Establishment of reference values for endocrine tests--part V: acromegaly.

BACKGROUND: Plasma insulin-like growth factor 1 (IGF-1) and the response of growth hormone (GH) to oral glucose are frequently used in the evaluation of patients suspected of acromegaly. Because of the implementation of new assay methodology for GH and IGF-1, we have established the reference values for these tests, as well as for urinary GH excretion. METHODS: From the general population, 50 subjects were recruited, equally distributed according to sex and age between 20 and 70 years. Two consecutive 24-hour urine samples were collected to determine urinary GH. Plasma IGF-1 was measured as well as the GH response during an oral glucose tolerance test (OGTT) with 100 g glucose. Basal plasma IGF-1 was also measured in 250 subjects recruited likewise from the general population who had participated in previous studies on reference values. RESULTS: The following reference ranges were established: urinary GH < 5-46 microU/24 h; nadir GH after OGTT < or =1.5 mU/l for males and < or =2.0 mU/l for females. IGF-1 was divided into age groups: 20-30 years 8-61 nmol/l; 31-40 years 8-41 nmol/; 41-50 years 7-36 nmol/l; 51-60 years 5-37 nmol/l; and 61-70 years 7-27 nmol/l. CONCLUSION: We have established reference values with state-of-the-art assay methodology for the diagnostic tests frequently used in the evaluation of patients suspected of acromegaly.

A questionnaire survey on the management of Graves' orbitopathy in Europe.

OBJECTIVE: To determine management patterns among clinicians who treat patients with Graves' orbitopathy (GO) in Europe. DESIGN AND METHODS: Questionnaire survey including a case scenario of members of professional organisations representing endocrinologists, ophthalmologists and nuclear medicine physicians. RESULTS: A multidisciplinary approach to manage GO was valued by 96.3% of responders, although 31.5% did not participate or refer to a multidisciplinary team and 21.5% of patients with GO treated by responders were not managed in a multidisciplinary setting. Access to surgery for sight-threatening GO was available only within weeks or months according to 59.5% of responders. Reluctance to refer urgently to an ophthalmologist was noted by 32.7% of responders despite the presence of suspected optic neuropathy. The use of steroids was not influenced by the age of the patient, but fewer responders chose to use steroids in a diabetic patient (72.1 vs 90.5%, P<0.001). Development of cushingoid features resulted in a reduction in steroid use (90.5 vs 36.5%, P<0.001) and increase in the use of orbital irradiation (from 23.8% to 40.4%, P<0.05) and surgical decompression (from 20.9 to 52.9%, P<0.001). More ophthalmologists chose surgical decompression for patients with threatened vision due to optic neuropathy, who were intolerant to steroids than other specialists (70.3 vs 41.8%, P<0.01). CONCLUSION: Deficiencies in the management of patients with GO in Europe were identified by this survey. Further training of clinicians, easier access of patients to specialist multidisciplinary centres and the publication of practice guidelines may help improve the management of this condition in Europe.

A reduced IL2R (CD25) expression level in first and second degree female relatives of autoimmune thyroid disease patients. A sign of a poor capability to preserve tolerance?

There is room for immune markers other than TPO-Abs to identify an increased risk to develop autoimmune thyroid disease (AITD). Our aim was to test the hypothesis that activation of CD4+ T cells is such marker in relatives of AITD patients, who have an increased risk to develop AITD. We established a controlled study on 20 TPO-Ab positive and 20 TPO-Ab negative euthyroid female relatives. All these cases had at least one 1st or 2nd degree relative with a documented autoimmune hyper- or hypothyroidism in whom we studied the percentages of circulating subsets of activated (MHC class-II, CD25 (IL-2R), CD71 or CD69+) CD4+ T cells and the level of the soluble (s)-IL2R in serum. We found that euthyroid female relatives did not show an activation of their T cell system, but a reduced expression of CD25 on CD4+ T cells. The level of the shed IL2R in serum was also lower in comparison with levels found in healthy control females. A reduced T cell activity was found in both TPO-Ab positive and negative relatives. In conclusion, female relatives with at least one 1st or 2nd degree relative with an AITD show signs of a reduced expansion capability of their T cell pool. It is hypothesized that this reduced expansion capability may affect T cell tolerance mechanisms more than T effector mechanisms.

Evaluation of endocrine tests. B: screening for hypercortisolism.

BACKGROUND: While reference values for 24-hour free urinary cortisol excretion and the overnight 1 mg dexa-methasone-suppression test in the healthy population are available, cut-off values in patients clinically suspected of Cushing's syndrome have to be established. METHODS: This was a prospective follow-up study in one academic centre of 144 patients with clinical suspicion of Cushing's syndrome (group A) and 50 patients with adrenal incidentaloma (group B) who were referred for putative hypercortisolism between 1 January 1993 and 1 January 2003. The 24-hour urinary free cortisol and post-dexamethasone plasma cortisol were measured. Accurate diagnosis of (absence of) Cushing's syndrome was confirmed by histopathological data and long-term follow-up. Based on the data obtained in group A, sensitivity, specificity and receiver operating characteristic (ROC) curves were calculated. RESULTS: Complete follow-up was obtained in 86%, and partial follow-up was obtained in 8% of patients. Median follow-up was 36 (1 to 122) months. In group A, 17 patients were found to have Cushing's syndrome. In this group median 24-hour urinary free cortisol was 77 (<5 to 51458) mmol/24 hours and median post-dexamethasone plasma cortisol was <50 (<50 to 4900) nmol/l. Area under the ROC curve was 0.958 for 24-hour urinary free cortisol and 0.985 for post-dexamethasone plasma cortisol. Optimal cut-off values were 180 nmol/24 hours (sensitivity 94%, specificity 94%) and 95 nmol/l (sensitivity 100%, specificity 94%) respectively. CONCLUSION: We established cut-off values for 24-hour free urinary cortisol excretion (180 nmol/24 hours) and for post-dexamethasone plasma cortisol (95 nmol/l) in the evaluation of patients referred for hypercortisolism.

Surgical or medical decompression as a first-line treatment of optic neuropathy in Graves' ophthalmopathy? A randomized controlled trial.

OBJECTIVE: Only a small percentage of Graves' ophthalmopathy (GO) patients develop optic neuropathy with impending loss of visual acuity. Therapy with methylprednisolone pulses is the treatment of first choice in severe and active GO patients. When the effect is insufficient, patients are usually treated with surgical decompression. We investigated whether surgery could become the first-line treatment, thus preventing treatment with steroids. DESIGN AND SUBJECTS: We performed a randomized trial in 15 patients with very active GO and optic neuropathy. Six patients were treated with surgical decompression, and nine with methylprednisolone i.v. pulses for 2 weeks, followed by oral prednisone for 4 months. The primary outcome was determined by changes in visual acuity. If the eye disease deteriorated despite treatment or did not improve sufficiently, patients were switched to the other treatment arm. RESULTS: The severity and activity of GO in both groups were similar at baseline. The Clinical Activity Score (CAS) was 6.3+/- 0.8 in the surgical group vs. 6.0+/- 0.5 in the steroids group and the Total Eye Score was 24+/- 6 vs. 25+/- 6. In the surgery group, 5/6 patients (82%) did not respond because of insufficient improvement in vision (n=3) or persistent chemosis (n=2), and all needed further immunosuppression. In the steroids group, 4/9 patients (45%) did not improve in visual acuity (P=0.132 vs. surgery group), and these needed decompressive surgery. All patients in whom therapy failed were switched to the other treatment arm and visual acuity improved in almost all patients. Visual acuity improved from 0.36 (0.02--0.40) to 0.90 (0.63--1.0) in the surgery group and from 0.50 (0.32--0.63) to 0.75 (0.32--1.0) in the steroids group at 52 weeks. At long-term follow-up in the surgery group 3/6 patients required squint surgery and 5/9 patients in the steroids group. Eyelid surgery was performed in 5/6 patients in the surgery group and in 4/9 patients in the steroids group. CONCLUSION: Immediate surgery does not result in a better outcome and therefore methylprednisolone pulse therapy appears to be the first-choice therapy.

Functional thyrotropin receptor expression in the pituitary folliculo-stellate cell line TtT/GF.

Thyrotropin secretion from the anterior pituitary is regulated mainly through TRH and thyroid hormones. Recent findings of a TSH receptor (TSHR) on folliculo-stellate (FS) cells in the human anterior pituitary indicate that TSH secretion might, in addition, be regulated in a paracrine manner via FS cells. In order to elucidate the physiological relevance of TSHR expression in FS cells we evaluated the effects of TSH on a murine FS cell line, TtT/GF. First, Western blot analysis confirmed the expression of TSHR protein in these cells. Second, three potential second messenger pathways were studied. Last, cDNA array hybridization was used to evaluate the effect of TSH on gene expression levels. TSH failed to induce either the adenylate cyclase/cAMP pathway, the phosphatidylinositol/calcium pathway, or the Janus kinase (JAK)/signal transducer and activator of transcription (STAT) 3 pathway. Most of the genes regulated by TSH were related to cell proliferation, cell differentiation, and apoptosis. Moreover, TSH induced STAT5a and TGFbeta2 expression. We report that TtT/GF cells express a functional TSHR that is not coupled to cAMP nor IP (3) but probably signals through the JAK/STAT5a pathway. Functional TSHR expression in this cell line offers an in vitro model to study the role of TSHR in FS cells.

Measuring disease activity to predict therapeutic outcome in Graves' ophthalmopathy.

OBJECTIVE: The concept of disease activity in Graves' ophthalmopathy (GO) might explain why as many as one-third of patients do not respond to immunosuppressive treatment, because only patients in the active stage of disease are expected to respond. The hypothesis was adopted that a parameter used to measure disease activity should be able to predict a response to immunosuppressive treatment. The aim of this study was to develop a multivariate prediction model in which all previous tested activity parameters are integrated. DESIGN AND PATIENTS: We included 66 consecutive patients with untreated moderately severe GO who had been euthyroid for at least 2 months. All patients were treated with radiotherapy. Measurements Treatment efficacy after 6 months follow-up was used as the primary outcome measure. Disease severity and 15 different disease activity parameters were assessed before treatment. Univariate and multivariate logistic regression models were used to predict response (model 1) or no change (model 2). RESULTS: In multivariate analyses, we found that duration of GO, soft tissue involvement, elevation, soluble interleukin-2 receptor (sIL-2R), soluble CD30 (sCD30), eye muscle reflectivity and octreotide uptake ratio were significant predictors of a response to radiotherapy. Gender, duration of GO, soft tissue involvement, eye muscle reflectivity, IL-6 and urinary glycosaminoglycan (GAG) excretion were significant predictors of no change upon radiotherapy. Prognostic score charts were developed for use in clinical practice to calculate the probability of response (model 1) and the probability of no change (model 2) for each new patient. Finally we used a combination of both models to define a recommended treatment modality for each individual patient, based on both the predicted probabilities of response and no change. We were able to identify the correct treatment (based on a comparison with the observed response) in 89% of the patients. CONCLUSIONS: Although we strongly recommend that our results should be confirmed in other studies, our findings are the first evidence for the idea that disease (in)activity should determine which kind of treatment should be used.

Establishment of reference values for endocrine tests. Part IV: Adrenal insufficiency.

BACKGROUND: The short Synacthen test, the overnight metyrapone test and the insulin tolerance test are frequently used in the evaluation of patients suspected of adrenal insufficiency. in the present study, we established reference values for these diagnostic tests, as well as for baseline morning plasma cortisol and adrenocorticotrophic hormone (ACTH). METHODS: We studied 50 subjects recruited from the general population, equally distributed according to sex and age between 20 and 69 years. A short ACTH stimulation test (250 microg Synacthen iv), an overnight metyrapone test (2.0, 2.5, or 3.0 g given orally depending on body weight at 23.30 hours) and an insulin tolerance test (0.15 U/kg actrapid iv) were performed. Reference intervals are given as the means +/- 2SD of observed hormone concentrations after logarithmic transformation. RESULTS: The following reference values were established: 09.00 hr plasma cortisol 150 to 802 nmol/l, 09.00 hr plasma ACTH 8 to 93 ng/l, peak plasma cortisol after Synacthen 591 to 1,113 nmol/l, peak plasma cortisol after insulin-induced hypoglycaemia 557 to 1,015 nmol/l, and plasma 11-deoxycortisol after metyrapone 197 to 759 nmol/l. CONCLUSION: We established reference values for diagnostic tests that are useful in the evaluation of patients suspected of primary or secondary/tertiary adrenal insufficiency.

Expression of adenohypophyseal-hormone receptors in a murine folliculo-stellate cell line.

Adenohypophyseal-hormone production is regulated by hypothalamic peptides and target-gland hormones. Additionally, paracrine regulation by folliculo-stellate cells within the pituitary has been suggested. We recently showed TSH receptor expression in human folliculo-stellate cells and speculated that receptors for other adenohypophyseal hormones might also be expressed by folliculo-stellate cells. Using RT-PCR, we evaluated the expression of receptors for TSH, GH, ACTH, LH, FSH and PRL in a murine folliculo-stellate cell line, TtT/GF. Transcripts of TSH receptor, GH receptor and ACTH receptor were detected in this cell line. LH receptor, FSH receptor and PRL receptor expression, however, could not be demonstrated. We conclude that the TtT/GF cells express some, but not all, receptors for anterior pituitary hormones. This indicates that folliculo-stellate cells might act as mediators in the paracrine regulation of at least some of the hormones secreted by the anterior pituitary.

[Subclinical hypothyroidism; the start of a clinical trial into the usefulness of treatment with radioactive iodine]. / Subklinische hyperthyreoïdie; start van klinische trial naar het nut van behandeling met radioactief jood.

Subclinical hyperthyroidism is defined as the presence of serum free thyroxine (T4) and triiodothyronine (T3) levels within the reference range and a reduced serum thyrotrophin (TSH) level. Evidence is accumulating that it has important clinical effects. Randomised clinical trials are needed to answer the question whether or not treatment of subclinical hyperthyroidism prevents cardiac problems, especially atrial fibrillation, and preserves bone mineral density. A randomised, Dutch multicentre trial has recently been started. Its goal is to study whether radioiodine treatment prevents the development of atrial fibrillation and prevents decreases in bone mineral density.

Effects of Graves' ophthalmopathy on quality of life.

General health-related quality of life is markedly impaired in patients with Graves' ophthalmopathy (GO), and even worse than in patients with other chronic conditions like diabetes, emphysema or heart failure. A disease-specific quality-of-life questionnaire for GO has been developed, the so-called GO-QOL, consisting of two subscales: one for visual functioning (8 questions referring to limitations due to decreased visual acuity and/or diplopia) and one for appearance (8 questions referring to limitations in psychosocial functioning due to changes in appearance). The GO-QOL was found to be a valid and reliable instrument. A minimal clinically important difference (MCID) in the GO-QOL score was derived from data obtained before and after specific eye treatments. Based on the patient's opinions, changes of > or = 6 points (minor surgery) or > or = 10 points (surgical decompression, immunosuppression) are recommended as MCID. It is concluded that the GO-QOL is an useful instrument for measuring changes over time in visual functioning and appearance of GO patients. The GO-QOL is available in six languages, and can be used as a separate outcome measure in clinical studies.

Serum IL-18 levels are not increased in patients with untreated Graves' ophthalmopathy.

OBJECTIVE: Cytokines play an important role in autoimmune thyroid diseases, and serum levels may reflect the activity of the immune process. This is particularly interesting in Graves' ophthalmopathy, where a reliable serum activity marker is warranted. Interleukin-18 (IL-18) is a potent Th1 cytokine, known to induce interferon (IFN)-gamma and the aim of this study was to evaluate serum IL-18 levels in Graves' ophthalmopathy. METHODS: Serum IL-18 was measured by ELISA in 52 patients with untreated Graves' ophthalmopathy (who all had been rendered euthyroid with antithyroid drugs), 52 healthy controls matched for sex, age, and smoking habits, and 15 euthyroid patients who had been treated for Graves' hyperthyroidism and ophthalmopathy in the past. RESULTS: Serum IL-18 (median values in pg/ml with range) levels did not differ between the untreated Graves' ophthalmopathy patients-226 (61-704) pg/ml, matched healthy controls-194 (17-802) pg/ml, and Graves' ophthalmopathy patients treated in the past-146 (0-608) pg/ml. No correlation was observed between serum IL-18 levels and thyroid function or antithyroid antibodies. There was no correlation between serum IL-18 levels and smoking habits. CONCLUSION: We conclude that Graves' ophthalmopathy does not affect serum IL-18.

On assessing responsiveness of health-related quality of life instruments: guidelines for instrument evaluation.

A lack of clarity exists about the definition and adequate approach for evaluating responsiveness. An overview is presented of different categories of definitions and methods used for calculating responsiveness identified through a literature search. Twenty-five definitions and 31 measures were found. When applied to a general and a disease-specific quality of life questionnaire large variation in results was observed, partly explained by different goals of existing methods. Four major issues are considered to claim the usefulness of an evaluative health-related quality of life (HRQL) instrument. Their relation with responsiveness is discussed. The confusion about responsiveness arises mostly from a lack of distinction between cross-sectional and longitudinal validity and from a lack of distinction between responsiveness defined as the effect of treatment and responsiveness defined as the correlation of changes in the instrument with changes in other measures. All measures of what is currently called responsiveness can be looked at as measures of longitudinal validity or as measures of treatment effect. The latter ones tell us little about how well the instrument serves its purpose and are only of use in interpreting score changes. We therefore argue that the concept of responsiveness can be rejected as a separate measurement property of an evaluative instrument.

Establishment of reference values for endocrine tests. III: Primary aldosteronism.

BACKGROUND: In our laboratory well-defined reference values for the screening test and confirmation test used in the diagnosis of primary aldosteronism were lacking. In this study we established the reference-values of the plasma aldosterone concentration (PA), plasma renin activity (PRA) and PA/PRA ratio after a two-hour upright period, and of the urinary aldosterone excretion after oral sodium loading. METHODS: Fifty healthy volunteers, equally distributed according to sex and aged between 20 and 70 years, went through the screening and confirmation test of primary aldosteronism. PA, PRA and the PA/PRA ratios were measured after a two-hour upright period (screening test). Urinary aldosterone excretion was determined in two 24-hour urine samples after an oral suppletion of 6 g NaCl a day for five days (confirmation test). RESULTS: The following reference values were established: PA (after two-hour upright position) <0.03-1.05 nmol/l (mean: 0.47), PA/PRA ratio 0.05-0.47 (mean: 0.15) and urinary aldosterone excretion after sodium loading <3.0-47.0 nmol/24h (mean: 10.5). PRA showed a significant decrease with advancing age: median values in the 3rd to 7th decade are 3.9, 3.5, 2.5, 1.6 and 2.1 ng A1/ml/h respectively (p=0.04). PA was lower in subjects > or = 50 years old. Age did not affect the PA/PRA ratio or the urinary aldosterone excretion. There were no significant differences between the sexes in any of the above-mentioned parameters. CONCLUSION: In this study we established reference values for the screening and confirmation test used in the diagnosis of primary aldosteronism.

Evaluation of endocrine tests. A: the TRH test in patients with hyperprolactinaemia.

BACKGROUND: In a previous study, we determined reference values for basal and thyrotropin-releasing hormone (TRH)-stimulated plasma concentrations of prolactin (PRL). The aim of the present study was to determine the clinical usefulness of the PRL response to TRH in the work-up of patients with hyperprolactinaemia. METHODS: We studied 92 consecutive patients referred for evaluation of hyperprolactinaemia. Patients with confirmed hyperprolactinaemia were divided into three groups: group A (pharmacological hyperprolactinaemia; n=2), group B (pathological hyperprolactinaemia; n=6) and group C (all other patients). Patients in group C underwent MRI of the pituitary and were subdivided into C1 (normal pituitary on MRI; n=6), C2 (slightly abnormal MRI; n=21), and C3 (evident microadenoma or macroadenoma on MRI; n=25 and 12, respectively). The MRI was technically insufficient in four patients. Basal PRL as determined by fluoroimmunometric assay and the PRL response to 400 microg TRH were determined in all patients. RESULTS: Hyperprolactinaemia was confirmed in 83% of the referred patients. Non-response, defined as a <2.5-fold PRL increase after TRH, occurred in one patient (50%) in group A, in 66% of patients in group B and in 99% of patients in group C. Within group C, basal PRL was not different between group C1 and C2, but higher (p=0.06) in group C3. The absolute PRL increase after TRH did not differ between the three subgroups. The relative PRL increase was smaller (p=0.03) in group C3 but overlapped considerably with groups C1 and C2. All patients except one in group C were so-called non-responders. Basal PRL and absolute PRL increases after TRH correlated with the adenoma diameter on MRI (r=0.66, p=0.0002 and r=0.49, p=0.008, respectively). CONCLUSION: In patients referred for elevated serum PRL, hyperprolactinaemia should be confirmed under standardised conditions. The absolute or relative PRL increase after 400 microg TRH does not help to differentiate between patients with prolactinoma or idiopathic hyperprolactinaemia. Therefore, the TRH stimulation test is not useful in the work-up of hyperprolactinaemia.

Increased prevalence of antibodies to enteropathogenic Yersinia enterocolitica virulence proteins in relatives of patients with autoimmune thyroid disease.

Infections have been implicated in the pathogenesis of a number of autoimmune diseases, and Yersinia enterocolitica (YE) might play a role in the development of autoimmune thyroid disease (AITD). Clinical evidence in support of this hypothesis has been inconclusive. We reasoned that looking earlier in the natural course of AITD might enhance chances of finding evidence for YE infection. Consequently, we determined seroreactivity against YE in subjects at risk of developing AITD, i.e. in 803 female relatives of AITD patients in self-proclaimed good health. As a comparison group we used 100 healthy women who participated in a program for reference values. IgG and IgA antibodies to virulence-associated outer membrane proteins (YOPs) of YE were measured by a specific assay. Serum thyroid peroxidase antibodies (TPO-Ab) as indicators of AITD were considered to be positive at levels of> 100 kU/l. The prevalence of YOP IgG-Ab was higher in AITD relatives than in controls (40.1% vs. 24%, P = 0.002), and the same was true for YOP IgA-Ab (22% vs. 13%, P < 0.05). Of the 803 AITD relatives, 44 had an increased or decreased plasma TSH, and 759 were euthyroid as evident from a normal TSH; the prevalence of YOP-Ab did not differ between these three subgroups. TPO-Ab were present in 10% of controls and in 27% of the AITD relatives (P < 0.001). The prevalence of TPO-Ab in the euthyroid AITD relatives was not different between YOP IgG-Ab positive and negative subjects (23.3% vs. 24.7%, NS), nor between YOP IgA-Ab positive and negative subjects (21.2% vs. 24.9%, NS). In conclusion, healthy female relatives of AITD patients have an increased prevalence of YOP antibodies, which, however, is not related to the higher prevalence of TPO antibodies in these subjects. The findings suggest a higher rate of persistent YE infection in AITD relatives. Susceptibility genes for AITD may also confer a risk for YE infection.

TSH-R expression and cytokine profile in orbital tissue of active vs. inactive Graves' ophthalmopathy patients.

OBJECTIVE: From in vitro studies using cultures of orbital fibroblasts, it has become clear that cytokines play an important role in the orbital inflammation in Graves' ophthalmopathy (GO). Orbital fibroblasts seem to be the key target cells of the autoimmune attack, and they are able to express the TSH receptor (TSH-R). In vivo data on the presence of cytokines in orbital tissues are sparse, and mostly limited to samples obtained from patients with endstage, inactive GO; the same holds true for the presence of the TSH-R. The aim of the present study was to determine whether the cytokine profile and TSH-R expression differ in the active vs. the inactive stage of GO. DESIGN AND MEASUREMENTS: Orbital fat/connective tissue was obtained from six patients with active, untreated GO undergoing emergency orbital decompression, and from 11 patients with inactive GO subjected to rehabilitative decompressive surgery. The mRNA levels of various cytokines and the TSH-R were assessed by real-time polymerase chain reaction (PCR) using the LightCycler. Data are expressed as ratios (unknown mRNA/beta-actin mRNA). RESULTS: Active GO patients had much higher TSH-R expression than inactive patients: 4/0-24 (median value/range) vs. 0/0-9, P = 0.01. TSH-R expression was related to the Clinical Activity Score (r = 0.595, P = 0.015). Patients with active GO compared to those with inactive GO had higher mRNA levels of the proinflammatory cytokines interleukin-1beta (IL-1beta) (445/153-877 vs. 0/0-455, P = 0.001), IL-6 (1583/968-18825 vs. 559/0-7181, P = 0.01), IL-8 (1422/38-7579 vs. 32/0-1081, P = 0.046) and IL-10 (145/58-318 vs. 27/0-189, P = 0.002). In active GO there also existed a trend towards a predominance of T helper 1 (Th1)-derived cytokines as evident from higher IL-2 (37/0-158 vs. 0/0-68, P = 0.043), interferon-gamma (IFN-gamma) (20/0-79 vs. 0/0-16, P = 0.12) and IL-12 (2.3/0-14.8 vs. 0/0-1.6, P = 0.10) mRNAs. IL-1 receptor agonist (IL-1RA), IL-2 receptor (IL-2R), IL-3, IL-4, IL-5, IL-13, IL-18 and tumour necrosis factor-alpha (TNF-alpha) mRNAs were similar in both groups. CONCLUSIONS: These data show that at the mRNA level, TSH-R expression is largely present only during the active stages of GO. The active phase is characterized by the presence of proinflammatory and Th1-derived cytokines, whereas other cytokines, among them Th2-derived cytokines, do not seem to be linked to a specific stage of GO.

Smoking and disease severity are independent determinants of serum adhesion molecule levels in Graves' ophthalmopathy.

Adhesion molecules play a key role in autoimmune disorders, and serum concentrations of soluble adhesion molecules are increased in Graves' ophthalmopathy (GO). Whether this is due to the strong association with smoking is unknown. It is also not known if the severity or activity of GO determine the serum levels of adhesion molecules. We measured serum concentrations of sICAM-1, sVCAM-1 and sELAM-1 in 62 euthyroid Graves' patients with untreated GO, in 62 healthy controls matched for sex, age and smoking habits, and in 26 euthyroid Graves' patients without GO. GO severity was assessed by the Total Eye Score and the activity by the Clinical Activity Score. Adhesion molecules were measured by highly sensitive ELISAs. GO patients had higher levels than controls (median values in ng/ml with range): sICAM-1 300 [171--575] versus 244 [119--674], P < 0.001; sVCAM-1 457 [317--1060] versus 410 [238--562], P < 0.001; and sELAM-1 61 [19--174] versus 53 [23--118], P = 0.021. Euthyroid Graves' disease patients without GO had levels similar to controls: sICAM-1 273 138--453), sVCAM-1 386 [260--1041] and sELAM-1 46 [22--118]. Smoking had an independent effect and was associated with higher levels of sICAM-1 and lower levels of sVCAM-1 in both GO patients and controls; sELAM-1 levels were comparable. In the 62 GO patients, sICAM-1 correlated significantly with severity of eye disease (r = 0.40, P = 0.002). No correlation was found with the duration of GO, the Clinical Activity Score or TBII levels. Multivariate analysis of all 150 subjects showed that the presence of GO and smoking are independent determinants of sICAM-1 and sVCAM-1 concentrations. In GO patients, the Total Eye Score was a stronger determinant than smoking. It is concluded that (i) smoking is associated with increased sICAM-1 and decreased sVCAM-1 levels; (ii) independent from smoking, euthyroid GO patients have higher levels of sICAM-1, sVCAM-1 and sELAM-1 than patients with euthyroid Graves' disease or healthy controls; (iii) the major determinant of sICAM-1 in GO patients is the severity of their eye disease.

Suppression of serum TSH by Graves' Ig: evidence for a functional pituitary TSH receptor.

Antithyroid treatment for Graves' hyperthyroidism restores euthyroidism clinically within 1-2 months, but it is well known that TSH levels can remain suppressed for many months despite normal free T(4) and T(3) levels. This has been attributed to a delayed recovery of the pituitary-thyroid axis. However, we recently showed that the pituitary contains a TSH receptor through which TSH secretion may be down-regulated via a paracrine feedback loop. In Graves' disease, TSH receptor autoantibodies may also bind this pituitary receptor, thus causing continued TSH suppression. This hypothesis was tested in a rat model. Rat thyroids were blocked by methimazole, and the animals were supplemented with L-T(4). They were then injected with purified human IgG from Graves' disease patients at two different titers or with IgG from a healthy control (thyroid hormone binding inhibitory Ig, 591, 127, and < 5 U/liter). Despite similar T(4) and T(3) levels, TSH levels were indeed lower in the animals treated with high TSH receptor autoantibodies containing IgGs; the 48-h mean TSH concentration (mean +/- SEM; n = 8) was 11.6 +/- 1.3 ng/ml compared with 16.2 +/- 0.9 ng/ml in the controls (P < 0.01). The intermediate strength TSH receptor autoantibody-treated animals had levels in between the other two groups (13.5 +/- 2.0 ng/ml). We conclude that TSH receptor autoantibodies can directly suppress TSH levels independently of circulating thyroid hormone levels, suggesting a functioning pituitary TSH receptor.