Differential Diagnosis Of Hyperthyroidism Research Articles

Comparison of serum thyrotrophin concentrations determined by a third generation assay in patients with various types of overt and subclinical thyrotoxicosis.

Recent increases in the sensitivity of methods used to measure TSH, especially third generation assays, have enabled separation of partial from complete pituitary suppression in patients with thyrotoxicosis. We have investigated the use of a sensitive chemiluminescent enzymeimmunoassay in the differential diagnosis of thyrotoxicosis. Serum TSH concentrations were determined by chemiluminescent enzymeimmunoassay in patients with various types of overt and subclinical thyrotoxicosis. The assay was highly sensitive with an analytical sensitivity of 0.0016 mU/l. Among 45 hyperthyroid patients with untreated Graves' disease, 37 (82.2%) showed undetectably low levels (< 0.002 mU/l). Serum TSH in the remaining 8 patients (17.8%) was 0.003-0.005 mU/l. In contrast, TSH was undetectably low in only 5 (20.0%) of 20 patients with painless thyroiditis and in 2 (12.5%) of 16 patients with subacute thyroiditis. Eleven (55.0%) with painless thyroiditis and 12 (75.0%) with subacute thyroiditis had TSH values greater than 0.005 mU/l (0.006-0.032 and 0.006-0.228 mU/l, respectively; normal range 0.5-5.0 mU/l). Serum TSH levels were subnormal in 10 of 12 patients with euthyroid ophthalmic Graves' disease, including 4 with undetectably low levels. Among 11 patients with an autonomously functioning thyroid nodule 6, including 1 with normal free T4 and free T3 and 2 with normal free T3, showed TSH values less than 0.002 mU/l. No significant correlation was observed between serum free T4 or free T3 and TSH concentrations in thyrotoxic patients. Together with the incomplete suppression of TSH observed in those with destructive thyroiditis, this suggests that the grade of TSH suppression was influenced by the duration of illness at the time of blood sampling. The third-generation TSH assay is useful for the differential diagnosis of various types of thyrotoxicosis, especially between Graves' disease and destructive thyroiditis.

Differential diagnosis of hyperthyroidism with highly sensitive assay of blood TTH: clinical review and practical recommendations for use in Russia and USA

Highly sensitive methods for determining the level of TSH, carried out using test kits of the second and third generation, make it possible to differentiate with high accuracy the normal and subnormal levels of TSH in the blood and are currently widely used to examine patients with thyroid pathology. These methods have been used for a long time in clinical practice in the United States of America, and recently they are also increasingly used in Russia. The level of TSH below normal values ​​is determined in almost all cases of hyperthyroidism (with the exception of cases of TSH-secreting pituitary adenoma or resistance of the pituitary to thyroid hormones), which makes it possible to do without additional testing with tyroliberin (TRH). Methods for determining second generation TSH usually have a lower sensitivity limit of about 0.1 mU/L. When using the third generation methods, it is possible to accurately determine the level of TSH up to 0.01 mU/L. The fourth generation methods, which are still under development, will have a lower limit of determination of 0.001 mU/L, but they are unlikely to be used for routine clinical studies in the near future. At the Endocrinology Research Center of the Russian Academy of Medical Sciences in Moscow, third-generation methods are currently being used for routine clinical research (the Amerlight system, produced in Russia by the Amerkard joint venture). In addition to this system, other test systems of both domestic and foreign production are also available in Russia. In the USA, methods for determining TTG of the second and third generation are used. Third-generation systems are noticeably more expensive than second-generation systems. Given that in most patients with hyperthyroidism, the TSH level is in the range of less than 0.1 mU/L, methods for determining the third generation are more preferable. In general, the normal level of TSH in the blood of individuals in a state of euthyroidism is from 0.5 to 5.0 mU/L, although there are some interlaboratory differences in the standards for the level of TSH.

甲状腺由来可溶性蛋白の測定による甲状腺中毒症の鑑別について

甲状腺由来可溶性蛋白の測定による甲状腺中毒症の鑑別について

Is soluble CD25 antigen (interleukin-2 receptor) a useful parameter for differential diagnosis of thyrotoxicosis?

Soluble CD25 antigen was measured in 28 patients with Graves' disease and 20 patients with thyroid autonomy in order to address the question of whether this parameter could be used in the differential diagnosis of thyrotoxicosis. Soluble CD25 was significantly elevated in active Graves' disease (2430 +/- 442 U/ml, mean +/- SEM) compared to patients with thyroid autonomy (1295 +/- 225 U/ml, mean +/- SEM). However, compared to normal controls (mean 605 +/- 49 U/ml), both groups of patients had significantly elevated CD25 plasma levels. Investigations in thyroidectomized thyroid cancer patients on and off T4 suppressive therapy showed no influence of T4 on the CD25 level. Soluble CD25 concentrations did not differ in thyroid cancer patients compared to normal controls. We conclude that soluble CD25 may indicate a stimulation of the immune system with high sensitivity; however, due to the low specificity of elevated CD25 levels, its usefulness for differential diagnosis of thyrotoxicosis is limited.

Erythrocyte zinc in differential diagnosis of hyperthyroidism in pregnancy: a preliminary report.

Erythrocyte zinc in differential diagnosis of hyperthyroidism in pregnancy: a preliminary report.

Thyroid function in patients with hyperemesis gravidarum

An increased free thyroxine (T4) index was observed in 73% of 33 consecutive pregnancies complicated by severe hyperemesis gravidarum. The free triiodothyronine (T3) index was increased in only four of 11 hyperthyroxinemic patients. In five hyperthyroxinemic patients tested, no increase in serum thyrotropin was observed after the injection of thyrotropin-releasing hormone (TRH). Goiter, exophthalmos, or previous history of hyperthyroidism was absent in all patients. The thyroxinemia returned to normal in one to several weeks, whether or not it was treated with antithyroid drugs. The thyroid function during the period of hyperemesis had no influence on the subsequent rate of abortion or duration of pregnancy. A lower birth weight, however, was observed in children born to hyperthyroxinemic mothers. Hyperemesis gravidarum should be included in the differential diagnosis of elevations in free T4 index during pregnancy and included in the differential diagnosis of hyperthyroidism.

Radioimmunological estimation of triiodothyronine in plasma. Diagnostic value in an area with endemic goitre (author's transl)

In 896 patients from a low-iodine area the results of the radioimmununological triiodothyronine estimations in plasma were compared with the clinical and radioisotope findings of thyroid function. It was superior to the total thyroxine estimation (T4-test) in the differential diagnosis of hyperthyroidism. In euthyroid goitre the mean triiodothyronine concentration was significantly higher than in normal persons whereas the plasma thyroxine levels at the same time were significantly lower. Only in (primary) hypothyroidism is the triiodothyronine estimation diagnostically less important than the T4-test. In summary, the radioimmunochemical method permits a clearly more precise evaluation of thyroid function even in areas of endemic goitre.

Protein-bound blood iodine in cardiovascular disease.

Excerpt Patients with cardiovascular disease accompanied by signs or symptoms suggesting hyperactive thyroid function are frequently encountered. In some instances, especially when goiter is presen...

Chapter IX: The use of the radioactive iodine tolerance test in the differential diagnosis of thyrotoxicosis

Acta Medica ScandinavicaVolume 135, Issue S235 p. 132-157 Chapter IX: The use of the radioactive iodine tolerance test in the differential diagnosis of thyrotoxicosis First published: January/December 1949 https://doi.org/10.1111/j.0954-6820.1949.tb06187.xAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat Volume135, IssueS235January/December 1949Pages 132-157 RelatedInformation

Differential diagnosis of hyperthyroidism

1. 1. The recognition of hyperthyroidism when the cardiac symptoms dominate, is dependent upon a carefully taken history and thorough physical examination. Failure to obtain results with the medical management of heart disease should arouse suspicion of thyroid toxicity. 2. 2. Cardiovascular neurosis may present nearly all of the symptoms of hyperthyroidism. Differentiation of the two conditions may require prolonged study. Again, a complete history and painstaking examination of the patient are the most important diagnostic aids. 3. 3. The true basal metabolic rate can often, only be determined by repeated observations. The test is of little practical value in the differential diagnosis of hyperthyroidism. Neither the diagnosis nor the therapy of goiter can be determined by a test in which the opportunity for error is so great.