A. J. Van Herle

Characterization of a human follicular thyroid carcinoma cell line (UCLA RO 82 W-1)

SummaryA thyroid tumor cell line has been established from the metastases of a follicular carcinoma in a female patient. Although the primary tumor released thyroglobulin (Tg) into the circulation (> 10000 ng/ml), the uptake of I131 was less than 2%. After 37 replications the doubling time was 4 days and confluency was reached after 7 days from inoculation of 3 × 107 cells. This human thyroid tumor cell line has now been growing in culture for several years. An aneuploid chromosomal pattern was observed (62–82 chromosomes). A pair of X chromosomes was present but no Y chromosome was found which is compatible with the female origin of the cell line. EM studies revealed the presence of microvilli. Immunoperoxidase staining using specific anti-human Tg antisera indicated the presence of Tg within the cells. Nude mice developed solid-cystic tumors within 6 months after injection of the cells. The basal release of immunodetectable Tg, as measured in a perifusion system, increased in response to thyroid stimulating hormone (TSH) (p< 0.025) or TSH combined with theophylline (p< 0.001). Unusual isoenzyme patterns for galactose-1-phosphate-uridyltransferase (GALT) and phosphoglucomutase1 (PGM1) were detected in the tumor, compared with normal human fibroblasts and blood cells and isoenzyme patterns from the patient’s lymphocytes. Because this malignant human thyroid follicular cell line has retained the ability to synthesize Tg it represents a valuable model for the study of human follicular carcinomas.

Brain Glucose Metabolism in Hypothyroidism: A Positron Emission Tomography Study before and after Thyroid Hormone Replacement Therapy

CONTEXT Hypothyroidism is frequently associated with subtle behavioral and psychiatric symptoms. The consequences of inadequate thyroid hormone availability to brain metabolism are poorly understood. OBJECTIVE This study assessed the relationships between neuropsychiatric symptoms and changes in relative regional cerebral glucose metabolism in hypothyroid patients undergoing thyroid hormone replacement therapy. DESIGN, SETTING, AND OUTCOME MEASURE: Relative regional cerebral glucose metabolism was compared in 13 previously untreated hypothyroid patients and 10 healthy control participants. Effects of thyroid hormone replacement therapy (levothyroxine, 3 months) were assessed using neuropsychiatric measures and positron emission tomography with [(18)F]fluorodeoxyglucose. RESULTS Before treatment, hypothyroid patients exhibited lower regional activity than control subjects in the bilateral amygdala, hippocampus, and perigenual anterior cingulate cortex (ACC), left subgenual ACC, and right posterior cingulate cortex. Severity of depressive symptoms covaried negatively with pretreatment activity in the bilateral middle frontal gyrus and right subgenual and dorsal ACC. Thyroid hormone replacement therapy abolished pretreatment group differences in regional activity, robustly increased activity in the ventral ACC, and significantly reduced both clinician-rated and self-rated behavioral and psychiatric symptoms. Increased activity within the ventral ACC was associated with reduced somatic complaints, whereas increased activity within the dorsal ACC was associated with reduced depressive symptoms. CONCLUSIONS Reduction of the behavioral complaints during thyroid hormone therapy is associated with a restoration of metabolic activity in brain areas that are integral to the regulation of affect and cognition. The findings suggest that thyroid hormone modulates regional glucose metabolism and psychiatric symptoms in the mature brain.

Thyroid dysfunction in a prospectively followed series of patients with progressive systemic sclerosis

Thirty-nine patients with progressive systemic sclerosis (PSS) in stable clinical conditions were extensively evaluated for the presence of thyroid disease. Two patients had previously undetected hypothyroidism while 7 additional patients had normal serum thyroid hormone levels but an exaggerated TSH response to thyrotropin -releasing hormone (TRH) administration, consistent with subclinical hypothyroidism. Four of the 9 subjects with abnormal TRH responses had positive antithyroid antibodies and of the remaining 5, 4 had been on chlorambucil or prednisone. Basal TSH and TSH response to TRH were significantly higher in PSS patients as a group when compared to a control group and increased with increasing duration of PSS. Serum antithyroid antibodies (an-tithyroglobulin and/or antimicrosomal antibodies) were positive in 18% and thyroid scans were abnormal in 18% of the patients. The euthyroid sick syndrome was not seen. Our findings indicate an increased frequency of, sometimes previously unsuspected, clinical and subclinical hypothyroidism in stable PSS patients which appears to be autoimmune in nature and becomes more prevalent with increased PSS duration. Careful and regular monitoring of the thyroid function in PSS patients is advisable.

Assessment of hypothalamic-pituitary-adrenal (HPA) axis dysfunction: comparison of ACTH stimulation, insulin-hypoglycemia and metyrapone

The response to ACTH stimulation, insulin-hypoglycemia and metyrapone in patients with suspected HPA axis dysfunction due to corticosteroid therapy (Group I, n = 10), or pituitary surgery (Group II, n = 7) and in a control population (Group III, n = 8) was studied. Group I patients had been maintained on a stable low dose of prednisone 5.0–7.5 mg/day for 1 month-16 yr (mean = 31 mos) prior to testing. Basal 08:00 h cortisol levels in this group were not different from control values. However, the mean responses to all three testing procedures were suppressed (Group I vs III, ACTH p < 0.001, insulin p< 0.01, metyrapone p< 0.05). Group II patients had undergone surgery 1–26 months (mean = 10 mo) prior to testing and had been maintained subsequently on a stable dose of prednisone 5.0–7.5 mg/day. In this group basal mean 08:00 h cortisol and the cortisol response to ACTH and insulin-hypoglycemia were not significantly different from control values while the response to metyrapone was suppressed (Group II vs III p< 0.02). Basal serum DHEA-S levels were suppressed in both Groups I and II when compared to Group III (p< 0.001 ). Discordant responses to the three testing procedures were noted in 6 patients with suspected HPA dysfunction with abnormal test results in 1/6 using cortrosyn, 3/6 using insulin-hypoglycemia and 4/6 using metyrapone. We conclude that: (1) Low doses of prednisone cause subtle, but significant HPA axis suppression, (2) DHEA-S levels do not correlate with standard tests of the HPA axis, and (3) Although no single test identified every subject with an abnormal HPA axis, metyrapone was more useful in detecting subtle degrees of HPA dysfunction than ACTH or insulin-hypoglycemia. Metyrapone is simple, safe and may be the test of choice in assessing patients with suspected secondary adrenal insufficiency.

Amyloid goiter in a case of systemic amyloidosis secondary to ankylosing spondylitis

Infiltrative diseases of the thyroid include systemic sclerosis, hemochromatosis, sarcoidosis, chondrocalcinosis and amyloidosis. Only rarely does thyroid amyloidosis result in clinically palpable goiter. Classically, amyloidosis is associated with tuberculosis, rheumatoid arthritis, multiple myeloma or inflammatory bowel disease. Only rarely does clinical amyloidosis develop in the setting of ankylosing spondylitis. We describe a case of amyloid goiter in a patient with ankylosing spondylitis-associated amyloidosis.

Paper Chromatography prior to Cortisol RIA Allows for Accurate Use of the Dexamethasone Suppression Test in Chronic Renal Failure

The assessment of the hypothalamic-pituitary-adrenal axis in patients with chronic renal failure (CRF) on hemodialysis is often hampered by abnormal responses to the standard 1-mg dexamethasone suppression test. Various mechanisms have been proposed to explain this lack of suppressibility. The present study was designed to look into the mechanisms possible for these findings in patients with CRF. We studied 6 patients with CRF on hemodialysis and 5 healthy subjects utilizing the 1-mg dexamethasone suppression test as well as the 50-mg hydrocortisone suppression test. Samples were assayed for dexamethasone, adrenocorticotropic hormone, corticosterone, and cortisol by both direct radioimmunoassay (RIA) and RIA after paper chromatography. Utilizing the direct cortisol RIA, 4 of 6 patients with CRF exhibited blunted dexamethasone suppression, while all 6 patients showed normal suppressibility after dexamethasone when cortisol was measured after paper chromatography. In contrast, all controls showed normal suppressibility regardless of the cortisol assay procedure used. The hydrocortisone suppression test was unreliable in the setting of CRF. Mean dexamethasone levels were similar in both groups. Plasma adrenocorticotropic hormone levels were significantly higher in the CRF patients, possibly indicative of an underlying hypothalamic-pituitary-adrenal axis abnormality. Abnormalities in dexamethasone suppression testing in patients with CRF may be explained by the overestimation of cortisol levels by direct RIA rather than by alteration of dexamethasone absorption or metabolism. Measurement of cortisol after paper chromatography is superior to direct RIA of cortisol in patients with CRF.

Immunoreactive thyroglobulin in sera and saliva of patients with various thyroid disorders: Role of autoantibodies

The present study was designed to assess the transfer of thyroglobulin (Tg) and anti-Tg antibodies (TgAb) to saliva in subjects with positive TgAb in their sera. Group I consisted of normal euthyroid control subjects (n = 10). Group II were patients with various thyroid disorders and no TgAb in their sera (n = 6). Group III were patients with thyroid disorders and TgAb in their sera (n = 31). The mean serum Tg level (± SE) and mean TgAb level [mean % binding ± SE (range)] were as follows: Group I, Tg: 22.0 ng/ml ± 1.64 (n = 10); TgAb 1.91 % ± 0.34 (range 0.6% to 4%). Group II, Tg: 119.8 ng/ml ± 28.0 (n = 6) TgAb 1.59% ± 0.34 (0.64% to 2.7%). Group III Tg 167.9 ng/ml ± 41.0 (n = 31 ) TgAb 23.2% ± 3.87 (4.2% to 67.5%). The mean salivary Tg level (SaTg) and mean TgAb binding (% ± SE range) in saliva were as follows: Group I SaTg 2.07 ng/ml ± 0.39 (n = 10) SaTgAb 1.13% ± 0.38 (0% to 3.1). Group II SaTg 3.41 ng/ml ± 0.67 (n = 6), SaTgAb 0.55% ± 0.29 (0–1.9%). Group III SaTg 5.22 ng/ml ± 0.96 (n = 31), SaTgAb 3.1% ± 1.58 (0 to 47.7%). Salivary TgAb were only present in 4 out of 31 cases of Group III. Mean serum Tg in group IV-A was 75.01 ng/ml ±52.1 (n = 11). Mean serum TgAb in group IV-A was 1.94% ± 0.31 (n = 11). Mean serum Tg in group IV-A was 6.3 ng/ml ± 3.31 (n = 11), mean SaTgAb is 0.72% ± 0.29 (n = 11). Mean serum Tg in group IV-B was 439.5 ng/ml ± 385.8 (n = 9). Mean serum TgAb was 11.5% ± 4.24 (n = 9). Mean SaTg levels in group IV-B was 2.37 ng/ml ± 0.37 (n = 9). Mean SaTgAb in group IV-B was 0.71 % ± 0.32 (n = 9). It is concluded that Tg crosses the blood/salivary gland barrier in all groups studied but is quantitatively less important than previously reported. TgAb also cross the blood/salivary barrier, the concentration in saliva is however not strictly proportional to the TgAb concentrations in serum. Salivary Tg cannot be relied upon in subjects with positive TgAb titers in the follow-up for thyroid cancer or Graves’ disease.

Immunoheterogeneity of parathyroid hormone in parathyroid cysts: diagnostic implications

Parathyroid cysts are uncommon lesions of the neck leading to hypercalcemia in a significant percentage of cases. The distinction between parathyroid and thyroid cysts is difficult to make on a clinical basis alone and relies on the demonstration of elevated PTH levels in cyst fluid. We describe a case of a parathyroid cyst in which intact PTH (1–84) levels were misleadingly low while midmolecule 44–68 PTH was markedly elevated. To explain this discrepancy, we studied cyst fluid from this and two other patients using Sephadex G-75 gel chromatography. Fractions were analyzed using an immunoradiometric assay for intact hPTH (1–84) and a RIA specific for the midmolecular 44–68 region of hPTH. Immunoreactivity corresponding to hPTH (1–84) was absent in the first case but present in the remaining two. Immunoreactive peaks corresponding to PTH fragments were demonstrable in all three cyst samples. Patients with elevated hPTH (1–84) in cyst fluid were hypercalcemic; in contrast, the patient with a low cyst level of hPTH (1–84) was normocalcemic despite having markedly elevated levels of mid-molecule PTH (44–68) in both serum and cyst fluid. Parathyroid cysts may thus produce fragments rather than intact PTH; reliance on an intact hPTH assay could lead to misdiagnosis. The measurement of PTH by a midmolecular assay may be preferable to the measurement of intact PTH in the evaluation of fluid from cystic neck masses.

The effect of 131I for diagnostic purposes on serum thyroglobulin (hTg) levels in subjects with thyroidal disorders

The concentration of serum thyroglobulin was measured in sera of subjects with various thyroid disorders, before and after the administration of tracer doses of 131I. The mean serum human thyroglobulin (hTg) concentration before administration of the isotope was 35.2 ng/ml±7.8 (SE) in 13 subjects and 36.3 ng/ml±7.9 (SE) 24 h after the administration of 131I. The data indicate that no significant release of thyroglobulin occurs 24 h after the administration of tracer doses of 131I. In 2 of the 3 subjects, however, in whom samples were obtained at 4 and 8 h after diagnostic administration of 131I, a modest rise in serum Tg levels was observed. Determinations of serum thyroglobulin levels within 24 h after the administration of a tracer dose of 131I are nevertheless valid providing one allows sufficient time to elapse for tracer decay.

Characterization of high titer antithyroglobulin antibodies

Few autoantibodies directed against thyroglobulin (TgAbs) have been fully characterized in man. The present study was designed to characterize TgAbs from patients with unusually high titers (> 1: 512) using the tanned red cell hemagglutination technique (TRC). IgG was isolated from the sera of subjects with Hashimoto’s thyroiditis (n = 4), subacute thyroiditis (n = 1) and Graves’ disease (n = 1) using DEAE-Sephacel chromatography. Isolated TgAbs were substituted as first antibody in a double antibody thyroglobulin (Tg) RIA and the Ka’s were determined by Scatchard analysis. Molecular ratios of antibody to antigen, TgAb: Tg, were calculated from quantitative precipitin curves. The clonality of each antibody was determined using agarose isoelectric focusing and131 I labeled Tg as an autoradiographic probe. All six TgAbs were polyclonal. The Ka’s were on the order of 109–1010. In two sera TgAb: Tg ratios of 20: 1 and 8: 1 were obtained. These results are significant when compared to previously characterized Tg autoantibodies which have been of low titer, low Ka (105), and have been directed towards a restricted portion of the Tg molecule (TgAb: Tg ratios of 2: 1 to 6:1). In view of their high affinity constants and recognition of a less restricted portion of the Tg molecule, some of the TgAb’s with unusually high titers behave more like Tg heteroantibodies than autoantibodies.