Serum thyrotropin (TSH) levels in patients with suppressed pituitary function
The diagnosis of borderline hyperthyroidism is difficult. A sensitive radioimmunoassay capable of detecting subnormal levels of serum TSH may be of value in confirming this diagnosis because of the suppressed pituitary function in this disease state. This sensitive assay may also be useful in monitoring the suppression of pituitary function in thyroid cancer patients receiving thyroid hormone therapy. A sensitive radioimmunoassay capable of detecting serum TSH levels as low as 0.25 ..mu..U/m1 with coefficients of variation less than 17.2% was used to measure serum TSH levels in 80 healthy subjects, 44 hyperthyroid patients, and 25 athyrotic thyroid cancer patients on daily suppressive doses of thyroxine. All healthy subjects had detectable TSH levels with a mean value of 1.17 and two standard deviation ranges of 0.41 - 2.70 ..mu..U/m1 (lognormal distribution). Although the mean +-1 SEM value of 0.63 +- 0.003 ..mu..Um1 for hyperthyroid patients and 0.76 +- 0.08 ..mu..U/ml for thyroid cancer patients were significantly lower than that of healthy subjects (t-test, p<0.05), subnormal levels of serum TSH were found in only 28.6% (12/42) and 24% (6/25) of hyperthyroid and thyroid cancer patients, respectively. TSH stimulation tests performed in 6 of the cancer patients all gave suppressed responses. Because of considerable overlap, serum TSH levels alone cannot distinguish hyperthyroidsm from euthyroidism. However, a sensitive TSH radioimmunoassay such as the one described here may be of value in evaluating the extent of pituitary suppression in thyroid cancer therapy.
- Research Organization:
- E.L. Saenger Radioisotope Lab., Dept. of Radiology, Univ. of Cincinnati, College of Medicine, Cincinnati, OH
- OSTI ID:
- 6932860
- Report Number(s):
- CONF-840619-
- Journal Information:
- J. Nucl. Med.; (United States), Journal Name: J. Nucl. Med.; (United States) Vol. 25:5; ISSN JNMEA
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
62 RADIOLOGY AND NUCLEAR MEDICINE
AMINO ACIDS
BODY
CARBOXYLIC ACIDS
DIAGNOSIS
DISEASES
ENDOCRINE DISEASES
ENDOCRINE GLANDS
GLANDS
HORMONES
HYPERTHYROIDISM
IMMUNE SERUMS
IMMUNOASSAY
IMMUNOLOGY
INHIBITION
ISOTOPE APPLICATIONS
NEOPLASMS
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC HALOGEN COMPOUNDS
ORGANIC IODINE COMPOUNDS
ORGANS
PATIENTS
PEPTIDE HORMONES
PITUITARY GLAND
PITUITARY HORMONES
RADIOASSAY
RADIOIMMUNOASSAY
RADIOIMMUNOLOGY
SENSITIVITY
THERAPY
THYROID
THYROID HORMONES
THYROXINE
TRACER TECHNIQUES
TRH
TSH