The role of elastography in thyroid ultrasonography

PURPOSE OF REVIEW

Elastography is a novel noninvasive diagnostic tool that is helpful in the evaluation of thyroid nodules. The purpose of this review is to provide a comprehensive summary of the use of elastography in the clinical thyroid setting.

RECENT FINDINGS

Initial and subsequent studies show that elastography has both a sensitivity and specificity that approaches 100% for the determination of thyroid cancer within a thyroid nodule. In addition, the technique also has a very high negative predictive value and thus, may also be helpful in identification of thyroid nodules that do not need further diagnostic evaluation, including fine-needle aspiration biopsy. These characteristics also apply to both strain and shear wave elastography. However, as both the extent of tissue compression and the operator's classification of a nodule using a qualitative color code are subjective, intra and interobserver variability is an important reason for some conflicting findings.

SUMMARY

Elasticity within a thyroid nodule, as evaluated by elastography, offers diagnostic results that are equal to or sometimes even greater than that of conventional ultrasonography for the determination of thyroid malignancy. The integration of both techniques in the clinical work-up of thyroid nodules can thus significantly improve the accuracy of the diagnosis of thyroid nodules.

Normal human thyroid cells, BCPAP, and TPC-1 thyroid tumor cell lines display different profile in both basal and TNF-α-induced CXCL8 secretion

CXCL8 is secreted by both normal human thyrocytes (NHT) and thyroid cancer cell lines. CXCL8 displays several tumor-promoting effects and recent evidences indicate that its concentrations within the tumor microenvironment can impact the clinical course of the malignancy. Aim of this study was to compare the basal secretion of CXCL8 among NHT and thyroid cancer cell lines (TPC-1 and BCPAP), and to assess the specific cell response to TNF-α in terms of CXCL8 secretion. NHT primary cultures, TPC-1 and BCPAP cell lines were cultured with or without TNF-α (0, 0.1, 1, 10, and 100 ng/ml). CXCL8 levels were measured in the cell supernatants after 24 h. In basal condition, significant differences in the mean levels of CXCL8 were observed among the three cell types: NHT (110.5 ± 56.2 pg/ml), TPC1 (467.4 ± 43.2 pg/ml), and BCPAP (1731.8 ± 493.3 pg/ml), (F = 35.06; p < 0.0001). TNF-α significantly and in a dose-response manner induced CXCL8 secretion in NHT (F = 25.53; p < 0.00001), TPC-1 (F = 13.38; p < 0.0001), and BCPAP (F = 9.88; p < 0.001) cells. The magnitude of the TNF-α effect (fold-increase vs. basal level of CXCL8) differed significantly among the three cell types (F = 10.47; p < 0.0001). BCPAP were identified as the cells showing the highest basal secretion of CXCL8 and the less responsive to TNF-α. NHT, TPC-1, and BCPAP display significant differences in the secretion of both basal and TNF-α-induced CXCL8 secretion. These results indicate that the mechanisms regulating the secretion of CXCL8 differ in tumor cells harboring different genetic alterations suggesting that specific strategies aimed at inhibiting CXCL8 secretion will be required.

Anti-Mullerian hormone as a predictor of ovarian reserve in ART protocols: the hidden role of thyroid autoimmunity

BACKGROUND

Protocols of controlled ovarian hyper-stimulation (COH) require, as a crucial step, the identification of reliable predictors of ovarian reserve. Anti-Mullerian hormone (AMH) is one of the most reliable predictors of ovarian reserve but other factors including autoimmune thyroid diseases (ATD) have been associated with reduced fertility and poor COH outcome. Aim of the present study was to evaluate the relationship between ATD and AMH, and their role on the outcome of COH.

METHODS

The study group included 288 sub-fertile euthyroid women aged less than 40 years attending a single center for Reproductive Medicine. Among them, 55 were ATD-positive and 233 ATD-negative. The serum levels of AMH, FSH, LH, estradiol (E2), and TSH were measured before COH. The ratio between serum E2 concentration on the day of oocytes pick-up and the total dose of administered recombinant FSH (r-FSH) (E2/r-FSH ratio) was calculated.

RESULTS

The serum levels of AMH were significantly related to E2/r-FSH ratio, total dose of r-FSH and number of M II oocytes, both in ATD-positive and ATD-negative women. Within the low stratum of AMH levels, the presence of ATD did not further affect the outcome of COH. When the serum levels of AMH were in the high stratum, the presence of ATD significantly affected the E2/rFSH ratio, the total dose of r-FSH and the number of M II oocytes.

CONCLUSIONS

The probability of a poor response to COH is high, and independent from ATD, in women with low AMH serum levels. In women with a good ovarian reserve, as assessed by high AMH serum levels, the presence of ATD impairs the outcome of COH.

ER-alpha and ER-beta expression in differentiated thyroid cancer: relation with tumor phenotype across the TNM staging and peri-tumor inflammation

Thyroid cancer may express estrogen receptors (ERs) and various grades of peri-tumor inflammation. The aim of the study was to evaluate the expression of ERs in relation to the TNM stage and peri-tumor inflammatory infiltrate in differentiated thyroid cancers. 127 patients (109 females, 18 males) with differentiated thyroid cancer (T1 = 91, T2 = 18, T3 = 11, T4 = 7) were evaluated. In tumors and in the correspondent extra-tumor parenchyma, ERs expression was evaluated by immunohistochemistry. In 114 tumors and correspondent peri-tumor tissues, the presence of inflammatory infiltration was also recorded. ER-alpha expression was higher in clinical than in incidental tumors of the T1 subgroup (p = 0.037), and was associated with capsular invasion in T2 tumors (p < 0.0001). ER-beta expression was negatively associated with vascular invasion in T1 (p = 0.005) and T2 tumors (p = 0.015). No significant relationship between ERs expression and tumor phenotype emerged in T3 and T4 subgroups. Tumors without inflammatory cell infiltrate showed a higher expression of both ER-alpha (p = 0.035) and ER-beta (p = 0.026) than the ones with inflammatory infiltrate. The relationship between tumor phenotype and ERs expression did not vary in the presence or absence of peri-tumor inflammatory infiltration. ER-alpha positivity and ER-beta negativity are associated with a more aggressive phenotype in both T1 and T2 thyroid cancers, suggesting that tumor biology may be more relevant than tumor size for cancer risk assessment. Inflammatory status is also associated with ERs expression, but not with tumor growth or phenotype.

A male patient with acromegaly and breast cancer: treating acromegaly to control tumor progression

Background

Acromegaly is a rare disease associated with an increased risk of developing cancer.

Case presentation

We report the case of a 72-year-old man who was diagnosed with acromegaly (IGF-1 770 ng/ml) and breast cancer. Four years before he suffered from a colon-rectal cancer. Pituitary surgery and octreotide-LAR treatment failed to control acromegaly. Normalization of IGF-1 (97 ng/ml) was obtained with pegvisomant therapy. Four years after breast cancer surgery, 2 pulmonary metastases were detected at chest CT. The patient was started on anastrozole, but, contrary to medical advice, he stopped pegvisomant treatment (IGF-I 453 ng/ml). Four months later, chest CT revealed an increase in size of the metastatic lesion of the left lung. The patient was shifted from anastrozole to tamoxifen and was restarted on pegvisomant, with normalization of serum IGF-1 levels (90 ng/ml). Four months later, a reduction in size of the metastatic lesion of the left lung was detected by CT. Subsequent CT scans throughout a 24-month follow-up showed a further reduction in size and then a stabilization of the metastasis.

Conclusions

This is the first report of a male patient with acromegaly and breast cancer. The clinical course of breast cancer was closely related to the metabolic control of acromegaly. The rapid progression of metastatic lesion was temporally related to stopping pegvisomant treatment and paralleled a rise in serum IGF-1 levels. Normalization of IGF-1 after re-starting pegvisomant impressively reduced the progression of metastatic breast lesions. Control of acromegaly is mandatory in acromegalic patients with cancer.

Metformin reverts the secretion of CXCL8 induced by TNF-α in primary cultures of human thyroid cells: an additional indirect anti-tumor effect of the drug

CONTEXT

Metformin displays both direct and indirect anti-tumor effects. CXCL8 is a crucial downstream mediator of Nuclear-Factor-κB signaling related to the growth and progression of thyroid cancers. Targeting CXCL8 results in prolonged survival and reduced metastatic spread in in-vivo animal models of thyroid tumors.

OBJECTIVE

This study aimed to evaluate whether metformin inhibits the secretion of CXCL8 induced by Tumor-Necrosis-Factor-α (TNF-α) in primary cultures of normal and tumor human thyroid cells as well as in thyroid cancer cell lines.

METHODS

Normal human thyrocytes, papillary thyroid cancer cells, and thyroid cancer cell lines (TPC-1 and BCPAP) were stimulated with TNF-α (10 ng/mL) alone or in combination with metformin (0.01, 0.1, 1, 2.5, 5, and 10mM). CXCL8 levels were measured in the cell supernatants after 24 hours.

RESULTS

Metformin significantly and dose-dependently inhibited the TNF-α-induced CXCL8 secretion in both normal thyrocytes (ANOVA: F = 42.04; P < .0001) and papillary thyroid cancer cells (ANOVA: F = 21.691; P < .0001) but not in TPC-1 and BCPAP cell lines.

CONCLUSION

Metformin inhibits the TNF-α-induced CXCL8 secretion in primary cultures of normal thyroid cells and differentiated thyroid cancer cells at least of the most frequent poorly aggressive phenotype. The recruitment of neutrophils within the thyroid gland is a crucial metastasis-promoting factor, and it depends on the amount of CXCL8 produced by both tumor cells and by the more abundant normal thyroid cells exposed to TNF-α. Thus, the here-reported inhibiting effect of metformin on TNF-α-induced CXCL8 secretion could be considered as a further indirect anticancer property of the drug.

Exposure to perfluorinated compounds: in vitro study on thyroid cells

Perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) are widely used perfluorinated chemicals (PFCs). Previous studies detected PFOA and PFOS in human tissues including the thyroid gland. There are no studies on the in vitro effects of PFOA and PFOS on thyroid cells. Our study was aimed at evaluating the effect of the in vitro exposure to PFOA and PFOS on thyroid cell proliferation and viability. These objectives were investigated using Fisher rat thyroid line-5 (FRTL-5) cells. FRTL-5 cells cultured in the presence of PFOA and PFOS at concentrations up to 10(4) nM do not display changes in their viability and proliferation rate, while at a concentration of 10(5) nM of either PFCs, a significant inhibition of cell proliferation, mainly due to increased cell death, was found. PFOA and PFOS were detected in FRTL-5 cell pellets after 72 h of incubation with PFCs but not in control cultures. When FRTL-5 were incubated with PFCs then washed in PBS and re-cultured for 72 h without PFCs in the medium, no detectable concentrations of PFOA and PFOS were measured in the cell pellet. This indicates that PFOA and PFOS enter thyroid cells by a gradient-based passive diffusion mechanism. Future studies are required to evaluate the potential toxic effect resulting from prolonged in vivo exposure to even lower concentrations of PFCs.

Revised Genetic Classification of Limb Girdle Muscular Dystrophies

Limb girdle muscular dystrophies (LGMD) are a heterogeneous group of inherited progressive muscle disorders affecting predominantly the shoulder and pelvic girdle muscles. They present both with autosomal dominant and autosomal recessive patterns of inheritance. Recent development, including results from Next Generation Sequencing technology, expanded the number of recognised forms. Therefore a revised genetic classification that takes into account the novel entities is needed, allowing clinicians and researchers to refer to a common nomenclature for diagnostic and research purposes.

Serum negative autoimmune thyroiditis displays a milder clinical picture compared with classic Hashimoto's thyroiditis

BACKGROUND

Despite high sensitivity of current assays for autoantibodies to thyroperoxidase (TPO) and to thyroglobulin (Tg), some hypothyroid patients still present with negative tests for circulating anti-thyroid Abs. These patients usually referred to as having seronegative autoimmune thyroiditis (seronegative CAT) have not been characterized, and definite proof that their clinical phenotype is similar to that of patients with classic chronic autoimmune thyroiditis (CAT) is lacking.

OBJECTIVE

To compare the clinical phenotype of seronegative CAT (SN-CAT) and CAT as diagnosed according to a raised serum level of TSH with negative and positive tests for anti-thyroid Abs respectively.

METHODS

A case-control retrospective study enrolling 55 patients with SN-CAT and 110 patients with CAT was performed. Serum free triiodothyronine (FT3), free thyroxine (FT4), TSH, Tg Abs, and TPO Abs were measured in all patients.

RESULTS

Patients with SN-CAT displayed significantly lower mean levels of TSH (6.6±3.4 vs 10.2±9.8 μU/ml; P=0.009), higher mean FT4 levels (1.1±0.2 vs 0.9±0.2 ng/dl; P=0.0002), and similar FT3 levels when compared with CAT patients. Mean thyroid volume was significantly greater in patients with CAT when compared with SN-CAT patients (11.2±6.5 vs 8.1±3.7 ml; P=0.001). Logistic regression demonstrated that FT4 (0.123 (0.019-0.775); (P=0.026)) and thyroid volume (1.243 (1.108-1.394); (P=0.0002)) were significantly and independently related to the diagnosis (CAT/SN-CAT). Patients with SN-CAT had a similar prevalence of thyroid nodules and female gender but a lower prevalence of overt hypothyroidism (5.4 vs 20.9%; P=0.012) as opposed to patients with CAT.

CONCLUSIONS

These results suggest an autoimmune etiology of SN-CAT, which, however, seems to have a milder clinical course when compared with CAT.

Raised serum TSH in morbid-obese and non-obese patients: effect on the circulating lipid profile

Morbid obesity is associated with a high rate of raised serum TSH associated with normal free thyroid hormones. The body repercussions of this thyroid abnormality, suggesting subclinical hypothyroidism, are still debated. In particular, it is unclear whether the raised serum TSH of obesity results in changes of circulating lipids typically observed in hypothyroidism. Aim of this study was to evaluate the impact of a raised serum TSH on the lipid profile in morbid-obese and non-obese patients. Serum TSH, FT4, FT3, Tg-Ab, TPO-Ab and lipids were measured in 55 morbid-obese (BMI > 40 kg/m(2)) and 55 non-obese (BMI < 30 kg/m(2)) patients with a raised serum TSH. Despite similar serum levels of TSH, FT4 and FT3, morbid-obese patients displayed significantly lower mean levels of total cholesterol (200.8 ± 35.6 vs. 226.9 ± 41.4 mg/dl, p < 0.001) and a significantly lower prevalence of hypercholesterolemia (50.9 vs. 72.7 %, p < 0.01) when compared with non-obese patients. Morbid-obese patients also had lower mean serum HDL cholesterol and higher serum triglycerides. The impact of a raised serum TSH on the lipid profile differs in morbid-obese compared to non-obese patients, suggesting that obese patients might not be truly hypothyroid. Measuring total cholesterol could be a helpful tool for deciding whether a morbid-obese patient with a raised serum TSH should be given levothyroxine treatment.

Comparison of elastographic strain index and thyroid fine-needle aspiration cytology in 631 thyroid nodules

CONTEXT

Ultrasound (US) elastography (USE) was recently been reported as a sensitive, noninvasive tool for identifying thyroid cancer. However, the accuracy of this technique is hampered by the intra- and interoperator variability, some US features of the nodule, and the coexistence of autoimmune thyroid disease (ATD).

OBJECTIVES

The purpose of this article was to assess the accuracy of USE findings in the differential diagnosis of thyroid nodules compared with other US features to evaluate its feasibility in the presence of ATDs and identify the strain index (SI) cutoff with the highest diagnostic performance.

DESIGN

We evaluated 528 consecutive patients for a total of 661 thyroid nodules. All nodules underwent fine-needle aspiration cytology (FNAC) and USE evaluation. The SI was calculated as a ratio of the nodule strain divided by the strain of the softest part of the surrounding normal tissue.

RESULTS

The median SI value was significantly higher in THY4 and THY5 than in THY2 nodules in ATD-positive, ATD-negative, and ATD-unknown patients. The cutoff of SI for malignancy was estimated to be 2.905 by receiver operating characteristic curve analysis in a screening set (379 FNAC results), and then tested in a replication set (252 FNAC results). In all cases, a SI value of ≥ 2.905 conferred to the nodule a significantly greater probability of being malignant. This SI cutoff had the greatest area under the curve, sensitivity, and negative predictive value, compared with the conventional US features of malignancy.

CONCLUSION

The elastographic SI has a high sensitivity, specificity, and negative predictive value for the diagnosis of thyroid malignancy both in the presence and in the absence of ATD. If our data on USE are also confirmed in THY3 nodules, FNAC could be avoided in a number of thyroid nodules with certain features.

Impaired outcome of controlled ovarian hyperstimulation in women with thyroid autoimmune disease

BACKGROUND

Controlled ovarian hyperstimulation (COH) is a crucial step of assisted reproductive technology (ART). Thyroid dysfunction and autoimmune thyroid disease (ATD) may negatively affect the outcome of ART, but the underlying mechanisms are still poorly understood. Our aim was to evaluate the respective role of ATD and thyroid function, as assessed by serum thyrotropin (TSH), on the early outcome of COH.

METHODS

In total, 262 (202 ATD-negative and 60 ATD-positive) euthyroid subfertile women underwent ART. Before COH, serum follicle-stimulating hormone (FSH), luteinizing hormone, and estradiol (E2) were measured at cycle day 3, and progesterone at cycle day 21. At oocyte pickup and at embryo transfer, we evaluated the performance of recombinant FSH (r-FSH), as assessed by serum E2 concentration/total administered r-FSH units (E2/r-FSH) ratio and by oocyte quality.

RESULTS

At both oocyte pickup and embryo transfer, the performance of r-FSH was significantly poorer in ATD-positive than in ATD-negative women. In the ATD-positive group, women with a TSH <2.5 mIU/L displayed a higher serum E2 concentration at oocyte pickup, a higher E2/r-FSH ratio, and a greater number of mature metaphase II oocytes than women with a TSH >2.5 mIU/L. When ATD-positive women were divided into quartiles according to their serum TSH level, both the ovarian response to r-FSH and the number of mature metaphase II oocytes significantly increased from the lowest to the highest quartiles of serum TSH concentration.

CONCLUSIONS

ATD has a negative effect on the early outcome of COH, but this negative influence may be avoided with adequate levothyroxine therapy aimed at keeping TSH <2.5 mU/L. Thyroid antibodies and serum TSH should be checked in any woman undergoing ART.

Clinical evaluation and cellular electrophysiology of a recessive CLCN1 patient

Here we present the case of a 32-year-old female patient with myotonia congenita. She carried two mutations in the CLCN1 gene that encodes the chloride channel ClC-1: p.Phe167Leu, which was previously identified in several families, and p.Val536Leu, which has been previously reported but not yet characterized by electrophysiological investigations. The patient's symptoms included generalized stiffness, myotonia, and muscle cramps mostly localized in the lower limbs. These symptoms started during childhood and worsened over the following years. The symptoms were exacerbated by low outside temperature, rest, stress, and fasting and were improved by mild exercise, suggesting a warm-up phenomenon. The mutation p.Phe167Leu has previously been associated with a slight shift in the overall open probability. Here we further analysed this mutation to extrapolate the voltage-dependence of the fast and slow gates. In our experimental conditions, p.Phe167Leu exclusively affected the slow gate, increasing the minimum open probability and displacing the voltage-dependence toward depolarized potentials. p.Val536Leu showed more severe effects, dramatically influencing the slow gate as well as modifying properties of the fast gate. Co-expression of the mutants in a human cell line to reproduce the compound heterozygous condition of the patient produced channels with altered voltage-dependence of the slow gate but a restored fast gate. The alteration of the slow mechanism was reflected by the relative open probability, reducing the contribution of ClC-1 channels in maintaining the resting membrane potential of skeletal muscles and thus explaining the myotonic phenotype of the patient.

Type I and type II interferons inhibit both basal and tumor necrosis factor-α-induced CXCL8 secretion in primary cultures of human thyrocytes

Interferons (IFNs) and tumor necrosis factor-α (TNF-α) cooperate in activating several inflammation-related genes, which sustain chronic inflammation in autoimmune thyroid disease (AITD). Much is known about the positive signaling of IFNs to activate gene expression in AITD, while the mechanisms by which IFNs negatively regulate genes remain less studied. While IFNs inhibit CXCL8 secretion in several human cell types, their effects on thyroid cells were not evaluated. Our aim was to study the interplay between TNF-α and type I or type II IFNs on CXCL8 secretion by human thyroid cells. CXCL8 was measured in supernatants of primary cultures of thyroid cells basally and after a 24-h incubation with TNF-α. CXCL8 was detected in thyroid cell supernatants in basal conditions (96.2±23.5 pg/mL) being significantly increased (784.7±217.3 pg/mL; P<0.0001 vs. basal) by TNF-α. Twenty-four hour incubation with IFN-γ or IFN-β or IFN-α dose dependently and significantly inhibited both basal and TNF-α-induced CXCL8 secretion. The degree of the inhibitory effect was IFN-γ>IFN-β>IFN-α. This study demonstrates that type I and type II IFNs downregulate both basal and TNF-α-induced CXCL8 secretion by human thyrocytes, IFN-γ being the most powerful inhibitor. Future studies aimed at a better comprehension of the interplay between CXCL8 and thyroid diseases appear worthwhile.

Interferon-γ and tumor necrosis factor-α sustain secretion of specific CXC chemokines in human thyrocytes: a first step toward a differentiation between autoimmune and tumor-related inflammation?

CONTEXT

Chemokines are chemotactic cytokines responsible for the attraction and recruitment of different cell types during leukocyte infiltration, the histopathological hallmark of autoimmunity. Previous data demonstrate that thyrocytes secrete CXC chemokines, particularly CXCL8 and CXCL10. However, the physiopathological significance of such secretion and the effects of a combination of proinflammatory stimuli in terms of preferential CXCL8 and CXCL10 release remain unclear.

OBJECTIVE

The aim of this study was to investigate whether the secretion of chemokines by human thyrocytes is a generalized inflammatory response or whether it is dependent upon specific proinflammatory stimuli.

METHODS

CXCL8 and CXCL10 were measured in supernatants of human thyrocytes in primary cultures basally and after 24 h stimulation with interferon-γ (IFNγ) (1000 U/ml) and TNFα (10 ng/ml), alone or in combination.

RESULTS

CXCL8 but not CXCL10 was detected in basal conditions. The two chemokines showed differences in their response to proinflammatory cytokines. Indeed, significant secretion of CXCL10 was induced by IFNγ (P < 0.01) and not TNFα, whereas CXCL8 was secreted in response to TNFα (P < 0.01) being inhibited by IFNγ (P < 0.01). The combination of TNFα plus IFNγ synergistically increased the IFNγ-induced CXCL10 secretion (P < 0.01) and reversed the TNFα-induced CXCL8 secretion (P < 0.01).

CONCLUSIONS

These results confirm that human thyrocytes secrete CXC chemokines and demonstrate that the secretion of CXCL8 and CXCL10 is sustained by specific proinflammatory cytokines or their combination, which ultimately determines the nature of the infiltrating lymphocytes in human thyroid diseases. These results indirectly support a major role for CXCL10 in thyroid autoimmunity whereas CXCL8 might be involved in tumor-related inflammation.

Severe disability in patients with relapsing-remitting multiple sclerosis is associated with profound changes in the regulation of leptin secretion

OBJECTIVES

Experimental evidences indicate that leptin is involved in the neuroinflammatory process sustaining multiple sclerosis (MS). However, the relationship between leptin and body fat, as assessed by body mass index (BMI), in MS was not previously evaluated. It was the aim of this study to compare serum leptin levels between patients with MS and healthy controls and to evaluate the possible relationship between circulating leptin levels and disease severity.

PATIENTS AND METHODS

Eighty-four MS patients and 57 sex-matched healthy volunteers were enrolled. Serum leptin levels were measured in all patients and controls. MS patients were stratified in 3 groups according to their degree of disability as assessed by the Expanded Disability Status Scale (EDSS). Patients were classified as having low (33 patients with an EDSS score <1.5), intermediate (28 patients with an EDSS score from 2 to 3) and high disability (23 patients with an EDSS score ≥3.5).

RESULTS

No significant differences in serum leptin levels and BMI were observed between patients and controls. In patients with MS, serum leptin levels were significantly correlated with BMI in those patients with low (R(2) = 0.363; p < 0.001) and intermediate disability (R(2) = 0.408; p < 0.001), but not in patients with a higher disability score (R(2) = 0.064; p = 0.256).

CONCLUSION

BMI, the major determinant of leptin level in physiological conditions, has a minor role in determining the serum levels of leptin in MS patients with a high EDSS score. Future longitudinal studies will be required in order to provide further insights into the regulation of leptin secretion in patients with MS.

Expression of estrogen and androgen receptors in differentiated thyroid cancer: an additional criterion to assess the patient's risk

Estrogen receptor (ER) and androgen receptor (AR) may be expressed in thyroid tumors, but their prognostic role is controversial. We investigated whether ER and AR expressions could confer a more aggressive phenotype to thyroid tumors. We enrolled 91 patients (13 males and 78 females, mean age 49.3±14.8 years) bearing small (T1 in the 2006 TNM system) differentiated thyroid cancers (DTC). Thirty-eight tumors were incidental histological findings. Using immunohistochemistry, we evaluated ERα, ERβ, and AR expressions in tumors and in its correspondent extra-tumor parenchyma. In tumors, 13 (16.7%) women and one (7.7%) man expressed ERα; 42 (53.8%) women and six (46%) men expressed ERβ; and 16 (20.5%) women and three (23.1%) men expressed AR. In normal thyroid parenchymas, ERβ was expressed in 52 (66.7%) women and nine (69.2%) men, ERα in three (3.8%) women, and AR in 13 (16.7%) women. Compared with normal thyroid parenchyma, tumors gained ERα and lost ERβ expressions. Incidental cancers were more commonly ERα(-) than ERα(+) (47.7 vs 14.3%, P=0.037). Postsurgical serum thyroglobulin was higher in ERα(+) tumors than in the ERα(-) tumors (P=0.04). ERβ(-) tumors showed vascular invasion more frequently than the ERβ(+) tumors (26.2 vs 4.1%, P=0.005). AR(+) tumors showed capsular invasion more frequently than the AR(-) tumors (77.8 vs 46.6%, P=0.014). In conclusion, ERα positivity, ERβ negativity, and AR expressions are associated with a more aggressive phenotype of small T1-DTC. ER and AR expressions may represent an additional criterion in deciding whether to perform radioiodine ablation in these tumors.

Shear wave elastography in the diagnosis of thyroid nodules: feasibility in the case of coexistent chronic autoimmune Hashimoto's thyroiditis

OBJECTIVE

ShearWave™ Elastography (SWE) is real-time, quantitative and user-independent technique, recently introduced in the diagnostic work-up of thyroid nodules. Hashimoto's thyroiditis (HT), characterized by variable degrees of lymphocytic infiltration and fibrosis, might affect shear wave propagation. The aim of this study was to assess the feasibility of SWE in cytologically benign thyroid nodules within both Hashimoto's and nonautoimmune thyroid glands. The effect of autoimmunity on the gland stiffness was also evaluated.

DESIGN

longitudinal study in a single centre.

PATIENTS

SWE was performed in 75 patients with a benign thyroid nodule at cytology: 33 with Hashimoto's thyroiditis (HT group) and 42 with uni- or multi-nodular goitre, negative for thyroid autoimmunity (non-HT group).

RESULTS

The elasticity index (EI) of the extra-nodular tissue was greater, though not statistically significant, in the HT than in the non-HT group (24·0 ± 10·5 kPa vs 20·8 ± 10·4 kPa; P = 0·206). However, the EI of extra-nodular tissue was related to the TPOAb titre in the HT group (P = 0·02) and was significantly higher in patients with HT receiving L-thyroxine than in the euthyroid subjects (P = 0·02). The EI of thyroid nodules was similar in HT and non-HT groups. In both groups, the stiffness of nodules was significantly higher than that of the embedding tissue.

CONCLUSIONS

Our data indicate that SWE correctly defines the elasticity of thyroid nodules independently from the coexistence of autoimmune thyroiditis, always being able to differentiate nodular tissue from the surrounding parenchyma. In HT, the stiffness of extra-nodular tissue increases in relation to both the thyroid antibody titre and the degree of impairment of thyroid function.

Thyroidal effect of metformin treatment in patients with polycystic ovary syndrome

OBJECTIVE

Metformin is widely used for the treatment of type 2 diabetes. Growing evidence supports the beneficial effects of metformin also in patients with polycystic ovary syndrome (PCOS). It was recently reported that metformin has a TSH-lowering effect in hypothyroid patients with diabetes being treated with metformin.

DESIGN

Aim of this study was to evaluate the effect of metformin treatment on the thyroid hormone profile in patients with PCOS.

PATIENTS AND MEASUREMENTS

Thirty-three patients with PCOS were specifically selected for being either treated with levothyroxine for a previous diagnosis of hypothyroidism (n = 7), untreated subclinically hypothyroid (n = 2) or euthyroid without levothyroxine treatment (n = 24) before the starting of metformin. The serum levels of TSH and FT(4) were measured before and after a 4-month period of metformin therapy.

RESULTS

Thyroid function parameters did not change after starting metformin therapy in euthyroid patients with PCOS. In the 9 hypothyroid patients with PCOS, the basal median serum levels of TSH (3·2 mIU/l, range = 0·4-7·1 mIU/l) significantly (P < 0·05) decreased after a 4-month course of metformin treatment (1·7 mIU/l, range = 0·5-5·2 mIU/l). No significant change in the serum levels of FT4 was observed in these patients. The TSH-lowering effect of metformin was not related to the administered dose of the drug, which was similar in euthyroid as compared with hypothyroid patients with PCOS (1406 ± 589 vs 1322 ± 402 mg/day, respectively; NS).

CONCLUSIONS

These results indicate that metformin treatment has a TSH-lowering effect in hypothyroid patients with PCOS, both treated with l-thyroxine and untreated.

Hyperplasia-adenoma sequence in pituitary tumorigenesis related to aryl hydrocarbon receptor interacting protein gene mutation

Mutations of the aryl hydrocarbon receptor interacting protein (AIP) gene are associated with pituitary adenomas that usually occur as familial isolated pituitary adenomas (FIPA). Detailed pathological and tumor genetic data on AIP mutation-related pituitary adenomas are not sufficient. Non-identical twin females presented as adolescents to the emergency department with severe progressive headache caused by large pituitary macroadenomas require emergency neurosurgery; one patient had incipient pituitary apoplexy. Post-surgically, the patients were found to have silent somatotrope adenomas on pathological examination. Furthermore, the light microscopic, immunohistochemical, and electron microscopic studies demonstrated tumors of virtually identical characteristics. The adenomas were accompanied by multiple areas of pituitary hyperplasia, which stained positively for GH, indicating somatotrope hyperplasia. Genetic analyses of the FIPA kindred revealed a novel E216X mutation of the AIP gene, which was present in both the affected patients and the unaffected father. Molecular analysis of surgical specimens revealed loss of heterozygosity (LOH) in the adenoma but showed that LOH was not present in the hyperplastic pituitary tissue from either patient. AIP immunostaining confirmed normal staining in the hyperplastic tissue and decreased staining in the adenoma in the tumors from both patients. These results demonstrate that patients with AIP germline mutation can present with silent somatotrope pituitary adenomas. The finding of somatotrope hyperplasia unaccompanied by AIP LOH suggests that LOH at the AIP locus might be a late event in a potential progression from hyperplastic to adenomatous tissue.

Interferon-β but not Glatiramer acetate stimulates CXCL10 secretion in primary cultures of thyrocytes: a clue for understanding the different risks of thyroid dysfunctions in patients with multiple sclerosis treated with either of the two drugs

Autoimmune thyroid disease (AITD) has been reported in patients with multiple sclerosis (MS) receiving interferon-beta (IFN-β), but not in those receiving Glatiramer acetate (GA). CXCL10 is a chemokine playing a pathogenetic role in AITD and MS. Our aim was to evaluate the effects on CXCL10 secretion of IFN-β and GA, alone and in combination with TNF-α, in primary cultures of thyrocytes (PCT). Significant and dose-dependent secretions of CXCL10 were induced by IFN-β but not GA. TNF-α synergistically increased IFN-β induced CXCL10 secretion. These results may provide an explanation for the occurrence of AITD during IFN-β, but not during GA, treatment for MS.

Clinical characteristics and therapeutic responses in patients with germ-line AIP mutations and pituitary adenomas: an international collaborative study

CONTEXT

AIP mutations (AIPmut) give rise to a pituitary adenoma predisposition that occurs in familial isolated pituitary adenomas and less often in sporadic cases. The clinical and therapeutic features of AIPmut-associated pituitary adenomas have not been studied comprehensively.

OBJECTIVE

The objective of the study was to assess clinical/therapeutic characteristics of AIPmut pituitary adenomas.

DESIGN

This study was an international, multicenter, retrospective case collection/database analysis.

SETTING

The study was conducted at 36 tertiary referral endocrine and clinical genetics departments.

PATIENTS

Patients included 96 patients with germline AIPmut and pituitary adenomas and 232 matched AIPmut-negative acromegaly controls.

RESULTS

The AIPmut population was predominantly young and male (63.5%); first symptoms occurred as children/adolescents in 50%. At diagnosis, most tumors were macroadenomas (93.3%); extension and invasion was common. Somatotropinomas comprised 78.1% of the cohort; there were also prolactinomas (n = 13), nonsecreting adenomas (n = 7), and a TSH-secreting adenoma. AIPmut somatotropinomas were larger (P = 0.00026), with higher GH levels (P = 0.00068), more frequent extension (P = 0.018) and prolactin cosecretion (P = 0.00023), and occurred 2 decades before controls (P < 0.000001). Gigantism was more common in the AIPmut group (P < 0.000001). AIPmut somatotropinoma patients underwent more surgical interventions (P = 0.00069) and had lower decreases in GH (P = 0.00037) and IGF-I (P = 0.028) and less tumor shrinkage with somatostatin analogs (P < 0.00001) vs. controls. AIPmut prolactinomas occurred generally in young males and frequently required surgery or radiotherapy.

CONCLUSIONS

AIPmut pituitary adenomas have clinical features that may negatively impact treatment efficacy. Predisposition for aggressive disease in young patients, often in a familial setting, suggests that earlier diagnosis of AIPmut pituitary adenomas may have clinical utility.

Burkitt-like lymphoma infiltrating a hyperfunctioning thyroid adenoma and presenting as a hot nodule

BACKGROUND

Most solitary hyperfunctiong regions on thyroid scan consist of benign tissue. Here we report a patient with a Burkitt-like lymphoma that was infilterated into a region containing a hyperfunctioning nodule.

SUMMARY

A 56-year-old man was referred to our Endocrine Unit in May 2009 due to the incidental discovery of a large left thyroid lobe nodule by a computed tomography study. This had been performed to search for a primitive tumor in a patient with bone metastasis. He was clinically and biochemically thyrotoxic with no evidence of humoral thyroid autoimmunity. The nodule had a dyshomogenous appearance at neck ultrasonography, with multiple hypoechogenic areas and calcifications. (99m)-Technetium thyroid scintiscan revealed a hot nodule with suppression of the contralateral lobe. Fine-needle aspiration cytology indicated the presence of neoplastic cells not of thyroid origin. Remission of hyperthyroidism was obtained with methimazole, and the patient was submitted to left lobe thyroidectomy and istmectomy. Histological analysis of the surgical specimen led to a diagnosis of Burkitt-like large B-cell lymphoma harbored within a thyroid adenoma. After further staging, the final diagnosis was stage IV E Burkitt-like lymphoma with the involvement of the bone and the thyroid. This is the first description of an aggressive Burkitt-like lymphoma that infiltrated an hyperfunctioning thyroid adenoma, thus presenting as a hot nodule at thyroid scintiscan. In our patient there was no humoral or histological evidence of thyroid autoimmunity, thus suggesting a metastatic seeding of the lymphoma within the hyperfunctioning thyroid nodule.

CONCLUSIONS

Involvement of the thyroid gland by Burkitt-like lymphoma is extremely rare as is close localization of malignancy and a hyperfunctioning thyroid nodule. As highlighted by the present report, performing fine-needle aspiration cytology should be always considered in the clinical context of a metastatic disease of unknown origin or when there are ultrasonography signs suggesting malignancy, even when the nodule is hyperfunctioning.

Intraepidermal nerve fiber density reduction as a marker of preclinical asymptomatic small-fiber sensory neuropathy in hypothyroid patients

AIM

To evaluate, by using skin biopsy technique, the intraepidermal nerve fiber (IENF) density in a group of untreated patients with hypothyroidism, either overt (OH) or subclinical (SH), who did not complain of neurologic symptoms.

METHODS

We evaluated 18 neurologically asymptomatic patients newly diagnosed with OH or SH. Fifteen healthy, age-matched, controls were also studied. A nerve conduction study was performed. Skin biopsy was carried out from the skin of upper thigh and distal leg. Nerve fiber density was measured using an immunofluorescence technique. The density of innervation was calculated by counting only fibers crossing the basement membrane.

RESULTS

Electroneurographic parameters were similar in patients and controls. When compared with healthy controls, patients with OH or SH showed a significantly lower IENF density. As assessed by the proximal/distal fiber density ratio, the hypothyroid neuropathy was length dependent. When individually considered, an abnormally reduced IENF was observed in 60% of patients with OH at the distal leg and in 20% at the proximal site. In patients with SH, an abnormal IENF density was found at the distal leg in 25% of cases and at the proximal thigh in 12.5% of cases.

CONCLUSIONS

Our study provides the first direct demonstration of reduced IENF density in patients with OH or SH. In all patients, the IENF density reduction was length dependent. These findings suggest that a considerable number of untreated hypothyroid patients may have preclinical asymptomatic small-fiber sensory neuropathy.

A hypoechoic pattern of the thyroid at ultrasound does not indicate autoimmune thyroid diseases in patients with morbid obesity

OBJECTIVE

Thyroid ultrasound (US) scan is a valuable tool for diagnosing thyroid diseases. In autoimmune thyroid disease (AITD), an hypoechoic pattern of the thyroid at US is related to circulating thyroid antibodies (Abs). The aim of this study was to evaluate the diagnostic accuracy of thyroid US for the detection of AITD in patients with morbid obesity.

DESIGN

Thyroid US scans showing an hypoechoic pattern of the thyroid were collected from 105 morbid obese patients (body mass index (BMI) >40 kg/m(2)) and 105 non-obese patients (BMI<or=30 kg/m(2)).

RESULTS

A thyroid hypoechoic pattern at US was consistent with clinical/biochemical features of AITD in 90/105 (85.7%) non-obese patients and in 22/105 (20.9%) morbid-obese patients (P<0.0001). By performing a complete thyroid work-up, including clinical examination, thyroid morphology, serum hormones, and auto-Ab measurements, the discrepancy between the US pattern and the results of the thyroid Ab tests was justified in 6/15 non-obese patients, and only in 1/83 morbid obese patients. Thus, an unexplained hypoechoic pattern of the thyroid at US, defined as negative tests for thyroid Ab and absence of justifying thyroid disturbances, was found in 2/105 (1.9%) non-obese patients and in 68/105 (64.8%) morbid obese patients (P<0.0001).

CONCLUSIONS

Our results suggest that i) morbid obesity may affect thyroid morphology, and ii) an hypoechoic pattern of the thyroid at US, a well-established parameter for diagnosing AITD, has a poor diagnostic accuracy when patients with morbid obesity are taken into account.

Prevalence of double pituitary adenomas in a surgical series: Clinical, histological and genetic features

BACKGROUND

The term double pituitary adenomas (DPA) is usually referred to those rare lesions showing two distinct cellular components. Genetic background may sustain the proliferation of more than one cell at the same time but no information is available on the presence of aip mutations in these patients.

AIM

We report the prevalence and the endocrinological, neuroradiological, histopathological and genetic features of DPA detected in a large surgical series. The contribution of pituitary transcription factor immunostains in DPA was also evaluated.

SUBJECTS AND METHODS

One-hundred-forty-four patients undergoing surgery for tumors of the sellar region were evaluated. Histopathology, immunohistochemistry and the mutational analysis for the entire coding region of the AIP and MEN1 genes were performed.

RESULTS

One-hundred-seventeen patients out of 144 had a pituitary adenoma. DPA was found in 3 (2.6%) out of 117 patients with pituitary adenoma. Immunohistochemistry and transcription factors analysis demonstrated two not yet described histotype associations in DPA. The coexistence of somatotroph-lactotroph and silent mammosomatotroph histotype in 1 case and the coexistence of sparsely granulated lactotroph and null cell adenomas in the remaining two cases were first identified. Sequencing data for the coding region of the aip and the menin gene resulted in wild type sequences in all patients with DPA.

CONCLUSIONS

The prevalence of DPA observed in our unselected surgical series is not negligible (2.6%). Furthermore, the evaluation of the treatment outcome would suggest that the clinical management of DPAs requires a careful diagnostic approach and follow- up.

Intravenous contrast ultrasound examination using contrast-tuned imaging (CnTI) and the contrast medium SonoVue for discrimination between benign and malignant adnexal masses with solid components

OBJECTIVE

To determine whether intravenous contrast ultrasound examination is superior to gray-scale or power Doppler ultrasound for discrimination between benign and malignant adnexal masses with complex ultrasound morphology.

METHODS

In an international multicenter study, 134 patients with an ovarian mass with solid components or a multilocular cyst with more than 10 cyst locules, underwent a standardized transvaginal ultrasound examination followed by contrast examination using the contrast-tuned imaging technique and intravenous injection of the contrast medium SonoVue(R). Time intensity curves were constructed, and peak intensity, area under the intensity curve, time to peak, sharpness and half wash-out time were calculated. The sensitivity and specificity with regard to malignancy were calculated and receiver-operating characteristics (ROC) curves were drawn for gray-scale, power Doppler and contrast variables and for pattern recognition (subjective assignment of a certainly benign, probably benign, uncertain or malignant diagnosis, using gray-scale and power Doppler ultrasound findings). The gold standard was the histological diagnosis of the surgically removed tumors.

RESULTS

After exclusions (surgical removal of the mass > 3 months after the ultrasound examination, technical problems), 72 adnexal masses with solid components were used in our statistical analyses. The values for peak contrast signal intensity and area under the contrast signal intensity curve in malignant tumors were significantly higher than those in borderline tumors and benign tumors, while those for the benign and borderline tumors were similar. The area under the ROC curve of the best contrast variable with regard to diagnosing borderline or invasive malignancy (0.84) was larger than that of the best gray-scale (0.75) and power Doppler ultrasound variable (0.79) but smaller than that of pattern recognition (0.93).

CONCLUSION

Findings on ultrasound contrast examination differed between benign and malignant tumors but there was a substantial overlap in contrast findings between benign and borderline tumors. It appears that ultrasound contrast examination is not superior to conventional ultrasound techniques, which also have difficulty in distinguishing between benign and borderline tumors, but can easily differentiate invasive malignancies from other tumors.

Reliability of the North Star Ambulatory Assessment in a multicentric setting

The aim of this study was to investigate the suitability of the North Star Ambulatory Assessment as a possible outcome measure in multicentric clinical trials. More specifically we wished to investigate the level of training needed for achieving a good interobserver reliability in a multicentric setting. The scale was specifically designed for ambulant children with Duchenne Muscular Dystrophy and includes 17 items that are relevant for this cohort. Thirteen Italian centers participated in the study. In the first phase of the study we provided two training videos and an example of the scale performed on a child. After the first session of training, all the 13 examiners were asked to send a video with an assessment performed in their centre and to score all the videos collected. There were no difficulties in performing the items and in obtaining adequate videos with a hand held camera but the results showed a poor interobserver reliability (<.5). After a second training session with review and discussion of the videos previously scored, the same examiners were asked to score three new videos. The results of this session had an excellent interobserver reliability (.995). The level of agreement was maintained even when the same videos were rescored after a month, showing a significant intra-observer reliability (.95). Our results suggest that the NSAA is a test that can be easily performed, completed in 10 min and can be used in a multicentric setting, providing that adequate training is administered.

Pretransplant positivity for circulating thyroid antibodies and graft survival in patients undergoing kidney transplant

BACKGROUND

Thyroid disturbances are common in kidney graft recipients and they may influence graft function. CXC chemokine ligand 10 plays a role in both autoimmune thyroiditis and graft rejection. Thyroid antibody (Ab) positivity has been regarded as a marker of imbalance of the immune system.

AIM

To relate pretransplant positivity for antithyroperoxidase (TPO) Ab and antithyroglobulin (Tg) Ab with kidney graft outcome.

METHODS

Pretransplant thyroid antibodies were measured in 211 kidney graft recipients.

RESULTS

The 5-year death-censored graft survival rate was 91.5%. Pretransplant circulating Tg Ab and TPO Ab were detected in 12 (5.7%) and 13 (6.2%) patients, respectively. Lifetime analysis showed similar 5-year graft survival rates in patients negative or positive for Tg Ab and TPO Ab (91.5 vs. 91.7% for Tg Ab and 91.9 vs. 84.6% for TPO Ab). However, patients with pretransplant positivity for TPO Ab showed a significantly lower 5-year graft survival when early graft loss (12 months after transplant) was excluded (84.6 and 96.8% for TPO Ab+ and TPO Ab- patients, respectively; p < 0.05). Occurrence of acute rejection and chronic allograft nephropathy was unrelated to thyroid Ab positivity. Serum CXC chemokine ligand 10 levels were similar independent of Tg Ab and TPO Ab positivity.

CONCLUSION

Pretransplant positivity for TPO Ab may affect long-term graft survival in kidney graft recipients independent of occurrence of acute rejections and chronic allograft nephropathy.

Prevalence of parathyroid cysts by neck ultrasound scan in unselected patients

BACKGROUND

Parathyroid cysts (PC) are a rare entity, representing only 0.5-1% of all parathyroid lesions and <1% of neck masses. Since its first description, in the second half of the 19th century, fewer than 300 cases have been reported. By reviewing the literature, it appears that the data available arose from surgical series, and the precise incidence of PC as detected by ultrasound (US) has not been described. The aim of this study was to review 5 yr of routine neck US, mainly performed for thyroid diseases, in order to estimate the prevalence of PC in a large series of patients.

METHODS

We reviewed our database of neck US investigations performed from 2003 to 2007: all data regarding patient's clinical history, US images, and fine needle aspiration cytology were retrospectively collected.

RESULTS

Among 6621 patients submitted to neck US investigation, a PC (mean diameter 36.4+/-14.2 mm; range 25-61 mm) was diagnosed in 5 cases. Serum PTH levels were high in all the patients (221+/-140.7 pg/ml; range 111-456 pg/ml), whereas serum calcium levels only in 3 subjects (10.8+/-1.4 mg/dl; range 9.2-12.9 mg/ml).

CONCLUSION

This is the first study evaluating the prevalence of PC in a large series of unselected patients by US. Our results demonstrate a much lower incidence (0.075%) of incidentally detected PC than previously reported.

Raised serum TSH levels in patients with morbid obesity: is it enough to diagnose subclinical hypothyroidism?

OBJECTIVE

Morbid obesity (body mass index (BMI)> or =40 kg/m(2)) is associated with thyroid function disturbances, with a high rate of subclinical hypothyroidism (SH) being the most consistently reported. We evaluated the circulating thyroid function parameters in morbid obese patients and related the results to the presence of circulating thyroid antibodies (Thyr-Ab).

DESIGN AND METHODS

Morbid obese patients were consecutively enrolled (n=350). Two control groups were used: control group (CG)1, healthy normo-weight subjects (n=50); CG2, normo-weight patients with SH (n=56) matched for TSH with the obese patients with SH. Serum levels of free triiodothyronine (FT(3)), free thyroxine (FT(4)), TSH, antithyroglobulin antibodies, and antithyroperoxidase antibodies were measured in all patients.

RESULTS

i) Compared with CG1, obese patients having thyroid function parameters in the normal range and negative Thyr-Ab showed significantly higher serum TSH and lower free thyroid hormones levels, but a similar FT(4)/FT(3) ratio; ii) SH was recorded in 13.7% obese patients; iii) compared with CG2, obese patients with untreated SH had a significantly lower rate of positive Thyr-Ab (32.1 vs 66.1%; P<0.005); iv) no gender prevalence was observed in SH obese patients with negative Thyr-Ab; and v) the comparison of the untreated SH patients (obese and normo-weight) with CG1 demonstrated that in SH obese subjects, unlike normo-weight SH patients, the FT(3) levels were significantly lower. This resulted in a normal FT(4)/FT(3) ratio in SH obese patients.

CONCLUSION

Thyroid autoimmunity is not a major cause sustaining the high rate of SH in morbid obese patients. In these patients, the diagnosis of SH itself, as assessed by a raised TSH alone, appears questionable.

The effect of pregnancy on subsequent relapse from Graves' disease after a successful course of antithyroid drug therapy

OBJECTIVE

Pregnancy and the postpartum (PP) period are associated with profound changes of the immune system, which largely influence the clinical activity of autoimmune diseases. The aim of this study was to evaluate the effect of pregnancy and/or the PP period in driving a clinical relapse of hyperthyroidism in patients with Graves' disease (GD) who are in remission after antithyroid drug (ATD) treatment. Data were retrospectively collected from 150 female patients with GD, who were assigned to two groups according to the occurrence of a successful pregnancy after ATD withdrawal.

RESULTS

Relapsing Graves' hyperthyroidism was observed in 70 of 125 patients in group I (no pregnancy after ATD withdrawal) (56.0%) and 21 of 25 patients in group II (pregnancy after ATD withdrawal) (84.0%) (P < 0.05). Logistic regression analysis (dependent variable: relapse/nonrelapse; covariates: age, positive family history for autoimmune thyroid disease, duration of treatment with ATD, number pregnancies at diagnosis, number of pregnancies after ATD withdrawal) showed a significant effect only for the number of pregnancies after ATD withdrawal [4.257 (1.315-13.782)]. The effect was ascribed to the PP period rather than to pregnancy itself because in 20 of 21 patients of group II (95.2%), the relapse of Graves' hyperthyroidism occurred between 4 and 8 months after delivery.

CONCLUSIONS

The PP period is significantly associated with a relapse of hyperthyroidism in GD patients being in remission after ATD. We therefore recommend that patients with GD in remission after a course of ATD should have their thyroid function tested at 3 and 6 months after delivery.