Screening for drugs potentially interfering with MCT8-mediated T3 transport in vitro identifies dexamethasone and some commonly used drugs as inhibitors of MCT8 activity

BACKGROUND

Monocarboxylate transporter 8 (MCT8) is the first thyroid hormone transporter that has been linked to a human disease. Besides genetic alterations other factors might impair MCT8 activity.

AIM

This study aimed at investigating whether some common drugs having a structural similarity with TH and/or whose treatment is associated with thyroid function test abnormalities, or which behave as antagonists of TH action can inhibit MCT8-mediated T₃ transport.

METHODS

[¹²⁵I]T₃ uptake and efflux were measured in COS-7 cells transiently transfected with hMCT8 before and after exposure to increasing concentrations of hydrocortisone, dexamethasone, prednisone, prednisolone, amiodarone, desethylamiodarone, dronedarone, buspirone, carbamazepine, valproic acid, and L-carnitine. The mode of inhibition was also determined.

RESULTS

Dexamethasone significantly inhibited T₃ uptake at 10 μM; hydrocortisone reduced T₃ uptake only at high concentrations, i.e. at 500 and 1000 μM; prednisone and prednisolone were devoid of inhibitory potential. Amiodarone caused a reduction of T₃ uptake by MCT8 only at the highest concentrations used (44% at 50 μM and 68% at 100 μM), and this effect was weaker than that produced by desethylamiodarone and dronedarone; buspirone resulted a potent inhibitor, reducing T₃ uptake at 0.1-10 μM. L-Carnitine inhibited T₃ uptake only at 500 mM and 1 M. Kinetic experiments revealed a noncompetitive mode of inhibition for all compounds. All drugs inhibiting T₃ uptake did not affect T₃ release.

CONCLUSION

This study shows a novel effect of some common drugs, which is inhibition of T₃ transport mediated by MCT8. Specifically, dexamethasone, buspirone, desethylamiodarone, and dronedarone behave as potent inhibitors of MCT8.

Genetic interaction analysis of VEGF-A rs3025039 and VEGFR-2 rs2071559 identifies a genetic profile at higher risk to develop nodular goiter

CONTEXT

Nodular goiter in patients from areas of iodine deficiency is due to the growth of follicular and endothelial cells, involving different vascular-related growth factors in its pathogenesis.

OBJECTIVE

The aim of our study was to examine the association of known single polymorphisms of vascular endothelial growth factor-A [VEGF-A], VEGF receptor-2 [VEGFR-2] and hypoxia-inducible factor-1α [HIF-1α] genes or their genetic interactions with the risk of nodular goiter development.

PATIENTS AND METHODS

116 normal subjects, without any thyroid disease, and 108 subjects with nodular goiter [subjects with goiter and at least one thyroid nodule of > 1 cm of maximum size and in absence of signs of autoimmunity] were selected from a homogeneous population living in a mild iodine deficiency geographic area. Analyses were performed on germline DNA obtained from blood samples and VEGF-A rs3025039, VEGFR-2 rs2071559, and HIF-1αrs11549465 SNPs were investigated by real-time PCR technique. The multifactor dimensionality reduction [MDR] methodology was applied to investigate the genetic interaction between SNPs. Hardy-Weinberg equilibrium was performed.

RESULTS

None of the studied polymorphisms were individually associated with a higher risk to develop nodular goiter [P > 0.05]. The combination of the VEGF-A rs3025039 and VEGFR-2 rs2071559 polymorphisms had the highest accuracy of 0.58 [P = 0.018] and the interaction of some genotypes was significantly associated with the risk of nodular goiter development.

CONCLUSIONS

Our results support a genetic interaction between the VEGF-A rs3025039 and VEGFR-2 rs2071559 polymorphisms as a predictor of the risk to develop nodular goiter in subjects coming from an area with mild iodine deficiency.

Treatment of Graves' hyperthyroidism with thionamides: a position paper on indications and safety in pregnancy

CONTEXT

Graves' disease affects 3% of women and 0.5% of men in the general population. The first line treatment of Graves' hyperthyroidism is based on the administration of antithyroid drugs (ATD), propylthiouracil (PTU), methimazole (MMI) and carbimazole. A recent warning from the Italian Drug Agency (Agenzia Italiana del Farmaco AIFA) reported the risk of MMI-induced acute pancreatitis. In addition, AIFA highlighted the possible association of MMI treatment during the first trimester of pregnancy with congenital malformations, thus recommending the use of effective contraceptive methods in women of childbearing age treated with MMI.

METHODS AND RESULTS

Revision of literature reported less than ten cases of the alleged MMI pancreatitis, allowing the inclusion of MMI in class III drug regarding the relative risk for drug-induced pancreatitis. Data available on the effect of hyperthyroidism per se on the risk of fetal malformations, although scanty, are sufficient to recommend treatment with ATD of the hyperthyroid pregnant woman. Case reports and population studies either suggesting or not suggesting MMI-induced fetal malformations do not allow unquestionable conclusions on this matter.

CONCLUSIONS

This consensus by experts from Italian Endocrine and Gynecologic Scientific Societies has edited recommendations derived form the available data and published guidelines of International Scientific Societies.

Features and outcome of differentiated thyroid carcinoma associated with Graves' disease: results of a large, retrospective, multicenter study

BACKGROUND

Whether differentiated thyroid cancer (DTC) occurring concomitantly with Graves' disease (GD) is more aggressive and bound to a less favorable outcome is controversial.

OBJECTIVE

Aim of this multicenter retrospective study was to compare baseline features and outcome of DTC patients with GD (DTC/GD+) or without GD (DTC/GD-).

PATIENTS

Enrolled in this study were 579 patients referred to five endocrine units (Cagliari, Pavia, Pisa, Siena, and Varese) between 2005 and 2014: 193 patients had DTC/GD+ , 386 DTC/GD-. Patients were matched for age, gender and tumor size. They underwent surgery because of malignancy, large goiter size, or relapse of hyperthyroidism in GD.

RESULTS

Baseline DTC features (histology, lymph node metastases, extrathyroidal extension) did not differ in the two groups, except for multifocality which was significantly more frequent in DTC/GD+ (27.5% vs. 7.5%, p < 0.0001). At the end of follow-up (median 7.5 years), 86% of DTC/GD+ and 89.6% DTC/GD- patients were free of disease. Patients with persistent or recurrent disease (PRD) had "biochemical disease" in the majority of cases. Microcarcinomas were more frequent in the DTC/GD+ group (60% vs. 37%, p < 0.0001) and had an excellent outcome, with no difference in PRD between groups. However, in carcinomas ≥ 1 cm, PRD was significantly more common in DTC/GD+ (24.4% vs. 11.5%; p = 0.005). In the whole group, univariate and multivariate analyses showed that GD+ , lymph node involvement, extrathyroidal invasion, multifocality and tall cell histotype were associated with a worse outcome. Female gender and microcarcinomas were favorable features. No association was found between baseline TSH-receptor antibody levels and outcome. Graves' orbitopathy (GO) seemed to be associated with a better outcome of DTC, possibly because patients with GO may early undergo surgery for hyperthyroidism.

CONCLUSIONS

GD may be associated with a worse outcome of coexisting DTC only if cancer is ≥ 1 cm, whereas clinical outcome of microcarcinomas is not related to the presence/absence of GD.

Very-low-calorie ketogenic diet (VLCKD) in the management of metabolic diseases: systematic review and consensus statement from the Italian Society of Endocrinology (SIE)

BACKGROUND

Weight loss is a milestone in the prevention of chronic diseases associated with high morbility and mortality in industrialized countries. Very-low calorie ketogenic diets (VLCKDs) are increasingly used in clinical practice for weight loss and management of obesity-related comorbidities. Despite evidence on the clinical benefits of VLCKDs is rapidly emerging, some concern still exists about their potential risks and their use in the long-term, due to paucity of clinical studies. Notably, there is an important lack of guidelines on this topic, and the use and implementation of VLCKDs occurs vastly in the absence of clear evidence-based indications.

PURPOSE

We describe here the biochemistry, benefits and risks of VLCKDs, and provide recommendations on the correct use of this therapeutic approach for weight loss and management of metabolic diseases at different stages of life.

Measurement of urinary free cortisol by LC-MS-MS: adoption of a literature reference range and comparison with our current immunometric method

PURPOSE

One of the best indicators of adrenal gland dysfunction is the level of free cortisol measured in the 24-h urine (UFC) which faithfully reflects the level of biologically active serum cortisol not subjected to circadian variations. Liquid chromatography coupled with tandem mass spectrometry (LC-MS-MS) is a sensitive, accurate and precise method recently available in routine laboratories that could remedy interference problems of immunoassays.

METHODS

In this study, a literature reference range for UFC measured by LC-MS-MS was verified, and UFC values measured by LC-MS-MS and immunoassay were compared. Immunometric UFC measurement was performed by ACCESS CORTISOL assay without preliminary extraction, using Beckman Coulter UniCel DxI 600 highly automated platform. Liquid chromatography-tandem mass spectrometry UFC measurement was performed by a home-made validated method using cortisol-D₄ as internal standard with preliminary deproteinization of urinary samples by centrifugal filter and injection on reverse-phase column. Cortisol was analyzed in positive ion mode with an ESI interface.

RESULTS

The reference interval from literature (11-70 μg/day) was confirmed by results obtained for healthy study group. Comparison study of the two methods highlighted a constant and proportional systematic error with a general tendency to overestimate results for the in-use method.

CONCLUSIONS

In conclusion, the direct immunometric method overestimates UFC results with respect to liquid chromatography-tandem mass spectrometry which represents the reference method. The literature reference range 11-70 μg/day was confirmed and can be adopted by our lab that will shift all UFC tests performed in routine to the mass spectrometry-based method, satisfying clinicians' request.

Serum antibodies against the insulin-like growth factor-1 receptor (IGF-1R) in Graves' disease and Graves' orbitopathy

BACKGROUND

A role of the insulin-like growth factor-1 receptor (IGF-1R) in the pathogenesis of Graves' orbitopathy (GO) has been proposed, but the existence and function of anti-IGF-1R-antibodies (IGF-1R-Abs) are debated.

METHODS

We designed a cross-sectional investigation to measure serum IGF-1R-Abs by a commercial assay in consecutive patients with Graves' disease (GD) compared with healthy subjects and patients with autoimmune thyroiditis (AT). A total of 134 subjects were screened including 27 healthy subjects, 80 GD patients (54 of whom with GO), and 27 AT patients. The main outcome measure was the prevalence of positive serum IGF-1R-Abs in GO, compared with GD without GO and with the other study groups.

RESULTS

Having established a cut-off value at 55.2 ng/ml for positive tests, positive IGF-1R-Abs were more frequent in GD (25%), than in AT (3.7%, P = 0.003) and healthy subjects (0%, P = 0.006). Within GD, there was no difference between patients with or without GO. Serum levels of IGF-1R-Abs differed across the study population (P < 0.0001), reflecting their higher concentrations in GD (P < 0.0001 vs both AT and healthy subjects), but with no difference between patients with or without GO. In patients with GO, there was an inverse correlation between serum IGF-1R-Abs and CAS (R = - 0.376, 95% CI: from - 0.373 to - 0.631; P = 0.005), the significance of which remains to be investigated.

CONCLUSIONS

Serum autoantibodies against the IFG-1R are present in one-fourth of GD patients, regardless of the presence of GO. Further functional studies are needed to investigate the significance of their inverse correlation with GO activity.

The mutational analysis in the diagnostic work-up of thyroid nodules: the real impact in a center with large experience in thyroid cytopathology

PURPOSE

Fine-needle aspiration (FNA) cytology is a mainstay in the evaluation of thyroid nodules, but fails to reach reliable results in 25-30% of cases. The role of molecular markers in helping clinical decisions has been investigated for the last years, but their clinical usefulness is still unsettled.

METHODS

Mutation analysis of BRAF, RAS genes and TERT promoter was performed in a series of 617 consecutive cytological specimens undergoing FNA.

RESULTS

The 617 nodules had the following cytological diagnosis: non diagnostic 22 (3.6%), benign 425 (68.9%), indeterminate 114 (18.5%), suspicious 11 (1.8%) and malignant 45 (7.3%). BRAF mutations were found in 31 cases (5.0%), all but two in suspicious and malignant nodules. RAS mutations were detected in 47 samples (7.6%): 25 benign (5.9%) and 19 indeterminate nodules (16.7%). TERT promoter mutation alone was detected in three samples. Histological outcome was available for 167 nodules, 81 of which proved malignant: all the 48 with suspicious or malignant cytology; 25 out of 56 (44.6%) with indeterminate and 8 out of 57 (14%) with benign cytology. BRAF mutations were associated with worse tumors pathological features. The presence of RAS mutations was indicative of follicular-patterned malignancies in 5 out of 8 benign nodules and 9 out of 11 indeterminate nodules.

CONCLUSIONS

Our study established mutational rates for BRAF and RAS genes in a large series of FNA specimens. BRAF mutations were confirmed as highly specific but not able to improve cytological diagnosis, while RAS testing proved effective in assessing malignancy in nodules with indeterminate and benign cytology.

Relationship between serum cholesterol and Graves' orbitopathy (GO): a confirmatory study

BACKGROUND

It has been suggested that high cholesterol represents a risk factor for Graves' orbitopathy (GO). In a recent cross-sectional study, a correlation between cholesterol and the presence of GO was found in patients with a Graves' disease (GD) of recent onset. To confirm this observation, we conducted a retrospective investigation in consecutive patients with GD. The primary outcome was the relationship between the presence of GO and low-density lipoprotein (LDL)-cholesterol.

METHODS

The design entailed the inclusion of consecutive patients with a GD of recent onset, with or without GO, who came to our observation to receive radioiodine over a period of 6 months, and a stratification aimed at having two homogeneous group of patients in terms of thyroid function. A total of 86 patients fulfilled the inclusion and evaded the exclusion criteria. All patients underwent an ophthalmological assessment and serum lipids were measured.

RESULTS

Serum levels of LDL-cholesterol were significantly higher in patients with GO (135.3 ± 41.3 mg/dL) compared with those without GO (106.6 ± 23.9 mg/dL, P = 0.0007). In a similar manner, serum levels of total cholesterol were higher in patients with GO (211.6 ± 44.0 mg/dL) than in those without GO (176.0 ± 27.2 mg/dL, P = 0.0001). There was no relationship between GO severity and activity and cholesterol. There was no relationship between GO and high-density lipoprotein-cholesterol or triglycerides.

CONCLUSIONS

Our study confirms a relationship between the presence of GO and cholesterol in patients with GD of recent onset. Whether lowering of cholesterol ameliorates, GO remains to be established.

mRECIST criteria to assess recurrent thyroid carcinoma treatment response after radiofrequency ablation: a prospective study

PURPOSE

Surgical removal is recommended for recurrent thyroid carcinomas (RTCs) unable to uptake radioiodine and/or not responsive to chemotherapy. However, repeated neck dissection is difficult for surgeons. Thus, radiofrequency ablation (RFA) was proposed for RTCs. The aim of this prospective study is to assess RTC treatment response after RFA, according to well-established criteria.

METHODS

Sixteen lesions in 13 patients were treated by RFA. All patients refused/were excluded from repeated surgery or other conventional therapy. CT and US examinations were performed before RFA to evaluate lesion volume and vascularization. All RFA procedures were performed under US-guidance by an 18-gauge, electrode. Treatment response was evaluated by CT, according to RECIST 1.1 and to mRECIST guidelines; CT examinations were performed during follow-up (6-18 months); the volume of residual vital tumour tissue and the percentage of necrotic tissue were estimated by contrast enhanced CT.

RESULTS

RFA was well tolerated by all patients; in two cases laryngeal nerve paralysis was observed. Mean pre-treatment volume was 4.18 ± 3.53 ml. Vital tumour tissue and percentage of necrosis at 6, 12 and 18 months were 0.18 ± 0.25, 0.11 ± 0.13, 0.29 ± 0.40 ml and 91.9 ± 11.1, 90.4 ± 13.3, 80.8 ± 23.1%. According to RECIST 1.1, target lesion response was classified as complete response (CR) in one case, partial response (PR) in 11/16, stable disease in 4/16 cases. According to mRECIST, 11/16 cases were classified as CR and the remaining 5 as PR.

CONCLUSION

RFA is a safe procedure to treat the viable tumour tissue and to reduce the RTC volume; as to the criteria to assess treatment response, mRECIST appears to be more accurate.

Thyroid ultrasonography reporting: consensus of Italian Thyroid Association (AIT), Italian Society of Endocrinology (SIE), Italian Society of Ultrasonography in Medicine and Biology (SIUMB) and Ultrasound Chapter of Italian Society of Medical Radiology (SIRM)

Thyroid ultrasonography (US) is the gold standard for thyroid imaging and its widespread use is due to an optimal spatial resolution for superficial anatomic structures, a low cost and the lack of health risks. Thyroid US is a pivotal tool for the diagnosis and follow-up of autoimmune thyroid diseases, for assessing nodule size and echostructure and defining the risk of malignancy in thyroid nodules. The main limitation of US is the poor reproducibility, due to the variable experience of the operators and the different performance and settings of the equipments. Aim of this consensus statement is to standardize the report of thyroid US through the definition of common minimum requirements and a correct terminology. US patterns of autoimmune thyroid diseases are defined. US signs of malignancy in thyroid nodules are classified and scored in each nodule. We also propose a simplified nodule risk stratification, based on the predictive value of each US sign, classified and scored according to the strength of association with malignancy, but also to the estimated reproducibility among different operators.

Rehabilitative orbital decompression for Graves' orbitopathy: results of a randomized clinical trial

PURPOSE

Orbital decompression (OD) is a consolidated procedure for the treatment of exophthalmos in Graves' orbitopathy (GO). The efficacy of the various procedures remains unclear due to the variability of the techniques used. To address this issue, we performed a randomized clinical trial to compare the efficacy of two surgical techniques. The primary endpoint was the reduction in proptosis. Secondary aims were the risk of post-operative diplopia (POD) in primary gaze and other surgical complications.

PATIENTS

38 patients (76 orbits) affected with GO were enrolled and randomized into single lateral decompression (LD) (n = 19) or balanced medial plus lateral wall decompression (MLD) (n = 19). Following surgery, patients were seen for a follow-up ophthalmological evaluation at 6 months. Pre-operative diplopia in secondary gaze was present in 13/38 patients (34.2%, 8/19 treated with LD and 5/19 treated with MLD).

RESULTS

The reduction of exophthalmos was greater in patients treated with MLD (5.1 ± 1.5 mm, range 2-8 mm) than in those treated with LD (3.5 ± 1.3 mm, range 1-6.5 mm) (p = 0.01). The overall incidence of POD in primary gaze was 5/38 (13.2%) and all of these patients had pre-operative diplopia in secondary gaze (5/13, 38.5%, vs patients with no pre-operative diplopia p = 0.005). Two of 19 patients (10.5%) treated with LD and 3/19 (15.8%) treated with MLD, developed POD in primary gaze, with no statistical difference between the two techniques.

CONCLUSION

MLD provides a better result in terms of proptosis reduction compared to LD. The two techniques used here appear to have a similar safety profile in terms of POD. Pre-operative diplopia in the secondary gaze remains a major risk factor for development of POD.

Antioxidant effects of β-carotene, but not of retinol and vitamin E, in orbital fibroblasts from patients with Graves' orbitopathy (GO)

BACKGROUND

Oxidative stress is involved in the pathogenesis of Graves' orbitopathy (GO) and several antioxidant agents, namely, selenium, quercetin, enalapril, vitamin C, N-acetyl-L-cysteine, and melatonin, have been shown to reduce oxidative stress and its consequences in primary culture of orbital fibroblasts. In addition, selenium is effective for the treatment of mild GO. Here, we investigated the action of three additional antioxidants in orbital fibroblasts, namely, retinol, β-carotene, and vitamin E.

METHODS

Primary cultures of orbital fibroblasts were established from GO patients and control subjects. To induce oxidative stress, cells were treated with H₂O₂, after which glutathione disulfide (GSSG) (a parameter of oxidative stress), cell proliferation, hyaluronic acid, TNFα, IFNγ, and IL1β were measured.

RESULTS

H₂O₂-dependent oxidative stress (augmented GSSG) was associated with increased cell proliferation and cytokine release. All the three antioxidant substances reduced GSSG in both GO and control fibroblasts. β-carotene reduced proliferation in GO, but not in control fibroblasts. IL1β was reduced by all three substances. Retinol reduced IFNγ in GO and control fibroblasts.

CONCLUSIONS

Our study supports an antioxidant role of retinol, β-carotene, and vitamin E in orbital fibroblasts from patients with GO and provides a basis for a possible clinical use these substances.

Italian consensus on diagnosis and treatment of differentiated thyroid cancer: joint statements of six Italian societies

BACKGROUND

Thyroid nodules are a common clinical problem, and differentiated thyroid cancer is becoming increasingly prevalent.

METHODS

Six scientific Italian societies entitled to cure thyroid cancer patients (the Italian Thyroid Association, the Medical Endocrinology Association, the Italian Society of Endocrinology, the Italian Association of Nuclear Medicine and Molecular Imaging, the Italian Society of Unified Endocrine Surgery and the Italian Society of Anatomic Pathology and Diagnostic Cytology) felt the need to develop a consensus report based on significant scientific advances occurred in the field.

OBJECTIVE

The document includes recommendations regarding initial evaluation of thyroid nodules, clinical and ultrasound criteria for fine-needle aspiration biopsy, initial management of thyroid cancer including staging and risk assessment, surgical management, radioiodine remnant ablation, and levothyroxine therapy, short-term and long-term follow-up strategies, and management of recurrent and metastatic disease. The objective of this consensus is to inform clinicians, patients, researchers, and health policy makers about the best strategies (and their limitations) relating to the diagnosis and treatment of differentiated thyroid cancer.

Use of low-dose radioiodine ablation for Graves' orbitopathy: results of a pilot, perspective study in a small series of patients

OBJECTIVE

Elimination of thyroid antigens by total thyroid ablation (TTA), namely, thyroidectomy followed by radioiodine, may be beneficial for Graves' Orbitopathy (GO). TTA is usually performed with a ¹³¹I dose of 30 mCi. In Italy, this dose must be followed by a 24-h protected hospitalization, with increase in the waiting lists. In contrast, a 15 mCi dose can be given without hospitalization and with lower costs. Here, we investigated whether a lower dose of radioiodine can be used to ablate thyroid remnants in patients with GO, after thyroidectomy.

METHODS

The study was performed in two small groups of consecutive thyroidectomized patients (six patients per group) with Graves' hyperthyroidism and GO. Patients underwent ablation with either 15 or 30 mCi of ¹³¹I following treatment with recombinant human TSH (rhTSH). The primary outcome was rhTSH-stimulated serum thyroglobulin (Tg) at 6 months. The secondary outcome was baseline Tg at 6 months.

RESULTS

Baseline Tg and rhTSH-stimulated Tg after at 6 months did not differ between two groups, suggesting a similar extent of ablation. rhTSH-stimulated Tg was reduced significantly compared with rhTSH-stimulated Tg at ablation in both groups. GO outcome following treatment with intravenous glucocorticoids did not differ between the two groups.

CONCLUSIONS

Our findings may provide a preliminary basis for the use of a 15 mCi dose of radioiodine upon rhTSH stimulation in thyroidectomized patients with Graves' hyperthyroidism and GO.

Action of three bioavailable antioxidants in orbital fibroblasts from patients with Graves' orbitopathy (GO): a new frontier for GO treatment?

OBJECTIVE

Oxidative stress is involved in the pathogenesis of Graves' orbitopathy (GO) and an antioxidant approach has been advocated for GO treatment. Here, we investigated the action of three antioxidants in orbital fibroblasts, namely, vitamin C, N-acetyl-L-cysteine, and melatonin.

METHODS

Primary cultures of orbital fibroblasts from six GO patients and six control subjects were established. Cells were treated with H₂O₂ to induce oxidative stress. Cell vitality assays were performed to determine the non-cytotoxic dose of each antioxidant. The following assays were performed: glutathione disulfide (GSSG), as a measure of oxidative stress, cell proliferation, hyaluronic acid (HA), TNFα, IFNγ, and IL1β.

RESULTS

H₂O₂ induced oxidative stress (augmented GSSG), increased cell proliferation as well as cytokine release, but did not affect HA release. All of the three antioxidant substances reduced H₂O₂-dependent oxidative stress. Vitamin C reduced proliferation in GO, but not in control fibroblasts. N-acetyl-L-cysteine reduced proliferation and IFNγ in GO, and HA and IL1β in both GO and control fibroblasts. Melatonin reduced IL1β and HA in GO and control fibroblasts, and IFNγ only in GO fibroblasts.

CONCLUSIONS

Our study provides evidence in support of an antioxidant role of vitamin C, N-acetyl-L-cysteine and melatonin in orbital fibroblasts. Some of the effects of these compounds are exclusive to GO fibroblasts, whereas some other are observed also in control fibroblasts. Our observations provide a basis for a possible clinical use of these substances in patients with GO.

Binding of thyroglobulin (Tg) to the low-density lipoprotein receptor-associated protein (RAP) during the biosynthetic pathway prevents premature Tg interactions with sortilin

OBJECTIVE

Sortilin, a Vps10p family member, is expressed by thyroid epithelial cells (TEC), where it binds to internalized thyroglobulin (Tg) molecules. Premature binding of Tg to sortilin during biosynthesis may cause intracellular retention of Tg. Such a premature interaction may be prevented by one or more inhibitor/s. Because both sortilin and Tg bind to the low-density lipoprotein receptor-associated protein (RAP), we investigated whether RAP serves such a function.

METHODS

Immunofluorescence staining for sortilin, Tg, and RAP was performed in FRTL-5 cells. Co-immunoprecipitation experiments were performed in extracts from FRTL-5 or COS-7 cells, the former co-transfected with Tg and/or RAP and/or sortilin, or in thyroid extracts from RAP KO mice.

RESULTS

Tg and sortilin did not co-localize in FRTL-5 cells following inhibition of protein synthesis, suggesting that newly synthesized, endogenous sortilin and Tg do not interact, in confirmation of which an anti-sortilin antibody did not co-precipitate Tg in FRTL-5 cells. In contrast, Tg co-localized with RAP in FRTL-5 cells. Co-immunoprecipitation of Tg with an anti-sortilin antibody in COS-7 cells transfected with sortilin and Tg was abolished when cells were co-transfected with RAP, indicating that RAP prevents binding of Tg to sortilin during biosynthesis, in confirmation of which an anti-sortilin antibody co-precipitated Tg in thyroid extracts from RAP KO mice to a greater extent than in thyroid extracts from WT mice.

CONCLUSIONS

Tg does not bind prematurely to sortilin because of its interaction with RAP during protein biosynthesis. These findings add new information to the knowledge of thyroid physiology.

Graves' orbitopathy, idiopathic orbital inflammatory pseudotumor and Epstein-Barr virus infection: a serological and molecular study

OBJECTIVE

One of the hypotheses on the pathogenesis of autoimmune diseases, including Graves' disease (GD) and Graves' orbitopathy (GO), involves bacterial or viral infections. Recently, Epstein-Barr virus (EBV) has been proposed to play a role in the pathogenesis of idiopathic orbital inflammatory pseudotumor (IOIP) in Asians. The aim of the present study was to investigate the possible association of GO with EBV infection/exposure, as compared with IOIP, using serum and tissue samples, as well as primary cultures of orbital fibroblasts.

METHODS

Thirty-one patients were studied, including four with IOIP, ten with GO, nine with GD without GO and eight control patients without IOIP, GD and GO. All patients with IOIP and GO underwent orbital decompression. Control patients underwent palpebral surgery. Fibroadipose orbital tissue samples were collected. Serum anti-EBV antibodies were measured in all patients. EBV-DNA was measured in blood samples, orbital tissue samples and primary cultures of orbital fibroblasts.

RESULTS

Serum assays showed that the vast majority of patients have had a previous exposure to EBV, but no one had an acute infection. EBV-DNA was detected in ~40% of blood samples from GO, GD and control patients, but in none of the IOIP samples. EBV-DNA was not detected in any of the orbital tissue samples tested or in primary cultures of orbital fibroblasts.

CONCLUSIONS

EBV infection does not seem to be associated with GD, GO and IOIP in Caucasians. Whether EBV is involved in IOIP in Asians or other populations remains to be confirmed.

Effects of selenium on short-term control of hyperthyroidism due to Graves' disease treated with methimazole: results of a randomized clinical trial

OBJECTIVE

In spite of previous conflicting results, an adjuvant role of selenium in the treatment of Graves' disease (GD) hyperthyroidism has been proposed. To address this issue, a randomized clinical trial was carried out aimed at investigating whether selenium is beneficial on the short-term control of GD hyperthyroidism treated with methimazole (MMI).

METHODS

Thirty newly diagnosed hyperthyroid GD patients were randomly assigned to treatment with: (i) MMI or (ii) MMI plus selenium. Primary outcomes were: control of hyperthyroidism and clinical and biochemical manifestations of hyperthyroidism [heart rate, cholesterol, sex hormone-binding globulin (SHBG), hyperthyroidism symptoms] at 90 days.

RESULTS

Baseline features of the two groups did not differ. Serum selenium at baseline was similar in the two groups and within the recommended range to define selenium sufficiency. Selenium increased with treatment in the MMI-selenium group and became significantly higher than in the MMI group. Serum malondialdehyde, a marker of oxidative stress, was similar in the two groups and decreased significantly with treatment, with no difference between groups. Administration of MMI was followed by a reduction of FT₃ and FT₄, with no difference between groups. Heart rate, SHBG and symptoms of hyperthyroidism decreased, whereas total cholesterol increased in both groups with no difference between groups.

CONCLUSIONS

Our study, carried out in a selenium-sufficient cohort of GD patients, failed to show an adjuvant role of selenium in the short-term control of hyperthyroidism. However, selenium might be beneficial in patients from selenium-deficient areas, as well as in the long-term outcome of antithyroid treatment.

The phenotype of newly diagnosed Graves' disease in Italy in recent years is milder than in the past: results of a large observational longitudinal study

OBJECTIVE

The Merseburg triad (hyperthyroidism, goiter, and orbitopathy) characterizes classical description of Graves' disease (GD). Aim of this observational, longitudinal study was to evaluate the current clinical features of newly diagnosed GD in Italy.

MATERIALS AND METHODS

In two Northern Italy centers (Varese and Pavia), 283 consecutive patients (211 women, 72 men; mean age 47.4 years) with newly diagnosed GD were recruited in the years 2010-2014. Diagnosis was based on established criteria, and thyroid volume was assessed by ultrasonography. A clinical severity score (CSS) to assess the overall disease severity was developed by grading each component of the Merseburg triad.

RESULTS

At diagnosis, 45 % of patients had no goiter, and 30 % had a small goiter. The proportion of goitrous patients was much lower than in two Italian studies performed 20-30 years ago. Hyperthyroidism was subclinical in 16 % and mild in 29 % of patients, and Graves' orbitopathy was present in 20 %, usually mild, and active in only 2.5 % of patients. Using the CSS, less than half (44 %) of the patients had severe GD, while 22 % had mild and 34 % moderate disease. CSS was associated with a significantly higher risk of poorly controlled hyperthyroidism at 6 months.

CONCLUSIONS

In Italy, a relevant proportion of Graves' patients at diagnosis have mild to moderate GD; about half of them have no goiter, slightly less than one-fifth have subclinical hyperthyroidism, and only 20 % have GO. Thus, the clinical phenotype of GD is milder than in the past, possibly due to both earlier diagnosis and treatment, and improved iodine nutrition.

Recommendations for treatment of hypothyroidism with levothyroxine and levotriiodothyronine: a 2016 position statement of the Italian Society of Endocrinology and the Italian Thyroid Association

Levothyroxine (L-T4) is recommended as lifelong replacement therapy for hypothyroidism. Recent clinical and experimental data support the addition of levotriiodothyronine (L-T3) treatment in some selected hypothyroid patients when their symptoms persist and their quality of life remains impaired despite adequate L-T4 monotherapy. An increase in L-T3 prescriptions has been recently observed in Italy due to availability of different L-T3 formulations, making it possible to clinicians to prescribe L-T3 alone or in combination with L-T4. The aim of the present position statement was to define the correct clinical indications, schedule, duration of treatment and contraindications of combined treatment with L-T4 and L-T3 in hypothyroid patients in an attempt to guide clinicians and to avoid potential adverse effects of overtreatment.

Statins are not a risk factor for liver damage associated with intravenous glucocorticoid pulse therapy for Graves' orbitopathy

OBJECTIVE

Acute liver damage (ALD) is associated with high-dose intravenous (iv) glucocorticoid (GC) (ivGC) pulse therapy in ~1 % of patients for Graves' orbitopathy (GO). It has been proposed that statins may increase the risk of ALD. Here we investigated the frequency of ALD according to the assumption of statins in a large retrospective cohort study.

METHODS

We studied 1076 consecutive patients with GO given ivGC. ALD was defined as an increase in alanine aminotransferase ≥300 U/l.

RESULTS

At the time of ivGC, 62 patients were taking statins and 1014 were not. The frequency of ALD has been reported to be 1.2 cases/100,000 statins users and 1300/100,000 in GO patients given ivGC. Thus, the expected frequency of ALD in patients given both statins and ivGC is 1560/100,000. Transferring these data to our series, one would have expected at least 0.96 cases of ALD (~one case), in the 62 patients given both ivGC and statins. However, no cases of ALD were observed in patients given statins, and the previously reported 14 cases of ALD in this series were seen in patients who were not taking statins.

CONCLUSIONS

The lack of observation of cases of ALD in patients given ivGC and statins is quite reassuring. Although caution should be applied to any patient candidate to ivGC treatment and this should be particularly accurate in patients given statins, our findings somehow justify the use of ivGC in patients under statins, although further studies in larger cohorts are needed to confirm our conclusions.

Management of hyperthyroidism due to Graves' disease: frequently asked questions and answers (if any)

Graves' disease is the most common cause of hyperthyroidism in iodine-replete areas. Although progress has been made in our understanding of the pathogenesis of the disease, no treatment targeting pathogenic mechanisms of the disease is presently available. Therapies for Graves' hyperthyroidism are largely imperfect because they are bound to either a high rate of relapsing hyperthyroidism (antithyroid drugs) or lifelong hypothyroidism (radioiodine treatment or thyroidectomy). Aim of the present article is to offer a practical guidance to the reader by providing evidence-based answers to frequently asked questions in clinical practice.

Intracellular retention of thyroglobulin in the absence of the low-density lipoprotein receptor-associated protein (RAP) is likely due to premature binding to megalin in the biosynthetic pathway

OBJECTIVE

The low-density lipoprotein receptor associated protein (RAP) is expressed by thyroid epithelial cells (TEC) in a TSH-dependent manner. In the thyroid RAP functions as a molecular chaperone for the thyroglobulin (Tg) endocytic receptor megalin/LRP2, which is retained intracellularly in RAP KO mice rather than being expressed on the apical membrane of TEC, its usual location. RAP binds also to Tg, which is also retained intracellularly in RAP KO mice, thereby suggesting a role of RAP in Tg secretion. Here we investigated whether Tg intracellular retention in the absence of RAP is due to premature Tg-megalin interactions during the biosynthetic pathway or to a direct action of RAP on Tg secretion.

METHODS

We performed immunoprecipitation experiments in thyroid extracts from RAP KO and WT mice. In addition, we investigated Tg secretion in COS-7 cells co-transfected with human RAP (hRAP) and mouse Tg (mTg).

RESULTS

An anti-megalin megalin precipitated greater amounts of Tg in thyroid extracts from RAP KO than from WT mice, suggesting increased intracellular interactions between megalin and Tg in the absence of RAP. COS-7 cells transiently transfected with hRAP, mTg or both, expressed the two proteins accordingly. RAP was found almost exclusively in cell extracts, whereas Tg was found both in extracts and media, as expected from the knowledge that RAP is ER-resident and that Tg is secreted. Regardless of whether cells were transfected with mTg alone or were co-transfected with hRAP, similar proportions of the total Tg synthesized were detected in cell extracts and media.

CONCLUSIONS

The intracellular retention of Tg in the absence of RAP is likely due to its premature interaction with megalin, whereas RAP does not seem to affect Tg secretion directly.

Outcomes and Risk Factors for Complications of Laser Ablation for Thyroid Nodules: A Multicenter Study on 1531 Patients

BACKGROUND

Image-guided laser ablation therapy (LAT) of benign thyroid nodules demonstrated favorable results in randomized trials with fixed modalities of treatment. The aim of this retrospective multicenter study was to assess the effectiveness, tolerability, and complications of LAT in a large consecutive series of patients from centers using this technique in their routine clinical activity.

PATIENTS

Clinical records of 1534 consecutive laser-treated nodules in 1531 patients from eight Italian thyroid referral centers were assessed. Inclusion criteria were as follows: solid or mixed nodules with fluid component up to 40%; benign cytological findings; and normal thyroid function.

METHODS

LAT was performed with a fixed-power protocol, whereas the number of applicators and illumination times were different according to target size. From one to three illuminations with pullback technique and with a total energy delivery based on the nodule volume were performed during the same session. Patients were evaluated during LAT, within 30 days, and 12 months after the procedure.

RESULTS

Total number of treatments was 1837; 1280 (83%) of nodules had a single LAT session. Mean nodule volume decreased from 27 ± 24 mL at baseline to 8 ± 8 mL 12 months after treatment (P < .001). Mean nodule volume reduction was 72% ± 11% (range 48%-96%). This figure was significantly greater in mixed nodules (79% ± 7%; range 70%-92%) because they were drained immediately before laser illumination. Symptoms improved from 49% to 10% of cases (P < .001) and evidence of cosmetic signs from 86% to 8% of cases (P < .001). Seventeen complications (0.9%) were registered. Eight patients (0.5%) experienced transitory voice changes that completely resolved at the ear-nose-throat examination within 2-84 days. Nine minor complications (0.5%) were reported. No changes in thyroid function or autoimmunity were observed.

CONCLUSIONS

Real practice confirmed LAT as a clinically effective, reproducible, and rapid outpatient procedure. Treatments were well tolerated and risk of major complications was very low.

Pregnancy outcome in women treated with methimazole or propylthiouracil during pregnancy

PURPOSE

Control of thyroid function in hyperthyroid women during pregnancy is based on antithyroid drugs (ATD) [propylthiouracil (PTU) and methimazole (MMI)]. While a teratogenic effect has been suggested for MMI and, more recently, for PTU, a clear demonstration is still lacking. Aim of this study was to assess the safety of ATD during pregnancy.

METHODS

A total of 379 pregnancies were retrospectively recruited in eight Italian Departments of Endocrinology and divided in five groups: (1) MMI-treated and euthyroid throughout pregnancy (n = 89); (2) MMI-treated and hyperthyroid on at least two occasions (n = 35); (3) PTU-treated women and euthyroid throughout pregnancy (n = 32); (4) PTU-treated women and hyperthyroid on at least two occasions (n = 20); and (5) non-ATD-treated (n = 203). Data on maternal thyroid function, miscarriages, type of delivery, neonatal weight, length and TSH, perinatal complications and congenital malformation were analyzed.

RESULTS

The gestational age at delivery, the rate of vaginal delivery, neonatal weight, length and neonatal TSH did not significantly differ among groups. In all groups, the rates of spontaneous miscarriage and of major congenital malformations were not higher than in the general population. No newborns were born with a phenotype similar to those described in the "MMI embryopathy".

CONCLUSIONS

While a clear demonstration of a teratogenic effect of MMI is currently lacking, it seems reasonable to follow the current guidelines and advice for PTU treatment in hyperthyroid women during the first trimester of pregnancy. Further, large and prospective worldwide studies will be needed to fully clarify the issue of ATD safety during pregnancy.

Total thyroid ablation in Graves' orbitopathy

Graves' orbitopathy (GO) is an autoimmune condition almost always associated with autoimmune thyroid disease, especially Graves' disease (GD). According to the most widely accepted model, the autoantigens responsible for GO would include molecules expressed by thyroid epithelial cells that are present also in orbital tissues. The high likelihood that the etiologies of GO and of the underlying autoimmune thyroid diseases are somehow linked is confirmed by the very close relationship between GO, the onset and the course of Graves' diseases, the size of the thyroid gland, and most importantly, thyroid function and thyroid treatment. Based on these considerations, it has been proposed that complete removal of thyroid antigens and of thyroid infiltrating lymphocytes, the so-called total thyroid ablation (TTA), may be followed by an attenuation of the immune reaction against orbital antigens, and ultimately by an amelioration of GO. The possibility that TTA, achieved by near total thyroidectomy followed by radioiodine, may be beneficial for GO was initially suggested by two retrospective studies and more recently by two prospective, randomized clinical trials conducted in patients with moderate GO treated with intravenous glucocorticoids. Although there seemed to be no difference in the long term, compared with near total thyroidectomy alone TTA was associated with a shorter time required for GO to improve, or anyway to reach its best possible outcome, and with a lesser requirement for additional treatments for GO to improve. Whether this is sufficient to offer ablation to patients remains a matter of discussion. At present, this procedure could be offered only to patients scheduled to thyroidectomy and glucocorticoid treatment.

Long-term outcome of Graves' orbitopathy following high-dose intravenous glucocorticoids and orbital radiotherapy

OBJECTIVE

Intravenous (iv) glucocorticoids (GC) (ivGC) and orbital radiotherapy (ORT) are commonly used in active Graves' orbitopathy (GO), with favorable outcomes in up to 80% of patients. However, little is known on the factors that may affect GO outcome in the long term, an issue that we investigated here.

METHODS

We studied retrospectively 96 untreated patients with GO, identified out of 787 consecutive patients who came to our GO Clinic for a follow-up visit between September 2010 and June 2013. After the first observation, patients were treated with ivGC and ORT and were then re-examined after a median period of 55.5 months. The primary end-point was the possible relation between GO outcome and several individual variables.

RESULTS

Exophthalmometry, eyelid aperture, CAS, diplopia and visual acuity (the latter only in patients with an initial reduction) improved significantly after treatment. Overall, 67.7% of patients had improved and were considered as responders, whereas the remaining (29.1% stable and 4.5% worsened) were considered as non-responders. Age, smoking, thyroid volume, thyroid treatment, serum anti-TSH receptor autoantibodies and individual GO features at first observation did not affect the outcome of GO, which, in contrast, was affected by gender and by the time elapsed between first and last observation. Thus, the prevalence of responders was higher in females (76.4 vs 48% in males, P = 0.02) and the time elapsed between first and last observation was greater in responders (58 vs 39 months in non-responders, P = 0.02). Whereas the prevalence of responders and non-responders was similar up to 36 months, there was an increase in responders beginning between 37 and 48 months and reaching a peak of ~80% between 61 and 72 months, to plateau thereafter.

CONCLUSIONS

Given the limitations of retrospective investigations, our study confirms that the combination of GC and ORT is effective in GO and shows that females have greater chances to respond to treatment. The notorious tendency of GO to improve spontaneously with time most likely contributes the long-term outcome of the eye syndrome.

Prophylactic central compartment lymph node dissection in papillary thyroid carcinoma: clinical implications derived from the first prospective randomized controlled single institution study

BACKGROUND

The benefits of prophylactic central compartment lymph node dissection (pCCND) in papillary thyroid cancer (PTC) are still under investigation. This treatment seems to reduce PTC recurrence/mortality rates but has a higher risk of surgical complications. The lack of prospective randomized trials does not allow definitive recommendations. The aim of this prospective randomized controlled study was to evaluate the clinical advantages and disadvantages of pCCND.

PATIENTS

A total of 181 patients with PTC without evidence of preoperative/intraoperative lymph node metastases (cN0) were randomly assigned to either Group A (n = 88) and treated with total thyroidectomy (TTx) or Group B (n = 93) and treated with TTx + pCCND.

RESULTS

After 5 years of followup, no difference was observed in the outcome of the two groups. However, a higher percentage of Group A were treated with a higher number of (131)I courses (P = .002), whereas a higher prevalence of permanent hypoparathyroidism was observed in Group B (P = .02). No preoperative predictors of central compartment lymph node metastases (N1a) were identified. Only three patients were upstaged, and the therapeutic strategy changed in only one case.

CONCLUSIONS

cN0 patients with PTC treated either with TTx or TTx + pCCND showed a similar outcome. One advantage of TTx + pCCND was a reduced necessity to repeat (131)I treatments, but the disadvantage was a higher prevalence of permanent hypoparathyroidism. Almost 50% of patients with PTC had micrometastatic lymph nodes in the central compartment, but none of the presurgical features analyzed, including BRAF mutation, was able to predict their presence; moreover, to be aware of their presence does not seem to have any effect on the outcome.

Role of genetic and non-genetic factors in the etiology of Graves' disease

In spite of the advancements in understanding the pathogenic mechanisms of Graves' disease (GD), its ultimate cause remains elusive. The majority of investigators agree that GD is likely a multifactorial disease, due to a complex interplay of genetic and non-genetic factors that lead to the loss of immune tolerance to thyroid antigens and to the initiation of a sustained autoimmune reaction. Twin and family studies support a role of genetic factors, among which the HLA complex, CD40, CTLA-4, PTPN22, FCRL3, thyroglobulin, and the TSH receptor may be involved. Among non-genetic factors, iodine, infections, psychological stress, gender, smoking, thyroid damage, vitamin D, selenium, immune modulating agents, and periods of immune reconstitution may contribute the development of the diseases. Here we review in detail the respective role of genetic and non-genetic factors in the etiology of GD, taking advantage of the great bulk of data generated especially over the past 30 years.

Exploring the concept of eating dyscontrol in severely obese patients candidate to bariatric surgery

Eating dyscontrol constitutes a potential negative predictor for the outcome of treatment strategies for obese patients. The aim of this study was to examine the qualitative characteristics of eating dyscontrol in obese patients who engage in binge eating (BE) compared with those who do not (NBE), and to analyse the relationship between eating dyscontrol and axis-I, axis-II, spectrum psychopathology using instruments that explore mood, panic-agoraphobic, social-phobic, obsessive-compulsive and eating disorders spectrum psychopathology (SCI-MOODS-SR, SCI-PAS-SR, SCI-SHY-SR, SCI-OBS-SR, SCI-ABS-SR). This was a cross-sectional study involving a clinical sample of adult obese patients with severe obesity (average body mass index = 45 ± 8 kg m(-2) ) and candidate to bariatric surgery who were recruited between November 2001 and November 2010 at the Obesity Center of the Endocrinology Unit, University Hospital of Pisa. All participants completed a face-to-face interview, including a diagnostic assessment of axes-I and II mental disorders (using the Structured Clinical Interview for Manual of Mental Disorders, fourth edition [SCID]-I and SCID-II) and filled out self-report spectrum instruments. Among obese patients not affected by BE, eating dyscontrol was highly represented. Indeed, 39.7% (N = 177) of subjects endorsed six or more items of the Anorexia-Bulimia Spectrum Self-Report, lifetime version domain exploring this behaviour. The cumulative probability of having axis-I, axis-II and a spectrum condition disorder increased significantly with the number of eating dyscontrol items endorsed. In both BE and NBE obese subjects, eating dyscontrol may represent an independent dimension strongly related to the spectrum psychopathology and axes I/II disorders. A systematic screening for eating dyscontrol symptoms by means of self-report spectrum instruments may be valuable to assign specific treatment strategies.

Fuel homeostasis and locomotor behavior: role of leptin and melanocortin pathways

BACKGROUND

While it is now accepted that genes and their products affect food intake, the concept that locomotor behavior or the propensity for physical activity is controlled by neuro hum oral regulators is frequently underappreciated. In mammals, complex interactions have developed to allow the cross-talk between fuel homeostasis and physical activity.

AIM

The aim of this review is to provide a synopsis of the influence of the leptin-melanocortin pathway, a well-studied pivotal player in body weight regulation, on locomotor behaviors.

CONCLUSIONS

In rodents, reductions in leptin levels that physiologically occur following acute food deprivation or a reduction of the fat mass consequent to prolonged caloric restrictions are associated with a decrease in total locomotor activity and simultaneous increase in food-anticipatory activity, a locomotor behavior which reflects a foraging attitude. These actions can be prevented by leptin administration and are at least partially mediated by the neurons of the melanocortin pathway. In humans, twin studies have attributed to genetic factors approximately 50% of the variance of physical activity. An elevated number of the genes or loci which may affect physical activity are involved in body weight homeostasis. Polymorphisms of the melanocortin-4 and leptin receptors have repeatedly been associated with the level of physical activity. Unraveling the complexity of the regulation of locomotor behavior and the interconnections with the pathways involved in energy homeostasis may help explain the substantial individual variability in physical activities in humans and disentangle the harmful effects of sedentary lifestyle, which may be distinct from the detrimental effects of obesity.

Thyroglobulin autoantibodies switch to immunoglobulin (Ig)G1 and IgG3 subclasses and preserve their restricted epitope pattern after 131I treatment for Graves' hyperthyroidism: the activity of autoimmune disease influences subclass distribution but not epitope pattern of autoantibodies

The subclass distribution of thyroglobulin autoantibodies (TgAb) is debated, whereas their epitope pattern is restricted. Radioidine ((131)I) treatment for Graves' disease (GD) induces a rise in TgAb levels, but it is unknown whether it modifies subclass distribution and epitope pattern of TgAb as well. We collected sera from GD patients before (131) I treatment and 3 and 6 months thereafter. We measured total TgAb, TgAb light chains and TgAb subclasses by enzyme-linked immunosorbent assay (ELISA) in 25 patients. We characterized the TgAb epitope pattern in 30 patients by inhibiting their binding to (125-) (I) Tg by a pool of four TgAb-Fab (recognizing Tg epitope regions A, B, C and D) and to Tg in ELISA by each TgAb-Fab. Total TgAb immunoglobulin (Ig)G rose significantly (P = 0.024). TgAb κ chains did not change (P = 0.052), whereas TgAb λ chains increased significantly (P = 0.001) and persistently. We observed a significant rise in IgG1 and IgG3 levels after (131)I (P = 0.008 and P = 0.006, respectively), while IgG2 and IgG4 levels did not change. The rise of IgG1 was persistent, that of IgG3 transient. The levels of inhibition of TgAb binding to Tg by the TgAb-Fab pool were comparable. A slight, non-significant reduction of the inhibition by the immune-dominant TgAb-Fab A was observed 3 and 6 months after (131)I. We conclude that (131)I treatment for GD increases the levels of the complement-activating IgG1 and IgG3 subclasses and does not influence significantly the epitope pattern of TgAb. In autoimmune thyroid disease subclass distribution of autoantibodies is dynamic in spite of a stable epitope pattern.

Long-term efficacy of ultrasound-guided laser ablation for benign solid thyroid nodules. Results of a three-year multicenter prospective randomized trial

BACKGROUND

The aim of the present trial on ultrasound (US)-guided laser ablation therapy (LAT) of solid thyroid nodules is to assess long-term clinical efficacy, side effects, and predictability of outcomes in different centers operating with the same procedure.

PATIENTS

Two hundred consecutive patients were randomly assigned to a single LAT session (group 1, 101 cases) or to follow-up (group 2, 99 cases) at four thyroid referral centers. Entry criteria were: solid thyroid nodule with volume of 6-17 mL, repeat benign cytological findings, normal thyroid function, no autoimmunity, and no thyroid gland treatment.

METHODS

Group 1: LAT was performed in a single session with two optical fibers, a 1064 nm Nd-YAG laser source, and an output power of 3 W. Volume and local symptom changes were evaluated 1, 6, 12, 24, and 36 months after LAT. Side effects and tolerability of treatment were registered. Group 2: Follow-up with no treatment.

RESULTS

One patient was lost to follow-up in each group. Group 1: Volume decrease after LAT was -49 ± 22%, -59 ± 22%, -60 ± 24%, and -57 ± 25% at 6, 12, 24, and 36 months, respectively (P < .001 vs baseline). LAT resulted in a nodule reduction of >50% in 67.3% of cases (P < .001). Local symptoms decreased from 38 to 8% of cases (P = .002) and cosmetic signs from 72 to 16% of cases (P = .001). Baseline size, presence of goiter (P = .55), or US findings (fluid component ≤ 20% [P = .84], halo [P = .46], vascularization [P = .98], and calcifications [P = .06]) were not predictive factors of a volume decrease > 50%. The procedure was well tolerated in most (92%) cases. No changes in thyroid function or autoimmunity were observed. In group 2, nodule volume increased at 36 months (25 ± 42%; P = .04). The efficacy and tolerability of the procedure were similar in different centers.

CONCLUSIONS

A single LAT treatment of solid nodules results in significant and persistent volume reduction and local symptom improvement, in the absence of thyroid function changes.

Detection of metastases from differentiated thyroid cancer by different imaging techniques (neck ultrasound, computed tomography and [18F]-FDG positron emission tomography) in patients with negative post-therapeutic ¹³¹I whole-body scan and detectable serum thyroglobulin levels

INTRODUCTION

DTC patients having detectable Tg and negative post-therapeutic (131)I-WBS have to be investigated by different imaging techniques to detect metastases.

PURPOSE

Comparison of neck US, CT and [18F]-FDG PET scan.

METHODS

In 49 DTC patients with biochemical disease, neck was examined by US, CT and [18F]-FDG PET. FNA was performed and Tg was determined by FNA-Tg in selected cases of suspicious lymph nodes. Thorax was examined by CT and PET. Serum Tg was measured on LT4 therapy (basal Tg) and after the stimulation with recombinant human TSH (peak Tg).

RESULTS

A thyroid remnant was seen by US, CT and PET in eight patients; recurrences were seen by US, CT and PET in six, five and five patients, respectively. Two metastatic nodes were identified by US and CT but not by PET. Lung micronodules were detected by CT in 7/49 (14.3 %) patients and by FDG PET in three of them. Basal Tg ranged from 0.5-1,725 ng/ml while peak Tg ranged from 0.5 to 2,135 ng/ml: the distribution between positive and negative patients was similar. Bone scan was negative in all cases.

CONCLUSIONS

In DTC patients with detectable Tg and negative I-131 post-therapy WBS, imaging examination revealed remnant or metastases in 43 % of cases. Remnant and recurrences were equally detected by the three techniques; US was better than [18F]-FDG PET for lymph node metastases since this latter method can give false both positive and negative results; chest examination is best made by CT versus FDG PET due to its higher spatial resolution.

BRAF mutation analysis in thyroid nodules with indeterminate cytology: our experience on surgical management of patients with thyroid nodules from an area of borderline iodine deficiency

PURPOSE

Fine-needle aspiration (FNA) with cytologic evaluation is the most reliable tool for malignancy prediction in thyroid nodules, but cytologic diagnosis remains indeterminate for 12-18 % of nodules. BRAF V600E mutation has been reported to show a high specificity for malignant thyroid nodules and the use of this marker to refine indeterminate FNA cytology results may be a useful diagnostic adjunctive tool in the pre-operative evaluation of thyroid nodules. The aim of this study was to estimate the prevalence of BRAF exon 15 mutation (V600E) and its clinical value as a diagnostic tool in a series of thyroid nodules with indeterminate cytology from an area of borderline iodine deficiency.

SUBJECTS AND METHODS

One hundred and fifty-three thyroid samples obtained by FNA of thyroid nodules from 151 patients were subjected to the analysis of BRAF V600E mutation by direct sequencing. In the study 54 nodules with indeterminate cytology, 56 benign and 43 malignant thyroid nodules were included.

RESULTS

V600E BRAF gene mutation was demonstrated in 19/43 malignant nodules, in 0/56 benign nodules and in only 1/54 indeterminate nodules that, after histology, turned out to be at a papillary thyroid carcinoma.

CONCLUSIONS

The application of BRAF exon 15 analysis showed limitations when applied to discriminate thyroid nodules with indeterminate cytology if wild-type BRAF is found, and there is no role for avoiding diagnostic thyroid surgery.

Frequency and effect on serum TSH of phosphodiesterase 8B (PDE8B) gene polymorphisms in patients with sporadic nonautoimmune subclinical hypothyroidism

BACKGROUND

Nonautoimmune subclinical hypothyroidism (NSH) is characterized by elevated serum TSH in presence of normal thyroid hormone levels and absence of anti-thyroid antibodies. As result of a genomic-wide study, a strong association between three polymorphic variants in intron 1 of human PDE8B gene (rs4704397, rs6885099, rs2046045) and serum TSH has been reported in euthyroid subjects.

AIM

The aim of this study was to evaluate frequency and effects on serum TSH of PDE8B gene polymorphisms in patients with sporadic NSH and verify if differences in serum TSH levels are associated to these polymorphic variants.

SUBJECTS AND METHODS

A total of 58 Italian selected patients affected by NSH, with elevated serum TSH, normal FT3 and FT4 and without TSHr gene mutations, were subjected to genotyping for specific single nucleotide polymorphism of PDE8B gene.

RESULTS

In all patients, the integrity of TSH receptor gene was attested. The ancestral allele associated with increased serum TSH was present in 42/58 patients (72.4 %) for rs4704397, in 42/58 patients (72.4 %) for rs6885099 and in 44/58 patients (75.9 %) for rs2046045. However, similar values of serum TSH were detected in patients with minor or major allele for each polymorphism.

CONCLUSIONS

A prevalence of the minor allele of PDE8B gene polymorphism associated with elevated serum levels of TSH was demonstrated in patients affected by sporadic NSH; however, significant differences in circulating TSH in patients with minor or major alleles for each polymorphism were not identified demonstrating the lack of association between the polymorphisms and serum TSH levels in these patients.

Follicular-derived neoplasms: morphometric and genetic differences

BACKGROUND

The distinction between follicular adenomas (FAs) and well differentiated follicular and papillary carcinomas is often a demanding task and sometimes only intuitive.

AIM

We report an histomorphological evaluation of follicular neoplasms [FAs, follicular carcinomas (FCs), and follicular variant of papillary carcinomas (FVPTCs)], supported by a qualitative and quantitative image analysis and by a molecular characterization.

MATERIAL AND METHODS

Tumor fibrosis and haemorrhage, neoplastic capsule thickness, follicle diameter, number of neoplastic cells, nuclear diameter of neoplastic cells, vessels density, vessels area and intratumoral distribution were evaluated. Ras and BRAF mutations, RET/PTC1, RET/PTC3, and PAX8/PPARγ rearrangements were analyzed. Correlations with clinico-pathological features have been studied.

RESULTS

We found that FAs had a more extensive intratumoral haemorrhage, while malignant neoplasms were characterized by an evident fibrosis, higher cellularity and larger size. FVPTCs had higher nuclear diameter; cells count was higher in the minimally invasive follicular thyroid carcinomas, as well as a thickener neoplastic capsule. The CD34 stain showed a higher microvessel density in the FVPTCs group. A higher peripheral vessels distribution was observed only in malignant neoplasms. We observed overall Ras mutations in 2.4% of adenomas, in 41.5% of FVPTCs, and in 44.8% of FCs. It is outstanding that there is a marked difference in the Ras mutation distribution between the benign and malignant tumors in our series.

CONCLUSIONS

We found that genotyping of Ras gene family together with an accurate analysis of selected morphological features could help in the differential diagnosis of follicular-derived thyroid neoplasms.

Does thyroid peroxidase provide an antigenic link between thyroid autoimmunity and breast cancer?

Women with breast cancer (BC) and antithyroid peroxidase (TPO) autoantibodies (TPOAb) have a better prognosis than women lacking TPOAb. Sera from women with TPOAb displayed immunoreactivity to BC tissue by immunofluorescence that was not apparent in women without TPOAb. We hypothesize a BC/thyroid shared antigen that provides a target for humoral or cell-mediated immune activity; candidates include the sodium/iodide symporter (expressed in thyroid and BC), cross-reacting epitopes in TPO and lactoperoxidase (LPO) or TPO itself. As the association is with TPOAb, we investigated TPO expression in BC, breast peritumoral tissue (PT), other tissues (tumoral and not) and thyroid as positive control. Transcripts for known and novel TPO isoforms were detected in BC (n = 8) and PT (n = 8) but at approximately 10(4) -fold lower than in thyroid while in non-BC tumors (n = 5) they were at the limit of detection. TPO was expressed also in adipose tissue (n = 17), 10(3) -fold lower than in thyroid. Full length TPO (Mr 105-110 kDa) was detected in Western blots in the majority of examined tissues; preabsorption of the TPO antibody with recombinant TPO (but not LPO) reduced the signal, indicating specificity. The same occurred with some lower molecular weight bands, which could correspond to smaller TPO transcript isoforms, present in all samples. In conclusion, TPO is weakly expressed in BC and other tissues; this could partly explain the high frequency and protective role of TPOAb in BC patients. Further studies will investigate tissue specificity, function and immunogenicity of the novel TPO variants (some BC-specific) identified.

Frequency of the GPR7 Tyr135Phe allelic variant in lean and obese subjects

BACKGROUND

GPR7, the endogenous coupled receptor for neuropeptide B and neuropeptide W, is expressed in several regions of the central nervous system, which are involved in the regulation of feeding behavior. GPR7 affects the regulation of energy balance through a mechanism independent of leptin and melanocortin pathways.

AIM

Aim of this study was to investigate whether GPR7 gene mutations can be detected in human subjects and, in that event, if they are differently distributed among lean and obese subjects.

SUBJECTS AND METHODS

The coding region of GPR7 were sequenced in 150 obese patients and 100 normal-weight unrelated controls. Functional studies of the allelic variants were performed.

RESULTS

One genetic GPR7 variant was found (Tyr135Phe - rs33977775) in obese subjects (13.3%) and lean control (25%). Functional studies did not reveal significant differences between the wild type and the Tyr135Phe allelic variants in their NPW-mediated capacity to inhibit forskolin-induced cAMP production.

CONCLUSIONS

Screening of GPR7 gene mutations among lean and obese subjects revealed a Tyr135Phe allelic variant that was fairly common in the study population. As indicated by in vitro and in silico studies, this variant is unlikely to cause a functional derangement of the receptor.

In vivo assessment about the effects of a diet containing iodine-enriched foodstuffs. A pilot study in 30 volunteers

BACKGROUND

Iodine deficiency (ID) still now represents one of the major worldwide health problems. ID is the result of insufficient dietary iodine intake. Iodine is an essential micronutrient but scarcely present in nature. The main strategy for the correction of ID is the fortification of table salt with iodide/iodine but Italy is far from reaching an iodized salt use higher 90% of population. Also because of the evidence for the risk on blood pressure, it is recommended to decrease the daily salt intake to less than 5 g/d. An opportunity to increase the iodine intake is the possibility to introduce iodine fortification in the industrial processing of foods.

AIM

The aim was to evaluate the effectiveness of a diet containing iodized foods enriched during industry processing with protected iodized salt (Presal®).

SUBJECTS AND METHODS

The evaluation of increasing of iodine intake was assessed by measuring the urinary iodine excretion (UIE) in 30 healthy volunteers who added to their alimentary habits a basket of iodine-enriched foodstuffs.

RESULTS

Median UIE at baseline was 105 μg/l, 156 μg/l during the enriched diet and 90.5 μg/l a week after withdrawal of enriched diet.

CONCLUSIONS

Stable iodized salt (Presal®) represents a good way to introduce iodine with the normal diet without increasing the normal consumption of salt for the healthy problems related to the blood pressure. The availability of stable iodized salt (Presal®) allows the preservation of iodine after cooking.

Is the risk of primary hyperparathyroidism increased in patients with untreated breast cancer?

BACKGROUND

An increased frequency of primary hyperparathyroidism (PHP) has been reported in patients with treated breast cancer (BC). PHP has been found in about 7% of BC patients after surgery and radio-, chemio- or hormonal therapy.

AIM

To evaluate the frequency of PHP in untreated BC patients.

SUBJECTS AND METHODS

We evaluated 186 women with BC and 233 women with thyroid cancer (TC, no.=122) or benign thyroid diseases (BTD, no.=111). In all patients, serum calcium, albumin, PTH, and 25-hydroxyvitamin D (25-OH vitD) were measured before any treatment.

RESULTS

Serum calcium concentrations were significantly higher in BC than in TC and BTD groups (median values 9.5 mg/dl, 9.3 mg/dl and 9.3 mg/dl, respectively) but, according to a logistic regression model, calcium was not significantly different between the 3 groups when age was taken into account. In all patients, serum calcium was in the normal range, indicating that no case of overt PHP was present. Five patients (1 in BC, 2 in TC, and 2 in BDT groups) had serum calcium close to the upper limit of normal range, high PTH and low 25-OH vitD, indicating a possible PHP with hypercalcemia masked by concomitant 25-OH vitD deficiency.

CONCLUSIONS

In untreated BC group, no patient had overt PHP and 1/186 (0.5%) presented a possible PHP masked by 25-OH vitD deficiency, a PHP frequency much lower than that observed in treated BC patients. These data suggest that the treatments of BC may be responsible for the increased frequency of PHP reported in previous studies.

The size of the community rather than its geographical location better defines the risk of iodine deficiency: results of an extensive survey in Southern Italy

AIM

The objective of this study was to establish the status of iodine nutrition in Southern Italy.

MATERIAL AND METHODS

The survey was carried out on 11-14 yr old children attending primary school and living in urban and non urban areas of 8 regions of Southern Italy. Urinary iodine excretion (UIE) was measured in 23,103 urinary samples randomly collected.

RESULTS

Median UIE in the whole studied population was 74 μg/l [interquartile range (IR) 34-139 μg/l]. UIE was significantly higher in chief towns compared to non chief towns (81 μg/l, IR 39-145 μg/l vs 73 μg/l, IR 33-138 μg/l, p<0.0001) and in areas with >500 inhabitants per km² (median 87 μg/l, IR 43-154 μg/l) compared to areas with 100-500 per km² (median 66 μg/l, IR 29-126 μg/l, p<0.0001) and with <100 per km² (median 61 μg/l, IR 25-121 μg/l, p<0.0001). Median UIE was significantly lower in inland mountainous/hilly areas (68 μg/l, IR 30-129 μg/l) compared to coastal mountainous/hilly areas (79 μg/l, IR 37-144 μg/l, p<0.0001) and lowland (79 μg/l, IR 37-146 μg/l, p<0.0001). According to a binary logistic regression model, population density was the only independent parameter significantly associated with UIE ≥ 100 μg/l.

CONCLUSION

The results of the present survey indicate that: 1) in Southern Italy mild to moderate iodine deficiency is still present; 2) median UIE in non urban areas is lower than in urban areas and is related to the size of the community rather than to its geographical location, being higher in a larger community. This may be due to better diversification of dietary habits and the easier availability of iodized salt and processed food through commercial facilities, more common in larger communities. Future monitoring surveys should take into account these observations.

The effect of voluntary iodine prophylaxis in a small rural community: the Pescopagano survey 15 years later

CONTEXT

Iodine deficiency disorders are a major public health problem, and programs have been implemented to improve iodine nutrition.

OBJECTIVE

The objective of the study was to verify the effects of voluntary iodine prophylaxis in a small rural community (Pescopagano, Italy).

DESIGN

The design of the study was the evaluation of the prevalence of thyroid disorders 15 years after a previous survey conducted before iodine prophylaxis.

SETTING

The setting for this study was a general community survey.

PARTICIPANTS

One thousand one hundred forty-eight residents were examined in 2010 and 1411 in 1995.

RESULTS

In 2010, 757 of 1148 subjects (65.9%) routinely used iodized salt, urinary iodine excretion being significantly higher than in 1955 (median 98.0 μg/L, vs 55.0 μg/L, P < .0001). The prevalence of goiter was lower in 2010 than in 1995 (25.8% vs 46.1%, P < .0001), mainly due to the reduction of diffuse goiter (10.3% vs 34.0%, P < .0001). In 2010 vs 1995, thyroid autonomy in subjects younger than 45 years old (3 of 579, 0.5% vs 25 of 1010, 2.5% P = .004) and nonautoimmune hyperthyroidism in subjects older than 45 years old (8 of 569, 1.4% vs 18 of 401, 4.5%, P = .03) were less frequent. The prevalence of hypothyroidism was higher in 2010 vs 1995 (5.0% vs 2.8%, P = .005), mainly because of an increased frequency of subclinical hypothyroidism in subjects younger than 15 years old (7 of 83, 8.4% vs 0 of 419, 0.0%, P < .0001). Accordingly, serum thyroid autoantibodies (19.5% vs 12.6%; P < .0001) and Hashimoto's thyroiditis (14.5% vs 3.5%; P < .0001) were more frequent in 2010 than in 1995.

CONCLUSIONS

In the present work, the role of voluntary iodine prophylaxis was assessed in a small rural community relatively segregated, in which genetic and other environmental factors have not substantially changed between the 2 surveys. Iodine intake strongly affected the pattern of thyroid diseases, but the benefits of correcting iodine deficiency (decreased prevalence of goiter and thyroid autonomy in younger subjects and reduced frequency of nonautoimmune hyperthyroidism in older subjects) far outweighs the risk of development of thyroid autoimmunity and mild hypothyroidism in youngsters.

Salivary glands ultrasound examination after radioiodine-131 treatment for differentiated thyroid cancer

BACKGROUND

The most important side effect of radioiodine ((131)I) therapy is sialoadenitis and xerostomy.

AIM

To evaluate by ultrasound (US) parotid and submandibular glands after (131)I therapy for differentiated thyroid cancer (DTC).

PATIENTS

Seventy-six subjects thyroidectomized for DTC submitted to salivary glands US examination. Forty-three of them had been previously treated with (131)I: 22 with 1.11 GBq (30 mCi) for remnant ablation, and 21 with higher doses [up to 44.4 GBq (1200 mCi)] for metastases. Thirty-three subjects studied before (131)I therapy served as controls. Parotid and submandibular volume, homogeneity, and echogenicity were determined. (131)I-treated patients filled a questionnaire about sialoadenitis symptoms.

RESULTS

Parotid gland volume was significantly higher in treated patients (28.3±16.2 ml) than in untreated patients (20.7±10.4 ml, p=0.0154) and related to the time from last (131)I therapy. Three had parotid volume <1.5 ml and complained severe xerostomy. Submandibular gland volume was similar in treated (11.2±7.6 ml) and untreated patients (8.6±4.2 ml, p=0.0602). Homogeneity and echogenicity were similar in treated and untreated patients. Sialoadenitis symptoms were reported in 26% and were related to the (131)I cumulative dose. Symptoms were not related to gland volume. Hypoechogenicity and inhomogeneity of the parotids were more frequent in patients with salivary stickiness.

CONCLUSION

Parotid, but not submandibular, volume is increased after (131)I treatment depending on the received activity and the time from irradiation but not on sialoadenitis symptoms. Xerostomy is associated to gland atrophy at US.