The Birmingham pituitary database: auditing the outcome of the treatment of acromegaly

OBJECTIVE Graves' disease is recognized as an organ-specific autoimmune disorder caused by the presence of TSH receptor antibodies. The long-term effects of ¹³¹I treatment for Graves' disease on TSH receptor antibodies have not previously been studied. We have measured the TSH-binding Inhibitory immunoglobulin (TBII) Index and thyroid stimulating antibody (TSAb) activity in patients with Graves' disease following treatment with ¹³¹I. DESIGN A retrospective study. PATIENTS Two hundred and twenty-five patients with Graves' disease who were treated with ¹³¹I 1–13 years earlier were studied (1 year: 27 patients; 2–5 years: 42 patients; 6–9 years: 79 patients; 10–13 years: 77 patients). MEASUREMENTS The TBII index was measured as the percentage ¹²⁵I-TSH bound to pig thyroid membranes and TSAb activity as the amount of cAMP produced by cultured FRTL-5 cells. RESULTS TBII was detected in 78% of patients prior to ¹³¹I administration. Following ¹³¹I administration, the Incidence of positive TBII was 85% at the end of the first year decreasing to 40,19 and 17% at 2–5,6–9 and 10–13 years, respectively. The frequency of a positive TSAb was 74% at the end of the first year, and also decreased to 49, 27 and 29% at 2–5, 6–9 and 10–13 years, respectively. At more than 2 years after ¹³¹I therapy, the frequencies of hyperthyroidism In TBII and TSAb positive patients were 42% (19/45) and 30% (19/63), respectively, which were significantly higher than those In TBII and TSAb negative patients (8%: 12/153 and 8%:11/131, respectively). The frequency of hyperthyroidism after ¹³¹I treatment in patients with negative TBII before treatment (7%: 2/29) was significantly lower than that (29%: 30/102) In patients with positive TBII before treatment. CONCLUSIONS These results indicate that (1) the TBII Index and TSAb activity decreased over a period of more than 2 years after ¹³¹I therapy for Graves' disease, and (2) the TBII index before treatment may influence the long-term outcome of ¹³¹I therapy.     

PRODUCTION OF NON-STIMULATORY IMMUNOGLOBULINS THAT INHIBIT TSH BINDING IN Graves'' DISEASE AFTER RADIOIODINE ADMINISTRATION

The effect of a single dose of ¹³¹I upon thyroid stimulating immunoglobulins has been studied in twenty-two patients with Graves' disease. The thyroid stimulating immunoglobulins were assessed by parallel measurements of thyrotrophin receptor binding inhibitory immunoglobulins (TBII) and of thyroid adenylate cyclase stimulating immunoglobulins (TACSI) in serum by radioreceptor assay and stimulation of adenylate cyclase respectively. Prior to ¹³¹I therapy TBII were present in fourteen and TACSI in sixteen patients; seventeen were positive in one of the assays and thirteen in both assays. After radioiodine the level of both TACSI and TBII increased in most patients, but in six patients ¹³¹I therapy appeared to lead to a dissociation between the TBII and TACSI. After 12 months, nine patients were still positive in both assays, and twenty-one in one of the assays. In total, five patients developed hypothyroidism within 1 year after radioiodine. The TBII levels were significantly higher both before and 3 months after therapy in these patients than in those who remained euthyroid. Two of the hypothyroid patients developed non-stimulatory TSH binding inhibitory antibodies. The present study thus confirms that radioiodine therapy is followed by an increase of TBII and TACSI in most patients with Graves' disease. The level of TBII can probably provide a marker for development of hypothyroidism following ¹³¹I therapy and might be involved in its pathogenesis.     

EFFECT OF RADIOIODINE ON STIMULATORY ACTIVITY OF GRAVES'IMMUNOGLOBULINS

The effects of ¹³¹I therapy on the activity of thyroid stimulating antibody (TSAb) and thyrotrophin binding inhibiting immunoglobulin (TBII) in nineteen patients with Graves’disease have been studied. Prior to ¹³¹I administration TSAb was detected in 84%, and TBII in 68% of patients. Following ¹³¹I administration TSAb and TBII were detectable in 100% of patients. The elevation 3 months after treatment of the means of both the TSAb and TBII indices for the group of nineteen patients was highly significant compared with pre treatment values. All the patients went into remission during the course of the study and the TSAb index declined in all patients, becoming undetectable in eleven; TBII also declined in most patients but remained detectable in thirteen. The study furthermore afforded the opportunity for a direct comparison of binding with stimulatory activity. These results show that after ¹³¹I therapy for Graves’hyperthyroidism there is a transient increase in TSAb as well as TBII, followed by a decline, and that the measurement of binding and stimulatory activities are in good general agreement.     

Immunological findings and thyroid function of untreated Graves' disease patients with undetectable TSH-binding inhibitor immunoglobulin

OBJECTIVE TSH-binding inhibitory immunoglobulin (TBII) is undetectable in about 10% of untreated Graves' disease patients, but the clinical characteristics and immunological significance of this finding are unknown. In this study we evaluated the clinical characteristics of TBII negative Graves' disease. PATIENTS We examined TBII in 1048 untreated patients at Kuma hospital from 1986 to 1990 and found 69 TBII undetectable patients (12 men and 57 women, mean age ± SEM 35 ± 2 years, group A). MEASUREMENTS We compared the clinical characteristics and immunological findings of group A with 57 untreated TBII detectable Graves' patients who were selected randomly (11 men and 46 women, mean age ±SEM 40 ±2 years, group B). T4, TSH, FT4, FT3, 1231 thyroid uptake, TBII, thyroid stimulating antibodies (TSAb) and the volume of the thyroid using ultrasonography were measured at the first visit. RESULTS Serum T4, FT4 and FT3 levels in group A were significantly lower than those in group B (P<0 001). The values of TSAb in group A were significantly lower than those in group B (593±67 (mean±SE) vs 2143±280%, respectively, P < 0001). The 1231 thyroid uptake in group A was significantly lower than that in group B (53 1 ±11 vs 61 -4±14%, respectively, P<0.01).The thyroid volume in group A was significantly smaller than that in group B (391 ±3 0 vs 51 3±3 3 ml, respectively, P<0 01). TSAb was undetectable in about 10% (6) of the TBII negative untreated Graves' patients at their first visit. CONCLUSION In the present study, untreated TBII negative patients with Graves' disease were characterized by mild elevation of thyroid hormones, mildly elevated ¹²³l uptake, weak TSAb activities and small goitres. The finding of both TBII and TSAb negative titres in untreated Graves' disease patients was also confirmed.     

Influence of compensated radioiodine therapy on thyroid volume and incidence of hypothyroidism in Graves' disease

Abstract. Objectives . To investigate the long-term effect of radioactive iodine (¹³¹I) on thyroid function and size in patients with Graves' disease. Setting . Out-patient clinic in Herlev Hospital. Subjects . One hundred and seventeen consecutive patients (104 women) with Graves' disease selected for ¹³¹I treatment and followed for a minimum of 12 months (range 1–10 years, median 5 years). Interventions . ¹³¹I dose was calculated based on thyroid volume and 24-h ¹³¹I uptake. Main outcome measures . Standard thyroid function variables and ultrasonically determined thyroid volume before treatment as well as 0.75, 1.5, 3, 6 and 12 months after treatment, and then once a year were investigated. Results . Seventy-eight patients were cured by one ¹³¹I dose and 30 by two doses, while the remaining nine patients received additional doses (range one to five doses, median one dose). Within one year, 25% developed hypothyroidism, and hereafter, hypothyroidism developed at a constant rate of 3% per year independent of antithyroid pretreatment. The cumulative 10-year risk of hypothyroidism was 60%. Initial median thyroid volume was 33 mL (range 9–106 mL). At 12 months after the last ¹³¹I dose, median thyroid volume was reduced to 14 mL (range 6–36 mL) (P < 0.00001). The median reduction being 58% (range 0–80%,), hereafter no further reduction occurred. A significant reduction in thyroid volume was also noted in patients needing subsequent ¹³¹I doses and in those developing hypothyroidism within the first year. Conclusions . ¹³¹I normalizes thyroid volume in patients with Graves' disease. Hypothyroidism seems an inevitable end result of this treatment. The present study suggests that it will be impossible to modify ¹³¹I therapy in a way to achieve both early control of hyperthyroidism and a low incidence of hypothyroidism.     

Metastatic thyroid cancer presenting as thyrotoxicosis: report of three cases

Three patients with metastatic thyroid follicular carcinoma developed thyrotoxicosis. Two had mild T3 toxicosis without detectable TSH binding inhibitor immunoglobulins (TBII) or thyroid stimulating antibodies (TSAb). Considerable concentration of ¹³¹***I by tumours occurred, although serum TSH was undetectable. The third patient developed thyrotoxicosis several months after treatment with ¹³¹I had commenced and this was associated with concurrent increase in both TBII (90%; normal, less than 11%) and TSAb (2100%). We conclude that thyrotoxicosis in patients with metastatic thyroid carcinoma may result from a large bulk of tumour functioning either autonomously or after stimulation by TSH receptor antibodies.     

Prediction of post-partum Graves' thyrotoxicosis by measurement of thyroid stimulating antibody in early pregnancy

OBJECTIVE Autoimmune thyroid diseases often occur after delivery. However, it has been difficult to predict who will develop Graves' thyrotoxicosis after delivery. We tried to establish a systematic method for predicting postpartum onset of Graves' thyrotoxicosis. DESIGN We followed up the pregnant women with antithyroid microsomal antibody (MCAb) from early pregnancy to the post-partum period and analysed the relation between the activities of thyroid stimulating antibodies (TSAb) in early pregnancy and post-partum occurrence of Graves' disease. PATIENTS Seventy-one women with positive MCAb in early pregnancy were studied. They were randomly selected from 262 MCAb-positive subjects found in 3405 consecutive early pregnant women who attended our maternity clinic during the last ten years. MEASUREMENTS MCAb was measured with a commercially available agglutination kit. For 71 MCAb-positive subjects, TSH-binding inhibitory immunoglobulin (TBII) and TSAb were measured in early pregnancy, and serially until 6 months after delivery for the subjects with either positive TBII or TSAb. Thyroid function and goitre size were recorded at every observation. RESULTS Among the 71 subjects, 7 showed positive TSAb in early pregnancy without any thyroid dysfunction; all 7 developed thyroid dysfunction in the post-partum period. Five of them (70% of TSAb-positive subjects) developed Graves' disease, two showing persistence and three transiently. None of 64 TSAb-negative subjects developed Graves' thyrotoxicosis, though 44 developed various types of thyroid dysfunction as a result of postpartum autoimmune thyroiditis. CONCLUSION The Individuals at high risk of post-partum onset of Graves' thyrotoxicosis can be found early in their pregnancy by the detection of TSAb. Overall occurrence of post-partum Graves' disease in the general population is estimated above 0–54%, that is, one in 200 post-partum women may develop Graves' thyrotoxicosis, although thyrotoxicosis may be transient in half of the patients.     

A study of untreated Graves' patients with undetectable TSH binding inhibitor immunoglobulins and the effect of anti-thyroid drugs

OBJECTIVE We previously reported the clinical characteristics of Graves' disease with undetectable TSH binding inhibitor immunoglobulins (TBII) at first visit, but a study of the prognosis of untreated TBII negative patients with anti-thyroid drug medication has never been undertaken. The aim of this paper is to study the difference between negative and positive TBll Graves' disease in relation to the effect of anti-thyroid drug treatment. PATIENTS From January 1986 to April 1991,1545 patients with untreated Graves' disease were referred to Kuma Hospital, Kobe, Japan. Of these, 94 TRAb negative patients were identified. Another 83 TRAb positive patients were randomly selected from the other Graves' disease patients and served as a comparison group. Fifty-six of the 94 patients in the TBII negative group and 52 of the 83 patients in the TBII positive group completed treatment with methimazole only. MEASUREMENTS The trial was conducted as a retrospective study with a maximum treatment period of 36 months and a follow-up period of a further 12 months. From the original pool of patients, we classified 56 TBII negative patients into two groups according to the clinical course taken; Group A in whom TBII remained undetectable throughout methimazole treatment (9 men and 34 women, age 37.2 ± 2.2 years), and Group B who became TBII positive (4 men and 9 women, 31.2 ± 44 years). Fifty-two TBII positive patients served as the comparison Group C (8 men and 44 women, age 38.1 ± 2.0 years). RESULTS Serum free T4 and free T3 levels in groups A and B were significantly lower before treatment than those of Group C (P < 0.001). The thyroid volumes of Group A and B patients were significantly smaller than those of Group C (P < 0.01). The level of TBII in Groups A and B was significantly lower than that in Group C (8.3 ± 0.7 and 8.8·1.1 vs 57.0 ± 28%, respectively, P < 0.001). The level of thyroid stimulating antibody (TSAb) in Groups A and B was significantly lower than that in Group C (478 ± 71.0 and 761 ± 140.3 vs 2143 ± 280%, respectively, P < 0.01), and there were no significant differences in TSAb activities between Groups A and B. The remission rates in Groups A, B and C were 77.4, 36.4 and 36.5%, respectively. These data Indicate that Group A has a good prognosis, but Group B has the same prognosis as Group C. CONCLUSION We conclude that patients In whom TSH binding inhibitor Immunoglobulins remained negative have a much better prognosis than TSH binding inhibitor immunoglobulins positive patients or those who become TSH binding inhibitor immunoglobulins positive, having been initially negative.     

Prediction of the Course of Graves' Disease after Medical Antithyroid Treatment

ABSTRACT The course of thyrotoxicosis in 33 patients with Graves' disease was evaluated clinically and biochemically (free thyroxine index, serum triiodothyronine, thyroid stimulating antibodies, (TSAb), thyroid stimulating hormone binding inhibiting immunoglobulins (TBII)). Relapse of the disease was found to be correlated to anamnestic information of thyrotoxicosis among first degree relatives (predictive value 90%) and to concomitantly raised levels of TSAb and TBII at the start of treatment (predictive value 71%). Mean duration of treatment of patients with long-lasting remission was 16.8 months. When comparing various information used to predict relapse of Graves' disease, anamnestic information of familial predisposition to thyrotoxicosis carries the highest predictive value.     

Development of postpartum spontaneously resolving transient Graves' hyperthyroidism followed immediately by transient hypothyroidism

A 25-year-old woman with a history of Graves' disease, in remission for 8.5 years following 6 months of methimazole therapy, first came to our attention 5 months after her first delivery with clinical and biochemical hypothyroidism, markedly elevated titre of anti-thyroid microsomal antibody (MCHA; 1:102400) and mildly elevated activity of thyrotropin-binding inhibitory immunoglobulins (TBII; 29.5%). After short-term (3 months) treatment with L-thyroxine therapy, the development of hyperthyroidism in the first trimester of the second pregnancy, which remitted through the second and third trimesters, was observed. TBII showed a peak value (93.1%) 1 month after the onset of hyperthyroidism, and a normal value (12.4%) 6 d after delivery. One month after the second delivery, the patient developed hyperthyroidism, with an elevation of 99mTc thyroid uptake (5.58%; normal range 0.5-2.5%), which was immediately followed by transient clinical and biochemical hypothyroidism. Concomitant increases in MCHA titre and TBII activity were observed after delivery, and both reached peak levels (1:409600 and 81.0%, respectively) one and a half months after the onset of hypothyroidism. Thyroid-stimulating antibody (TSAb), measured using FRTL-5 thyroid cells, was detected at a weakly positive level (161%) on initial examination, and the serial change in TSAb was almost identical to that in TBII. Patients with Graves' disease may develop Graves' type hyperthyroidism, followed immediately by transient hypothyroidism due to coexisting destructive autoimmune thyroiditis during the early postpartum period, despite increasing TSAb activity.     

The occurrence of thyrotropin binding-inhibiting immunoglobulins and thyroid-stimulating antibodies in patients with silent thyroiditis

Silent (painless) thyroiditis has been recognized as a clinical entity for over a decade and is characterized by spontaneously resolving thyrotoxicosis. Its etiology is uncertain; however, a few reports have indicated the occurrence of TSH binding-inhibiting immunoglobulins (TBII) and thyroid-stimulating antibodies (TSAb) in some of the patients. The present study was undertaken to evaluate thyroid function and the occurrence of TBII and TSAb and thyroid autoantibodies (antithyroglobulin and antimicrosomal) in 53 patients with silent thyroiditis during the course of their disease. The patients were divided into 2 major groups: I) those who developed transient hypothyroidism and II) those who did not. All patients initially had significantly increased concentrations of serum T4, free T4, and free T3, suppressed TSH levels, and decreased thyroid radioiodine uptake. TBII and TSAb were initially positive in 8 (15.1%) and 10 patients (18.9%), respectively. Forty patients were available for follow-up. TBII was positive in 6 of 24 (25.0%), and TSAb was positive in 8 of 24 (33.3%) of the patients who developed transient hypothyroidism during the course of their disease. Among the patients who did not become hypothyroid at any time, TBII was positive in only 2 of 16 (12.5%), and none of the patients became TSAb positive. The findings indicate that increased TSAb and TBII activity may be detected in patients with silent thyroiditis and, when present, are associated with transient hypothyroidism during the course of the disease.     

Measurement of TSH receptor blocking immunoglobulins using 3H-adenine incorporation into FRTL-5 and JPO9 cells: use in a child with neonatal hypothyroidism

OBJECTIVE The aim of this study was to develop an assay for the measurement of thyroid blocking antibodies (TBAb), based on the ability of patient serum to inhibit TSH stimulated ³H-cAMP production following incubation of FRTL-5 or JPOS cells with ³H-adenine. The assay was then used to evaluate a child born with neonatal hypothyroidism. DESIGN The levels of TBAb, TSAb (thyroid stimulating antibodies), TBII (TSH binding Inhibitory antibodies), and the thyroid antibodies anti-thyroid peroxidase and thymoglobulin antibodies were measured in both mother and child over a 6-month post-natal period. PATIENT The assay for TBAb was used to evaluate a child born with neonatal hypothyroidism whose mother had a history of hypothyroidism due to Haehimoto's thyrolditis. A ^99mTc pertechnetate scan showed no evidence of functioning thyroid tissue. At 20 months of age an ultrasound verified a normally positioned thyroid. RESULTS Initially, high levels of TBII and antithyroid antibodies were present in the serum of both mother and child. In both, the levels of TSAb were undetectable but there were significant levels of TBAb. The levels of TBAb decreased to control levels in the child within 2 months of birth but remained elevated in the mother's serum. CONCLUSIONS This case of neonatal hypothyroidism associated with the passage of thyroid blocking antibodies demonstrates the utility of this new assay in the differential diagnosis of neonatal hypothyroidism.     

THE EFFECT OF SUBTOTAL THYROIDECTOMY WITH PROPRANOLOL PREPARATION ON ANTIBODY ACTIVITY IN GRAVES' DISEASE

The effect of subtotal thyroidectomy on thyroid stimulating antibodies (TSAb), thyrotrophin binding inhibitory immunoglobulins (TBII) and antimicrosomal antibodies (MsAb) was studied in 26 patients with Graves' hyperthyroidism treated pre-operatively with propranolol, but without antithyroid drugs. Following surgery, two patients relapsed in the first year and eight patients became hypothyroid. Eighteen patients (69%) had detectable TSAb at entry and no significant change in titre was seen during propranolol therapy. Following surgery TSAb levels fell within 24 h in eight patients, and at 6 weeks only seven patients had detectable TSAb. TSAb were still detectable in seven patients at 6 months. TSAb activity did not predict the late relapses. TBII were present in 13 patients (50%) before surgery and titres remained unchanged in all but two patients during the immediate postoperative period. At 6 weeks TBII had disappeared from the serum of only three patients. During the early postoperative period TBII became transiently detectable in five of the 13 patients initially TBII negative. The two patients who subsequently relapsed remained TBII positive throughout. Microsomal antibodies were present in the sera of 22 patients (85%). Surgery was followed by a decline in titre, which was substantial in only six of 13 patients studied in detail. Thus, in 92% patients hyperthyroidism was successfully eradicated. Propranolol treatment had no effect on antibody activity. TSAb and TBII disappeared from the circulation in 61 % and 46% patients, respectively. These data are compatible with the concept that lymphocytes within the thyroid are the major site of TSAb production but other important sites for synthesis of thyroidal autoantibodies probably exist. Although outcome from surgery could not be accurately predicted from TSAb or TBII status either pre- or post-operatively, the two patients who relapsed had the most severe disturbances of thyroid autoimmunity; all patients in whom initially detectable TSAb or TBII disappeared remained in remission.     

Characterization of thyroid-stimulating blocking antibodies that appeared during transient hypothyroidism after radioactive iodine therapy.

Hypothyroidism after radioactive iodine (RAI) therapy for Graves' disease can be transient or permanent. The cause for early transient hypothyroidism is unknown. We evaluated 11 patients who developed transient hypothyroidism within 6 months of RAI and 12 who remained euthyroid after RAI. Approximately equal numbers of patients in each group had thyroid-stimulating antibody (TSAb) that increased cyclic adenosine monophosphate (cAMP) levels in Chinese hamster ovary (CHO) cells transfected with the recombinant human thyrotropin receptor (TSHR) (WT cells). Approximately equal numbers of patients from both groups had an increase in TSAb activity post-RAI. All TSAbs had their dominant functional epitope on the N-terminus of the TSHR extracellular domain, requiring residues 90-165 for activity because they, but not TSH, completely lost stimulating activity in a receptor chimera, wherein TSHR residues 90-165 were substituted by equivalent residues of the lutropin/choriogonadotropin receptor (LH/CGR). Although equal numbers of patients in both groups had thyrotropin-binding inhibiting immunoglobulin activity (TBII), as measured by radioreceptor assay before RAI, patients with transient hypothyroidism had a surge in TBII activity and all except one became positive for thyroid-stimulating blocking antibodies (TSBAb), as measured by inhibition of TSH-stimulated cAMP from WT cells. When immunoglobulin G (IgGs) were epitope-mapped using TSHR/LH-CGR chimeras with different substitutions, 8 hypothyroid subjects had TSBAbs directed against residues 90-165 of the TSHR, as well as TSHR residues 261-370. Two had functional epitopes directed at residues 9-89 as well as TSHR residues 261-370. None of the euthyroid control patients developed TSBAbs and their TBII activity decreased post-RAI. When patients with transient hypothyroidism reverted to a euthyroid state, TSAb was still detectable in 5; however, TBII was present in all and TSBAb, although decreased, was still positive in 9. In summary, RAI therapy was associated with a change in thyroid antibody characteristics in most patients. Additionally, patients with a surge in TBII and the appearance of TSBAb developed transient hypothyroidism after RAI.     

THYROID STIMULATING ANTIBODIES (TSAb) IN PATIENTS WITH GRAVES' DISEASE UNDERGOING ANTITHYROID DRUG TREATMENT: INDICATORS OF ACTIVITY OF DISEASE

Thyroid-stimulating antibodies (TSAb) were studied in patients with Graves' disease using a method based on cAMP production in isolated human thyroid membranes. Stimulation was detected in forty-one (82%) of fifty patients with untreated Graves' disease. In these subjects, the TSAb levels were correlated with the thyroid hormone levels. Among twenty patients treated for 1–2 months with carbimazole, 16 (80%) had positive TSAb. During prolonged treatment TSAb gradually diminished and finally normalized. In fifteen patients, it was possible to compare TSAb levels after cessation of previous medical therapy with TSAb levels at relapse. In nine of these patients, an increase of the TSAb level within the normal range at the time of relapse was found, in four the litres were positive. The results indicate that positive TSAb litres are markers of active Graves' disease and suggest that in such patients antithyroid therapy should be continued. A normal TSAb titre after anti-thyroid therapy does not exclude the possibility of relapse.     

Graves' hyperthyroidism showing transient hypothyroidism during interferon therapy for chronic hepatitis type C

We report a patient with Graves' disease in whom thyroid function was changed from initial hyperthyroidism to transient hypothyroidism and back to hyperthyroidism during interferon (IFN) therapy. A 43-year-old man was admitted to our hospital to receive IFN treatment for chronic active hepatitis (type C) in June 1998. His thyroid function was normal and testing for thyroid gland antibodies (TSH binding inhibitor immunoglobulins; TBII, anti-thyroglobulin antibodies; TgAb and anti-thyroid peroxidase antibodies; TPOAb) was negative before IFN therapy. The patient had neither history of thyroid disease nor any particular family history. He developed hyperthyroidism four months after its initiation of IFN therapy. When he was hyperthyroid, TBII, the activity of thyroid-stimulating antibodies (TSAb) and thyroid stimulation-blocking antibodies (TSBAb) were 40.2% (normal range, -15 approximately +15.0%), 1201% (normal range, 相似文献   

The role of thyroid stimulating antibody (TSAb) in the thyroid function of patients with post-partum hypothyroidism

OBJECTIVE: We investigated the association between thyroid function and the biological activities of thyroid stimulating antibodies (TSAb) and thyroid stimulation blocking antibodies (TSBAb) in patients with post-partum hypothyroidism. DESIGN: A prospective study. PATIENTS: We studied 25 patients with post-partum hypothyroidism who visited our thyroid clinic during the period from 1985 to 1990. MEASUREMENTS: We measured TSH binding inhibitory immunoglobulin (TBII) and TSAb activity at the initial presentation of each of the 25 patients. Women found to have elevated TSAb activity were followed up. Upon finding negative TSAb activity along with positive TBII activity in the serum at the initial presentation, we measured TSBAb activity. Women found to have elevated levels of TSBAb at the initial presentation were also followed up. RESULTS: Elevated TBII activity was found in six of the 25 patients, as was high TSAb activity (205-2651%, normal 55.0-145.0%) in five of these six and in one other patient at the initial presentation. Markedly elevated TSBAb activity (89%) was found in one TBII positive patient. We were able to follow up serially five TSAb positive patients and the TSBAb positive patient over periods ranging from 11.5 to 26.5 months post-partum. The maximal value of TSAb activity was observed at the initial presentation in all TSAb positive patients, following which the activities gradually decreased. One of these patients developed Graves' hyperthyroidism associated with high TSAb activity (1223%) at 10.5 months post-partum. One of the other patients was restored to euthyroid with elevated TSAb activity (279%), but thereafter developed hypothyroidism in conjunction with the disappearance of TSAb activity at 26.5 months post-partum. In the other two patients, normalization of thyroid function was observed with elevated TSAb activity. Thereafter, thyroid function remained within the normal range even with the disappearance of TSAb activity. In the other patient, normalization of thyroid function was observed at 11.5 months post-partum, 3 months after the disappearance of TSAb activity. In the TSBAb positive patient, TSBAb activity decreased to 21% by 17.5 months post-partum associated with normalization of thyroid function. CONCLUSION: The present study demonstrates the presence of elevated levels of TSAb activity in some patients with post-partum hypothyroidism. In these patients, Graves' hyperthyroidism may be induced by TSAb activity, and hypothyroidism may reoccur with the disappearance of the TSAb activity. Furthermore, post-partum hypothyroidism may be due to increased TSBAb activity in some patients.     

Appearance of thyroid stimulating antibody and Graves' disease after radioiodine therapy for toxic nodular goitre

A patient with toxic nodular goitre is described in whom radioiodine (¹³¹I) therapy paradoxically induced typical Graves' disease. This patient had a goitre with two autonomously functioning nodules suppressing uptake by the remainder of the gland. Circulating thyroid peroxidase antibody indicated the coexistence of focal lymphocytic thyroiditis. Radioiodine therapy was followed by the development of severe and persistent Graves' hyperthyroidism associated with diffuse ¹³¹I uptake by the gland. A second administration of ¹³¹I produced a further worsening of hyperthyroidism, and the appearance of ophthalmopathy. TSH-receptor antibody and thyroid stimulating antibody were undetectable before ¹³¹I, appeared after the first administration of radioiodine, and showed a further increase after the second dose of ¹³¹I. We suggest that, in a patient genetically susceptible to thyroid autoimmunity, the release of TSH-receptor antigenic components from follicular cells damaged by radioiodine therapy triggered an autoimmune response to the TSH-receptor, thus turning a toxic nodular goitre into Graves' disease.     

Improvement of infiltrative ophthalmopathy in parallel with decrease of thyroid-stimulating antibody (TSAb) activity in two patients with hypothyroid Graves' disease

Two patients with primary hypothyroidism associated with infiltrative ophthalmopathy without previous history of hyperthyroidism are presented. Anti-TSH receptor antibodies (TRAb) were detected by radioreceptor assay (TBII), and unexpectedly their biological activity was not of a blocking (TSBAb), but of a thyroid-stimulating type (TSAb). After the initiation of levothyroxine therapy, the TBII and TSAb activities both decreased gradually with normalization of the elevated TSH level. The inflammatory eye signs improved strikingly in parallel with decrease of these antibody activities. These data indicate that (1) TRAb in primary hypothyroidism do not always show TSAb activity, (2) the decrease in TRAb following levothyroxine therapy in these patients appeared to correlate with suppression of TSH, (3) changes in infiltrative ophthalmopathy were associated with that of TSAb even in primary hypothyroidism, and (4) the hypothyroidism in these patients is justifiably diagnosed as "hypothyroid Graves' disease". TSAb might be somewhat related to the pathogenesis of ophthalmopathy in autoimmune thyroid diseases.     

The mechanism of spontaneous hypothyroidism in patients with Graves' disease after antithyroid drug treatment

The natural course of Graves' disease results in hypothyroidism in up to 20% of patients previously treated with antithyroid drugs. The precise mechanisms are not known, although autoimmune destruction of thyroid tissue has been proposed. We studied sequentially obtained serum samples from three patients with hyperthyroid Graves' disease previously treated with an antithyroid drug who became hypothyroid to determine possible causes of their hypothyroidism. Antithyroglobulin and antithyroid microsomal autoantibodies, TSH binding inhibitory immunoglobulin (TBII), thyroid-stimulating antibody (TSAb), and thyroid stimulation-blocking activity were measured. Autoantibodies were markedly elevated throughout the clinical course in all three patients. Patient 1 had no TBII and blocking activity and extremely high TSAb when she was euthyroid as well as hypothyroid. Hypothyroidism was probably the result of autoimmune thyroid destruction. In patient 2, TSAb disappeared, and TBII and blocking activity increased markedly when she developed hypothyroidism, which thus appeared to result from blocking antibodies. Patient 3 had intermittent periods of hyper- and hypothyroidism before becoming and remaining euthyroid. While initially hypothyroid, TBII was weakly positive, and TSAb was strongly positive; subsequently, when hyperthyroidism recurred, TBII and TSAb were strongly positive. Hypothyroidism appeared to result from focal autoimmune thyroiditis. Patients with hyperthyroid Graves' disease may develop hypothyroidism later by different means. Autoimmune thyroiditis, diffuse or focal, with thyroid destruction is one mechanism. The appearance of antibodies that block TSH stimulation may be another.