The Role of Core Needle Biopsy and Its Impact on Surgical Management in Patients with Medullary Thyroid Cancer: Clinical Experience at 3 Medical Institutions

BACKGROUND AND PURPOSE

Medullary thyroid carcinoma is an uncommon malignancy that is challenging to diagnose. Our aim was to present our experience using core needle biopsy for the diagnosis of medullary thyroid carcinoma compared with fine-needle aspiration.

MATERIALS AND METHODS

Between January 2000 and March 2012, 202 thyroid nodules in 191 patients were diagnosed as medullary thyroid cancer by using sonography-guided fine-needle aspiration, core needle biopsy, or surgery. One hundred eighty-three thyroid nodules in 172 patients were included on the basis of the final diagnosis. We evaluated the sensitivity and positive predictive value of fine-needle aspiration and core needle biopsy for the diagnosis of medullary thyroid cancer. We compared the rate of a delayed diagnosis, a diagnostic surgery, and surgery with an incorrect diagnosis for fine-needle aspiration and core needle biopsy and investigated the factors related to the fine-needle aspiration misdiagnosis of medullary thyroid cancer.

RESULTS

Fine-needle aspiration showed 43.8% sensitivity and 85.1% positive predictive value for the diagnosis of medullary thyroid cancer; 25.7% (44/171) of patients had a delayed diagnosis, while 18.7% (32/171) underwent an operation for accurate diagnosis, and 20.5% (35/171) underwent an operation with an incorrect diagnosis. Core needle biopsy achieved 100% sensitivity and positive predictive value without a delay in diagnosis (0/22), the need for a diagnostic operation (0/22), or an operation for an incorrect diagnosis (0/22). A calcitonin level of <100 pg/mL was the only significant factor for predicting the fine-needle aspiration misdiagnosis of medullary thyroid cancer (P = .034).

CONCLUSIONS

Core needle biopsy showed a superior sensitivity and positive predictive value to fine-needle aspiration and could optimize the surgical management in patients with medullary thyroid cancer. Because the ability of fine-needle aspiration to diagnose medullary thyroid cancer significantly decreases in patients with serum calcitonin levels of <100 pg/mL, core needle biopsy could be indicated for these patients to optimize their surgical management.

Basal STAT3 activities are negatively correlated with tumor size in papillary thyroid carcinomas

BACKGROUNDS

Signal transducer and activators of transcription-3 (STAT3) plays a critical role in promoting survival and cell growth as well as facilitating angiogenesis and metastasis in several cancers.

AIM

This investigation focused on evaluation of STAT3 activities in human papillary thyroid cancers (PTC).

METHODS

STAT3 activities of nuclear extracts of tumor tissue were measured from 35 PTC patients using enzyme- linked immunosorbent assay-based kits.

RESULTS

STAT3 activities of PTC tissues were significantly lower than those of surrounding normal thyroid tissues [0.36 (interquartile range 0.24-0.72) vs 0.50 (0.29-1.11) arbitrary units, p<0.01]. We further analyzed the association between STAT3 activity and clinicopathologic factors in PTC tissue. Tumors with size ≥2 cm displayed significantly lower STAT3 activities than those <2 cm [0.25 (0.21-0.37) vs 0.53 (0.37-0.61) arbitrary units, p<0.01]. Notably, tumor size was inversely correlated with STAT3 activities in T1799A BRAF mutation-positive cases (Rs=-0.58, p<0.05), but not mutation-negative cases.

CONCLUSIONS

STAT3 activities of PTC measured via DNA binding are suppressed in contrast to other human cancers. Tumor size larger than 2 cm is the only clinicopathologic parameter associated with low STAT3 activity. Moreover, tumor size appears inversely correlated with STAT3 activity, specifically in T1799A BRAF mutation-positive cases.

Collapsing benign cystic nodules of the thyroid gland: sonographic differentiation from papillary thyroid carcinoma

BACKGROUND AND PURPOSE

The US features of benign and malignant nodules overlap, and benign thyroid lesions can mimic thyroid malignancy on US. Benign cystic nodules after spontaneous collapse or needle aspiration, can mimic malignant thyroid nodules. Our aim was to evaluate the US features of CBCNs of the thyroid that distinguish such nodules from malignant thyroid nodules.

MATERIALS AND METHODS

US and clinical findings in 13 patients, each with a single CBCN, were evaluated to determine if they showed >50% cystic content on initial US or CT and >30% decrease in maximum diameter on follow-up US. We compared these findings with those of 26 patients, each with a single surgically confirmed PTMC. US scans were analyzed for internal content, shape, margin, echogenicity, presence of echogenic dots suggesting micro- and macrocalcification, inner isoechoic rim, and low-echoic halo.

RESULTS

Six of the 13 (46%) CBCNs were classified as malignant on US due to their marked hypoechogenicity, microcalcification, or spiculated margins. US features that differed between CBCNs and PTMCs were shape (ovoid-to-round versus taller-than-wide, P = .016); margins (ill-defined versus spiculated, P < .000); low-echoic halo (P < .000); inner isoechoic rim (P < .000) with high negative predictive values (100%, 91%, 91%, and 89%, respectively); and clinically acceptable diagnostic accuracy (59%, 80%, 82%, and 85%, respectively).

CONCLUSIONS

US features helpful for differential diagnosis of CBCNs from PTMCs include shape, margin, and the presence of an inner isoechoic rim and a low-echoic halo. Familiarity with US features suggesting CBCNs may be helpful in reducing unnecessary repeated FNABs.

Prevalence of echocardiographic criteria for the diagnosis of pulmonary hypertension in patients with Graves' disease: before and after antithyroid treatment

BACKGROUND

Right-sided heart failure with clinical manifestation is only occasionally seen in patients with Graves' disease (GD). Recent studies revealed that pulmonary hypertension (PHT) detected by echocardiography was not rare in patients with GD. We performed this study to investigate the prevalence of PHT in patients with GD before and after antithyroid treatment, and to assess potential mechanisms from the relationship with clinical and echocardiographic features.

SUBJECTS AND METHODS

Serial echocardiographic examinations were performed in 64 patients with newly diagnosed GD before and after antithyroid treatment to measure cardiac factors, such as pulmonary artery systolic pressure (PAPs), cardiac output, total vascular resistance, left ventricular filling pressure and right ventricular (RV) function. PHT was defined as PAPs of at least 35 mmHg.

RESULTS

The prevalence of PHT in untreated GD patients was 44% (28 out of 64 patients). The presence of systemic hypertension was associated with PHT, especially with pulmonary venous hypertension. GD patients with PHT showed reduced RV function represented by higher RV myocardial performance index without difference of pulmonary vascular resistance, RV wall thickness and peak systolic velocity of free wall side of tricuspid annulus. Follow-up echocardiography was performed in 20 out of 28 GD patients with PHT, and PHT disappeared in all except one patient.

CONCLUSION

PHT is a frequent and reversible complication in patients with GD. Our study suggests that PHT in GD may not be related to underlying autoimmune process and increased pulmonary blood flow from thyrotoxicosis might contributes to the pathogenesis of PHT related to GD.

Plasma isocitrate dehydrogenase as a marker of centrilobular hepatic necrosis in patients with hyperthyroidism

Isocitrate dehydrogenase (ICDH) may be useful for differentiating centrilobular from periportal necrosis in rats with liver injury. In this study, we assessed the usefulness of ICDH as a marker of centrilobular necrosis in patients with hyperthyroidism. Isocitrate dehydrogenase and alanine aminotransferase (ALT) activities were measured in the plasma of 56 patients with hyperthyroidism, 16 patients with chronic viral hepatitis (CVH), and 17 controls. Isocitrate dehydrogenase levels were higher in patients with hyperthyroidism than in those with CVH or in the controls (p < 0.01 and p < 0.001, respectively), even though ALT levels were higher in patients with CVH than in patients with hyperthyroidism (p < 0.01). Isocitrate dehydrogenase/ALT ratios were also higher in patients with hyperthyroidism than in those with CVH (p < 0.0001). Isocitrate dehydrogenase correlated to ALT levels in patients with hyperthyroidism or CVH (p < 0.05). In a patient with hyperthyroidism, ICDH levels decreased progressively to normal, and the ALT level and thyroid function were normalized. Thus, the plasma ICDH or ICDH/ALT ratio might be useful for differentiating centrilobular from periportal necrosis and for monitoring the degree of hepatic necrosis in patients with hyperthyroidism.

Increased urinary albumin excretion in Cushing's syndrome: remission after correction of hypercortisolaemia

OBJECTIVES

Increased urinary albumin excretion (UAE) in diabetic and nondiabetic subjects is frequently associated with insulin resistance syndrome and central obesity. Cushing's syndrome is also characterized by central obesity and insulin resistance. This study was undertaken to see whether increased UAE is found in Cushing's syndrome.

DESIGN

Cross-sectional study.

PATIENTS

Thirteen consecutive patients with Cushing's syndrome.

MEASUREMENTS

Patients collected three overnight urine samples for the measurement of UAE by radioimmunoassay. UAE was also measured in 479 nondiabetic subjects who comprised the control population for this study. In the patients who had initial microalbuminuria, UAE was remeasured 2 months after successful removal of pituitary or adrenal tumours. Kidney biopsy was performed in three patients during adrenalectomy.

RESULTS

Eleven out of 13 patients (84.6%) had increased UAE (> 9.6 micrograms/min), and eight patients (61.5%) had microalbuminuria or overt proteinuria (> 20 micrograms/min). Kidney biopsy revealed apparently normal glomerular structures without evidence of diabetic nephropathy. After correction of hypercortisolaemia, UAE declined profoundly in all of the patients.

CONCLUSIONS

More than 80% of patients with Cushing's syndrome had increased UAE. This was almost completely reversed after successful treatment of hypercortisolaemia. These results indicate that endogenous hypercortisolaemia increases UAE by a mechanism that is presently unknown.

Suppression of endogenous insulin secretion by exogenous insulin in patients with insulinoma

OBJECTIVE

Previous studies have demonstrated that endogenous insulin secretion is not suppressed by exogenous insulin in patients with insulinoma. In this study we examined whether insulin secretion in insulinoma patients is suppressed by exogenous insulin during hypoglycaemia.

SUBJECTS AND METHODS

Sixteen insulinoma patients (5 men and 11 women) and 10 normal subjects were studied. Hyperinsulinaemic glucose clamp studies were performed at both euglycaemia (4.5 mmol/l glucose) and hypoglycaemia (2.5 mmol/l glucose).

RESULTS

In normal subjects, plasma C-peptide levels were suppressed by 66% during the euglycaemic hyperinsulinaemic clamps (P < 0.01). In contrast, in insulinoma patients, plasma C-peptide levels increased by 25% during the clamps (P < 0.05). In the hypoglycaemic hyperinsulinaemic clamps, plasma C-peptide levels were nearly completely (91%) suppressed in normal subjects and partially (39%) suppressed in patients with insulinoma (P < 0.01). The decrease in C-peptide levels during the hypoglycaemic clamps was > 30% in 12 (75%) of 16 insulinoma patients and > 50% in 8 (50%) patients.

CONCLUSIONS

This study demonstrated that in patients with insulinoma, insulin secretion was not suppressed by exogenous insulin during euglycaemia but was suppressed during hypoglycaemia, although the degree of suppression was less than that in normal subjects. Our results suggest that the feedback regulation of insulin secretion by exogenous insulin is partially retained in patients with insulinoma.

Thyroid hormone stimulates basal and interleukin (IL)-1-induced IL-6 production in human bone marrow stromal cells: a possible mediator of thyroid hormone-induced bone loss

It is well known that excessive thyroid hormone in the body is associated with bone loss. However, the mechanism by which thyroid hormone affects bone turnover remains unclear. It has been shown that it stimulates osteoclastic bone resorption indirectly via unknown mediators secreted by osteoblasts. To determine if interleukin-6 (IL-6) or interleukin-11 (IL-11) could be the mediator(s) of thyroid hormone-induced bone loss, we studied the effects of 3,5,3'-tri-iodothyronine (T3) on basal and interleukin-1 (IL-1)-stimulated IL-6/IL-11 production in primary cultured human bone marrow stromal cells. T3 at 10(-12)-10(-8) M concentration significantly increased basal IL-6 production in a dose-dependent manner. It also had an additive effect on IL-1-stimulated IL-6 production, but failed to elicit a detectable effect on basal or IL-1-stimulated IL-11 production. Treatment with 17beta-estradiol (10(-8) M) did not affect the action of T3 on IL-6/IL-11 production. These results suggest that thyroid hormone may stimulate bone resorption by increasing basal and IL-1-induced IL-6 production from osteoblast-lineage cells, and these effects are independent of estrogen status.

Paget bone disease involving young adults in 3 generations of a Korean family

Although the etiology of Paget bone disease (PBD) is unknown, increasing evidence implicates a "slow virus" infection of the skeleton, perhaps in genetically predisposed individuals. PBD is rare in Asia. We describe a Korean family with PBD. The propositus noticed bowed limbs at approximately 25 years of age. Radiologic studies made when he was 55 years old revealed essentially panostotic PBD. Serum alkaline phosphatase (ALP) activity and osteocalcin (OC) levels were markedly elevated. An iliac crest specimen showed classic histopathologic changes of PBD. Additionally, palpable swellings were first observed at age 45 years at his occiput, pubic ramus, ileum, and facial bones. They contained numerous multinucleated cells and were originally diagnosed as giant cell tumors. However, we found that, like osteoclasts, these cells expressed considerable tartrate-resistant acid phosphatase activity. These "extraskeletal osteoclastomas" resolved rapidly with dexamethasone treatment. Two daughters, 20- and 24-years-of-age, were discovered by study of his 5 children to have elevated serum ALP activity and OC levels and widespread PBD. Both women, however, are without palpable masses and are asymptomatic. The propositus' father, who died at age 55 years, had similar skeletal deformities beginning at age 20 years, but was not examined. Leukocytopenia was found in the 3 living family members with PBD. There was no evidence for linkage of the PBD to HLA loci. The condition appears to be transmitted as an autosomal dominant trait and is manifest in young adult life. Multicentric extraskeletal osteoclastomas with remarkable sensitivity to dexamethasone treatment appear to be another unusual feature of this family's disorder. In this family, the stimulus for PBD is so great that the PBD is apparent at an early age, affects essentially the entire skeleton, and leads to the formation or extension of osteoclast-like cells into nonosseous tissues (extraskeletal osteoclastomas). This 3-generation kindred in Korea, where PBD is rare, shows a strong clustering of PBD compatible with autosomal dominant inheritance. Leukocytopenia appears to distinguish affected family members, but any role for this abnormality in the pathogenesis of PBD is unclear. Our findings support a heritable diathesis for PBD, perhaps mediated by an immune deficiency.

Nesidioblastosis in an adult with hyperinsulinemic hypoglycemia

A 50-year-old Korean man with repeated episodes of temporary loss of consciousness was diagnosed as having hyperinsulinemic hypoglycemia. Under the tentative diagnosis of insulinoma, localization procedures were carried out but no tumor was found. By percutaneous transhepatic portal venous sampling, no definite gradient in insulin concentration was found. During exploratory laparotomy no tumor was palpable in the pancreas, and intraoperative ultrasonography showed low echogenicity in the pancreatic head. Whipple's operation was performed and 70% of the proximal pancreas was removed. Histomorphometric examination of the resected specimen revealed graded hyperplasia of the islet cells. The most profuse hyperplasia was noted in the head with progressive decrease in the degree of hyperplasia to the body and tail. The patient remains euglycemic and tolerates 24 h fasting without any medication until 15 months after operation.

High prevalence and little change in TSH receptor blocking antibody titres with thyroxine and antithyroid drug therapy in patients with non-goitrous autoimmune thyroiditis

OBJECTIVE

We have reevaluated the prevalence and pathogenetic importance of TSH receptor blocking antibodies (TRBAb) in autoimmune hypothyroidism, and investigated the changes in TRBAb activities during thyroxine and antithyroid drug treatment.

DESIGN

Serum TSH binding inhibitor immunoglobulin (TBII) and thyroid stimulation blocking antibody (TSBAb) were measured serially in all patients with non-goitrous autoimmune thyroiditis (AT) and measured monthly during methimazole treatment in 6 patients.

PATIENTS

Ninety patients with non-goitrous AT and 95 patients with goitrous AT were entered consecutively into this study. All patients with non-goitrous AT were treated with thyroxine and followed at intervals of 6 months for 2 years initially and then yearly intervals. The duration of follow-up was 1-8 years. Six patients from the TRBAb-positive non-goitrous AT group who were treated with thyroxine were randomly selected and given additional treatments with methimazole (40 mg per day) for 6 months.

MEASUREMENTS

Serum TBII was measured by a radioreceptor assay, TSBAb by using FRTL-5 cells, and antithyroid peroxidase and antithyroglobulin antibodies by radioimmunoassay.

RESULTS

The prevalences of TBII and TSBAb is non-goitrous AT were 47.8 and 58.9%, respectively, which were significantly higher than those in goitrous AT (6.3% for TBII, 10.5% for TSBAb). All but one patient showed persistent TBII and TSBAb activities during the thyroxine treatment for up to 8 years. A high dose of methimazole (40 mg per day) did not affect the titres of TBII and TSBAb in 5 out of 6 patients with non-goitrous AT tested. However, antithyroid peroxidase and antithyroglobulin antibodies activities were significantly decreased during the methimazole treatment.

CONCLUSION

The high prevalence of TSH receptor blocking antibodies (TRBAb) suggests that TRBAb may play a major role in the development of hypothyroidism and thyroid atrophy in the vast majority of patients with non-goitrous autoimmune thyroiditis. Most TRBAb activities are stable for at least 8 years and are now affected by thyroxine and antithyroid drug treatment.

A strong association between thyrotropin receptor-blocking antibody-positive atrophic autoimmune thyroiditis and HLA-DR8 and HLA-DQB1*0302 in Koreans

We investigated whether the associations between HLA alleles of patients with autoimmune hypothyroidism varied according to the presence or absence of TSH receptor-blocking antibody (TRBab). We analyzed the HLA-A, -B, -C, and -DR antigens by serotyping and the DQA1 and DQB1 genes using both enzymatic DNA amplification and sequence-specific oligonucleotide hybridizations. The patient population consisted of 47 Korean patients with atrophic autoimmune thyroiditis and 62 patients with goitrous autoimmune thyroiditis. The antigen frequency of HLA-DR8 was significantly increased in 23 atrophic autoimmune thyroiditis patients that were positive for TSH binding inhibitor immunoglobulin (TBII) compared to 136 controls [52% vs. 16%; chi 2 = 13.1; Pc (corrected P value) = 0.003]. This relative risk was 5.7; the etiological fraction was 0.43. HLA-DQB1*0302 was also increased in patients with TBII-positive atrophic autoimmune thyroiditis (24% vs. 7%; chi 2 = 11.2; Pc = 0.012; relative risk = 4.4; etiological fraction = 0.19). No specific DR antigens or DQB1 alleles were increased in either TBII-negative atrophic autoimmune thyroiditis or goitrous autoimmune thyroiditis. A significant decrease in the frequency of HLA-DR6 antigen was observed in both TBII-positive atrophic autoimmune thyroiditis (0% vs. 32%; chi 2 = 8.4; Pc = 0.03) and goitrous autoimmune thyroiditis (0% vs. 32%; chi 2 = 23.2; Pc < 0.001) patients. The frequency of the HLA-Cw1 antigen was significantly increased in all patient groups. We conclude that TRBab-positive atrophic autoimmune thyroiditis is immunogenetically different from both goitrous autoimmune thyroiditis and TRBab-negative atrophic autoimmune thyroiditis. It is possible that HLA-DR8 and/or DQB1*0302 may be related to the susceptibility genes involved in the production of TRBab in Koreans.

Development of thyroid autoimmunity after administration of recombinant human interferon-alpha 2b for chronic viral hepatitis

To investigate the frequency and clinical characteristics of autoantibody formation and development of autoimmune thyroid disease after interferon therapy, we measured the autoantibodies to thyrotropin receptor (TBII), thyroglobulin (ATA), and microsomal antigen (AMA) in 28 patients with histologically proven chronic viral hepatitis [25 males, three females; mean age 38.7 +/- 8.7 (SD) yr] receiving recombinant interferon-alpha 2b (IFN-alpha) treatment. Twenty patients with chronic hepatitis B (positive for HBsAg, HBeAg, and HBV DNA) and eight patients with chronic hepatitis C (positive for anti-HCV and HCV RNA) received IFN-alpha, 3 million units subcutaneously, three times a week for 6 months. Before, during, and up to 6 months after IFN-alpha therapy, thyroid hormone levels and titers of AMA, ATA, and TBII were measured every 2 months. None of them had thyroid dysfunction or antithyroid autoantibodies before IFN-alpha treatment. A 34-yr-old male patient developed Graves' disease during the last month of therapy. He required long-term antithyroid medications, even after discontinuation of IFN-alpha. Another 44-yr-old female patient developed AMA during IFN-alpha treatment; however, thyroid function remained normal and goiter did not develop in this patient. No other patient developed thyroid autoantibodies and thyroid dysfunction. In summary, only a small minority of patients will develop thyroid autoimmunity during IFN-alpha therapy, and much less often with this low dose of IFN-alpha.

Vitiligo in autoimmune thyroid disease

The authors studied the association between vitiligo and autoimmune thyroid disease. Vitiligo was found in 20 of 293 patients with autoimmune thyroid disease (6.83%), 2 out of 227 patients with nonautoimmune thyroid disease (0.88%), and 3 out of 386 control group (0.78%). These results showed that vitiligo is closely associated with autoimmune thyroid disease (chi 2 = 24.33, p < 0.0001), but not with nonautoimmune thyroid disease. Prevalence of vitiligo in nonautoimmune thyroid disease was not different from that in control. Vitiligo in autoimmune thyroid disease was most frequently found on dorsum hands and forearms, and usually preceded the onset of thyroid disease. Four out of twenty patients with vitiligo associated autoimmune thyroid disease had another presumed autoimmune disease, that is, alopecia areata, alopecia totalis, and rheumatoid arthritis. These findings suggested that autoimmunity plays an important role in the pathogenesis of vitiligo.

Changes in thyrotropin receptor antibody after subtotal thyroidectomy in Graves' disease: comparison with the degree of lymphocytic infiltration in the thyroid

To evaluate changes in TSH receptor antibody after surgery in Graves' disease and its relationship with the degree of lymphocytic infiltration, serial serum levels of TSH receptor antibody were measured before and after the subtotal thyroidectomy in 50 patients with Graves' disease. In 22 (44%) out of 50 patients, thyrotropin binding inhibitor immunoglobulin (TBII) levels gradually decreased and disappeared completely within 12 months after surgery (TBII disappearing group). Twenty-eight (56%) patients showed persistent TBII activity and their levels were not changed until 12 months after surgery (TBII persistent group). The changes of thyroid stimulating antibody (TSab) levels were very similar to those of TBII in both groups. The thyroidal lymphocytic infiltration was more prominent in the TBII disappearing group. The degree of the decrease of TBII levels after surgery correlated with the grade of thyroidal lymphocytic infiltration. There was no significant difference of TSH receptor antibody (both TBII and TSab) levels between the thyroid and peripheral venous blood. These data suggest that the persistence or disappearance of TSH receptor antibody after surgery may reflect the difference between patients in whom the thyroid is the major site of TSH receptor antibody and those in whom additional sites of TSH receptor antibody synthesis exist.

Changes in the properties of the thyrotropin receptor antibody in patients with Graves' disease after radioiodine treatment

We investigated the effect of a single dose of 131I upon thyrotropin receptor antibodies (TRAb) in 21 patients with Graves' disease. The thyrotropin receptor antibodies were assessed by parallel measurements of thyrotropin binding inhibitor immunoglobulin (TBII), thyroid stimulating antibody (TSAb) and thyroid stimulation blocking antibody (TSBAb) in serum by radoreceptor assay, stimulation of adenlate cyclase and inhibition of TSH-stimulated adenylate cyclase activation in FRTL-5 cells, respectively. Prior to radioiodine treatment, TBII was detected in all 21 patients and TSAb in 19 patients. After radioiodine treatment, TBII activities did not change during the 12-months observation period, but in eight patients TSAb activities gradually decreased and were undetectable at the end of the 12-month observation period. Persistence of TSAb was not associated with the clinical outcome. Eight patients developed hypothyroidism within one year after radioiodine treatment. Three of the hypothyroid patients developed TSBAb, and the appearance of TSBAb coincided with the development of hypothyroidism. These results suggest that TSBAb might develop after radioiodine treatment in a minority of patients with Graves' disease and that the appearance of TSBAb, in addition to radiation-induced thyroid destruction, might be involved in the development of hypothyroidism following radioiodine treatment.

Changes in the properties of the thyrotropin receptor antibody in patients with Graves' disease after radioiodine treatment

We investigated the effect of a single dose of 131I upon thyrotropin receptor antibodies (TRAb) in 21 patients with Graves' disease. The thyrotropin receptor antibodies were assessed by parallel measurements of thyrotropin binding inhibitor immunoglobulin (TBII), thyroid stimulating antibody (TSAb), and thyroid stimulation blocking antibody (TSBAb) in serum by radioreceptor assay, stimulation of adenylate cyclase and inhibition of TSH-stimulated adenylate cyclase activation in FRTL-5 cells, respectively. Prior to radioiodine treatment TBII was detected in all 21 patients and TSAB in 19 patients. After radioiodine treatment TBII activities did not change during 12 months observation period, but in eight patients TSAb activities gradually decreased and were undetectable at the end of a 12 month observation period. Persistence of TSAb was not associated with clinical outcome. Eight patients developed hypothyroidism within 1 year after radioiodine treatment. Three of the hypothyroid patients developed TSBAb, and the appearance of TSBAb coincided with the development of hypothyroidism. These results suggest that TSBAb might develop after radioiodine treatment in a minority of patients with Graves' disease, and that the appearance of TSBAb, in addition to radiation induced thyroid destruction, might be involved in the development of hypothyroidism following radioiodine treatment.

Role of blocking TSH receptor antibodies on the development of hypothyroidism and thyroid atrophy in primary myxedema

We studied blocking type TSH receptor antibodies in 28 patients with primary myxedema and 21 patients with goitrous Hashimoto's thyroiditis by measuring the ability of their IgG to inhibit TSH binding to its receptor, and to inhibit TSH-stimulated cAMP increases and 3H-thymidine incorporation in a rat thyroid cell line, FRTL-5. The incidences of TSH binding inhibitor immunoglobulin (TBII), thyroid stimulation blocking antibody (TSBAb) and thyroid growth blocking antibody (TGBAb) in patients with primary myxedema were 53.6%, 75% and 65.2%, respectively. However, in goitrous Hashimoto's thyroiditis, these were 14.3%, 0% and 17.7%, respectively. These antibodies inhibited the receptor binding of 125I-bTSH dose-dependently, and also inhibited dose-dependently not only TSH-stimulated but also Graves' IgG-stimulated cAMP increase and 3H-thymidine incorporation. TBII activities of patients with primary myxedema were significantly correlated with both their TSBAb (r = 0.665; p less than 0.01) and TGBAb (r = 0.618; p less than 0.01) activities. Thirteen patients whose TBII activities were more than 50% had both strong TSBAb (75.1-100%) and TGBAb (57.4-100%) activities. Transient neonatal hypothyroidism was found in an infant born to a mother having potent TBII activities. Serum of the baby also had potent TBII activities and the baby's IgG inhibited TSH-stimulated cAMP increase and 3H-thymidine incorporation. These data suggest that a significant proportion of patients with primary myxedema have potent blocking type TSH receptor antibodies. These might play a role in primary myxedema causing hypothyroidism and thyroid atrophy through inhibition of TSH-stimulated cAMP generation.

Pathogenetic role of thyrotropin receptor antibody in the development of hyperthyroidism following primary hypothyroidism

The authors measured thyrotropin binding inhibitory immunoglobulin (TBII), thyroid stimulating antibody (TSAb), and thyroid stimulation blocking antibody (TSBAb) sequentially in patients who developed hyperthyroidism following primary hypothyroidism, and compared changes in these various functional parameters of thyrotropin receptor antibody (TRAb) with clinical manifestations, in order to investigate the role of TRAb in the development of hyperthyroidism following primary hypothyroidism. In a patient with goitrous chronic thyroiditis, TBII, TSAb and TSBAb were not detected at the initial hypothyroid phase. But with appearance of TBII and TSAb, the patient developed hyperthyroidism. In a patient with primary nongoitrous myxedema, initially high TBII and TSBAb were detected without TSAb activity. His TSBAb disappeared and TSAb appeared with development of goiter growth and hyperthyroidism. These two mechanisms, that is, appearance of previously absent TSAb and conversion of TSBAb to TSAb, might play a causative role in the development of hyperthyroidism following primary hypothyroidism. These phenomena might be evidence that Graves' disease, chronic thyroiditis, and primary nongoitrous myxedema are on a continuing spectrum of a common syndrome sharing similar pathophysiology, at least with respect to TRAb.

Graves' hyperthyroidism following primary hypothyroidism: sequential changes in various activities of thyrotropin receptor antibodies

A 40-year-old male who developed Graves' hyperthyroidism following primary hypothyroidism is reported. He presented with clinical signs of hypothyroidism and concomitant myasthenia gravis. The thyroid was not palpable. He was treated with T4, pyridostigmine and prednisolone. One year later he developed hyperthyroidism and goitre. His initial serum IgG had no intrinsic thyroid stimulating activity, but showed almost complete inhibition of TSH-stimulated cAMP generation (99.4%, normal less than 38%) and [3H]thymidine incorporation (99.5%, normal less than 40%) into rat thyroid cells, FRTL-5 cells, with very high activity (80.2%, normal less than 15%) of TSH binding inhibitor immunoglobulin. When he developed hyperthyroidism and goitre, his IgG showed a strong thyroid stimulation, both cAMP production (27-fold increase) and [3H]thymidine incorporation (5.5-fold increase). No inhibitory activities were noted. These findings suggest that clinical states of autoimmune thyroid diseases can be changed in accordance with changes of functional properties of TSH receptor antibodies.

Anti-bovine TSH antibodies in patients with Graves' disease and primary myxedema

Three patients with Graves' disease and one patients with primary myxedema had serum TSH-binding immunoglobulins of high affinity detected by the TSH binding inhibition immunoglobulin (TBII) assay. These IgGs bound 61%, 33%, 60% and 53% of radiolabeled TSH, respectively, higher than the maximal specific binding (25%) in the TBII assay. Such binding was detected even in the absence of TSH receptor with only small differences in the precipitable radioactivity (61%, 28%, 61%, 54%, respectively, in comparison with the assay non-specific binding 11.3%). The 125I-bTSH binding of IgGs was competitively inhibited by the addition of bTSH, but not inhibited by hTSH. Moreover IgG binding to bTSH was not inhibited by the addition of serial dilutions of TBII positive pooled Graves' IgG (0.1-10 mg/ml) from different untreated patients. The titers of these TSH binding antibodies were not changed during the treatment of Graves' disease. Following guinea pig fat cell membrane receptor purification, the IgG of one patient with Graves' disease revealed TBII activity of 43.7% inhibition of 125I-bTSH binding to the TSH receptor without binding activity of 125I-bTSH in the absence of the TSH receptor. These studies suggest that anti-TSH antibodies and TSH receptor antibodies are present independent of one another in sera of some patients with autoimmune thyroid diseases and anti-TSH antibodies result in false TBII assay results.

Inhibition of thyrotropin-stimulated adenylate cyclase activation and growth of rat thyroid cells, FRTL-5, by immunoglobulin G from patients with primary myxedema: comparison with activities of thyrotropin-binding inhibitor immunoglobulins

We studied the blocking type TSH receptor antibodies in 28 patients with primary myxedema and 21 patients with goitrous Hashimoto's thyroiditis by measuring the ability of their IgGs to inhibit TSH binding to its receptor, and to inhibit TSH-stimulated cAMP increase and [3H]thymidine incorporation in a rat thyroid cell line, FRTL-5. The incidences of TSH binding inhibitor immunoglobulin, thyroid stimulation inhibiting immunoglobulin and thyroid growth inhibiting immunoglobulin in patients with primary myxedema were 54.6, 75 and 65.2%, respectively, against 14.3, 0 and 17.7%, respectively, in goitrous Hashimoto's thyroiditis. The antibodies inhibited dose-dependently not only TSH stimulated but also Graves' IgG-stimulated cAMP increase and [3H]thymidine incorporation. The TSH binding inhibitor immunoglobulin activities in patients with primary myxedema were significantly correlated with both the thyroid stimulation inhibiting immunoglobulin (r = 0.665; P less than 0.01) and the thyroid growth inhibiting immunoglobulin (r = 0.618; P less than 0.01) activity. Thirteen patients whose TSH binding inhibitor immunoglobulin activities were more than 50% had both strong thyroid stimulation inhibiting immunoglobulin (75.1-100%) and thyroid growth inhibiting immunoglobulin (57.4-100%) activities. These data suggest that the vast majority of patients with primary myxedema have potent blocking type TSH receptor antibodies. These might play a role in primary myxedema causing hypothyroidism and thyroid atrophy through inhibiting TSH-stimulated cAMP generation.

Transient neonatal hypothyroidism due to transplacental transfer of maternal immunoglobulins that inhibit TSH binding, TSH-induced cAMP increase and cell growth

Transient neonatal hypothyroidism due to transplacental transfer of maternal blocking type TSH receptor antibodies (TRAb) was found in a baby born to a 27-yr-old mother, who had been receiving thyroxine medication for primary myxedema. Maternal IgG inhibited radiolabelled TSH binding to its receptor (TBII), TSH-stimulated thyroid adenylate cyclase (AC) activation (TSII) and TSH-stimulated 3H-thymidine uptake (TGII) in cultured rat thyroid cells (FRTL-5). At birth, the baby's IgG showed similar activities to maternal IgG but all these activities decreased gradually, and disappeared from her serum within 12 weeks of age. In the baby, initially nonvisualized thyroid was clearly visualized on 99 m-Tc thyroid scintigraphy when all these blocking activities disappeared, TSII and TGII being decreased more slowly than TBII, and the baby remained euthyroid after discontinuation of thyroxine. This study suggests that such IgGs induced hypothyroidism and thyroid atrophy in the mother and were responsible for transient neonatal hypothyroidism in the baby.

HLA-DR antigen expression on the thyrocytes of Graves' disease patients

To confirm the expression of HLA-DR antigen on the thyrocytes of Graves’ disease patients and study the relation between the degree of DR antigen expression and clinical or laboratory indices, double immunofluorescence and immunoenzymatic staining were performed on frozen thyroid sections. DR antigen was expressed on the thyrocytes of 8 of 11 patients with Graves’ disease (73%) but not found on the thyrocytes from 6 normal controls. The degree of DR antigen expression had no apparent correlation with the age, duration of the disease, activity of TBII, titers of antimicrosomal and antithyroglobulin antibody. There was no apparent spatial or quantitative relation between lymphoid follicle formation and the DR antigen expression on the thyroid follicles. But DR antigen tended to be expressed on the thyroid tissue with interstitial, lymphocyte infiltration. In conclusion, DR antigen was expressed on the thyrocytes of Graves’ disease patients but the clinical and immunological significance remains to be clarified.

Characteristics of anti-TSH antibody and its relationship with TSH receptor antibody

Using the TSH binding inhibition IgG (TBII) assay three patients with Graves’ disease were discovered to have serum TSH-binding immunoglobulins of high affinity. These IgGs bound 61%, 33% and 60% of radiolabeled TSH, respectively, higher than the maximal specific binding (25%) in the TBII assay. Such binding was detected even in the absence of TSH receptor with only small differences in the precipitable radioactivity (61 %, 28%, and 61 %, respectively) compared with non-specific binding (11.3%). The ¹²⁵I-bTSH binding of IgGs was competitively inhibited by the addition of bTSH. The 7s fraction was found to be a major binding component by gel filtration chromatography. Myxedema sera with high TSH levels did not affect the reaction. Moreover IgG binding to bTSH was not inhibited by the addition of serial dilutions of TBII positive pooled Graves’ IgG (0.1–10mg/ml) from a different untreated patient. The titers of these TSH binding antibodies were not changed during the treatment of Graves’ disease. Following guinea pig fat cell membrane receptor purification, the IgG of one patient with Graves’ disease revealed TBII activity of 46.3%. However, no binding of ¹²⁵I-bTSH in the absence of the TSH receptor was evident. These studies suggest that 1) anti-TSH antibodies and TSH receptor antibodies are present independent of one another in the sera of some patients with Graves’ disease, and 2) TSH receptor antibodies do not affect the binding of anti-TSH antibodies to TSH.

Diffuse striated muscle heteroplasia of the lung. An autopsy case

We studied a diffuse, striated muscle heteroplasia in the lungs in a 20-week-old stillborn fetus. The lung was small, but retained normal shape. There was no tumefaction. Histologically, a massive and diffuse distribution of the striated muscle cells was found among the interstitia of the dysplastic lung, representing solid adenomatoid malformation. Based on the findings in this case and the cases of others, we believe that the presence of the striated muscle and adenomatoid malformation are causally related, and the striated muscle cells arise from the heteroplastic transformation of the pluripotential embryonal mesenchymal cells.