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At least 217 records · Page 12Linked to original sources
PubMed1995

Thyroid volume in type 1 diabetes patients without overt thyroid disease.

An association between insulin-dependent diabetes mellitus (type 1) and thyroid diseases has long been reported, but the morphological evaluation of the thyroid in type 1 diabetes patients without overt thyroid disease has always been limited to physical examination. Ultrasonography of the thyroid gland was performed in 45 patients with type 1 diabetes without overt thyroid disease, to study thyroid volume and the prevalence of thyroid nodules. Data were compared with those obtained in 45 age- and sex-matched control subjects residing in the same area. In the patients, thyroid volume had increased on average by 46%; 35% of male and 32% of female patients had a thyroid volume exceeding the 95% confidence limits of the matched controls. The prevalence of thyroid nodules was only slightly raised. On average, free thyroxine was increased in the presence of normal triiodothyronine levels. Four patients were frankly hyperthyroid. The patients also showed a higher prevalence of thyroid-microsomal antibodies, but the thyroid hormone status was not different in relation to thyroid volume, nor was thyroid volume in relation to the presence of autoantibodies. Patients with type 1 diabetes without overt thyroid disorders may have morphological, ultrasonographically detectable alterations of the thyroid gland, the expression of a possible involvement of the thyroid in an autoimmune disorder not limited to the islet cells.

Adolescent↗
PubMedDate not supplied

Temporal relationship between the appearance of thyroid autoantibodies and development of destructive thyroiditis in patients undergoing treatment with two different type-1 interferons for HCV-related chronic hepatitis: a prospective study.

In this prospective study we performed repeated evaluations of thyroid status in patients undergoing treatment with different preparations of recombinant interferons (IFNs), in order to identify early markers of thyroid dysfunction. Moreover, we aimed to investigate whether the development of thyroid dysfunction was related to the appearance of thyroid autoimmunity. Our study included 51 consecutive patients without pre-existing thyroid disease, admitted to our hospital for Hepatitis C virus (HCV)-related chronic hepatitis. Thirty-six patients (Gr. A) were treated with IFN-alpha 2b plus ribavirin (RIBA), whereas 15 patients (Gr. B) underwent treatment with IFN-alphacon-1 (CIFN) plus RIBA. Thyroid autoimmunity and function were prospectively evaluated before, every month during treatment and for 6 months after IFN withdrawal. At study entry, all patients were euthyroid and negative for thyroid autoantibodies. In Gr. A, 10 patients developed thyroid autoimmunity after a median period of 3 months (range: 1-6) treatment with IFN-alpha+RIBA. At the time of appearance of thyroid autoantibodies, 4 patients developed destructive thyrotoxicosis (overt in one case, subclinical in 3 cases), while other 4 patients showed a high reduction of serum TSH levels (median decrease: -75.7%, range: -61.9- -84.2), which reached the low values of normal range. After a median period of 2 months (range: 1-3) from these biochemical abnormalities, 6 patients continuing antiviral treatment developed hypothyroidism (overt in 3 cases and subclinical in the other 3). In Gr. B, 5 patients developed thyroid autoimmunity after a median period of 3 months (range: 2-10) of treatment with CIFN+RIBA. Soon after the appearance of thyroid autoantibodies, all patients developed an overt thyrotoxicosis (with hyperthyroidism in 2 cases). Antiviral treatment was discontinued in all 5 cases. Thereafter, thyroid function recovered spontaneously without significant modifications of serum TGAb and TPOAb levels until the end of the study. In conclusion our prospective study demonstrated that: 1) the appearance of thyroid autoantibodies during treatment with IFN was accompanied in most cases by the occurrence of a destructive process in the thyroid gland; 2) The clinical expression of destructive thyroiditis was more evident in patients treated with CIFN than that in patients treated with IFN; 3) The thyroid clinical outcome of these patients was strictly correlated to the continuation of cytokine treatment.

Adult↗
PubMed1986

The production and characterization of thyroid-derived T-cell lines in Graves' disease and Hashimoto's thyroiditis.

Although the thyroid gland itself is a major site of the autoimmune response, the study of T-cell function in autoimmune thyroid disease has usually relied on peripheral blood as a source of cells. In this study, we have established thyroid-derived T-cell lines from six patients with Graves' disease and one patient with Hashimoto's thyroiditis by culturing the thyroid lymphocytes on an autologous thyroid follicular cell monolayer in the presence of exogenous interleukin 2 (IL-2). These T-cell lines have allowed in vitro investigation of thyroid-derived T-cell function, an approach which was previously limited by the number of lymphocytes obtained from the gland. The lines were predominantly OKT3, OKT4, and HLA-DR positive but showed heterogeneous proliferative responses. Some lines gave autologous or allogeneic mixed lymphocyte reactions but other did not. Only one of the seven lines responded well to the thyroid antigens thyroglobulin and microsomes presented by autologous monocytes. However, six of the lines proliferated in the presence of live but not dead autologous thyroid follicular cells, particularly when interferon-gamma (IFN-gamma) was added. This treatment has been shown to enhance HLA-DR and -DQ antigen expression by thyroid follicular cells in vitro. Furthermore, the proliferation induced by IFN-gamma-treated thyroid follicular cells was increased when thyroglobulin was also added. Together these results support the hypothesis that the expression of Ia antigens such as HLA-DR by thyroid follicular cells in autoimmune thyroid disease may be important in enhancing the autoimmune response, conferring on these cells the ability to present thyroid autoantigens to T cells. The use of thyroid-derived T-cell lines should permit a more detailed evaluation of the disordered immuno-regulation in Graves' disease and Hashimoto's thyroiditis than has been possible previously.

Adult↗
PubMed1998

The neuropeptides, VIP and NPY, that are present in the thyroid nerves are not released into the thyroid vein.

In the present study, we tested the hypothesis that the neuropeptides, vasoactive intestinal peptide (VIP) and neuropeptide Y (NPY), which are present in the thyroid nerves, act as physiological neurotransmitters involved in the regulation of thyroid hormone secretion and thyroid blood flow. Specifically, we examined whether these neuropeptides can be released into thyroid blood vessels by electrical stimulation of the major thyroid nerves or whether their expression is altered by changes in iodine intake. Sprague-Dawley rats were used in this study. The cervical sympathetic trunk or the superior laryngeal nerve was stimulated by bipolar electrodes in anesthetized rats. During nerve stimulation, blood samples were withdrawn from the thyroid vein. Thyroid blood flow was monitored by laser Doppler blood flowmetry. Sympathetic stimulation caused a marked decrease in thyroid blood flow, which was associated with a significant increase in release of norepinephrine. However, these effects were not accompanied by any change in NPY release into the thyroid vein. Stimulation of the superior laryngeal nerve was not associated with changes in thyroid blood flow or VIP release into the thyroid vein. In a separate experiment, rats were fed a diet containing low-, high-, or normal iodine concentrations. Triiodothyronine (T3) and thyroxine (T4) levels in thyroid venous plasma were significantly reduced in rats fed a low-iodine diet but not in a separate group of rats fed a high iodine diet. However, these treatments had no effect on VIP or NPY concentrations in thyroid venous plasma or in thyroid ganglia. Thus, our results indicate that VIP and NPY, which are present in the thyroid nerves, may not be directly involved in the regulation of thyroid function.

Animals↗
PubMed2001

Postpartum thyroiditis and autoimmune thyroiditis in women of childbearing age: recent insights and consequences for antenatal and postnatal care.

Postpartum thyroiditis is a syndrome of transient or permanent thyroid dysfunction occurring in the first year after delivery and based on an autoimmune inflammation of the thyroid. The prevalence ranges from 5-7%. We discuss the role of antibodies (especially thyroid peroxidase antibodies), complement, activated T cells, and apoptosis in the outbreak of postpartum thyroiditis. Postpartum thyroiditis is conceptualized as an acute phase of autoimmune thyroid destruction in the context of an existing and ongoing process of thyroid autosensitization. From pregnancy an enhanced state of immune tolerance ensues. A rebound reaction to this pregnancy-associated immune suppression after delivery explains the aggravation of autoimmune syndromes in the puerperal period, e.g., the occurrence of clinically overt postpartum thyroiditis. Low thyroid reserve due to autoimmune thyroiditis is increasingly recognized as a serious health problem. 1) Thyroid autoimmunity increases the probability of spontaneous fetal loss. 2) Thyroid failure due to autoimmune thyroiditis-often mild and subclinical-can lead to permanent and significant impairment in neuropsychological performance of the offspring. 3) Evidence is emerging that as women age subclinical hypothyroidism-as a sequel of postpartum thyroiditis-predisposes them to cardiovascular disease. Hence, postpartum thyroiditis is no longer considered a mild and transient disorder. Screening is considered.

Adult↗
PubMed1984

Thyroid T4 5'-deiodinase activity in normal and abnormal human thyroid glands.

To investigate the activity of the thyroid gland to convert T4 to T3, we measured the activity of thyroid T4 5'-deiodinase in the following human thyroid glands: 9 normal glands, 5 Hashimoto's thyroiditis, 13 follicular adenomas, 11 methimazole (MMI)-treated Graves' disease (GD), 11 propranolol iodide-treated GD, and 8 propylthiouracil (PTU)-treated GD. The enzyme activity was determined by the ability of 100,000 X g pellet of the thyroid homogenate to convert T4 to T3 in vitro. Normal thyroids showed the enzyme activity of 1.59 +/- 0.18 (mean +/- SEM) pmol T3/mg protein/min. Euthyroid Hashimoto's thyroiditis displayed the enzyme activity of 1.01 +/- 0.15 pmol T3/mg protein/min, which was similar to the normal thyroid enzyme activity. The hypothyroid gland of Hashimoto's thyroiditis showed the enzyme activity of 1.8 pmol T3/mg protein/min. Follicular adenomas showed a wide range of enzyme activity with the mean level of 3.24 +/- 0.82 pmol T3/mg protein/min that did not differ significantly from that of the normal thyroids. Interestingly, one adenoma, despite TSH suppression that ordinarily decreases enzyme activity, showed the greatest activity of 11.0 pmol T3/mg protein/min. Graves' thyroids following treatment with MMI, PTU, and propranolol-iodide showed enzyme activities of 4.61 +/- 0.53, 3.95 +/- 0.43, and 3.51 +/- 0.46 pmol T3/mg protein/min, respectively; all these values were greater than that of the normal thyroids (P less than 0.01), but did not differ significantly when compared with each other. In summary, thyroid glands with Hashimoto's thyroiditis had activities of T4 to T3 conversion similar to the normal thyroid glands.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenoma↗
PubMed1994

Routine measurement of serum calcitonin in nodular thyroid diseases allows the preoperative diagnosis of unsuspected sporadic medullary thyroid carcinoma.

To assess whether routine measurement of serum calcitonin (CT) could improve the preoperative diagnosis of sporadic medullary thyroid carcinoma (MTC), 1385 consecutive patients presenting for nodular thyroid disease during the year 1991 were submitted to serum CT determination and fine needle aspiration cytology (FNAC). The clinical diagnosis was nontoxic nodular goiter in 1197 (86.4%) patients, toxic multinodular goiter in 65 (4.7%), autonomously functioning thyroid nodule (AFTN) in 64 (4.6%), and autoimmune thyroid disease (Graves' disease or Hashimoto's thyroiditis) with nodule(s) in 59 (4.3%). As controls, 177 patients with nonnodular thyroid disease and 32 normal subjects were also studied. Patients with FNAC suspicious of any kind of thyroid carcinoma and patients with elevated basal and pentagastrin-stimulated serum CT, regardless of the results of FNAC, were submitted to surgery. Eight (0.57%) patients (7 with nontoxic nodular goiter and 1 with AFTN) had elevated basal serum CT levels, ranging between 55-10,000 pg/mL. The pentagastrin test was abnormal in all of them. FNAC was suggestive of MTC in 2, thyroid carcinoma in 1, benign nodule in 3, and inadequate in 2. By histology, immunohistochemistry, and Northern blot analysis of total tumor RNAs, MTC was confirmed in all patients, including the 1 with AFTN, who had the association of microfollicular adenoma and a small MTC in the same lobe. After surgery, serum CT decreased to undetectable levels in 7 patients and remained undetectable in 6 of them during a mean follow-up of 22 months, although 1 of them had a positive response to pentagastrin. Forty-four patients in the group with normal serum CT levels had FNAC suspicious for differentiated thyroid carcinoma and were treated by surgery. Differentiated thyroid carcinoma, mostly papillary, was confirmed at histology in 43 subjects (3.1% of all thyroid nodules). In conclusion, the results of our study indicate that serum CT measurement is useful for the screening of sporadic MTC in patients with thyroid nodule(s). The prevalence of MTC, diagnosed by serum CT measurement in a 12-month period, among an unselected series of 1385 patients with nodular thyroid disease was surprisingly high: 0.57% of all thyroid nodules and 15.7% of all thyroid carcinomas. Serum CT measurement was superior to FNAC in suggesting the diagnosis of MTC and was devoid of falsely positive results. Increasing the diagnostic accuracy helped the surgeon to perform more radical treatment of MTC, thus achieving frequent normalization of postoperative serum CT levels. Whether this result indicates definitive cure remains to be established on the basis of longer follow-up.(ABSTRACT TRUNCATED AT 400 WORDS)

Adolescent↗
PubMed1984

[Detection of anti-thyroid plasma membrane antibody in patients with various thyroid diseases by solid phase enzyme-immunoassay].

Antibodies against thyroid cell surface antigens have been demonstrated by indirect immunofluorescence on viable cells and by mixed hemadsorption using monolayer cell culture. Recently quantitative assays using thyroid plasma membrane or cultured thyroid cell were also reported. The present study reports a novel quantitative assay for the detection of anti-thyroid plasma membrane antibody (APA) using solubilized and immobilized thyroid plasma membrane. Thyroid plasma membrane purified by sucrose density gradient centrifugation was solubilized with Triton X-100 and coupled to CNBr activated Sepharose 4B. Sera from patients with various thyroid diseases were incubated with this solid phase. Five microliters of serum was sufficient for the assay. After extensive washing, immunoglobulin G (Ig G) or immunoglobulin M (Ig M) bound to thyroid plasma membrane was detected by horseradish-peroxidase labeled rabbit anti-human Ig G or Ig M antibody. Significantly elevated values of Ig G class APA (Ig G-APA) were detected in the sera from patients with Graves' or Hashimoto's disease. Some of the patients with thyroid adenoma also showed positive Ig G-APA, although all of the patients with thyroid cancer had negative Ig G-APA. A significant correlation between Ig G-APA and anti-thyroid microsomal antibody (AMA) among patients with autoimmune thyroid diseases was observed. No significant correlation, however, was found between anti-thyroglobulin antibody (ATA) and Ig G-APA. A large amount of thyroglobulin (Tg), which was reported to have the receptor in thyroid plasma membrane, inhibited the binding of Ig G-APA does dependently. Ten micrograms of ATA and one milligram of bovine serum albumin, however, had no influence on the binding. Ig G-APA also significantly correlated with thyrotropin binding inhibitor immunoglobulin (TBII). The binding, however, was not inhibited by one hundred milliunits of TSH. These findings suggested that most of Ig G-APA was bound to different sites from TSH receptor, although some part of Ig G-APA might have TBII activity. Ig M class APA (Ig M-APA) among various thyroid diseases was also detected. In Graves' disease, more than sixty percent of patients had positive Ig M-APA. There was no significant difference in the value of Ig M-APA between untreated and treated patients. Positive Ig M-APA was found even in some euthyroid patients. Ig M-APA in Graves' disease correlated with neither AMA nor TBII. Some of patients with Hashimoto's disease and subacute thyroiditis also showed positive Ig M-APA.(ABSTRACT TRUNCATED AT 400 WORDS)

Adenocarcinoma↗