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PubMed1989

Multi-center study of a new technique for measuring free thyroxin in serum.

In a multi-center trial we evaluated the accuracy of a new assay kit for free thyroxin (T4), the Behring free T4 RIAgnost, in 1036 subjects: 379 normal subjects, 536 patients with thyroid dysfunction, and 121 subjects with no thyroid dysfunction but with conditions that potentially could interfere with the assay. The kit combines immunoextraction and the use of a modified tracer. Although some limitations remained in using a direct assay method for free T4 in certain nonthyroid conditions, this test was superior to one based on the use of a T4 analog. This kit seems to be very accurate for the diagnosis of untreated thyroid pathologies.

Adolescent↗
PubMed1987

Plasma atriopeptin concentrations in hyperthyroidism, euthyroidism, and hypothyroidism: studies in man and rat.

Atriopeptin (AP) is a polypeptide produced by atrial myocytes that is capable of inducing diuresis, natriuresis, and vasodilatation. Because thyroid dysfunction is known to be associated with alterations in both renal function and vasomotor control, we investigate the possible effects of varying thyroid function on AP in humans and rats. Plasma AP concentrations were determined in hyperthyroid and hypothyroid patients and normal subjects. Plasma AP was also measured in some patients after the iv infusion of 1 L 150 mmol/L NaCl and after treatment of hyperthyroidism or hypothyroidism. Plasma and atrial AP concentrations were measured in hyperthyroid, euthyroid, and hypothyroid rats. Plasma AP concentrations did not differ in the hyperthyroid (n = 22), euthyroid (n = 45), and hypothyroid (n = 16) subjects [47.1 +/- 18.2 (mean +/- SD), 45.1 +/- 28.9, and 42.4 +/- 20.0 pg/mL, respectively]. After NaCl infusion, mean plasma AP concentrations did not increase significantly in any of the three groups. Treatment of hyperthyroidism and hypothyroidism did not result in a significant change in plasma AP levels. In contrast, plasma AP concentrations were significantly higher in T4-treated (hyperthyroid) rats than in either euthyroid or propylthiouracil-treated (hypothyroid) rats [621 +/- 17 vs. 266 +/- 41 (P less than 0.01) and 210 +/- 28 pg/mL (P less than 0.001), respectively], whereas atrial AP contents were similar in the three groups of rats. We conclude that hyperthyroidism and hypothyroidism in man are not associated with significantly altered plasma AP concentrations. The higher plasma AP levels in T4-treated rats may reflect the relatively shorter duration or greater severity of thyroid dysfunction or thyroid hormone-induced myocardial hypertrophy in the animals.

Adult↗
PubMed1995

Superior limbic keratoconjunctivitis. A prognostic sign for severe Graves ophthalmopathy.

PURPOSE: To study superior limbic keratoconjunctivitis in a relatively large group of patients and to determine whether a relation exists with thyroid dysfunction. METHODS: The medical records of 57 patients with superior limbic keratoconjunctivitis who were examined between 1980 and 1993 were reviewed. RESULTS: Thirty-seven patients (64.9%; 95% confidence interval, 51.1-77.1) had objective evidence of thyroid dysfunction. Of patients with superior limbic keratoconjunctivitis and thyroid disease, 33 (89.2%) had ophthalmopathy, which in 16 patients (48.5%) was sufficiently severe to require orbital decompression. CONCLUSION: Superior limbic keratoconjunctivitis is associated with thyroid dysfunction and appears to be a prognostic marker for severe Graves ophthalmopathy.

Adult↗
PubMed2005

Thyroid disease in pregnancy and childhood.

The subject of thyroid disease in pregnancy is receiving increasing attention from many scientific disciplines. Thyroid function in pregnancy is characterised by a T4 surge at 12 weeks declining thereafter. Serum thyroid hormone concentrations fall in the second half of pregnancy but there are few data on normal reference ranges. Fetal brain development depends on T4 transport into the fetus which in turn depends on sufficient maternal iodine supply. There is current concern that adequate iodisation is not present in large parts of Europe. There is increasing evidence that thyroid autoimmunity is associated with fetal loss but the mechanism is unclear and therapy requires carefully conducted studies. While hyperthyroidism in pregnancy is uncommon, effects on both mother and child are critical if untreated. The use of propylthiouracil is recommended together with measurement of TSH receptor antibodies at 36 weeks gestation. Women receiving thyroxine therapy for hypothyroidism or as suppressive therapy should have their dose increased by up to 50% during pregnancy. There are now substantial data to show deleterious effects on child IQ resulting from low maternal T4 (or high TSH) during gestation. Major advances in molecular biology have contributed to elucidation of many genetic causes of congenital hypothyroidism. However, the aetiology of the majority of cases is still unclear and further research is required. The presence of TPO antibodies in about 10% of pregnant women in early gestation is a predictor of an increased incidence of subclinical hypothyroidism during pregnancy and also of postpartum thyroid dysfunction. The latter condition occurs in 5-9% of women and 25-30% progress to permanent hypothyroidism. This review suggests that screening for thyroid function in early pregnancy and levothyroxine intervention therapy for maternal subclinical hypothyroidism should be considered but evidence is awaited. Screening for both thyroid dysfunction and thyroid antibodies ideally at a preconception clinic but certainly in early gestation is recommended.

Antithyroid Agents↗
PubMed2005

Thyroid disorders associated with pregnancy: etiology, diagnosis, and management.

Pregnancy has an effect on thyroid economy with significant changes in iodine metabolism, serum thyroid binding proteins, and the development of maternal goiter especially in iodine-deficient areas. Pregnancy is also accompanied by immunologic changes, mainly characterized by a shift from a T helper-1 (Th1) lymphocyte to a Th2 lymphocyte state. Thyroid peroxidase antibodies are present in 10% of women at 14 weeks' gestation, and are associated with (i) an increased pregnancy failure (i.e. abortion), (ii) an increased incidence of gestational thyroid dysfunction, and (iii) a predisposition to postpartum thyroiditis. Thyroid function should be measured in women with severe hyperemesis gravidarum but not in every patient with nausea and vomiting during pregnancy. Graves hyperthyroidism during pregnancy is best managed with propylthiouracil administered throughout gestation. Thyroid-stimulating hormone-receptor antibody measurements at 36 weeks' gestation are predictive of transient neonatal hyperthyroidism, and should be checked even in previously treated patients receiving thyroxine. Postpartum exacerbation of hyperthyroidism is common, and should be evaluated in women with Graves disease not on treatment. Radioiodine therapy in pregnancy is absolutely contraindicated. Hypothyroidism (including subclinical hypothyroidism) occurs in about 2.5% of pregnancies, and may lead to obstetric and neonatal complications as well as being a cause of infertility. During the last few decades, evidence has been presented to underpin the critical importance of adequate fetal thyroid hormone levels in order to ensure normal central and peripheral nervous system maturation. In iodine-deficient and iodine-sufficient areas, low maternal circulating thyroxine levels have been associated with a significant decrement in child IQ and development. These data suggest the advisability of further evaluation for a screening program early in pregnancy to identify women with hypothyroxinemia, and the initiation of prompt treatment for its correction. Hypothyroidism in pregnancy is treated with a larger dose of thyroxine than in the nonpregnant state. Postpartum thyroid dysfunction (PPTD) occurs in 50% of women found to have thyroid peroxidase antibodies in early pregnancy. The hypothyroid phase of PPTD is symptomatic and requires thyroxine therapy. A high incidence (25-30%) of permanent hypothyroidism has been noted in these women. Women having transient PPTD with hypothyroidism should be monitored frequently, as there is a 50% chance of these patients developing hypothyroidism during the next 7 years.

Abortion, Spontaneous↗
PubMed2003

Serum concentrations of adipocytokines in patients with hyperthyroidism and hypothyroidism before and after control of thyroid function.

OBJECTIVE: Adipose tissue is a hormonally active system that produces and releases different bioactive substances. Leptin, adiponectin and resistin are some of the recently discovered adipocytokines that participate in the regulation of intermediate metabolism. The aim of this study was to evaluate the circulating levels of leptin, adiponectin and resistin in patients with thyroid dysfunction before and after normalization of thyroid function with appropriate therapy. PATIENTS AND MEASUREMENTS: We studied 20 patients with hyperthyroidism (16 women and 4 men; mean age 47.2 +/- 3.9 years) and 20 patients with hypothyroidism (17 women and 3 men; 51.5 +/- 4.1 years). A group of 20 euthyroid subjects served as control group. Patients were evaluated at the time of diagnosis and again after normalization of thyroid function with appropriate therapy. Serum concentrations of free T4 (FT4), total T3, TSH, insulin, leptin, adiponectin and resistin were measured in all subjects. RESULTS: Hyperthyroid patients showed significantly decreased leptin levels in comparison with controls (11.0 +/- 1.1 vs. 30.4 +/- 5.0 microg/l, P < 0.001). No significant differences in adiponectin levels between hyperthyroid and control groups were found (27.8 +/- 4.0 vs. 46.0 +/- 12.0 mg/l, NS). Patients with hyperthyroidism exhibited reduced resistin levels in comparison with euthyroid subjects (6.4 +/- 0.8 vs. 8.4 +/- 0.7 microg/l, P < 0.05). Normalization of circulating thyroid hormone was accompanied by a nonsignificant increase in leptin levels (12.9 +/- 1.7 microg/l, P < 0.01 vs. control) and no significant modification both in adiponectin (32.0 +/- 7.1 mg/l, NS) and resistin (5.4 +/- 0.7 microg/l, NS) levels. Adjustment of adipocytokine concentrations for body mass index (BMI) showed that treatment of hyperthyroidism induced a significant reduction in adjusted resistin concentrations (0.21 +/- 0.03 vs. 0.28 +/- 0.03 microg/l/BMI units, P < 0.05), with no changes in adjusted leptin and adiponectin. Hypothyroid patients showed significantly lower leptin levels compared with the controls (16.0 +/- 3.5 vs. 30.4 +/- 5.0 microg/l, P < 0.05). Adiponectin levels in patients with hypothyroidism (71.8 +/- 16.0 mg/l) were similar to those in the control group and were not modified with therapy. Resistin levels were significantly reduced among hypothyroid patients (5.8 +/- 1.0 microg/l, P < 0.05), and were not increased after levothyroxine therapy. A significant rise in BMI-corrected leptin levels was observed after replacement therapy, with no changes in adiponectin- and resistin-corrected values. CONCLUSIONS: The results suggest that (1) low serum leptin levels are present in both hyperthyroid and hypothyroid patients but are only increased after therapy in the latter; (2) resistin might be implicated in the insulin resistance state that accompanies thyrotoxicosis; and (3) inadequate secretion of adiponectin seems to have no role in metabolic changes associated with thyroid dysfunction.

Adiponectin↗
PubMed1983

Different aetiologies in post-partum thyroiditis?

During a 4 year period 19 women with post-partum onset of thyroid dysfunction have been seen in our clinic. Five women had high radioiodine uptake thyrotoxicosis (Graves' disease). Twelve women had hypothyroid symptoms starting within 3-6 months of delivery. All of these women had thyroid microsomal and/or cytoplasmic autoantibodies and thyroid lymphocytic infiltration suggesting aggravation of pre-existing subclinical autoimmune thyroiditis (Hashimoto's disease). At follow-up thyroid function gradually improved in all but signs of persistent thyroid hypofunction remained in seven. Thus women developing symptomatic postpartum hypothyroidism should be followed regularly and when thyroxine treatment is commenced in the post-partum period, it has to be continued indefinitely in many cases. Two women presented with transient low radioiodine uptake thyrotoxicosis and a small painless goitre. Thyroid cytology revealed thyroiditis but they had no thyroid autoantibodies. When followed after a succeeding delivery none of these women developed post-partum thyroid dysfunction in contrast to women in the autoimmune group. Probably the aetiology of thyroid dysfunction in these 2 women was different.

Autoimmune Diseases↗
PubMed2003

Serum cystatin C is sensitive to small changes in thyroid function.

BACKGROUND: Serum cystatin C (CysC) is a novel marker for kidney function. The impact of mild thyroid dysfunction on CysC has never been investigated. METHODS: CysC was determined at the time of diagnosis of subclinical hypo- and hyperthyroidism, and when TSH returned into the normal range in 40 consecutive patients with mild thyroid dysfunction. RESULTS: Twenty-six patients with subclinical hypothyroidism and 14 patients with subclinical hyperthyroidism were included. In patients with subclinical hypothyroidism median (range) TSH was 7.8 (4.3-26.7) mU/l (reference 0.27-4.2) at diagnosis and decreased to 2.3 (0.36-4.0) mU/l following treatment with levothyroxine. Mean (+/-S.D.) CysC increased from 0.88+/-0.23 mg/l (reference 0.63-1.33) in the hypothyroid state to 1.01+/-0.21 mg/l when TSH normalized (p<0.001). In patients with subclinical hyperthyroidism, median TSH at diagnosis was 0.08 (0.001-0.26) mU/l and increased to 1.6 (0.28-4.0) mU/l in the euthyroid state. CysC declined from 1.04+/-0.29 mg/l at diagnosis of subclinical hyperthyroidism to 0.91+/-0.25 mg/l when TSH normalized (p<0.05). CONCLUSIONS: Mild thyroid dysfunction significantly alters CysC levels. Therefore, thyroid function has to be considered when CysC is used as a marker of kidney function.

Adolescent↗
PubMed1992

Sustained hypothyroidism induced by recombinant alpha interferon in patients with chronic hepatitis C.

Thyroid dysfunction has been reported in patients with malignant disease treated with recombinant alpha interferon. Two cases of hypothyroidism in patients with chronic hepatitis C treated with recombinant alpha interferon are reported. In one patient, interferon induced hypothyroidism in the absence of pre-existing thyroid dysfunction and in the other it aggravated a pre-existing thyroid dysfunction. Both patients developed a severe, sustained hypothyroidism requiring thyroxine treatment for one year or more after stopping alpha interferon. Diagnosis of hypothyroidism during treatment can be difficult because of the common side effects of alpha interferon. Thyroid function should be assessed before and during alpha interferon therapy in patients with chronic hepatitis C.

Adult↗
PubMed2002

Hypothyroidism and hyperthyroidism in anxiety disorders revisited: new data and literature review.

BACKGROUND: The need for thyroid screening of patients presenting with panic disorder (PD), social phobia (SP) or generalized anxiety disorder (GAD) remains uncertain. METHODS: We examined thyroid histories and serum testing in 169 patients, 92 with PD, 48 with SP, and 29 with GAD. Combined prevalence rates of hyperthyroidism and hypothyroidism were compared with expected rates (2.7%) derived from the population based Whickham Survey. Data from previously published studies were also compared with these expected rates. RESULTS: In our sample, only 2/169 patients had thyroid dysfunction detected by serum testing, but 5/169 [1/92 (1%) with PD, 1/48 (2%) with SP, and 3/29 (10%) with GAD], all currently euthyroid, reported a history of thyroid disease. The rates were statistically significant only for GAD (10.4%; z = 2.56, p = 0.01). However, combining prior PD studies that examined both thyroid history and test results with our data also suggests significantly elevated rates of thyroid dysfunction (6.5%; z = 4.69, p < 0.0001). LIMITATIONS: As with previous data, the 95% confidence interval for our findings is broad, reflecting the instability of low rates of illness in relatively small samples. Further, methods for obtaining thyroid histories and tests were not uniform. CONCLUSIONS: Despite relatively low yields on serum testing, lifetime prevalence of thyroid dysfunction does appear elevated for GAD and PD, with minimal data addressing this issue for SP. The data support the need to query GAD and PD patients regarding thyroid history and perform serum testing in those without prior testing.

Adolescent↗
PubMed1991

[Iodine containing drugs and thyroid gland function. A diagnostic and therapeutic problem].

Iodine-induced thyroid dysfunction will become more important in Austria in the near future, because of the augmentation of the iodine content in salt in 1990. This review therefore tries to summarize the diagnostic and therapeutic problems that may arise in iodine-induced thyroid disease. After discussion of the physiologic reaction of the normal thyroid to iodine the most frequently used iodine-containing drugs used in Austria are presented. Special emphasis is laid on iodine containing antiseptics and on the antiarrhythmic drug amiodarone. The influence of iodine supplementation on the reaction of diseased thyroid glands to iodine overload is stressed. The diagnosis of iodine induced thyroid dysfunction is relatively simple, once it is thought of. Amiodarone-iodine induced thyroid disease may be an exception, because of the intrinsic effect of this drug on thyroid hormone metabolism. Since high intra-thyroidal iodine content inhibits the action of thyrostatics, therapy of iodine-induced hyperthyroidism may be complicated. Alternative possibilities such as cortisone, perchlorate or surgery in thyroid storm are presented. Substitution with 1-thyroxine in iodine-induced hypothyroidism may be harmful in elderly patients with cardiac problems. In conclusion, this review tries to present the state of the art of the solution of diagnostic and therapeutic problems in thyroid dysfunction due to iodine administration.

Amiodarone↗
PubMedDate not supplied

[Amyotrophic lateral sclerosis: its relationship with thyroid function and phosphate calcium metabolism].

INTRODUCTION: Amyotrophic lateral sclerosis (ALS) is a progressive degenerative disease involving motor neurons of the spinal cord, brain stem, and motor cortex. Previous studies reported the coexistence of motor neuron disease with thyroid dysfunction and primary hyperparathyroidism. These findings suggested an eventual role of the previously mentioned endocrine disorders and the development of ALS. OBJECTIVE: Identify thyroid dysfunction and changes in mineral metabolism in patients affected by sporadic ALS. PATIENTS AND METHODS: We retrospectively analyzed data from 41 in ward patients from June 1998, to June 2001. All of them were diagnosed with sporadic ALS. The following laboratory test were performed: thyrotropin (TSH), thyroxine (T4), serum calcium, serum phosphate, parathyroid hormone (PTH) and ionic calcium concentrations. RESULTS: None of the studied patients was found to be hyperthyroid. Two patients had elevated TSH and normal T4, these findings suggested subclinical hypothyroidism. Elevated PTH was found in one patient; another had primary hyperparathyroidism. Low serum calcium was found in three patients and elevated phosphate was found in another four. CONCLUSIONS: All these findings do not allow us to assert a pathogenic association between thyroid dysfunction or alteration of phosphate calcium metabolism and ALS.

Adolescent↗
PubMed1995

[Endocrine involvement in immunotherapy].

Thyroid dysfunction and abnormalities in corticosteroid regulation were observed after clinical use of cytokines (IL2, IFN alpha), molecules with immunostimulating properties. Interleukin 2 administration induces hypothyroidism often associated with anti-thyroglobulin and anti-thyroid microsomal antibody. All these features recall Hashimoto's thyroiditis. Frequency of thyroid dysfunction during immunotherapy varies according to authors between 20 and 40 percent of all patients treated. A correlation between thyroid dysfunction and response to IL2 therapy was reported. Hypothyroidism and hyperthyroidism with development of anti-TSH receptor antibody are observed after IFN alpha administration. An auto-immune aetiology of these thyroid side effects was suggested because fine needle aspirates of the thyroid of these patients, when available, revealed a mixed cellular infiltrate with lymphocytes and histiocytes and immunocytochemical staining showed strong HLA-DR expression of all thyrocytes. Involvement of lymphokine activated killer (LAK) or direct effect of cytokines on thyroid are also possible. After intravenous injection of IL2, a marked increase in ACTH levels occurred, peaking at 4 hour with a comparable peak in cortisol level at 5 hour. Expression of IL2-Receptor in pituitary cells suggests a direct action of IL2 on anterior pituitary. Nevertheless, indirect action of IL2 via induction of other cytokines or possible secretion of ACTH by activated lymphocytes, cannot be ruled out. Testosterone serum levels decreased significantly after IL2 or IFN alpha administration. It is noteworthy that these endocrine effects induced by cytokines may modulate the clinical efficacy of these substances underlying the bi-directional communication between the immune and endocrine system.

Adrenal Cortex Hormones↗
PubMed2006

Peculiarities of lipid profile parameters in cardiac patients with hypo- and hyperthyroidism.

The problem of thyroid dysfunction is very actual in cardiac patients. The aim of the present study was to evaluate lipid profile parameters in 73 hypo-, hyper- and euthyroid cardiology patients visited the Emergency Cardiology Center. Most of the patients had coronary artery disease. Thyroid dysfunction was diagnosed on the basis of patients' clinical status and blood thyroid stimulating hormone. In hypothyroid patients blood levels of total cholesterol, low-density lipoprotein cholesterol and triglycerides were increased. In contrast, the patients with hyperthyroidism had normal concentrations of these parameters. Exception was antiatherogenic fraction of lipid profile - high-density lipoprotein cholesterol, which mean levels were normal in all patients' groups. It is noteworthy that the highest levels of atherogenic fractions were observed in the groups of patients who had hypothyroidism in combination with diabetes mellitus. In conclusion, the results of present study showed that thyroid dysfunction may play a potential independent role in changes of atherogenic lipid profile.

Cholesterol↗
PubMed2005

Thyroid function and mortality in patients treated for hyperthyroidism.

CONTEXT: Hyperthyroidism has been reported to cause excess all-cause and circulatory mortality. Whether this can be reversed is unknown, as is the influence of mild persisting thyroid dysfunction and treatment-induced hypothyroidism. OBJECTIVES: To determine whether radioiodine treatment is associated with increased mortality and to determine the influences of mild thyroid dysfunction and the development of overt hypothyroidism treated with thyroxine (T(4)). DESIGN, SETTING, AND PARTICIPANTS: A population-based study of 2668 individuals aged 40 years or older treated for overt hyperthyroidism with radioiodine in the West Midlands region of England from 1984-2002. MAIN OUTCOME MEASURES: Cause of death compared with age- and period-specific mortality in England and Wales and assessment of the influence of T(4) therapy for radioiodine-induced hypothyroidism and subclinical thyroid dysfunction on mortality. RESULTS: In 15,968 person-years of follow-up, 554 died vs 487 expected deaths (standardized mortality ratio [SMR], 1.14; 95% confidence interval [CI], 1.04-1.24, P=.002). Increased risks of all-cause and circulatory deaths vs age- and period-specific mortality were observed in follow-up in those not requiring, or prior to, T(4) therapy. These increased risks were not observed during follow-up on T(4) therapy (circulatory disease SMR prior to T(4), 1.33; 95% CI, 1.14-1.53 vs SMR, 0.91; 95% CI, 0.70-1.17 during T(4)). Patients receiving T(4) had decreased risk of mortality vs risk in the period not requiring, or prior to, T(4) therapy (all-cause mortality hazard ratio [HR], 0.65; 95% CI, 0.54-0.79; circulatory mortality HR, 0.65; 95% CI, 0.48-0.87). Increased all-cause mortality vs the background population was observed in the period prior to T(4) therapy in follow-up associated with low, normal, and high serum thyrotropin. The SMR for ischemic heart disease increased slightly when analyzed by serum thyrotropin, high serum thyrotropin being the highest SMR (low thyrotropin SMR, 1.06; 95% CI, 0.75-1.45; normal thyrotropin SMR, 1.17; 95% CI, 0.76-1.71; high thyrotropin SMR, 1.48; 95% CI, 0.86-2.37). Comparison within the cohort showed that mild hypothyroidism prior to T(4) therapy was associated with increased risk of mortality from ischemic heart disease vs biochemical euthyroidism (HR, 2.08; 95% CI, 1.04-4.19). CONCLUSIONS: Patients treated with radioiodine for hyperthyroidism had increased mortality vs age- and period-specific mortality in England and Wales, a finding no longer evident during T(4) therapy. This supports treating hyperthyroidism with doses of radioiodine sufficient to induce overt hypothyroidism. The association within the cohort of mortality from ischemic heart disease with subclinical hypothyroidism suggests T(4) replacement should be considered should this biochemical abnormality develop after radioiodine therapy.

Adult↗
PubMed2006

Atrial angiotensinase activity in hypothyroid, euthyroid, and hyperthyroid rats.

Thyroid dysfunction produces marked cardiovascular responses. Hypothyroidism and hyperthyroidism cause important changes in the circulating renin-angiotensin system (RAS). Modifications in cardiac RAS have also been involved in cardiovascular alterations. Studies have revealed that thyroid hormones activate some components of cardiac RAS. Angiotensin (Ang) peptides are regulated by the activity of several aminopeptidases (AP) called angiotensinases. Previous results in our laboratory have demonstrated that thyroid dysfunction altered angiotensinase activities in hypothalamus, pituitary, and kidney. In the present study, we investigated the relationship between thyroid status and local angiotensinase activities in the atrium of hypothyroid, euthyroid, and hyperthyroid adult male rats. We have determined fluorometrically soluble and membrane-bound alanyl, glutamyl, and aspartyl aminopeptidase activities using naphthylamide derivatives as substrates. These activities have been, respectively, involved in the metabolism of Ang III to Ang IV, Ang II to Ang III, and Ang I to des-Asp Ang I. Hyperthyroidism was induced with subcutaneous injections of tetraiodothyronine (300 microg/kg/day), and the hypothyroid rats were obtained with 0.03% methimazole via the drinking water. Compared with that in euthyroid rats, a highly significant increase (by 50%) of soluble aspartyl aminopeptidase activity (P < 0.001) was observed in the atrium of hyperthyroid and hypothyroid animals. In membrane fractions, T4 treatment produced an increase in alanyl aminopeptidase (37%; P < 0.05) and aspartyl aminopeptidase activities (30%; P < 0.01). These results suggest higher formation of des-Asp Ang I in both hypothyroid and hyperthyroid rats but also suggest higher metabolism of Ang III to Ang IV in hyperthyroid animals, which is in agreement with the described alterations of cardiac RAS after thyroid dysfunction.

Animals↗
PubMedDate not supplied

[Autoimmunity in thyroid disease secondary to amiodarone: heredofamilial aspects].

Spontaneous autoimmune thyroid disease (SATD) shows familial aggregation. Some patients receiving amiodarone treatment have been found to develop thyroid dysfunction. Previously, we reported genetic predisposition among this group of patients, now we inform a prospective study which includes the search for autoantibodies and family history to identify risk factors in amiodarone treated patients, 40 of them with amiodarone related thyroid disfunction, and 100 without it; for comparison, 30 patients with SATD and a control group of healthy subjects were also studied. We looked for the presence of autoantibodies against thyroglobulin, smooth muscle, gastric mucosa, myocardium, mitochondria, epithelial intercellular substance, and basal membrane as well as antinuclear antibodies and rheumatoid factors; in addition the history of thyroid disease in first degree relatives was investigated. Organ-specific antibodies anti-thyroglobulin, gastric mucosa and myocardium were found with increased frequency in the three groups of patients compared with controls (p less than 0.05). The frequency of antihydroglobulin antibodies was similar in patients receiving amiodarone with or without thyroid dysfunction. Prognostic stratification revealed that this finding is independent of sex, age, dosage or duration of treatment. A family history of thyroid dysfunction was found more frequently among patients with SATD and amiodarone related dysthyroidism in comparison with patients receiving amiodarone without altered thyroid function (p less than 0.005). The appearance of clinical thyroid disease depends on individual genetical predisposition. In patients with a positive family history, the risk of developing clinical, thyroid disease is 7.6 when treated with amiodarone.

Adolescent↗
PubMed1990

Thyroiditis after treatment with interleukin-2 and interferon alpha-2a.

Serial thyroid functions studies were carried out in patients with melanoma and renal cell carcinoma treated with interleukin-2 (3 MU m-2 by continuous infusion days 1-4) and interferon alpha-2a (6 MU m-2 subcutaneously on days 1 and 4), both given on alternate weeks. The results on eight patients who completed at least three cycles of treatment are described. Four patients developed thyroid dysfunction with a hyperthyroid phase of 2 weeks followed by a hypothyroid phase ranging from 12 to 24 weeks. Two patients became clinically symptomatic and required treatment. Fine-needle aspirates of the thyroid were obtained in three patients with thyroid dysfunction. The cytology revealed a mixed cellular infiltrate with lymphocytes and histiocytes, and immunocytochemical staining showed strong HLA-DR expression of all thyrocytes, both suggestive of an autoimmune thyroiditis. One patient with thyroiditis developed anti-thyroglobulin antibodies, the serology of all other patients was normal. Patients with thyroid dysfunction tended to have higher in vivo stimulated lytic activity of peripheral mononuclear blood cells and had significantly higher levels of CD16 positive blood cells as compared to euthyroid patients. The possibility of autoimmune thyroiditis should be anticipated in future trails combining interleukin-2 and interferon alpha-2a.

Adult↗