Amiodarone and the thyroid: a 2012 update

Amiodarone-induced thyroid dysfunction occurs in 15-20% of amiodarone-treated patients. Amiodarone-induced hypothyroidism (AIH) does not pose relevant problems, is easily controlled by L-thyroxine replacement, and does not require amiodarone withdrawal. Most frequently AIH develops in patients with chronic autoimmune thyroiditis. Amiodarone- induced thyrotoxicosis (AIT) is most frequently due to destructive thyroiditis (type 2 AIT) causing discharge of thyroid hormones from the damaged, but otherwise substantially normal gland. Less frequently AIT is a form of hyperthyroidism (type 1 AIT) caused by the iodine load in a diseased gland (nodular goiter, Graves' disease). A clearcut differentiation between the two main forms is not always possible, despite recent diagnostic advances. As a matter of fact, mixed or indefinite forms do exist, contributed to by both thyroid damage and increased thyroid hormone synthesis. Treatment of type 1 (and mixed forms) AIT is based on the use of thionamides, a short course of potassium perchlorate and, if treatment is not rapidly effective, oral glucocorticoids. Glucocorticoids are the first-line treatment for type 2 AIT. Amiodarone should be discontinued, if feasible from a cardiac standpoint. Continuation of amiodarone has recently been associated with a delayed restoration of euthyroidism and a higher chance of recurrence after glucocorticoid withdrawal. Whether amiodarone treatment can be safely reinstituted after restoration of euthyroidism is still unknown. In rare cases of AIT resistance to standard treatments, or when a rapid restoration of euthyroidism is advisable, total thyroidectomy represents a valid alternative. Radioiodine treatment is usually not feasible due to the low thyroidal iodine uptake.

Hashimoto's thyroiditis in a benign cystic teratoma of the ovary: case report and literature review

Ectopic thyroid tissue in ovarian teratoma or in struma ovarii appears to be histologically identical to the thyroid gland tissue and may virtually exhibit all the pathological patterns found in the thyroid gland. However, the concurrent lymphocytic infiltration of the thyroid gland, as found in Hashimoto's thyroiditis, and of the ectopic thyroid tissue is extremely rare. We describe the case of an 18-years old patient, in which a right ovarian 4 cm cyst has been found during pelvic ultrasound exam. The cyst was resected and microscopic examination of the mass revealed a mature cystic teratoma in which epidermal-like lining with skin adnexa, admixed with respiratory type epithelium, and areas of mature fatty, chondroid and dentigerous tissues were found. In a peripheral area of 0.7 cm  ×  0.5 cm, a prominent lymphocytic infiltrate surrounding thyroid follicles was identifiable. Thyroid function evaluation at different time points after surgery, revealed the development of mild hypothyroidism. Anti-TPO and anti-Tg autoantibodies were elevated, at fine needle aspiration biopsy a lymphocytic infiltrate, compatible with Hashimoto's thyroiditis, was present. We report here a rare case of Hashimoto's thyroiditis occurring both in the thyroid and in the ectopic thyroid tissue in the context of a benign cystic teratoma of the ovary.

A functioning FSH-secreting pituitary macroadenoma causing an ovarian hyperstimulation syndrome with multiple cysts resected and relapsed after leuprolide in a reproductive-aged woman

Bioactive gonadotropin-secreting pituitary adenomas are very rare in fertile women and can cause an ovarian hyperstimulation syndrome (OHSS). A 31-year-old woman with oligo-amenorrhea, severe ovarian cystic swelling and high serum estradiol was submitted to the resection of ovarian cysts and then treated with long-acting leuprolide 11.25 mg. Two months later, the ovarian multicystic hyperplasia relapsed, thus a pituitary MRI was performed and a pituitary macroadenoma was detected. In January 2010, she was referred to our Endocrinology Department where her hormonal evaluation showed high serum estradiol, FSH, α-subunit and inhibin with low LH. In April 2010, she underwent a trans-sphenoidal pituitary adenomectomy, which rapidly regularized the hormonal profile, the ovary and pituitary morphology and the menses. The case presented confirms that gonadotrophinomas occurring in reproductive-aged women frequently produce symptoms of ovarian hyperstimulation and proves that the use of GnRH analogs is not indicated in this condition.

Continuation of amiodarone delays restoration of euthyroidism in patients with type 2 amiodarone-induced thyrotoxicosis treated with prednisone: a pilot study

CONTEXT

Type 2 amiodarone-induced thyrotoxicosis (AIT) is a destructive thyroiditis usually responsive to glucocorticoids. Whether continuation of amiodarone affects treatment outcome is unsettled.

OBJECTIVE

The objective of the study was to compare the outcome of glucocorticoid treatment in type 2 AIT patients who continued or withdrew amiodarone.

DESIGN

This was a matched retrospective cohort study.

SETTING

The study was conducted at a university center.

PATIENTS

Eighty-three consecutive patients with untreated type 2 AIT participated in the study. After matching with patients continuing amiodarone (AMIO-ON, n = 8), patients interrupting amiodarone were randomly selected in a 4:1 ratio (AMIO-OFF, n = 32).

INTERVENTION

All patients were treated with oral prednisone. Patients whose thyrotoxicosis recurred after glucocorticoid withdrawal were treated with a second course of prednisone.

MAIN OUTCOME MEASURE

Time and rate of cure were measured.

RESULTS

Median time to the first normalization of serum thyroid hormone levels did not significantly differ in AMIO-ON and AMIO-OFF patients (24 and 31 d, respectively; P = 0.326). Conversely, median time for stably restoring euthyroidism was 140 d in AMIO-ON patients and 47 d in AMIO-OFF patients (log rank, P = 0.011). In fact, AIT recurred in five of seven AMIO-ON patients (71.4%) and in only three of 32 AMIO-OFF patients (9.4%, P = 0.002), requiring readministration of prednisone. One AMIO-ON patient never reached thyroid hormone normalization during the study period. Factors associated with glucocorticoid failure were thyroid volume and amiodarone continuation.

CONCLUSIONS

Prednisone restores euthyroidism in most type 2 AIT patients, irrespective of amiodarone continuation or withdrawal. However, continuing amiodarone increases the recurrence rate of thyrotoxicosis, causing a delay in the stable restoration of euthyroidism and a longer exposure of the heart to thyroid hormone excess.

Vitamin D status may contribute to serum insulin-like growth factor I concentrations in healthy subjects

OBJECTIVE

The aim of the study was to evaluate whether vitamin D [25-(OH) D3] status affects serum IGFI concentrations in healthy subjects.

DESIGN AND PATIENTS

Two hundred and forty-one consecutive healthy subjects were included in the present study.

MEASUREMENTS

Serum IGF-I and 25-(OH) D3 concentrations.

RESULTS

As expected, serum IGF-I concentrations progressively decreased with age (r=-0.55, p<0.0001); on the contrary, gender was not related to serum IGF-I levels. A positive relationship was identified between serum 25-(OH) D3 and IGF-I concentrations (r=0.33, p<0.0001); the 25-(OH) D3-dependent changes of serum IGF-I concentrations were observed also when subjects were divided on the basis of vitamin D deficiency; in fact, those with severe 25-(OH) D3 deficiency (<20 ng/ml) had lower (185 ± 83 μg/l) IGF-I values than those with mild-to absent 25-(OH) D3 deficit (225 ± 83 μg/l, p=0.0004).

CONCLUSIONS

25-(OH) D3 status may contribute to determine serum IGF-I levels in healthy population.

Pituitary autoimmunity is associated with hypopituitarism in patients with primary empty sella

OBJECTIVE

Some evidence suggests that late stage autoimmune hypophysitis (AH) may result in empty sella (ES). Aim of the study was to assess the prevalence of serum pituitary antibodies (PitAb) and their correlation with pituitary function in patients with ES.

DESIGN

In this casecontrol study 85 patients with primary ES, 16 patients with ES secondary to head trauma, 214 healthy controls, and 16 AH were enrolled in a tertiary referral center.

METHODS

PitAb were assessed in all cases and controls. Endocrine function was assessed by basal hormone measurement and dynamic testing in all ES cases.

RESULTS

PitAb prevalence was higher in primary ES (6%) than in healthy subjects (0.5% p=0.003) and lower than in AH patients (50%, p<0.0001). PitAb were not found in patients with secondary ES. Hypopituitarism was found in 49% of primary ES and in 62% of secondary ES (p=0.34). A positive correlation between the presence of PitAb and hypopituitarism was found in primary ES (p=0.02).

CONCLUSIONS

The significant association between pituitary autoimmunity and hypopituitarism suggests that ES, in selected cases, could be the final result of AH.

Diagnosis and treatment of autoimmune hypophysitis: a short review

Medical therapy of autoimmune hypophysitis with immunosuppressive drugs can be effective to induce remission of the disease by treating both pituitary dysfunction and compression symptoms. We describe the case of a 41-yr-old man with autoimmune hypophysitis in whom prednisone therapy induced remission of the disease but was followed by a sudden relapse after withdrawal. A second trial of corticosteroid was started and succeeded in inducing remission of the disease. Eight months after the second withdrawal pituitary function was restored, pituitary mass had disappeared, only partial diabetes insipidus remained unchanged. Review of the literature identified 30 articles, among case reports and case series, reporting a total of 44 cases of autoimmune hypophysitis treated with glucocorticoids and/or azathioprine. Combining all the cases, medical therapy resulted to be effective in reducing the pituitary mass in 84%, in improving anterior pituitary function in 45%, and in restoring posterior pituitary function in 41%. Clinical aspects of autoimmune hypophysitis are discussed and a possible algorithm for the diagnosis and treatment of the disease is proposed.

Cardiac extrinsic apoptotic pathway is silent in young but activated in elder mice overexpressing bovine GH: interplay with the intrinsic pathway

Apoptosis may occur through the mitochondrial (intrinsic) pathway and activation of death receptors (extrinsic pathway). Young acromegalic mice have reduced cardiac apoptosis whereas elder animals have increased cardiac apoptosis. Multiple intrinsic apoptotic pathways have been shown to be modulated by GH and other stimuli in the heart of acromegalic mice. However, the role of the extrinsic apoptotic pathways in acromegalic hearts is currently unknown. In young (3-month-old) acromegalic mice, expression of proteins of the extrinsic apoptotic pathway did not differ from that of wild-type animals, suggesting that this mechanism did not participate in the lower cardiac apoptosis levels observed at this age. On the contrary, the extrinsic pathway was active in elder (9-month-old) animals (as shown by increased expression of TRAIL, FADD, TRADD and increased activation of death inducing signaling complex) leading to increased levels of active caspase 8. It is worth noting that changes of some pro-apoptotic proteins were induced by GH, which seemed to have, in this context, pro-apoptotic effects. The extrinsic pathway influenced the intrinsic pathway by modulating t-Bid, the cellular levels of which were reduced in young and increased in elder animals. However, in young animals this effect was due to reduced levels of Bid regulated by the extrinsic pathway, whereas in elder animals the increased levels of t-Bid were due to the increased levels of active caspase 8. In conclusion, the extrinsic pathway participates in the cardiac pro-apoptotic phenotype of elder acromegalic animals either directly, enhancing caspase 8 levels or indirectly, increasing t-Bid levels and conveying death signals to the intrinsic pathway.

Impact of different cut-off limits of peak GH after GHRH-arginine stimulatory test, single IGF1 measurement, or their combination in identifying adult patients with GH deficiency

OBJECTIVE

To evaluate the impact of different peak GH cut-off limits after GHRH-Arg test, IGF1 measurement, or their combination in identifying patients with GH deficit (GHD).

DESIGN AND PATIENTS

Totally, 894 normal subjects (used for determining IGF1 normative limits) and 302 patients with suspected GHD were included. Different peak GH cut-off limits (used by European (depending on body mass index (BMI)) or North American (4.1 μg/l) Endocrine Societies, by HypoCCs (2.5 μg/l), or with 95% specificity (based on BMI), Method 1, 2, 3, or 4 respectively) and IGF1 were considered.

METHODS

Peak GH after GHRH-Arg and IGF1.

RESULTS

Different peak GH cut-off limits recognized different proportions of GHD (range, 24.8-62.9%). Methods 1 and 2 with high sensitivity recognized a higher proportion (95.5 and 92.5% respectively) of GHD among patients with three (T) pituitary hormone deficits (HD), whereas Method 4 (with high specificity) identified 96.7% normal subjects among those without pituitary HD; on the contrary, Method 4 identified only 75% GHD among patients with THD, whereas Method 1 recognized a high proportion (40%) of GHD among subjects without HD. Of the total patients, 82% with THD and 84.5% without HD were recognized as GHD or normal respectively by IGF1. Among the remaining patients with THD and normal IGF1, 75% was recognized as GHD by Method 1; among patients without HD and abnormal IGF1, 87.5% was identified as normal by Method 4. Overall, combination of IGF1 and Method 1 or Method 4 identified 95.5% GHD among patients with THD and 98.1% normal subjects among those without HD.

CONCLUSIONS

Single peak GH cut-offs have limits to sharply differentiate GHD from normal subjects; IGF1 may be used for selecting patients to be submitted to the GHRH-Arg test; the peak GH cut-off limits to be used for identifying healthy or diseased patients depend mainly on the clinical context.

Effect of rosiglitazone on serum IGF-I concentrations in uncontrolled acromegalic patients under conventional medical therapy: results from a pilot phase 2 study

OBJECTIVE

Current therapies for acromegaly are unsatisfactory for some patients. High-dose thiazolidinediones have been reported to reduce serum GH levels in animal models of acromegaly. The objective of the study was to evaluate the effect of increasing doses of rosiglitazone on serum GH and IGF-I concentrations in acromegalic patients.

DESIGN

Phase 2 clinical trial.

PATIENTS AND METHODS

Five consecutive patients with active and uncontrolled acromegaly under conventional medical therapies were treated with increasing doses of rosiglitazone [4 mg/day every month, starting from 8 up to 20 mg/day] added to previous medical therapies for acromegaly.

RESULTS

Mean serum IGF-I concentrations decreased from 547 ± 91 to 265 ± 126 μg/l (p<0,001) during rosiglitazone treatment: 4 patients had normal serum IGF-I concentrations, and a patient had lowered serum IGF-I values, although still abnormal, at the end of the study. On the contrary, serum GH concentrations did not significantly changed during rosiglitazone therapy as well as other pituitary hormones. No relevant side effects of rosiglitazone were observed during the study period. Quantitative real time PCR and Western blotting showed that rosiglitazone lowered GH-dependent hepatic generation of IGF-I in HepG2 cell line.

CONCLUSIONS

Rosiglitazone reduces serum IGF-I concentrations in patients with uncontrolled acromegaly under conventional medical therapies, likely acting on the GH-dependent hepatic synthesis of IGF-I. Large studies are necessary to confirm the role of rosiglitazone as an adjunctive therapy for uncontrolled acromegalic patients under conventional medical therapies.

Somatostatin analogues do not affect calcium metabolism in patients with acromegaly and primary hyperparathyroidism [corrected] due to MEN 1-like syndrome

Patients with clinical features of MEN 1 without mutations in the menin gene fulfill the criteria of MEN1-like syndrome. Primary hyperparathyroidism (PHP) is the most frequent clinical finding in both syndromes and is usually treated by surgery. However, PHP has been reported to respond to somatostatin analogues (SSA) in MEN 1 patients. 7 patients with PHP in the context of MEN 1-like syndrome (and absence of mutations in the menin gene) were enrolled in the study and treated with SSA for 6 months for the non-PHP disease before parathyroidectomy. Serum ionized calcium, phosphorus, and PTH concentrations, and 24-h urinary calcium and phosphorus excretion were measured before and after SSA therapy. Mean serum ionized calcium, phosphorus, and PTH concentrations did not significantly change after a 6-month course with SSA. SSA scintigraphy did not reveal uptake in the neck region corresponding to the parathyroid adenoma identified at surgery and confirmed at histology. However, immunohistochemistry revealed SS-type 2A receptor in parathyroid tissue samples of 6 out of 7 patients. SSA therapy does not affect calcium-phosphorus metabolism in patients with MEN 1-like syndrome, suggesting that the drug has no role in controlling PHP in these subset of patients.

Changes in coagulation indexes and occurrence of venous thromboembolism in patients with Cushing's syndrome: results from a prospective study before and after surgery

OBJECTIVES

To evaluate whether patients with Cushing's syndrome (CS) had i) changes in coagulative and fibrinolytic parameters associated with CS activity and ii) higher prevalence of venous thromboembolic events (VTE).

DESIGN

Prospective study conducted on patients with CS evaluated at diagnosis and 12 months after surgery.

PATIENTS AND METHODS

Forty patients with active CS (36 with Cushing's disease (CD) and 4 with an adrenal adenoma) were evaluated. Forty normal subjects and 70 patients with non-ACTH-secreting pituitary adenomas served as controls. All patients and controls underwent an assessment of coagulation and fibrinolysis indexes before and after surgery.

RESULTS

CS patients at baseline had a hypercoagulative phenotype when compared with normal subjects (activated partial thromboplastin time (aPTT), fibrinogen, D-Dimer, von Willebrand factor (VWF), plasminogen activator inhibitor 1 (PAI-1 or SERPINE1), antithrombin III (ATIII or SERPINC1), P<0.0001, α(2) antiplasmin, P=0.0004, thrombin-antithrombin complex (TAT), P=0.01, factor IX (F9), P=0.03). Patients with still active disease after surgery had higher coagulative parameters than those in remission (VWF (P<0.0001), PAI-1 (P=0.004), TAT (P=0.0001), ATIII (P=0.0002) and α(2) antiplasmin (or SERPINF2; P=0.006)), whereas aPTT levels (P=0.007) were significantly reduced. VTE occurred in three patients with CD (7.5%): one had a pulmonary embolism and two patients had a deep venous thrombosis; no patients submitted to transsphenoidal surgery for non-Cushing's pituitary adenoma had VTE (P=0.04).

CONCLUSIONS

Patients with CS have a procoagulative phenotype due to cortisol-associated changes in haemostatic and fibrinolytic markers, leading to increased incidence of VTE. Thromboprophylaxis seems to be appropriated in patients with active disease, particularly in the postoperative period.

Comparison of colonoscopy and fecal occult blood testing as a first-line screening of colonic lesions in patients with newly diagnosed acromegaly

CONTENT

Patients with acromegaly have frequently colonic neoplasms; however, how acromegalic patients should be screened for colonic lesions is still unsettled.

AIMS

To compare fecal occult blood testing (FOBT) and colonoscopy in the screening program of patients with acromegaly.

DESIGN

Colonoscopy and FOBT were performed at the first diagnosis of acromegaly.

SETTING

Tertiary University center.

PATIENTS

Eighty-five consecutive patients with untreated active acromegaly submitted to colonoscopy and FOBT.

RESULTS

FOBT, which was positive in 16 (18.8%) out of 85 patients, identified 2 patients with colonic adenocarcinoma and 2 with adenoma; the remaining 12 patients had no detectable colonic lesions. Colonoscopy revealed colonic lesions in 29 patients: 3 (3.5%) cancers, 11 (12.9%) adenomas, and 15 (17.6%) hyperplastic polyps. The remaining 56 acromegalic patients had no detectable lesions. A patient with cancer and 9 patients with adenoma were missed if screened only by FOBT.

CONCLUSIONS

Colonoscopy is superior to FOBT in detecting colonic lesions at the first diagnosis of acromegaly.