GnRH-a can significantly increase serum TSH levels with possible development of subclinical thyroid dysfunction. Infertile patients with serum TSH > 2.5 mIU/L are more susceptible to GnRH-a while patients with basal TSH less than 2.5 mIU/L may get a higher clinical pregnancy rate when receiving IVF/ICSI.

Myxedema Coma Following the Administration of Gonadotropin-releasing Hormone Agonist Complicated by Acute Pancreatitis

Gonadotropin-releasing hormone (GnRH) agonists have been used for the treatment of various diseases. Although autoimmune thyroid disease has been reported as a rare complication of these agents, the symptoms are almost always transient and non-life-threatening. We herein report a rare case of an 83-year-old man receiving GnRH agonist treatment for prostate cancer who developed myxedema coma complicated by acute pancreatitis. This is the first report of myxedema coma potentially associated with a GnRH agonist. The follow-up of the thyroid function is necessary for patients undergoing treatment with GnRH agonists, especially those known to have or to be susceptible to autoimmune thyroid disease.

Three cases of transient hyperthyroidism after triptorelin treatment - case report and literature review

The impacts of gonadtropin-releasing hormone (GnRH) agonists on thyroid function have long been observed and the conclusions were controversial. We here reported three cases of transient hyperthyroidisms after triptorelin therapy. The three patients showed decreased thyroid-stimulating hormone (TSH), with or without elevated free triiodothyronine (FT3) and free thyroxine (FT4) 2 weeks after injection of triptorelin. Thyroid-specific autoantibody assays showed antithyroid microsome autoantibody (TMAb) and (or) antithyroglobulin autoantibody (TgAb) were positive in two patients while and antithyrotropin receptor autoantibody (TRAb) were negative in all three cases. One patient with all thyroid-specific autoantibodies negative showed enlarged thyroid in thyroid ultrasound scanning. Only mild symptoms of hyperthyroidism presented in one patient. Four weeks after triptorelin injection, thyroid function returned to normal in all three patients. These observations indicated transient hyperthyroidism due to thyroid destruction in patients receive triptorelin therapy. The hyperthyroidism was most possibly due to onset of the autoimmune thyroiditis, emphasizing monitoring thyroid function during triptorelin treatment in females.

Thyroid dysfunction associated with administration of the long-acting gonadotropin-releasing hormone agonist

Gonadotropin-releasing hormone (GnRH) agonist has been used in the treatment of a wide variety of sex-hormone-related diseases, as the administration of GnRH agonist can alter the secretion of gonadotropin and sex hormones. Recently, we found that the long-acting GnRH agonist aggravated hyperthyroidism and induced painless thyroiditis. This is the first report to demonstrate the association of thyroid dysfunction with GnRH agonist injection in Korea. Here, we report three cases and emphasize the clinical importance of this aggravating factor in autoimmune thyroid disease.

Study on cutoff value setting for differential diagnosis between Graves' disease and painless thyroiditis using the TRAb (Elecsys TRAb) measurement via the fully automated electrochemiluminescence immunoassay system

The purposes of this study are to set the Elecsys TRAb cutoff value by which GD and PT can be accurately diagnosed simply; and to investigate the usefulness of the vascularity index (VI) obtained from power Doppler sonography (PDS). Using 109 normal controls, 186 GD patients, and 109 PT patients who were diagnosed through Tc-99m uptake, we set the cutoff value by conducting ROC analysis on the Elecsys TRAb values. The cutoff value as a result of the ROC analysis on the Elecsys TRAb values of the normal controls and GD patients was 0.8 IU/L with 100% of sensitivity and specificity. Because all 89 cases (81.6% of the entire PT cases) with Elecsys TRAb =<0.8 IU/L are PT, the cutoff =<0.8IU/L can thus be diagnosed as PT. In contrast, because all 166 cases (88.7% of the entire GD) with Elecsys TRAb >=3.0 IU/L except for one case of PT are GD, the cutoff >=3.0 IU/L can be diagnosed as GD. So Elecsys TRAb between 0.8-3.0 IU/L was dubbed gray zone (GZ). Finally, the cutoff value of 1.5 IU/L from the ROC on the PT and GD cases was chosen as the cutoff with 96.2% of sensitivity and 94.6 of specificity. All PDS VI >=80% were GD including 4 of 6 cases with GZ and all PDS VI <50% plus Elecsys TRAb-negative cases were PT including 4 of 5 cases with GZ. In conclusion, Elecsys TRAb cutoff and VI value for differential diagnosis between GD and PT has been set successfully.

Thyroid outcome during long-term gonadotropin-releasing hormone agonist treatments for idiopathic precocious puberty

PURPOSE

To examine the effects of long-term gonadotropin-releasing hormone agonist (GnRHa) administration on thyroid function in children affected by central precocious puberty (CPP).

METHODS

We retrospectively evaluated circulating thyroid hormones in 73 GnRHa-treated girls who were diagnosed with idiopathic CPP. Monthly depot injections (.1 mg/body kg) of leuprorelin acetate (LA) and of triptorelin (TR) were continuously administered for 40.4 +/- .7 months to 34 and 39 CPP patients, respectively. Serum levels of thyrotropin (TSH), free triiodothyronine (FT3), free thyroxine (FT4), and thyroid antibodies were determined at baseline and after 6, 12, 18, 24, 30, 36, and 40 months of GnRHa administration.

RESULTS

While there was no difference in FT4 release (p > .05), FT3 levels significantly declined during both LA and TR treatments from untreated baseline (p < .05). Opposite to circulating FT4 and FT3 values (p > .05), FT3/FT4 ratio was significantly different among LA and TR groups (p < .05). Both GnRHa treatments did not affect TSH secretion (p > .05); however, LA induced lower TSH values than TR (p < .05).

CONCLUSIONS

There is no evidence of thyroid dysfunction during both GnRHa treatments, though changes in TSH, FT3, and FT3/FT4 ratios were noted. Finally, monitoring of thyroid activity during GnRHa administration is not required.

Familial occurrence of silent thyroiditis

Two brothers and their mother, who had allergic rhinitis caused by Japanese cedar pollen, developed silent thyroiditis in spring. In addition, these three patients had the same HLA haplotype. Another brother, the father, and the paternal grandmother, who did not have allergic rhinitis caused by Japanese cedar pollen, did not show symptoms of silent thyroiditis. The present study indicates that genetic and/or environmental factors are important in the development of this familial type of silent thyroiditis.

Treatment with leuprolide acetate decreases the threshold of the ventilatory response to carbon dioxide in healthy males

This investigation was designed to determine if suppression of testosterone alters the ventilatory response to carbon dioxide in the presence of high and low levels of oxygen. Eleven healthy male subjects completed a series of rebreathing trials during wakefulness, before and after treatment with a long-acting gonadotropin-releasing hormone agonist. Five subjects also completed studies during non-rapid eye movement (NREM) sleep. During wakefulness, subjects initially hyperventilated to reduce the partial pressure of carbon dioxide (P(ET,CO2)) below 25 Torr. Subjects then rebreathed from a bag containing a normocapnic (42 Torr), low (50 Torr) or high oxygen (140 Torr) gas mixture. During each trial P(ET,CO2) increased while oxygen was maintained at a constant level. The threshold of the ventilatory response to carbon dioxide was considered to be the point at which minute ventilation began to rise in a linear fashion as P(ET,CO2) increased. The slope of the ventilatory response above the threshold was used as a measure of sensitivity to carbon dioxide. During NREM sleep, hypocapnia was induced via nasal mechanical ventilation. Several trials were completed until the cessation of mechanical ventilation resulted in a central apnoea which demarcated the threshold of the ventilatory response to carbon dioxide. In response to treatment with leuprolide acetate, the threshold measured in wakefulness decreased during carbon dioxide rebreathing in the presence of low (41.05 +/- 0.77 versus 39.40 +/- 0.83 Torr; P = 0.01) and high (46.32 +/- 0.56 versus 44.78 +/- 0.83 Torr; P = 0.01) oxygen levels. An increase in sensitivity (4.82 +/- 0.61 versus 7.17 +/- 1.20 l min(-1) Torr(-1); P = 0.02) was also observed during rebreathing in the presence of high but not low oxygen levels. The increase in sensitivity was accompanied by an increase in carbon dioxide production. The findings observed during NREM sleep were similar to those observed during wakefulness, since the P(ET,CO2) that demarcated the threshold was decreased after leuprolide treatment (42.1 +/- 0.6 versus 39.6 +/- 0.6 Torr; P = 0.002). Additionally, the decrease in P(ET,CO2) required to induce an apnoea was greater after treatment with leuprolide (2.56 +/- 0.25 versus 4.06 +/- 0.29 Torr; P = 0.004). We conclude that suppression of testosterone decreases the threshold of the ventilatory response to carbon dioxide during both wakefulness and sleep.