The value of ultrasonography in predicting autoimmune thyroid disease.

Ultrasonography (US) may demonstrate a diffuse reduction in thyroid echogenicity (low-amplitude echoes) in autoimmune thyroid disease (AITD), which includes chronic lymphocytic thyroiditis and Graves' disease, as well as in subacute thyroiditis. The reported occurrence of this finding in AITD varies from 19% to 95%. To assess the validity of diffuse reduction in thyroid echogenicity as a predictor of AITD, 3,077 patients referred for US of the thyroid were examined prospectively with regard to reduced versus normal thyroid echogenicity. The most frequent reasons for referral were goiter, thyroid dysfunction, neck discomfort, and/or difficulty in swallowing. Ultrasonography demonstrated diffuse reduction in thyroid echogenicity in 485 patients. Of these, 452 patients had available records of fine-needle aspiration biopsy (FNAB), and were included in the study. From the remaining patients, with normal thyroid echogenicity, 100 consecutive patients were selected as controls. In 411 of the 452 study patients (90.9%) there was at least one laboratory finding consistent with possible AITD: cytology indicating lymphocytic thyroiditis, 287 of 363 patients (79.1%) with diagnostic specimens; elevated levels of peroxidase antibodies (TPOAb), 225 of 337 (66.8%); elevated thyrotropin (TSH) levels, 290 of 450 (64.4%); or low TSH levels, 79 of 450 (17.6%). The final diagnosis was: chronic autoimmune (Hashimoto's) thyroiditis in 352 patients; Graves' disease in 47 patients; subacute (granulomatous) thyroiditis in 7 patients; toxic nodular goiter in 3 patients; and toxic adenoma in 2 patients. In the remaining 41 patients, those without laboratory results consistent with AITD, the final diagnosis was colloid goiter in 37 and thyroid cancer in 4 patients. In the 100 controls, laboratory results were consistent with possible AITD in 14 patients: elevated TPOAb levels in 5 of 49 patients with retrieved antibody results; lymphocytic thyroiditis in 2 patients; elevated TSH levels in 2 patients; and low TSH levels in 2 patients. In these controls, the final diagnosis was: chronic autoimmune thyroiditis in 7; toxic nodular goiter in 6 patients, and toxic adenoma in 1 patient. The corresponding positive and negative predictive values of reduced thyroid echogenicity as an indicator of AITD were 399 of 452 (88.3% [95% CI, 85% to 91%]), and 93 of 100 (93.0% [95% CI, 88% to 98%]), respectively. Thus, diffuse reduction in thyroid echogenicity was a valid predictor of AITD.     

Clinical characteristics of amiodarone-induced thyrotoxicosis and hypothyroidism in Japan.

Since amiodarone was introduced in Japan in 1992, the incidence of the drug-induced thyroid dysfunction has been increasing. We studied the thyroid function of 13 patients with amiodarone-induced thyrotoxicosis (AIT) and 11 patients with amiodarone-associated hypothyroidism (AAH) who had been referred to our Institute in the last 6 years. AIT and AAH developed after 39+/-21 and 20+/-16 months of amiodarone treatment, respectively. One patient developed AAH followed by AIT. The AIT ranged from subclinical to overt thyrotoxicosis. Four patients with moderate to marked AIT were treated with methimazole. Their thyrotoxicosis persisted for 3 to 9 months, despite administration of antithyroid agents. One patient with mild thyrotoxicosis was treated with prednisolone, resulting in a euthyroid state in a few months. Eight patients with asymptomatic to moderate thyrotoxicosis resolved spontaneously without any treatment. In four asymptomatic patients with AIT, serum levels of T3 and T4 were in the upper normal range or slightly high (< 12 microg/dl), accompanied by suppressed TSH (<0.1 microU/ml) and high thyroglobulin levels, suggesting destruction-induced thyrotoxicosis. Such a subclinical thyrotoxicosis developed repeatedly in one patient. Ultrasonographic studies revealed no nodular lesion in the thyroid, and color flow Doppler sonography demonstrated no hypervascularity in the thyroid gland in any AIT patient. Although it is postulated in Europe that there are two types of AIT, namely type I, which develops in patients with latent Graves' disease or toxic multinodular goiter, and type II, which develops in an apparently normal thyroid as destructive thyroiditis, all AIT patients we have seen so far had developed destructive type AIT. Sufficient intake of iodide and a very low incidence of toxic multinodular goiter may account for the rare incidence of type I AIT in our country. Mild to moderate AIT resolved spontaneously without discontinuing amiodarone, but it was discontinued in two of 13 AIT patients because of extrathyroidal adverse reactions.     

Thyroid antibodies in autoimmune diseases of the thyroid and their dependence on the presence of autoantigens

Autoimmune thyroid diseases (especially diffuse toxic goiter) are characterized by a higher frequency of the detection and concentration of serum thyroglobulin. The frequency of the detection of antibodies to thyroglobulin in Hashimoto's thyroiditis was higher and their concentration lower than in diffuse toxic goiter. The frequency of the detection of antibodies to microsomal thyroid antigen in autoimmune thyroid diseases was lower than that of antibodies to thyroglobulin and did not depend on a type of disease. In diffuse toxic goiter the level of antibodies to thyroglobulin showed positive correlation with the level of antibodies to microsomal antigen and negative correlation with serum thyroglobulin concentration. In Hashimoto's thyroiditis the level of antibodies to thyroglobulin correlated with the level of serum thyrotropin. One-six years after thyroid extirpation serum thyroglobulin was practically absent in patients with Hashimoto's thyroiditis, and the frequency of the detection of thyroid autoantibodies (especially antimicrosomal ones) was sharply decreased.     

Recombinant human thyrotropin (TSH) receptor in a radioreceptor assay for the measurement of TSH receptor autoantibodies

We studied the suitability of using the recombinant human TSH receptor expressed in Chinese hamster ovary cells in a TSH binding inhibition (TBI) assay for autoantibodies against the TSH receptor. Purified immunoglobulin G (IgG) containing potent thyroid-stimulating immunoglobulin bioactivity competed for radiolabeled TSH binding to recombinant TSH receptor in parallel to inhibition by unlabeled TSH. Using polyethylene glycol-prepared IgG, this assay discriminated very well between sera from normal individuals [TBI, 0.98 +/- 0.04 (+/- SD); range, 0.92-1.08; n = 35] and patients with untreated Graves' disease (TBI, 0.49 +/- 0.23; range, 0.06-0.98; n = 93). Only four of the sera from the untreated Graves' patients were TBI negative (greater than or equal to 0.92), providing a sensitivity of 96%. In sera from patients with Graves' disease receiving antithyroid drug therapy, TBI was 0.63 +/- 0.18 (range, 0.19-0.97; n = 75). In this group of treated patients, 2 of 75 were TBI negative. Four of 12 patients with Hashimoto's thyroiditis (33%) were positive for TBI activity. All 18 patients with nonautoimmune thyroid diseases (toxic nodular goiter, single toxic adenoma, subacute thyroiditis, or thyroid cancer) were TBI negative. Correlation of the TBI values with thyroid-stimulating immunoglobulin bioactivity revealed a generally positive correlation (r = 0.31; P less than 0.05); however, there were many discrepancies among individual sera. TSI bioactivity was undetectable in all 4 patients with Hashimoto's thyroiditis who were TBI positive. These data indicate that the recombinant TSH receptor in Chinese hamster ovary cells is a suitable system for detecting TBI activity in the sera of patients with autoimmune thyroid disease.     

Soluble Fas is increased in hyperthyroidism independent of the underlying thyroid disease

In Hashimoto's thyroiditis, Fas-induced apoptosis is one of the mechanisms leading to cell destruction, whereas thyroid tissue in Graves' disease is prevented from it. The soluble form of the Fas molecule produced by alternative splicing prevents from apoptosis. We measured soluble Fas in the sera of 112 patients with Graves' disease, 21 patients with toxic goiter, and 24 patients with subclinical hyperthyroidism due to suppressive therapy with levothyroxine after near-total resection of the thyroid gland for nodular goiter. Soluble Fas was increased in thyrotoxic patients, toxic goiter, and patients with subclinical hyperthyroidism. Decreased levels of soluble Fas were found in euthyroid patients with Graves' disease after surgery, whereas soluble Fas was normal in euthyroid patients with Graves' disease receiving antithyroid drug treatment and in patients in stable remission. There was a good correlation between soluble Fas with free T(3) (r = 0.6) and free T(4) (r = 0.5). Our results show that soluble Fas is increased in hyperthyroidism independent of the underlying thyroid disease.     

Thyroid vascularity and blood flow are not dependent on serum thyroid hormone levels: studies in vivo by color flow doppler sonography

OBJECTIVE: Thyroid blood flow is greatly enhanced in untreated Graves' disease, but it is not known whether it is due to thyroid hormone excess or to thyroid hyperstimulation by TSH-receptor antibody. To address this issue in vivo patients with different thyroid disorders were submitted to color flow doppler sonography (CFDS). SUBJECTS AND METHODS: We investigated 24 normal subjects, and 78 patients with untreated hyperthyroidism (49 with Graves' hyperthyroidism, 24 with toxic adenoma, and 5 patients with TSH-secreting pituitary adenoma (TSHoma)), 19 patients with thyrotoxicosis (7 with thyrotoxicosis factitia, and 12 with subacute thyroiditis), 37 euthyroid patients with goitrous Hashimoto's thyroiditis, and 21 untreated hypothyroid patients with Hashimoto's thyroiditis. RESULTS: Normal subjects had CFDS pattern 0 (absent or minimal intraparenchimal spots) and mean intraparenchimal peak systolic velocity (PSV) of 4.8+/-1.2cm/s. Patients with spontaneous hyperthyroidism due to Graves' disease, TSHoma, and toxic adenoma had significantly increased PSV (P<0.0001, P=0.0004, P<0.0001 respectively vs controls) and CFDS pattern. Patients with Graves' disease had CFDS pattern II (mild increase of color flow doppler signal) in 10 (20%) and pattern III (marked increase) in 39 cases (80%). Mean PSV was 15+/-3cm/s. Patients with toxic adenoma had CFDS pattern I (presence of parenchymal blood flow with patchy uneven distribution) in 2 (8%), pattern II in 16 (70%) and pattern III in 5 (22%). Mean PSV was 11+/-2.4cm/s. Patients with TSHoma showed CFDS pattern I in one case (20%) and pattern II in 4 (80%). Mean PSV was 14.8+/-4.2cm/s. Patients with thyrotoxicosis had normal PSV (4.2+/-1. 1cm/s in subacute thyroiditis, 4+/-0.8cm/s in thyrotoxicosis factitia, P=not significant vs controls) and CFDS pattern 0. Untreated euthyroid patients with goitrous Hashimoto's thyroiditis had CFDS pattern 0, and mean PSV (4.3+/-0.9cm/s; P=not significant vs controls). Untreated hypothyroid patients with goitrous Hashimoto's thyroiditis had CFDS pattern I in 14 cases (67%), pattern II in 4 (19%) and pattern 0 in 3 (14%) and mean PSV (5.6+/-1. 4cm/s) was higher than that of controls (P=0.026). CONCLUSIONS: An increase in both intrathyroidal vascularity and blood velocity was observed in patients with spontaneous hyperthyroidism but not in thyrotoxicosis due to either ingestion of thyroid hormones or to a thyroidal destructive process. The slightly increased vascularity and blood velocity observed in patients with hypothyroid Hashimoto's thyroiditis suggests that thyroid stimulation by either TSH-receptor antibody or TSH is responsible for the increased thyroid blood flow.     

Endothelin-1 levels in patients with disorders of the thyroid gland.

The endothelium derived peptide endothelin-1 (ET-1) is the major isoform of the endothelin peptide family, which is produced and secreted in the endothelial cell system. We measured plasma levels in patients with thyroid diseases and investigated associations between laboratory and clinical markers of thyroid metabolism and ET-1 plasma levels. ET-1 plasma levels were determined in patients with Graves' disease (n = 54), endemic goiter (n = 26), patients with Hashimoto's thyroiditis (n = 21) and compared to healthy controls (n = 60). ET-1 plasma levels were significantly elevated in patients with Hashimoto's thyroiditis (p < 0.0001) and in patients with Graves' disease (p = 0.003), when compared to healthy controls. In patients with endemic goiter, no significant differences were found compared to healthy controls (p = 0.298) and when compared to patients with Graves' disease (p = 0.16). We did not observe an association between ET-1 plasma levels and parameters of thyroid disease (e.g. thyroidea-stimulating hormone, thyroxine, volume of the thyroid). Furthermore, patients with and without endocrine thyroid disease showed no significantly different ET-1 plasma levels (p = 0.78). These data suggest that the autoimmunologically induced inflammatory response of the thyroid gland in Hashimoto's thyroiditis and Graves' disease is responsible for increased ET-1 plasma levels. Furthermore, our data do not support a role for ET-1 as a valid quantitative indicator for stage or progression in endemic goiter, Graves' disease or Hashimoto's thyroiditis.     

定量检测人甲状腺过氧化物酶抗体化学发光酶免疫分析法的临床应用

目的 应用人甲状腺过氧化物酶抗体(hTPOAb)的化学发光酶免疫分析(CLEIA)试剂盒,检测正常人及各类甲状腺疾病患者,探讨该试剂盒在临床应用中的价值.方法 用该试剂盒共测定333例样品血清中的hTPOAb,包括正常人133名,各类甲状腺疾病患者200例,其中桥本甲状腺炎(HT) 94例,Graves病68例,结节性甲状腺肿19例,亚急性甲状腺炎10例,单纯性甲状腺肿9例.结果 确立本试剂盒hTPOAb阳性切限值为3.22 IU/ml,hTPOAb浓度以中位数表示,分别为HT5.48 IU/ml,阳性率为91.50％;Graves病1.88 IU/ml,阳性率为29.40％;结节性甲状腺肿1.83 IU/ml,阳性率为10.50％,亚急性甲状腺炎2.54 IU/ml,阳性率为20.00％;单纯性甲状腺肿2.21 IU/ml,阳性率为0.HT患者血清hTPOAb阳性率高于其他患者(x2=67.22,60.13,35.49,49.89,P均＜0.01).结论 该定量检测hTPOAb的CLEIA试剂盒在HT中有很高的阳性率,可作为HT有效的诊断手段.     

Musculoskeletal manifestations in patients with thyroid disease

OBJECTIVE: Thyroid dysfunction may cause musculoskeletal symptoms. We have evaluated the prevalence of adhesive capsulitis, Dupuytren's contracture, trigger finger, limited joint mobility and carpal tunnel syndrome in a series of patients with various thyroid diseases and differing levels of function. DESIGN AND PATIENTS: Patients with euthyroid (diffuse and/or nodular) goitre, Hashimoto's thyroiditis, Graves' disease, toxic nodular goitre, toxic diffuse goitre and patients with goitre who had partial thyroidectomy were included in the study (n = 137). Neurological and musculoskeletal examinations were performed after a standardized symptom questionnaire. The prevalence of musculoskeletal problems was analysed with respect to thyroid function and thyroid autoantibody status. MEASUREMENTS: Serum concentrations of free T3, free T4, TSH and thyroglobulin and thyroperoxidase antibodies were determined. Serum levels of creatine kinase, lactate dehydrogenase, calcium and phosphate along with erythrocyte sedimentation rate were measured to exclude other causes of musculoskeletal complaints. RESULTS: When the study group (n = 137) was divided according to thyroid status, 30.6% (n = 42) were thyrotoxic, 16.8% (n = 23) had subclinical thyrotoxicosis, 28.5% (n = 39) were euthyroid, 7.3% (n = 10) had subclinical hypothyroidism and 16.8% (n = 23) were hypothyroid. Overall, adhesive capsulitis was found in 10.9% (n = 15), Dupuytren's contracture in 8.8% (n = 12), limited joint mobility in 4.4% (n = 6), trigger finger in 2.9% (n = 4) and carpal tunnel syndrome in 9.5% (n = 13) of the patients. The prevalence of adhesive capsulitis was highest in patients with subclinical thyrotoxicosis (17.4%); Dupuytren's contracture, limited joint mobility and carpal tunnel syndrome were commonest in hypothyroid patients (21.7%, 8.7% and 30.4%, respectively). Trigger finger occurred in 10% of patients with subclinical hypothyroidism. When these prevalences were analysed with respect to thyroid status, carpal tunnel syndrome was significantly more prevalent in the hypothyroid group (P = 0.004). When thyroperoxidase antibody-positive and -negative patients were compared, adhesive capsulitis negatively (P = 0.03, r =-0.18) and trigger finger positively correlated with (P = 0.03, r = 0.21) thyroperoxidase antibody existence. CONCLUSIONS: These results demonstrate that musculoskeletal disorders often accompany thyroid dysfunction. In addition to the well-known observation that these disorders are common in patients with hypothyroidism, they are also observed in patients with thyrotoxicosis. Patients with thyroid dysfunction should be questioned for musculoskeletal complaints and referred to a specialist if necessary.     

A rare case of orbital involvement in Riedel's thyroiditis

We report a case of Riedel's thyroiditis in a 59-yr-old Caucasian female. She presented hypothyroidism and a stony hard, painful goiter. Due to fever, a high sedimentation rate and a high C-reactive protein (CRP), as well as high levels of anti-thyroid peroxidase antibodies (anti-TPOab), differential diagnostic considerations included acute and subacute thyroiditis as well as Hashimoto's thyroiditis and thyroid malignancy. At the same time the patient had clinical and radiological features of bilateral orbital pseudotumor with lacrimal gland involvement. During L-thyroxine therapy orbital symptoms and signs improved and thyroid size decreased. This case report serves as a reminder of differential diagnostic considerations in the etiology of goiter as well as ophthalmopathy. Although extremely rare, orbital sclerosing fibrosis can be seen in conjunction with Riedel's thyroiditis as part of multifocal fibrosclerosis.     

One-year prophylactic treatment of euthyroid Hashimoto's thyroiditis patients with levothyroxine: is there a benefit?

Studies in animal models of spontaneous Hashimoto's autoimmune thyroiditis (HT) show that prophylactic treatment with levothyroxine (LT4) can reduce incidence and degree of lymphocytic infiltration in HT. The aim of the present study was to clarify whether there is a benefit of prophylactic treatment with LT4 in patients with euthyroid HT with respect to the progression of the autoimmune process. Twenty-one patients with euthyroid HT were checked for thyroid function (thyrotropin [TSH], free triiodothyronine [FT3], free thyroxine [FT4]), thyroid volume, antibodies (thyroglobulin [Tg-Ab], thyroid peroxidase [TPO-Ab]), and lymphocyte subsets. Peripheral (PBL) and thyroid-derived lymphocytes (TL) were analyzed by triple color flow cytometry. One-half of the patients with euthyroid HT were treated with LT4 for 1 year (n = 10). The other half (n = 11) were never treated with LT4. TL were obtained by fine-needle aspiration biopsy (FNAB). Thirteen healthy subjects (C) without medical history of thyroid disease served as controls concerning PBL, and patients with non-toxic nodular goiter (NG; n = 10) served as controls concerning TL. Thyroid-derived T-helper cells were found more frequently in euthyroid patients with HT compared to patients with NG (p < 0.01). After 1 year of therapy with LT4, TPO-Abs and B lymphocytes decreased significantly only in the treated group of euthyroid patients with HT (p < 0.05). In contrast, TPO-Abs levels did not change or even increased in untreated euthyroid patients with HT. Thyroid volume did not differ before and after therapy. Prophylactic treatment of euthyroid patients with HT reduced both serological and cellular markers of autoimmune thyroiditis. Therefore, prophylactic LT4 treatment might be useful to stop the progression or even manifestation of the disease. However, the long-term clinical benefit of prophylactic LT4 therapy in euthyroid patients with HT is yet to be established.     

A comparison of plasma TSH levels in patients with diffuse and nodular non-toxic goiter.

Plasma TSH levels were measured in 115 euthyroid patients with simple goiter, of whom 52 had diffuse and 63 nodular enlargement of the thyroid gland, and in 191 euthyroid patients without goiter. There was no significant difference between the plasma TSH levels in the patients with diffuse goiter and the non-goitrous controls, implying that the maintenance of diffuse hyperplasia is not dependent upon a raised level of plasma TSH. On the other hand, plasma TSH levels in the patients with nodular goiter were significantly lower than those recorded in either the patients with diffuse goiter (P less than 0.01) or in the patients without goiter (P less than 0.0001), supporting the view that thyroid function may be autonomous in nodular goiters.     

ELISA测定TMAb和TGAb的临床意义

用ELISA对103例健康人和183例不同甲状腺病患者血清TMAb和TGAb测定,同时检测了血清T_3和T_4值。结果表明,在桥本甲状腺炎、甲状腺机能亢进和原发性甲状腺机能减退患者中,二种抗体的阳性率和阳性程度均显著增高,单纯甲状腺肿和甲状腺腺瘤患者抗体水平正常,亚急性甲状腺炎和甲状腺癌则介于二者之间。桥本甲状腺炎患者TMAb与T_3、T_4间、TGAb与T_4间存在显著的负相关关系。     

Serum free thyroid hormones in T3-toxicosis: a study of 35 patients

Few data are available on serum free thyroid hormone concentration in patients with T3-toxicosis. In this study total and free T4 and T3 and TBG were evaluated in 35 subjects with T3-toxicosis, including 12 with untreated Graves' disease, 5 Graves' patients on methimazole treatment, 13 with autonomous adenoma, 3 with multinodular goiter, and 2 with subacute thyroiditis. T4, T3, free T4 (FT4), free T3 (FT3) as well as calculated T4/TBG and T3/TBG ratios were significantly higher in patients than in 37 healthy controls. Serum FT4 levels above the normal range were found in 19 subjects with T3-toxicosis (9 with untreated and one with methimazole-treated Graves' disease, 6 with autonomous adenoma, 1 with multinodular goiter and 2 with subacute thyroiditis). These data, together with the few previous reports, indicate that high FT4 levels are present in about half of the patients with so called T3-toxicosis, and that this occurs more frequently in diffuse than nodular goiter. It is suggested that the term T3-toxicosis be used only for those subjects with normal total and free T4.     

Postpartum lymphocytic thyroiditis. Prevalence, clinical course, and long-term follow-up

A group of 238 women were surveyed for thyroid disease at six and 12 weeks post partum. Twenty-seven (11.3%) of 238 entered into the study were found to have thyroid disease. Fifteen (56%) of 27 had positive microsomal hemagglutinin antibody titers. A spectrum of thyroid disease was found: persistent hypothyroidism (two patients), transient thyrotoxicosis followed by persistent hypothyroidism (one) or transient hypothyroidism (three), euthyroid goiter (five), transient thyrotoxicosis (seven), transient hypothyroidism (three), high-normal thyroxine levels (five), and low-normal thyroxine levels (one). All nine patients who underwent biopsy had active lymphocytic thyroiditis. Three-year follow-up of 25 of the 27 affected individuals revealed that 12 (48%) still had thyroid disease. This study demonstrates that there is a high incidence of postpartum thyroid disease, usually of a transient nature, and that only about one fourth of the cases are detected or clinically obvious.     

Natural course of autoimmune thyroiditis in Thai children

Forty-seven pediatric patients with autoimmune thyroiditis were followed for an average of 5.18+/-2.89 years. The diagnosis was based on a firm goiter and a positive test for antithyroid antibodies. Initially, 23 patients had euthyroidism, 11 overt hypothyroidism, 6 compensated hypothyroidism and 7 with low TSH. All patients had clinical euthyroidism, except two who had overt hypothyroidism. The thyroid function tests, the size of the thyroid gland and the thyroid antibodies were regularly evaluated. After the follow-up, 26 patients had untreated euthyroidism, 12 with overt hypothyroidism received eltroxin for maintenance of euthyroidism, while 4 had compensated hypothyroidism and 5 low TSH levels. All had clinical euthyroid. The thyroid size was reduced in 12 patients (26%) while 4 (9%) had normal-sized gland. The goiter size in 35 patients (74%) remained unchanged. The antithyroglobulin and antimicrosomal antibody titers fluctuated higher in patients with overt hypothyroidism. Eltroxin was given only to those having overt hypothyroidism with diminished goiter size in 8 patients (73%).     

Prevalence of thyroid diseases in patients with acromegaly: results of an Italian multi-center study

Acromegaly is frequently associated with the presence of thyroid disorders, however the exact prevalence is still controversial. An Italian multicenter study was performed on 258 patients with active acromegaly (high levels of IGF-I and lack of suppression of serum GH levels below 2 microg/l after an OGTT). The control group was represented by 150 patients affected by non-functioning and PRL-secreting pituitary adenomas. Two hundred and two out of 258 acromegalic patients (78%) were affected by thyroid disorders with a significantly higher prevalence with respect to the control group (27%, p<0.0001). One hundred and three patients presented (39.9%) non-toxic nodular goiter, 46 (17.8%) non-toxic diffuse goiter, 37 (14.3%) toxic nodular goiter, 1 toxic diffuse goiter (0.4%), 12 (4.6%) Hashimoto's thyroiditis, 3 (1.2%) thyroid cancer. Two patients presented a co-secreting TSH pituitary adenoma. Thirty-six patients had been previously treated for various thyroid abnormalities. Among the 222 acromegalic patients never treated for thyroid disorders thyroid ultrasonography was performed on 194 subjects. Thyroid volume in patients with thyroid abnormalities was 28+/-17.5 ml (median 23) while it was 10.8+/-3.6 ml (median 10) in patients without thyroid disorders (p<0.0001). Thyroid volume was correlated with the estimated duration of acromegaly (r=0.7, p<000.1), but not with age or with serum GH, IGF-I and TSH concentrations. Thyroid volume was higher in acromegalic patients than in the above control population (23.5+/-16.9 ml vs 13.9+/-12.8 ml, p<0.0001). In 62 acromegalic patients 101 fine-needle biopsies of thyroid nodules were performed; 7 nodules were suspicious and the patients were submitted to thyroid surgery: papillary thyroid carcinoma was found in 3 patients. In conclusion, in a large series of acromegalic patients an increased prevalence of thyroid disorders (78%), particularly non-toxic nodular goiter, has been observed. Thyroid volume, evaluated by ultrasonography, was correlated to the estimated duration of acromegaly. Finally, the prevalence of thyroid carcinoma was slightly increased than in the general population.     

More on smoking habits and Graves' ophthalmopathy

Since a relationship between cigarette smoking and the occurrence of Graves' ophthalmopathy has been recently postulated, we reviewed the smoking habits of 1730 women, including subjects without thyroid disease, with nontoxic goiter (NTG), toxic nodular goiter or toxic adenoma (TNG), Hashimoto's thyroiditis (HT), Graves' disease without ophthalmopathy (GD) or with ophthalmopathy (GO). The prevalence of smokers in NTG, TNG and HT was about 30%, not different from that of controls. Smokers were 47.9% in GD and 64.2% in GO groups. The latter figures were highly different from those of the other groups and also from each other. The percentage of heavy smokers was higher in patients with more severe ophthalmopathy. No clear explanation for this phenomenon can be offered. The absence of a high prevalence of smokers among patients with non-toxic goiter, nonautoimmune hyperthyroidism and Hashimoto's thyroiditis, limits the impact that smoking might have had in the pathogenesis of goiter, hyperthyroidism and autoimmune phenomena of GD and GO.     

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.     

Correlation between thyrotropin-displacing activity and human thyroid-stimulating activity by immunoglobulins from patients with Graves' disease and other thyroid disorders.

Several reports have been published on the anti-TSH receptor antibody in putative autoimmune thyroid disorders using a radioreceptor assay. We have carried out correlative studies between the ability of serum immunoglobulins to displace radiolabeled TSH from the thyroid plasma membrane receptor [TSH-displacing activity (TDA)] and that of actual stimulation of the human thyroid gland [human thyroid-stimulating activity (hTSA)] in Graves' and other thyroid diseases and in control subjects. TDA was assayed by the use of a radioligand technique, while the activation of adenylate cyclase in human thyroid slices was measured as an index of hTSA. The same immunoglobulins were employed for both assays. In this series, positive TDA and hTSA values were found in 70.4% and 81.5% of the samples in active untreated Graves' disease, respectively. Samples from normal persons and from several patients with toxic nodular goiter gave generally negative results in both assays; in a small proportion of patients with either subacute thyroiditis or Hashimoto's thyroiditis, the TDA was positive but hTSA proved to be negative. In Graves' disease (including those patients on propylthiouracil) in remission and treated with 131I, the correlation between TDA and hTSA was not significant (r = 0.309; P greater than 0.1); even when the procedures were compared in the untreated group alone, there was no significant correlation between the two activities (r = 0.309, P greater than 0.1). These studies indicate that 1) significant TDA and hTSA are observed in Graves' disease; nevertheless, the correlation between them is not significant; 2) the hTSA assay appears to be more sensitive and specific than the TDA assay; and 3) TDA may not be synonymous with thyroid stimulation.