Low serum vitamin D is associated with anti-thyroid peroxidase antibody in autoimmune thyroiditis

PURPOSE

The association between autoimmune thyroid diseases (AITDs) and vitamin D deficiency is controversial. We aimed to evaluate the relationship between serum 25-hydroxy-vitamin D3 [25(OH)D3] and anti-thyroid antibody levels.

MATERIALS AND METHODS

25(OH)D3, anti-thyroid antibodies, and thyroid function measured in 304 patients who visited the endocrinology clinic were analyzed. The patients were subgrouped into the AITDs or non-AITDs category according to the presence or absence of anti-thyroid antibodies. The relationship between anti-thyroid peroxidase antibody (TPOAb) and 25(OH)D3 was evaluated.

RESULTS

The patients with elevated anti-thyroid antibodies had lower levels of serum 25(OH)D3 than those who did not (12.6±5.5 ng/mL vs. 14.5±7.3 ng/mL, respectively, p<0.001). Importantly, after adjusting for age, sex, and body mass index, a negative correlation (r=-0.252, p<0.001) was recognized between 25(OH)D3 and TPOAb levels in the AITDs group, but this correlation did not exist in the non-AITDs group (r=0.117, p=0.127). 25(OH)D3 level was confirmed as an independent factor after adjusting for co-factors that may affect the presence of TPOAb in the AITDs group.

CONCLUSION

25(OH)D3 level is an independent factor affecting the presence of TPOAb in AITDs. The causal effect of 25(OH)D3 deficiency to AITDs is to be elucidated.

Iodine contributes to thyroid autoimmunity in humans by unmasking a cryptic epitope on thyroglobulin

CONTEXT

The mechanisms linking thyroid autoimmunity and iodine use in humans are unknown.

OBJECTIVE

Our aim was to correlate iodine intake, thyroid autoimmunity, and recognition of thyroglobulin (Tg) epitopes after implementation of iodine prophylaxis.

SETTING

The general community living in an Italian village was evaluated.

MAIN OUTCOME MEASURES

Thyroglobulin autoantibodies (TgAb), thyroperoxidase autoantibodies (TPOAb), and urinary iodine excretion were assessed in 906 iodized salt users (IS-users) and 389 nonusers (IS-nonusers). Ultrasound (US) was performed to identify thyroid hypoechogenicity, suggestive of Hashimoto thyroiditis (HT). TgAb epitope pattern in 16 IS-users and 17 IS-nonusers was evaluated by an inhibition binding assay to Tg, using human monoclonal TgAb-Fab directed to A, B, C, and D epitopes on Tg.

RESULTS

Median urinary iodine excretion was slightly higher in IS-users than in IS-nonusers (112.0 μg/L vs 86.5 μg/L; P < .01). TgAb, and not TPOAb, was more frequent in IS-users (18.9% vs 13.6%, P = .02). HT-US was found in 87 subjects, among whom both positive TgAb (58.4% vs 31.8%, P = .03) and TPOAb (61.5% vs 45.4%. P = .04) were more frequent in IS-users. In this group significantly higher serum levels of TgAb (median 108 U/mL vs 30 U/mL; P = .02), but not of TPOAb, were present. Iodized salt use had no effect on the 1208 non HT-US subjects. TgAb directed to the epitope B of Tg were more frequent in IS-users than in IS-nonusers (27.5% vs 3.0%, P = .047).

CONCLUSIONS

Iodine-induced thyroid autoimmunity is related to TgAb and the unmasking of a cryptic epitope on Tg contributes to this relationship in humans.

Neck lymph nodes in chronic autoimmune thyroiditis: the sonographic pattern

BACKGROUND

Neck lymph nodes may be involved in the pathogenesis of chronic autoimmune thyroiditis (CAT). This study was undertaken to identify which of the sonographic features of cervical lymph nodes are readily applicable to patients affected by CAT compared to healthy control subjects.

METHODS

We recruited 106 patients (92 females and 14 males) with CAT and 70 control subjects (53 females and 17 males) without clinical, biochemical, and ultrasonographic evidence of thyroid and neck diseases. We performed laboratory tests (thyrotropin, antithyroperoxidase antibodies, antithyroglobulin antibodies, and ultrasonography) to evaluate in each group: (i) thyroid function, autoimmunity, and morphology; (ii) number, topographic distribution (levels I-VI), and morphology of neck nodes (long-axis diameter; short-axis diameter; short-axis/long-axis ratio; absence or presence of hilus).

RESULTS

Total number of neck nodes with long-axis diameter >10 mm was significantly higher in the CAT group than in the control group (mean±standard deviation [SD]: 3.7±2.4 vs. 0.8±1.3; p<0.001) with significantly increased differences in levels II (1.4±0.8 vs. 0.3±0.5; p<0.001), III (2±1.2 vs. 0.3±0.7; p<0.001), and IV (0.7±0.7 vs. 0.07±0.2; p<0.001). More nodes with a hilus were found in the CAT group than in the control group (mean number of nodes±SD: 2.8±1.9 vs. 0.7±1.1; p<0.001). Short-axis diameter of level III (4.4±1 vs. 3.7±1.2 mm; p=0.002) and level IV nodes (3.9±1 vs. 3.1±0.5 mm p=0.030) was increased in CAT patients when compared with healthy controls.

CONCLUSIONS

The present study is the first one aiming at a systematic description of the sonographic pattern of cervical lymph nodes in CAT. An increased number of benign hyperplastic neck nodes, especially in levels II-IV, appears to be a characteristic sonographic finding associated with CAT.

IgG4-related disease of the thyroid glands

Recent reports on Hashimoto's thyroiditis (HT) with increased numbers of IgG4-positive plasma cells suggest that this type of HT may have a close relationship to IgG4-related disease (IgG4-RD). This unique subgroup of HT is termed as IgG4 thyroiditis and reveals distinct clinical, serological, and sonographic features from the non-IgG4 thyroiditis group. On the basis of immunostaining for IgG4, HT was divided into an IgG4 thyroiditis group and a non-IgG4 thyroiditis group. Clinically, IgG4 thyroiditis was associated with younger age group, lower female-male ratio, higher levels of thyroid autoantibodies, diffuse low echogenicity, more rapid progress requiring surgical treatment and more subclinical hypothyroidism. Serum IgG4 concentrations elevated in IgG4 thyroiditis and decreased significantly after a thyroidectomy. Histopathologically, IgG4 thyroiditis showed a higher grade of stromal fibrosis, lymphoplasmacytic infiltration, and follicular cell degeneration than non-IgG4 thyroiditis. IgG4 thyroiditis may represent IgG4-RD of thyroid gland, because it shares common histopathological characteristics with IgG4-RD in other organs. The identification of IgG4-RD of the thyroid gland opens new insights not only for patient's treatment with HT but also for the development of new therapeutic approaches for this rapidly progressive destructive subtype of HT. This article mainly focuses on reviewing the unique histopathological, clinical, and serological features of IgG4 thyroiditis group of HT. The etiology and genetic changes of HT are also discussed.

Fluorodeoxyglucose positron emission tomography in primary thyroid lymphoma with coexisting lymphocytic thyroiditis

BACKGROUND

Primary thyroid lymphoma is an uncommon neoplasm frequently associated with lymphocytic thyroiditis (LT). Once the pathologic diagnosis of primary thyroid lymphoma is established, imaging plays an important role in tumor staging and evaluating treatment response. The present case discusses the role of fluorodeoxyglucose positron emission tomography (18F-FDG PET)/computed tomography (CT) in this clinical setting along with the potential diagnostic challenges.

PATIENT FINDINGS

A 44-year-old man with a history of LT and hypothyroidism presented with an enlarging goiter. Initial imaging evaluation showed markedly enlarged gland with bilateral cervical and mediastinal adenopathy. Histopathologic evaluation confirmed the diagnosis of primary thyroid lymphoma on a background of LT. An 18F-FDG PET/CT revealed increased uptake in the gland and lymph nodes. Follow-up 18F-FDG PET/CT after chemotherapy showed interval decrease in FDG uptake in the thyroid gland associated with interval decrease in the size and metabolic activity of the cervical and superior mediastinal lymph nodes.

CONCLUSIONS

The frequent association of LT with primary thyroid lymphoma and the overlap of their clinical and pathologic findings pose a significant diagnostic challenge. While other imaging techniques are helpful in evaluating anatomic local and regional extent of primary thyroid lymphoma, 18F-FDG PET/CT can be of an added value in evaluating its metabolic activity and detecting regional and distant disease as well as in assessing response to treatment.

Ultrasound, elastography, and fluorodeoxyglucose positron emission tomography/computed tomography imaging in Riedel's thyroiditis: report of two cases

BACKGROUND

Riedel's thyroiditis (RT) is a rare disease characterized by a chronic inflammatory lesion of the thyroid gland with invasion by a dense fibrosis. Publications of the imaging features of RT are scarce. To our knowledge, ultrasound elastography (USE) findings have not been previously reported. Therefore, we describe two patients with RT who were imaged with ultrasonography (US), USE, and fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT).

SUMMARY

Two women were referred for a large, hard goiter with compressive symptoms (dyspnea and dysphagia); in one patient, the goiter was associated with retroperitoneal fibrosis. In both cases, RT was confirmed by surgical biopsy with pathological examination. Thyroid US imaging was performed with a US scan and a 10-13 MHz linear transducer. The hardness of the tissues was analyzed using transient USE (ShearWave, Aixplorer-SuperSonic Imagine). PET/CT scanning was performed with a Philips Gemini GXL camera (GE Medical Systems). In the first patient, US examination revealed a compressive multinodular goiter with large solid hypoechoic and poorly vascularized areas adjacent to the nodules. The predominant right nodule was hypoechoic with irregular margins. The second patient had a hypoechoic goiter with large bilateral hypoechoic areas. In both cases, an unusual feature was observed: the presence of tissue surrounding the primitive carotid artery, associated with thrombi of the internal jugular vein. Further, USE showed heterogeneity in the stiffness values of the thyroid parenchyma varying between 21 kPa and 281 kPa. FDG-PET/CT imaging showed uptake foci in the thyroid gland. In both cases, US showed a decrease in the thyroid gland volume and the disappearance of encasement of the neck vasculature in response to corticosteroid treatment. In contrast, the FDG-PET/CT features remained unchanged.

CONCLUSIONS

US features, such as vascular encasement and improvement under corticosteroid treatment, seem to be specific to this rare disease. For the first time, USE documents the hardness of RT tissues. Apart from the FDG-PET/CT findings that merit further investigation, US and USE prove useful tools in the assessment of such a rare disease.

Epidemiological characteristics of children with autoimmune thyroid disease

OBJECTIVE

Chronic autoimmune thyroiditis (AT) is the most common cause of thyroid disease in children. The aim of the study was to define the epidemiological clinical and laboratory characteristics of children and adolescents with AT.

DESIGN

Various parameters including thyroid ultrasonography of 228 children and adolescents aged 10.2 ± 2.5 yrs (mean ± SD) with AT, who attended our Pediatric Endocrine Unit during a 5-year period were retrospectively analysed.

RESULTS

191 (83.8%) were female and 142 (62.3%) were pubertal. At AT diagnosis, 130 children (57.0%) were euthyroid, 75 (32.9%) had subclinical hypothyroidism, 19 (8.3%) had hypothyroidism and 4 (1.8%) had hyperthyroidism. There was a positive correlation between thyroid stimulating hormone (TSH) levels and thyroid volume SDS (r=0.15, p=0.02). Sixty-three children (28%) had a goiter and 32 (14%) had thyroid nodules. Three children (1.3%) had papillary thyroid carcinoma. Compared to euthyroid children, children with hypothyroidism were younger (9.2 ± 1.8 vs 10.6 ± 2.4 yrs, p<0.05) and had higher thyroid volume SDS (3.1 ± 1.9 vs 1.2 ± 1.2, p<0.05) and higher prevalence of goiter [11(57.9%) vs 29(22.3%), p<0.05].

CONCLUSIONS

Children and adolescents with AT are mostly asymptomatic; the majority are female, pubertal and euthyroid. Hypothyroid children with AT have higher thyroid volume, higher prevalence of goiter and higher antithyroid antibodies titers compared to euthyroid children. Diagnosing AT at an early stage offers the opportunity for a timely intervention. The potential association of AT with papillary thyroid carcinoma is an additional reason for a careful follow-up of the patients with AT.

Thyroid stiffness assessment by acoustic radiation force impulse elastography (ARFI)

PURPOSE

To evaluate and compare the values of thyroid tissue elasticity in subjects without known thyroid pathology, in patients with Graves' disease and with chronic autoimmune thyroiditis (CAT).

PATIENTS AND METHODS

We performed a prospective study that included 74 subjects, 23 without thyroid pathology, 29 with Graves' disease and 22 with CAT (diagnosed by specific tests). In all patients, 10 elastographic measurements were performed in the right thyroid lobe (RTL) and 10 in the left thyroid lobe (LTL) using a 2-6 MHz convex probe. Median values were calculated for each thyroid lobe, measured in meters/second (m/sec). We calculated a mean ARFI value from measurements made in the RTL and LTL.

RESULTS

Thyroid stiffness was statistically significant lower in normal subjects vs. those with Graves' disease (2.07±0.44 m/sec vs. 2.82±0.47 m/sec, p<0.001) and with CAT (2.07±0.44 m/sec vs. 2.49±0.48 m/sec, p=0.004). We also found a statistically significant difference between subjects without thyroid pathology and those with autoimmune thyroid pathology (Graves' disease and CAT) (2.07±0.44 m/sec vs. 2.68±0.50 m/sec, p<0.001).

CONCLUSION

ARFI seems to be a useful method for the evaluation of diffuse thyroid gland pathology and is able to predict with sufficient accuracy the presence of thyroid diffuse diseases (AUROC=0.80).

Thyroid ultrasound in patients with Turner syndrome: influence of clinical and auxological parameters

OBJECTIVES

To determine thyroid volume and structure by ultrasound (US) in patients with Turner syndrome (TS) compared to healthy controls; to evaluate the frequency and characteristics of autoimmune thyroid disease (ATD) and its association with clinical and auxological parameters.

PATIENTS

73 patients and 93 height-matched healthy female controls in the same age range were included in the study.

RESULTS

Thirty-two TS patients (43.8%) presented ATD. They had a larger body mass index (BMI) and presented the 45,X karyotype more frequently than those without. They were older, with a higher prevalence of lymphoedema at birth and pterygium colli without statistical significance. Thyroid volume was 20% larger in the presence of ATD (p=0.037). A dyshomogeneous thyroid structure was observed in all patients with ATD and less frequently in those without (p=0.016). Dyshomogeneity in TS without ATD was also associated with older age (p<0.001), larger BMI (p=0.003) and larger thyroid volume (p=0.006). Six TS patients presented solitary thyroid nodules (5 benign nodules). We observed a significant interaction between diagnosis and height (p=0.035) and age (p=0.047), indicating that both age and height conditioned the observed differences in thyroid volume.

CONCLUSIONS

Most TS patients presented ATD with a normal thyroid function or subclinical hypothyroidism, without goiter. Dyshomogeneous thyroid structure was also observed in TS patients without ATD. In TS, the evaluation of thyroid volume according to chronological age does not seem to be efficient because of a link between height and thyroid volume. The prevalence of nodular thyroid disease is similar to that observed in the general population.

"Hypoechoic triangle": a new sonographic sign or marker of advanced autoimmune thyroiditis

BACKGROUND

Ultrasonography (US) changes have been noted in patients with autoimmune thyroiditis (AT). Here, we report that some patients with late stage AT have a distinctive, previously unreported finding on US that we call the "hypoechoic triangle sign" (HET).

METHODS

On US, the HET sign was characterized as a well-defined area of low echogenicity, about 10 mm in diameter, between the lateral margin of one or both thyroid lobes, the medial wall of the carotid artery, and, posteriorly, the prevertebral muscles. Twenty-six patients with AT who had the HET sign (Group 1) were compared with 71 patients with AT who had normal serum thyrotropin (TSH) and free thyroid hormones levels (Group 2) and with 154 normal controls (Group 3). TSH was tested at least twice, first as part of their regular clinical care and then in follow-up. The groups were similar in terms of age, sex, and body mass index. Thyroid volume by US, TSH, free triiodothyronine, free thyroxine, antithyroid antibodies, and l-thyroxine treatment were evaluated. Sonographic gray-scale analysis and three-dimensional reconstruction of HET region were performed in five of the Group 1 patients.

RESULTS

Thyroid volume was significantly smaller (p < 0.01) in Group 1 than in Groups 2 and 3 (6.9 ± 2.18 vs. 10.4 ± 2.1 and 9.8 ± 2.5 mL, respectively). In Group 1, 61.5% of subjects were taking l-thyroxine for hypothyroidism; none of the Group 2 or 3 patients was taking thyroid hormone. Serum TSH was significantly higher (p < 0.01) in Group 1 versus Groups 2 and 3 (3.6 ± 1.3 vs. 2.18 ± 1.4 and 1.9 ± 1.1 mIU/L, respectively). None of the Group 2 or 3 patients had the HET sign. Gray-scale US demonstrated an overlap between HET zone and the surrounding muscle tissue.

CONCLUSIONS

The HET sign seems to be specific for overt thyroid failure in patients with AT as it was not noted in patients with AT not having overt thyroid failure. The incidental finding of the HET sign during cervical US examination should prompt obtaining thyroid function tests to rule out hypothyroidism. Our study provides data regarding specificity but not sensitivity of the HET sign for AT and thyroid failure because a consecutive group of AT patients with thyroid failure was not studied. In addition, the specificity of the HET sign for AT needs to be evaluated further by studying a diverse group of thyroid diseases.

Low concordance between positive antibodies to thyroperoxidase and thyroid ultrasound autoimmune pattern in pregnant women

The diagnostic and prognostic role of thyroid ultrasound (TUS) in pregnant women positive for antibodies to thyroperoxidase (TPOAb) is unclear. The aim of our study was to compare the relation of ultrasound thyroid texture to the thyroid laboratory tests in pregnant women and controls. Using a semi-quantitative assessment we compared TUS in two groups of women with positive TPOAb and/or with thyroid dysfunction (TSH out of 0.06-3.67 mIU/L): 186 women in 1(st) trimester of pregnancy recruited from universal screening and 67 asymptomatic age-comparable non-pregnant non-postpartum women recruited from screening of general population (controls). Women with previous history of thyroid diseases were excluded. Only 64/131 (48.9 %) of TPOAb-positive pregnant women were TUS-positive (TUS with autoimmune pattern) in comparison with 35/49 (71.4 %) TPOAb-positive controls (p <0.011). Pregnant women had more often TSH >10.0 mIU/L if they were TPOAb-positive/TUS-positive as compared to those TPOAb-positive/TUS-negative (8/64 (12.5 %) vs. 0/67 (0 %), p = 0.009). The prevalence of preterm deliveries among TPOAb-positive women was significantly lower if TPOAb-positivity was not accompanied by TUS-positivity (2/67 (3.0 %) vs. 10/64 (15.6 %) in TPOAb-positive/TUS-positive women, p = 0.028). In conclusion, nearly half of the TPOAb-positive pregnant women did not have an autoimmune pattern in TUS. Normal TUS image in TPOAb-positive pregnant women might be a protective factor for preterm delivery.

Thyroid hormonal disturbances related to treatment of hepatitis C with interferon-alpha and ribavirin

OBJECTIVE

To characterize thyroid disturbances induced by interferon-alpha and ribavirin therapy in patients with chronic hepatitis C.

INTRODUCTION

Interferon-alpha is used to treat chronic hepatitis C infections. This compound commonly induces both autoimmune and non-autoimmune thyroiditis.

METHODS

We prospectively selected 26 patients with chronic hepatitis C infections. Clinical examinations, hormonal evaluations, and color-flow Doppler ultrasonography of the thyroid were performed before and during antiviral therapy.

RESULTS

Of the patients in our study, 54% had no thyroid disorders associated with the interferon-alpha therapy but showed reduced levels of total T3 along with a decrease in serum alanine aminotransferase. Total T4 levels were also reduced at 3 and 12 months, but free T4 and thyroid stimulating hormone (TSH) levels remained stable. A total of 19% of the subjects had autoimmune interferon-induced thyroiditis, which is characterized by an emerge of antithyroid antibodies or overt hypothyroidism. Additionally, 16% had non-autoimmune thyroiditis, which presents as destructive thyroiditis or subclinical hypothyroidism, and 11% remained in a state of euthyroidism despite the prior existence of antithyroidal antibodies. Thyrotoxicosis with destructive thyroiditis was diagnosed within three months of therapy, and ultrasonography of these patients revealed thyroid shrinkage and discordant change in the vascular patterns.

DISCUSSION

Decreases in the total T3 and total T4 levels may be related to improvements in the hepatocellular lesions or inflammatory changes similar to those associated with nonthyroidal illnesses. The immune mechanisms and direct effects of interferon-alpha can be associated with thyroiditis.

CONCLUSION

Interferon-alpha and ribavirin induce autoimmune and non-autoimmune thyroiditis and hormonal changes (such as decreased total T3 and total T4 levels), which occur despite stable free T4 and TSH levels. A thyroid hormonal evaluation, including the analysis of the free T4, TSH, and antithyroid antibody levels, should be mandatory before therapy, and an early re-evaluation within three months of treatment is necessary as an appropriate follow-up.

Prevalence of malignant tumors and adenomatous lesions detected by ultrasonographic screening in patients with autoimmune thyroid diseases

BACKGROUND

Thyroid ultrasonography (US) is the most sensitive method for detecting thyroid nodules, and US-guided aspiration biopsy is the most accurate diagnostic procedure for thyroid nodules. We performed this retrospective study to establish the prevalence of thyroid nodules in Graves' disease and patients with Hashimoto's thyroiditis at the time of their initial visit.

METHODS

We performed thyroid US as routine screening in 1652 patients with Graves' disease and 2036 Hashimoto's thyroiditis and performed US-guided fine-needle aspiration biopsy when the diameter of a nodule >1 cm or a nodule was suspected of being malignant.

RESULTS

The prevalence of papillary carcinoma in the patients with Hashimoto's thyroiditis was higher than in the patients with Graves' disease (1.77% vs. 0.97%), and two patients with Hashimoto's thyroiditis (0.098%) were found to have malignant lymphoma. Adenomatous lesions were observed more frequently in the patients with Hashimoto's thyroiditis than in the patients with Graves' disease. The prevalence of adenomatous lesions increased in an age-dependent manner in both the patients with Graves' disease and those with Hashimoto disease; and adenomatous lesions were more frequent in younger patients with Hashimoto' s thyroiditis than in those with Graves' disease.

CONCLUSIONS

The prevalence of both thyroid papillary cancer and adenomatous lesions was greater in the patients with Hashimoto's thyroiditis than in those with Graves' disease; and adenomatous lesions were more frequent in younger patients with Hashimoto's thyroiditis. We recommend performing US at the time of the initial visit in patients with autoimmune thyroid disease, who have a high prevalence of thyroid papillary carcinoma, to detect malignant thyroid tumors and adenomatous lesions.

Relationship between serum zinc levels, thyroid hormones and thyroid volume following successful iodine supplementation

OBJECTIVE

Zinc is essential for many biochemical processes and also for cell proliferation. Thyroid hormones influence zinc metabolism by affecting zinc absorption and excretion. Additionally, zinc deficiency affects thyroid function. The aim of the present study was to evaluate a possible association of zinc levels with thyroid volume, thyroid hormones and thyroid autoantibody levels in healthy subjects, patients with autoimmune thyroid disease (AITD) and patients with nodular goitre following successful iodine supplementation. This is a cross-sectional study in which 201 subjects who were not under medical treatment and did not have previous thyroid surgery or radio-iodine treatment were evaluated. Seventy patients had nodular goitre, 67 AITD and 64 had normal thyroid. Thyroid volume was calculated by ultrasonographic measurements. Serum free T4, T3, TSH, anti-thyroglobulin and anti-thyroid peroxidase levels were determined by appropriate methodology.

RESULTS

In patients with normal thyroid, zinc levels were significantly positively correlated with free T3 levels (p<0.001). In the nodular goitre group, thyroid volume was negatively correlated with TSH and circulating zinc levels (p=0.014 and p=0.045, respectively). In the AITD group, thyroid autoantibodies and zinc were significantly positively correlated. Multiple regression analysis revealed a significant relationship between thyroid volume and zinc only in the patients with nodular goitre (p=0.043).

CONCLUSION

There was significant correlation of serum zinc levels with thyroid volume in nodular goitre patients, with thyroid autoantibodies in AITD and with free T3 in patients with normal thyroid.

Distinct clinical, serological, and sonographic characteristics of hashimoto's thyroiditis based with and without IgG4-positive plasma cells

CONTEXT

IgG4-related sclerosing disease is a new syndrome characterized by high serum IgG4 levels and increased IgG4-positive plasma cells in the involved organs. Recently the first description was made by our group of a subsection of Hashimoto's autoimmune thyroiditis (HT) patients showing indistinguishable histopathological features with IgG4-related sclerosing disease, which was termed as IgG4 thyroiditis.

OBJECTIVE

The objective of the study was analysis of the immunophenotypic features of IgG4 in 70 cases of HT patients and to clarify the histopathological and clinical characteristics of the patients with IgG4 thyroiditis.

DESIGN

Thyroid tissue samples were obtained from 70 patients with HT who were treated surgically. Quantitative analyses of the expression of IgG4 and IgG were performed. Statistical analyses of clinical and histopathological parameters were also conducted.

RESULTS

On the basis of immunohistochemistry of IgG4 and IgG4/IgG ratio, the 70 patients with HT were divided into two groups: IgG4 thyroiditis (19 cases) and non-IgG4 thyroiditis (51 cases). Histopathologically, IgG4 thyroiditis showed higher grade of stromal fibrosis, lymphoplasmacytic infiltration, and follicular cell degeneration than non-IgG4 thyroiditis. Moreover, these two groups were also demonstrated to be related with different clinical features, with IgG4 thyroiditis associated more with male gender, rapid progress, subclinical hypothyroidism, more diffuse low echogenicity, and higher level of circulating antibodies.

CONCLUSIONS

From both clinical and histopathological aspects, IgG4 thyroiditis and non-IgG4 thyroiditis were demonstrated to be distinct entities. Measuring serum IgG4 concentration provides a useful method of distinguishing IgG4 thyroiditis from non-IgG4 thyroiditis.

Sonography and fine-needle aspiration biopsy in the diagnosis of benign versus malignant nodules in patients with autoimmune thyroiditis

PURPOSE

To correlate sonographic (US) characteristics and results of fine-needle aspiration biopsy (FNAB) of thyroid nodules in autoimmune thyroiditis (AT) with surgical pathological findings.

METHOD

Forty AT patients with 40 nodular lesions were analyzed retrospectively. Five sonographic characteristics were recorded for each nodule: diameter, echogenicity, microcalcification, halo sign, and margin. Preoperative sonograms and FNAB results were compared with postoperative histopathological findings.

RESULT

Twenty-four of the 40 nodules were malignant, including 20 papillary carcinomas, 3 follicular carcinomas, and 1 medullary carcinoma. Of the 16 benign nodules, 8 were nodular hyperplasia, 6 lymphocytic thyroiditis, and 1 each follicular adenoma and Hürthle cell adenoma. The only US parameter that was significant in malignant vs. benign nodules was the presence of poorly defined margins. Based on preoperative cytology, 22 of the 23 malignant nodules were correctly diagnosed, and 10 of the 14 benign nodules were correctly identified. The positive predictive value was 78.6%, and the negative predictive value was 93.7%.

CONCLUSION

No single US parameter can predict thyroid malignancy in patients with AT. A combination of US and FNAB provides the most sensitive and specific approach available preoperatively.

Clinical evolution of autoimmune thyroiditis in children and adolescents

BACKGROUND

Few studies have addressed the clinical evolution of autoimmune thyroiditis (AIT) occurring in childhood and scant data are available on the role of thyroid ultrasonography. We aimed to evaluate the natural history of AIT diagnosed in children and adolescents and to assess the possible prognostic role of ultrasonography.

METHODS

Retrospective case series prospectively followed up for a further 3-year period.

RESULTS

A series of 23 patients with AIT, diagnosed before 18 years of age from 1994 to 2004, was further followed up from 2005 to 2007 with clinical, laboratory, and ultrasound evaluation. Hypothyroid patients were treated with levothyroxine (LT(4)), while euthyroid patients were left untreated. Patients with subclinical hypothyroidism were also evaluated 40 days after LT(4) withdrawal. At diagnosis seven patients were euthyroid, 14 with subclinical hypothyroidism, and two with overt hypothyroidism. Median follow-up was 4.7 years. At last follow-up visit, none of the seven euthyroid patients had developed hypothyroidism. Three of the 14 patients with subclinical hypothyroidism recovered a normal thyroid function while only one patient showed an increase in TSH level. By serological screening we identified three patients with other autoimmune disorders.

CONCLUSIONS

In young patients with normal or mildly increased TSH levels and minimal echographic changes, AIT may remain stationary for years. In fact, patients with subclinical hypothyroidism recover a normal thyroid function in approximately 20% of cases. In patients with subclinical hypothyroidism and goiter, LT(4) therapy may induce thyroid size reduction. Screening for other autoimmune disorders is useful to identify patients that need further diagnostic assessment.

Paratracheal lymph nodes: a new sonographic finding in autoimmune thyroiditis

PURPOSE

To assess the clinical value of paratracheal lymph nodes (PLNs) as a novel sonographic finding in autoimmune thyroiditis (AT).

METHODS

A total of 309 consecutive patients underwent sonographic examinations of the thyroid between 1998 and 2003. A single radiologist assessed the sonographic findings of AT and PLNs. All patients underwent serological tests for antimicrosomal antibodies (AMAs). Patients with clinical, cytological, or laboratory findings of thyroiditis formed the AT group with a positive AMA test (n = 199). Controls were patients with no signs of nodular thyroid disease, normal thyrotropin, negative AMA, and benign cytology (n = 110).

RESULTS

PLNs were seen in 184 of 199 patients in the AT group and in 28 of 110 controls (P < 0.001) (sensitivity of 93.4%, specificity of 74.5% in the diagnosis of AT). PLNs in controls were fewer (2.8 +/- 1.5 versus 4.7 +/- 2.6; P < 0.001) and smaller (8.2 +/- 2.4 mm versus 10.7 +/- 3.3 mm; P < 0.001) than in the AT group.

CONCLUSION

PLNs are often present in patients with AT and are detectable with sonography. Radiologists should be aware of the importance of including the paratracheal region in the evaluation of the thyroid gland.

Second-generation thyrotropin receptor antibodies assay and quantitative thyroid scintigraphy in autoimmune hyperthyroidism

Graves' disease (GD) is characterized by circulating TSH receptor antibodies (TRAb), and so-called hyperthyroid autoimmune thyroiditis (H-AIT) generally shows negative TRAb results with first-generation assays. However, a positive titer was observed in up to 13% of patients with euthyroid or hypothyroid autoimmune thyroiditis (AIT) by second-generation TRAb assays, and a larger increase is expected in hyperfunctioning forms. A thyroid 99mTc-pertechnetate uptake (TcTUs) cutoff of 2% previously was shown to accurately discriminate between GD and H-AIT. Here we evaluated the relationship between second-generation TRAb assays and TcTUs in 139 patients with untreated autoimmune hyperthyroidism. An increase in TRAb levels was found in 114 of 139 patients (82%). All patients with TcTUs >2% and 66% of those with lower values had positive TRAb measurements. When the cutoff was increased to 5.9 U/l, positive TRAb occurred in 92.6% of those having higher TcTUs and in 1.4% of those with lower TcTUs. TRAb levels significantly increased in patients with TcTUs higher than 2% as compared with those having lower values, while no differences occurred in patients with TcTUs ranging from 0 to 1%, from 1.1 to 1.5%, or from 1.6 to 2%. A significant relationship between TRAb and TcTUs (as well as fT3, fT4, and thyroid volume) was found. TcTUs, fT4, fT3, and thyroid volume significantly increased in patients with positive TRAb (cutoff 1.5 U/l) compared with those testing negative. Our data indicate that a large proportion of patients with hyperthyroidism and hypoechoic thyroid, including those previously diagnosed as having H-AIT, actually have circulating TRAb. TRAb levels predicate the degree of iodine uptake (as measured by TcTUs) and thyroid hyperfunction. The role of baseline TRAb measurement by second-generation assays to predict patients' outcome needs to be further evaluated and compared with TcTUs in prospective studies.

Evaluation of the role of ultrasonography in diagnosis of autoimmune thyroiditis in goitrous children

OBJECTIVES

To evaluate the role of thyroid ultrasound in children with autoimmune thyroiditis diagnosed either on cytopathology or by the presence of thyroid peroxidase antibodies.

DESIGN AND SETTINGS

Children presenting for the first time to the Thyroid Clinic at the Institute of Nuclear Medicine and Allied Sciences for the complaint of goiter over a two year period (January 2005-December 2006) were studied.

SUBJECTS

695 school children (244 boys and 451 girls) aged 5-18 year were studied.

METHODS

Children were subjected to thyroid ultrasound, cytopathology, thyroid peroxidase antibody and thyroid function tests.

RESULTS

Overall, 16% of goitrous children had hypoechogenicity on ultrasound, 15.2% had cytopathological evidence of thyroiditis, 10.6% had positive thyroid peroxidase antibodies and 25.2% had abnormal thyroid function tests. Subjects with hypoechogenicity had higher percentage of thyroiditis on cytopathology (41.4% vs. 10.3%; P<0.01), thyroid peroxidase antibody positivity (30.6% vs. 6.8%; P<0.01) and thyroid dysfunction (46.8% vs. 21.2%; P<0.01) than those with normal echogenicity.

CONCLUSION

Thyroid USG has a useful, though limited, role in excluding thyroid disease in children. The sensitivity of echogenicity for the diagnosis of autoimmune thyroiditis in children is less than that reported in adults.

[Evidences for subclinic chronic autoimmune thyroid disease in girls with Turner Syndrome]

Patients with Turner syndrome (TS) frequently exhibit transient, recurrent and asymptomatic variations of TSH and/or thyroid hormones (TH). This work was carried out to evaluate thyroid function and structure in patients with TS who had had such variations in hormone concentrations. Our sample comprised 24 patients, 17 less than 20-years old. Evaluation included serum levels of TSH, free T4, total T3, TPO and Tg autoantibodies, thyroid ultrasound (US) and scintigraphy with 99mTc-pertechnetate. Thirteen patients had abnormal TSH and/or TH levels; 23 exhibited US features compatible with chronic thyroid disorder, particularly thyromegaly (established according to volume expected for stature) and heterogeneous echogenicity. Uptake was normal in 21 cases and tracer distribution was homogeneous in 22. The finding of abnormal hormone concentrations was independent of age, length of time since the first similar finding, thyroid autoantibodies, number of abnormalities at US and abnormal scintigraphic findings. Patients aged more than 20 years had higher frequency of thyroid antibodies and heterogeneous echogenicity, and thyroid volume was significantly correlated to length of time since detection of the first hormone variation, indicating progressive thyroid disease. These results suggest that subclinical thyroid dysfunction in TS is due to chronic autoimmune thyroid disease.

Mood and thyroid immunity assessed by ultrasonographic imaging in a primary health care

BACKGROUND

Psychiatric morbidity is highly prevalent in the primary health care settings and it may be related to autoimmune thyroid disease (AITD). The aim of this study was to evaluate the impact of thyroid immunity, evident by hypo-echoic thyroid ultrasound pattern, on prevalence of depression and anxiety in a primary care setting.

METHODS

In a cross-sectional design, 504 consecutive primary care patients were invited to the study and 474 patients completed the study. They were screened for depression and anxiety using the Hospital Anxiety and Depression Scale (HADS), were interviewed for affective disorders using the Mini International Neuropsychiatric Interview, and were evaluated by ultrasonographic imagining of the thyroid gland.

RESULTS

Among patients with hypo-echoic thyroid (n=122) prevailed women and those patients were older than patients with normo-echoic thyroid (n=352). Women, but not men, with hypo-echoic thyroid compared to those with normo-echoic thyroid had higher scores on the anxiety subscale of the HADS (p=0.03). Among women with hypo-echoic thyroid, only those pre-menopause, but not those post-menopause, had greater prevalence of high scores on the depression subscale of the HADS (p=0.02) and a greater likelihood of using psychiatric medications (p=0.001).

LIMITATIONS

Lack of cytological evaluation of the thyroid gland; lack of serum thyroid antibodies concentrations; and lack of thyroid hormone concentrations.

CONCLUSIONS

Thyroid immunity is related to mood symptoms in primary care patients. These effects are gender specific and in women, they are most evident before menopause.

Levothyroxine treatment reduces thyroid size in children and adolescents with chronic autoimmune thyroiditis

CONTEXT

The use of levothyroxine to reduce thyroid size in pediatric patients with goiter due to chronic autoimmune thyroiditis (AIT) remains controversial. In overtly hypothyroid patients, reductions in thyroid volume have been reported, whereas the effect in subclinically hypothyroid and euthyroid patients is less clear.

OBJECTIVE

The objective of the study was to evaluate the effect of levothyroxine treatment on thyroid size (determined with thyroid ultrasonography) in children and adolescents with AIT.

DESIGN AND SETTING

This study included patients with AIT treated at a university hospital outpatient clinic between 1987 and 2004.

PATIENTS

Ninety children with AIT (73 girls and 17 boys, aged 6.1-17.7 yr) were included in the study.

INTERVENTION

Intervention was treatment with levothyroxine for a median 2.8 yr (range 0.5-10.2).

MAIN OUTCOME MEASURE

Change in thyroid volume sd score (SDS) during the study period was measured.

RESULTS

Median thyroid volume SDS was reduced in patients euthyroid (-0.4 SDS, P < 0.001), subclinically hypothyroid (-1.4 SDS, P < 0.001), and overtly hypothyroid (-1.8 SDS, P < 0.002) at diagnosis of AIT. Both hypothyroid and euthyroid patients with goiter (thyroid volume > 2.0 SDS) at baseline reduced their median thyroid volume SDS (-1.6 and -0.9, respectively, P < 0.001). Hypothyroid patients without goiter also reduced median thyroid volume SDS (-1.2, P < 0.004), whereas no change was noticed in euthyroid children without goiter.

CONCLUSIONS

Levothyroxine treatment is effective in reducing thyroid volume in pediatric patients and is suggested in treatment of goiter caused by AIT, especially in cases of hypothyroid, but also in euthyroid children.