Orbital diseases mimicking graves' orbitopathy: a long-standing challenge in differential diagnosis.

Graves' orbitopathy (GO) is the most common cause of orbital tissue inflammation, accounting for ~ 60% of all orbital inflammatory conditions in the population aged 21-60 years, and for ~ 40% in the population aged > 60 year. GO is observed in 25-30% of patients with Graves' hyperthyroidism and more rarely in association with hypothyroid autoimmune thyroiditis. In addition, a small proportion of GO patients (1-2%) do not have a clinically overt thyroid dysfunction. Clinically, GO is characterized by proptosis, inflammation involving the eyelids and the conjunctiva, extraocular muscle hypertrophy, with consequent reduction of ocular motility and diplopia, and in the most severe cases, compression of the optic nerves at the orbital apex, with reduction of visual acuity. At CT scan or MRI, a muscle increase involving the superior, medial and inferior rectus is quite typical. In the most severe forms, compression of the optic nerves at the orbital apex can be observed. Euthyroid GO is usually an early sign of a full-blown Graves' disease; however, in some cases, the orbital disease can remain isolated. Moreover, euthyroid GO can rarely be unilateral, which makes the picture even more confusing. Under those circumstances, the diagnostic process becomes obviously quite difficult, having other conditions mimicking GO been excluded. A number of inflammatory conditions affecting orbital tissue can mimic GO, thereby requiring an accurate evaluation for a proper differential diagnosis. The majority of these conditions are immune mediated. Most of them are benign, but they can be rather aggressive and some can cause visual loss. The most common inflammatory condition affecting orbital tissues and mimicking GO is idiopathic orbital inflammation. Other, more rare, orbital diseases that should be considered in the differential diagnosis are infections, orbital manifestations of systemic diseases, primitive and secondary orbital neoplasms, and orbital vascular alterations. In most instances, when an orbitopathy occurs in the absence of hyperthyroidism, the diagnosis of the disease underlying the ocular symptoms and signs is based on exclusion of the other conditions. Here we review the conditions that can mimic GO and how to distinguish them from this obnoxious eye disease.

Features and outcome of differentiated thyroid carcinoma associated with Graves' disease: results of a large, retrospective, multicenter study.

BACKGROUND: Whether differentiated thyroid cancer (DTC) occurring concomitantly with Graves' disease (GD) is more aggressive and bound to a less favorable outcome is controversial. OBJECTIVE: Aim of this multicenter retrospective study was to compare baseline features and outcome of DTC patients with GD (DTC/GD+) or without GD (DTC/GD-). PATIENTS: Enrolled in this study were 579 patients referred to five endocrine units (Cagliari, Pavia, Pisa, Siena, and Varese) between 2005 and 2014: 193 patients had DTC/GD+ , 386 DTC/GD-. Patients were matched for age, gender and tumor size. They underwent surgery because of malignancy, large goiter size, or relapse of hyperthyroidism in GD. RESULTS: Baseline DTC features (histology, lymph node metastases, extrathyroidal extension) did not differ in the two groups, except for multifocality which was significantly more frequent in DTC/GD+ (27.5% vs. 7.5%, p < 0.0001). At the end of follow-up (median 7.5 years), 86% of DTC/GD+ and 89.6% DTC/GD- patients were free of disease. Patients with persistent or recurrent disease (PRD) had "biochemical disease" in the majority of cases. Microcarcinomas were more frequent in the DTC/GD+ group (60% vs. 37%, p < 0.0001) and had an excellent outcome, with no difference in PRD between groups. However, in carcinomas ≥ 1 cm, PRD was significantly more common in DTC/GD+ (24.4% vs. 11.5%; p = 0.005). In the whole group, univariate and multivariate analyses showed that GD+ , lymph node involvement, extrathyroidal invasion, multifocality and tall cell histotype were associated with a worse outcome. Female gender and microcarcinomas were favorable features. No association was found between baseline TSH-receptor antibody levels and outcome. Graves' orbitopathy (GO) seemed to be associated with a better outcome of DTC, possibly because patients with GO may early undergo surgery for hyperthyroidism. CONCLUSIONS: GD may be associated with a worse outcome of coexisting DTC only if cancer is ≥ 1 cm, whereas clinical outcome of microcarcinomas is not related to the presence/absence of GD.

Rehabilitative orbital decompression for Graves' orbitopathy: results of a randomized clinical trial.

PURPOSE: Orbital decompression (OD) is a consolidated procedure for the treatment of exophthalmos in Graves' orbitopathy (GO). The efficacy of the various procedures remains unclear due to the variability of the techniques used. To address this issue, we performed a randomized clinical trial to compare the efficacy of two surgical techniques. The primary endpoint was the reduction in proptosis. Secondary aims were the risk of post-operative diplopia (POD) in primary gaze and other surgical complications. PATIENTS: 38 patients (76 orbits) affected with GO were enrolled and randomized into single lateral decompression (LD) (n = 19) or balanced medial plus lateral wall decompression (MLD) (n = 19). Following surgery, patients were seen for a follow-up ophthalmological evaluation at 6 months. Pre-operative diplopia in secondary gaze was present in 13/38 patients (34.2%, 8/19 treated with LD and 5/19 treated with MLD). RESULTS: The reduction of exophthalmos was greater in patients treated with MLD (5.1 ± 1.5 mm, range 2-8 mm) than in those treated with LD (3.5 ± 1.3 mm, range 1-6.5 mm) (p = 0.01). The overall incidence of POD in primary gaze was 5/38 (13.2%) and all of these patients had pre-operative diplopia in secondary gaze (5/13, 38.5%, vs patients with no pre-operative diplopia p = 0.005). Two of 19 patients (10.5%) treated with LD and 3/19 (15.8%) treated with MLD, developed POD in primary gaze, with no statistical difference between the two techniques. CONCLUSION: MLD provides a better result in terms of proptosis reduction compared to LD. The two techniques used here appear to have a similar safety profile in terms of POD. Pre-operative diplopia in the secondary gaze remains a major risk factor for development of POD.

Long-term outcome of Graves' orbitopathy following high-dose intravenous glucocorticoids and orbital radiotherapy.

OBJECTIVE: Intravenous (iv) glucocorticoids (GC) (ivGC) and orbital radiotherapy (ORT) are commonly used in active Graves' orbitopathy (GO), with favorable outcomes in up to 80% of patients. However, little is known on the factors that may affect GO outcome in the long term, an issue that we investigated here. METHODS: We studied retrospectively 96 untreated patients with GO, identified out of 787 consecutive patients who came to our GO Clinic for a follow-up visit between September 2010 and June 2013. After the first observation, patients were treated with ivGC and ORT and were then re-examined after a median period of 55.5 months. The primary end-point was the possible relation between GO outcome and several individual variables. RESULTS: Exophthalmometry, eyelid aperture, CAS, diplopia and visual acuity (the latter only in patients with an initial reduction) improved significantly after treatment. Overall, 67.7% of patients had improved and were considered as responders, whereas the remaining (29.1% stable and 4.5% worsened) were considered as non-responders. Age, smoking, thyroid volume, thyroid treatment, serum anti-TSH receptor autoantibodies and individual GO features at first observation did not affect the outcome of GO, which, in contrast, was affected by gender and by the time elapsed between first and last observation. Thus, the prevalence of responders was higher in females (76.4 vs 48% in males, P = 0.02) and the time elapsed between first and last observation was greater in responders (58 vs 39 months in non-responders, P = 0.02). Whereas the prevalence of responders and non-responders was similar up to 36 months, there was an increase in responders beginning between 37 and 48 months and reaching a peak of ~80% between 61 and 72 months, to plateau thereafter. CONCLUSIONS: Given the limitations of retrospective investigations, our study confirms that the combination of GC and ORT is effective in GO and shows that females have greater chances to respond to treatment. The notorious tendency of GO to improve spontaneously with time most likely contributes the long-term outcome of the eye syndrome.

NADPH oxidase activation and 4-hydroxy-2-nonenal/aquaporin-4 adducts as possible new players in oxidative neuronal damage presents in drug-resistant epilepsy.

A correlation between epilepsy and cellular redox imbalance has been suggested, although the mechanism by which oxidative stress (OS) can be implicated in this disorder is not clear. In the present study several oxidative stress markers and enzymes involved in OS have been determined. In particular, we examined the levels of 4-hydroxy-2-nonenal protein adducts (HNE-PA), a by-product of lipid peroxidation, and the activation of NADPH oxidase 2 (NOX2), as cellular source of superoxide (O(2)(-)), in surgically resected epileptic tissue from drug-resistant patients (N=50). In addition, we investigated whether oxidative-mediated protein damage can affect aquaporin-4 (AQP4), a water channel implicated in brain excitability and epilepsy. Results showed high levels of HNE-PA in epileptic hippocampus, in both neurons and glial cells and cytoplasmic positivity for p47(phox) and p67(phox) suggesting NOX2 activation. Interestingly, in epileptic tissue immunohistochemical localization of AQP4 was identified not only in perivascular astrocytic endfeet, but also in neurons. Nevertheless, negativity for AQP4 was observed in neurons in degeneration. Of note, HNE-mediated post-translational modifications of AQP4 were increased in epileptic tissues and double immunofluorescence clearly demonstrated co-localization of AQP4 and HNE-PA in epileptic hippocampal structures. The idea is that sudden, disorderly, and excessive neuronal discharges activates NOX2 with O(2)(-) production, leading to lipid peroxidation. The resulting generation of HNE targets AQP4, affecting water and ion balance. Therefore, we suggest that seizure induces oxidative damage as well as neuronal loss, thereby promoting neuronal hyperexcitability, also affecting water and ion balance by AQP4 modulation, and thus generating a vicious cycle.

Lateral wall orbital decompression in Graves' orbitopathy.

Orbital decompression can be carried out, for rehabilitative reasons, using various techniques, but a general consensus on the ideal surgical approach has not been reached. Postoperative diplopia is the most common side effect of decompression surgery. The authors report 39 patients (72 orbits) who underwent lateral wall orbital decompression. Mean preoperative and postoperative Hertel exophthalmometry were 22.8+/-2.2mm (mean+/-SD; range 16-26 mm) and 18.2+/-2.1mm (range 15-22 mm), respectively. Mean proptosis reduction was 4.5+/-1.9 mm. A new appearance of diplopia postoperatively in the extreme gaze direction was observed in three patients (8%). The complication rate in this series was low, making the procedure safe and well tolerated. In the authors' opinion, when a single-wall approach is feasible, lateral wall decompression should be the first choice because of its effectiveness in terms of proptosis reduction and safeness in terms of postoperative diplopia.

Novel aspects of immunosuppressive and radiotherapy management of Graves' ophthalmopathy.

Treatment of severe Graves' ophthalmopathy (GO) is a complex therapeutic challenge and, in spite of any efforts, about one third of patients are disappointed with the outcome of treatment. Glucocorticoids (GC), orbital radiotherapy (RT), or a combination of both, are most frequently used for their immunosuppressive effects. Novel immunosuppressive treatment procedures (or novel modalities of established treatments) are reviewed in the present article. GC has recently been used by the i.v. route and this treatment modality has been shown to be more effective and better tolerated than the oral route. Promising preliminary results have been reported by some authors with somatostatin analogs, octreotide and lanreotide. The number of patients treated so far is limited, most of the results have been obtained in nonrandomized or uncontrolled studies, and comparison with other validated methods of treatment is also needed. Because of the pathogenic role of cytokines, cytokine antagonists, currently evaluated in other autoimmune diseases, have been tested with positive results also in a small series of GO patients. The use of antioxidants might also be envisioned in the future, since in vitro studies have shown that oxygen free radicals might be involved in GO. Based on the shared antigen(s) theory, total thyroid ablation, by removing the bulk of shared antigens(s), might be beneficial for the course of GO. New data on recently performed placebo-controlled studies on orbital radiotherapy are discussed, together with studies on long-term safety of orbital radiotherapy.

Comparison of the effectiveness and tolerability of intravenous or oral glucocorticoids associated with orbital radiotherapy in the management of severe Graves' ophthalmopathy: results of a prospective, single-blind, randomized study.

Eighty-two consecutive patients with moderate-to-severe and active Graves' ophthalmopathy were randomly treated with orbital radiotherapy combined with either oral (prednisone; starting dose, 100 mg/d; withdrawal after 5 months) or iv (methylprednisolone; 15 mg/kg for four cycles and then 7.5 mg/kg for four cycles; each cycle consisted of two infusions on alternate days at 2-wk intervals) glucocorticoids. The two groups did not differ for age, gender, duration of hyperthyroidism and ophthalmopathy, prevalence of smokers, thyroid volume, and pretreatment ocular conditions. Both groups of patients received radioiodine therapy shortly before treatment for Graves' ophthalmopathy. Follow-up lasted for 12 months. A significant reduction in proptosis (from 23.2 +/- 3.0 to 21.6 +/- 1.2 mm in the iv glucocorticoid group, P < 0.0001; and from 23 +/- 1.8 to 21.7 +/- 1.8 mm in oral glucocorticoid group, P < 0.0001) and in lid width (from 13.3 +/- 2.5 to 11.8 +/- 2.2 mm, and from 13.6 +/- 2.0 to 11.5 +/- 1.9 mm, respectively; P < 0.001 in both cases) occurred, with no difference between the two groups. Diplopia significantly improved in both groups: it disappeared in 13 of 27 (48.1%) iv glucocorticoid patients (P < 0.005) and in 12 of 33 (36.4%) oral glucocorticoid patients (P < 0.03). The degree of amelioration of diplopia did not significantly differ between the two groups (P = 0.82). Optic neuropathy improved in 11 of 14 iv glucocorticoid (P < 0.01) and only in 3 of 9 oral glucocorticoid (P = 0.57) patients, with no significant difference in these outcomes. The Clinical Activity Score decreased from 4.5 +/- 1.2 to 1.7 +/- 1.0 (P < 0.0001) in the iv glucocorticoid group and from 4.2 +/- 1.1 to 2.2 +/- 1.2 (P < 0.0001) in the oral glucocorticoid group; final Clinical Activity Score was significantly lower in iv glucocorticoid than in oral glucocorticoid patients (P < 0.01). By self-assessment evaluation, 35 (85.3%) iv glucocorticoid and 30 (73.2%) oral glucocorticoid patients reported an improvement of ocular conditions (P = 0.27). Overall, both treatments produced favorable effects in most patients, but responders in the iv glucocorticoid group (36 of 41, 87.8%) were more than in the oral glucocorticoid group (26 of 41, 63.4%) (P < 0.02). Moreover, iv glucocorticoid treatment was better tolerated than oral glucocorticoid treatment. Side effects occurred in 23 (56.1%) iv glucocorticoid and 35 (85.4%) oral glucocorticoid patients (P < 0.01); in particular, cushingoid features developed in 5 of the former and 35 of the latter patients. One iv glucocorticoid patient had severe hepatitis of undetermined origin at the end of glucocorticoid treatment, followed by spontaneous recovery. In conclusion, high-dose iv glucocorticoid and oral glucocorticoid (associated with orbital radiotherapy) are effective in the management of severe Graves' ophthalmopathy, but the iv route seems to be more effective and better tolerated than the oral route and associated with a lower rate of side effects.

Synthesis, conformation and biological activity of linear and cyclic Thr6-bradykinin analogues containing N-benzylglycine in place of phenylalanine.

Three linear Thr6-bradykinin analogues in which either one or both the two phenylalanine residues in the peptide sequence have been substituted by N-benzylglycine (BzlGly) and their head-to-tail cyclic analogues were synthesized and tested on an isolated rat duodenum preparation. The linear (BzlGly5,Thr6-BK, BzlGly8,Thr6-BK and BzlGly(5,8),Thr6-BK) and the cyclic (cyclo BzlGly5,Thr6-BK, cyclo BzlGly8,Thr6-BK and cyclo BzlGly(5,8),Thr6-BK) peptoid-like analogues were characterized by amino acid analysis, optical rotation, analytical HPLC and MALDI-TOF mass spectroscopy. The conformational features of both the linear and cyclic derivatives were investigated by FT-IR and CD measurements. Preliminary molecular mechanics calculations were also performed on some synthetic peptides. Pharmacological screening using the relaxation of the isolated rat duodenum preparation showed that incorporation of N-benzylglycine at positions 5 and/or 8 in the linear Thr6-BK causes a substantial decrease in potency. Comparable incorporation in cyclo Thr6-BK, at position 8, or 5 and 8, resulted in nearly inactive analogues. However, cyclo BzlGly5,Thr6-BK showed a potency which is of the same order of magnitude as for cyclo-BK and cyclo Thr6-BK.

Soluble interleukin-1 receptor antagonist concentration in patients with Graves' ophthalmopathy is neither related to cigarette smoking nor predictive of subsequent response to glucocorticoids.

OBJECTIVE: The aim of the present study was to evaluate serum soluble interleukin-1 receptor antagonist (sIL-1RA) concentration and its relationship with the degree of cigarette smoking in patients with Graves' ophthalmopathy (GO). DESIGN AND SUBJECTS: Twenty-two consecutive GO patients (20 women, two men; age range 25-68 years, mean 48 years; 12 smokers, 10 non-smokers) submitted to IV glucocorticoid pulses over a 3-month period. MEASUREMENTS: sIL-1RA levels were measured by an immunoenzymatic assay (sensitivity, 4 ng/l; normal range, 50-290 ng/l) before glucocorticoid treatment, after two months of therapy, and 3 months after drug withdrawal. RESULTS: Thirteen patients responded to treatment (59%; five smokers and eight non-smokers), nine were non-responders (41%; seven smokers and two non-smokers). Baseline median sIL-1RA concentration did not differ in smokers and non-smokers (222 and 173 ng/l, respectively; P = 0.69). Likewise, no significant differences were found between the two groups during treatment (537 and 389 ng/l, respectively; P = 0.28); sIL-1RA concentration after treatment was higher in smokers (258 vs. 94 ng/l; P = 0.02). There was no correlation between basal sIL-1RA levels and the degree of cigarette smoking. Likewise, there was no difference in sIL-1RA levels in responders and non-responders, either at baseline (186 vs. 216 ng/l; P = 0.83), during or after treatment. CONCLUSION: Our study suggests that circulating soluble interleukin-1 receptor antagonist levels, both at baseline and during glucocorticoid treatment, are neither influenced by cigarette smoking nor predictive of subsequent response to glucocorticoid treatment.

Chromogenic and fluorogenic glycosylated and acetylglycosylated peptides as substrates for serine, thiol and aspartyl proteases.

We synthesized short chromogenic peptidyl-Arg-p-nitroanilides containing either (Galbeta)Ser or (Glcalpha,beta)Tyr at P2 or P3 sites as well as O-acetylated sugar moieties and studied their hydrolysis by bovine trypsin, papain, human tissue kallikrein and rat tonin. For comparison, the susceptibility to these enzymes of Acetyl-X-Arg-pNa and Acetyl-X-Phe-Arg-pNa series, in which X was Ala, Phe, Gln and Asn were examined. We also synthesized internally quenched fluorescent peptides with the amino acid sequence Phe8-His-Leu-Val-Ile-His-Asn14 of human angiotensinogen, in which [GlcNAcbeta]Asn was introduced before Phe8 and/or after His13 and ortho-aminobenzoic acid (Abz) and N-[2-, 4-dinitrophenyl]-ethylenediamine (EDDnp) were attached at N- and C-terminal ends as a donor/receptor fluorescent pair. These peptides were examined as substrates for human renin, human cathepsin D and porcine pepsin. The chromogenic substrates with hydrophilic sugar moiety increased their susceptibility to trypsin, tissue kallikrein and rat tonin. For papain, the effect of sugar depends on its position in the substrate, namely, at P3 it is unfavorable, in contrast to the P2 position that resulted in increasing affinity, as demonstrated by the higher inhibitory activity of Ac-(Gal3)Ser-Arg-pNa in comparison to Ac-Ser-Arg-pNa, and by the hydrolysis of Ac-(Glcalpha,beta)Tyr-Arg-pNa. On the other hand, the acetylation of sugar hydroxyl groups improved hydrolysis of the susceptible peptides to all enzymes, except tonin. The P'4 glycosylated peptide [Abz-F-H-L-V-I-H-(GIcNAcbeta)N-E-EDDnp], that corresponds to one of the natural glycosylation sites of angiotensinogen, was shown to be the only glycosylated substrate susceptible to human renin, and was hydrolysed with lower K(m) and higher k(cat) values than the same peptide without the sugar moiety. Human cathepsin D and porcine pepsin are more tolerant to substrate glycosylation, hydrolysing both the P'4 and P4 glycosylated substrates.

Graves' ophthalmopathy and 131I therapy.

Graves' ophthalmopathy is an autoimmune process initiated and maintained by antigen(s) shared by the thyroid and the orbit. A matter of argument concerns the choice of the method of treatment for Graves' hyperthyroidism when clinically evident ophthalmopathy is present. Restoration of euthyroidism appears to be beneficial for ophthalmopathy. On the other hand the continuing disease activity associated with the recurrence of hyperthyroidism appears to adversely affect the course of ophthalmopathy. For these reasons it is our opinion that in patients with Graves' hyperthyroidism and ophthalmopathy the permanent control of thyroid hyperfunction by ablation of thyroid tissue should be obtained by radioiodine therapy or thyroidectomy. The rationale for an ablative strategy is the following: i) permanent control of hyperthyroidism avoids exacerbations of eye disease associated with recurrence of hyperthyroidism; ii) hypothyroidism, which follows thyroid tissue ablation, should be regarded as a therapeutic end point rather than as an undesirable result; iii) ablation of thyroid tissue may result in the removal of both the thyroid-orbit cross-reacting antigen(s) and the major source of thyroid-autoreactive lymphocytes. The relationship between radioiodine therapy and the course of GO is a matter of controversy, and some authors have suggested that radioiodine administration may be associated with a worsening of preexisting ophthalmopathy. This was not observed when radioiodine treatment was associated with a 3-month oral course of prednisone. The development or progression of GO after radioiodine therapy might be due to the release of thyroid antigens following radiation injury and to subsequent exacerbations of autoimmune reactions directed towards antigens shared by the thyroid and the orbit. The view that radioiodine therapy may be associated with a progression of ophthalmopathy is not shared by some authors who claim that the apparent link between progression of ophthalmopathy and radioiodine therapy might simply be coincidental, reflecting the natural history of the disease. The radioiodine-associated exacerbation of eye disease might be used as an argument against the use of radioiodine therapy in patients with ophthalmopathy. We do not share this view, since the outward effects of radioiodine on eye disease can easily be prevented by concomitant administration of glucocorticoids. Glucocorticoid treatment should be limited, in our opinion, to patients with clinically evident eye disease and to those without ophthalmopathy but with other known risk factors, such as smoking.

Comparison of the immunogenicity of wasp venom peptides with or without carbohydrate moieties.

Three synthetic vespulakinin analogues either with or without carbohydrate moieties and mastoparan B isolated from Vespa basalis venom were investigated for their immunogenic activity and solution conformation. Mice immunized with these wasp venom peptides, with the exception of (Gal alpha)Thr3, (Gal alpha)Thr4-vespulakinin 1, showed positive antibody responses. However, the response elicited by mastoparan B was much higher than those induced by vespulakinin analogues. The class of antibody induced by these peptides was identified as an IgG1 isotype with kappa-light chain, suggesting stimulation of a T-cell-dependent immune response by these peptides. According to the circular dichroism spectra of these peptides, the structures of the vespulakinin analogues in solution were largely unordered, while mastoparan B exhibited a conformation rich in alpha-helices. The presence of carbohydrate moieties and the rather random structure in vespulakinins may interfere with T-cell recognition of the peptides, leading to lower immune responses.

Hyperfunctioning thyroid nodules in toxic multinodular goiter share activating thyrotropin receptor mutations with solitary toxic adenoma.

Toxic multinodular goiter is a cause of nonautoimmune hyperthyroidism and is believed to differ in its nature and pathogenesis from toxic adenoma. Gain-of-function mutations of the TSH receptor gene have been identified as a cause of toxic adenoma. The pathogenesis at the molecular level of hyperfunctioning nodules in toxic multinodular goiter has yet not been reported. Six patients with a single hot nodule within a multinodular goiter and 11 patients with toxic thyroid adenoma were enrolled in our study. At histology five hyperfunctioning nodules in multinodular goiters showed the features of adenomas, and one was identified as a hyperplastic nodule. The entire exon 10 of the TSH receptor gene was directly sequenced after PCR amplification from genomic DNA obtained from surgical specimens. Functional studies of mutated receptors were performed in COS-7 cells. Five out of 6 (83%) hyperfunctioning nodules within toxic multinodular goiters harbored a TSH receptor mutation. A TSH receptor mutation was also evident in the hyperfunctioning nodule that at histology had the features of noncapsulated hyperplastic nodule. Among toxic adenomas, 8 out of 11 (72%) nodules harbored a TSH receptor mutation. All the mutations were heterozygotic and somatic. Nonfunctioning nodules, whether adenomas or hyperplastic nodules present in association with hyperfunctioning nodules in the same multinodular goiters, had no TSH receptor mutation. All the mutations identified had constitutive activity as assessed by cAMP production after expression in COS-7 cells. Hyperfunctioning thyroid nodules in multinodular goiters recognize the same pathogenetic event (TSH receptor mutation) as toxic adenoma. Other mechanisms are implicated in the growth of nonfunctioning thyroid nodules coexistent in the same gland.

Outcome of thyroid function in Graves' patients treated with radioiodine: role of thyroid-stimulating and thyrotropin-blocking antibodies and of radioiodine-induced thyroid damage.

UNLABELLED: We investigated the interrelationship and the influence of thyroid-stimulating antibodies (TSAb), TSH-blocking antibodies (TSHBAb), and of radioiodine (131I)-induced thyroid damage in the early (within 1 yr) outcome of thyroid function in hyperthyroid patients with Graves' disease (GD) treated with 131I. TSAb, TSHBAb, and ultrasound thyroid volume (as an index of thyroid damage) were simultaneously measured before and at 1, 3, 6, and 12 months after 131I in 31 GD patients. One year after radioiodine, 9.7% of patients were hyperthyroid (Hyper-group), requiring methimazole; 12.9% were euthyroid (Eu-group); and 77.4% were hypothyroid (Hypo-group). Pretreatment thyroid volume in the Eu-group and Hyper-group was significantly greater (P = 0.009) than in the Hypo-group. Pre-131I TSAb levels were higher in the Hyper-group vs. the Hypo-group (P = 0.01) or the Eu-group (P = 0.03). A significant post-131I increase in TSAb levels occurred in 66% of patients developing hypothyroidism but not in those remaining hyperthyroid. After 131I, TSHBAb appeared in 7 patients, in all but one associated with high levels of TSAb. One year after radioiodine: 1) the mean percent reduction in thyroid volume was greater in the Hypo-group (80.7%) or the Eu-group (83.5%) than in the Hyper-group (35.7%) (P = 0.007 and 0.0033 respectively); 2) hypothyroid patients had smaller (P = 0.0058) post-131I thyroids than hyperthyroid patients; and 3) TSAb were still elevated in 75% hypothyroid patients, but all of them had a thyroid volume < or = 8 mL, indicating major postradioiodine gland damage. IN CONCLUSION: 1) the early outcome of thyroid function after 131I for GD is mainly related to pretreatment thyroid volume and to the degree of its reduction after therapy; 2) high TSAb levels before 131I are associated with a relative resistance to therapy; 3) a postradioiodine increase in TSAb levels is related to the development of hypothyroidism; and 4) the concomitant appearance of TSHBAb and disappearance of TSAb are not frequent after 131I and play a role in the development of early postradioiodine hypothyroidism only in a minority of patients.

Clinical features of patients with Graves' disease undergoing remission after antithyroid drug treatment.

The clinical course of 306 Graves' patients treated with methimazole (MMI) was reviewed with the aim of establishing criteria able to predict remission of hyperthyroidism after medical treatment. One hundred and ninety-four (149 females, 45 males) of 306 (63.4%) patients had relapse of hyperthyroidism after antithyroid drug (ATD) withdrawal. Relapse was more frequent during the first months of the follow-up, but still it was observed 3 years after MMI withdrawal. The relapse rate was dependent on the age of the patient, the size of goiter, and the level of TSH-receptor antibody (TRAb) at diagnosis, being observed in 40 of 47 (85%) patients with high (> 30 U/L) TRAb level and in 54 of 101 (53%) patients with low TRAb level (< or = 30 U/L; p <.0002). Remission was more frequent (43.3%) in patients having the combination goiter size < or = 40 mL, TRAb level < or = 30 U/L, than in patients with goiter size > 40 mL and high TRAb levels (9%). In the subgroup of patients with the combination: goiter < or = 40 mL- TRAb < or = 30 U/L - age at onset > 40 years, the remission rate was 80%, and all relapses occurred within the first 9 months after MMI withdrawal. In conclusion, our study confirms that hyperthyroidism relapses in the majority of patients with Graves' disease treated with ATD. Among different clinical and laboratory features, age at onset of hyperthyroidism, goiter size and TRAb level are particularly helpful in identifying those patients who are more prone to undergo a remission of hyperthyroidism after medical treatment and may be useful to select the minority of Graves' patients who will benefit from antithyroid drug treatment as a first choice.

Surgical treatment of Graves' disease: subtotal or total thyroidectomy?

BACKGROUND: The extent of thyroidectomy in Graves' disease is still controversial. We compared the outcome of two groups of patients with Graves' disease who underwent total and subtotal thyroidectomy, respectively. METHODS: One hundred forty patients were treated by subtotal (ST, n = 80) or total thyroidectomy (TT, n = 60) between 1988 and 1994 for a large goiter or recurrence of hyperthyroidism after antithyroid drugs. Surgical complications, relapse of hyperthyroidism, and serum levels of antibodies were evaluated. RESULTS: Thyroid-stimulating hormone receptor and thyroperoxidase antibodies significantly decreased in 44 of 60 and in 27 of 60, respectively, of TT patients and in 65 of 80 and 8 of 80, respectively, of ST patients. Thyroid-stimulating hormone antibody levels increased in three ST patients who had relapse of hyperthyroidism and in no TT patients; thyroperoxidase antibodies increased in nine ST patients (four with relapse of hyperthyroidism) and in no TT patients. Vocal cord palsy occurred in two ST (2.5%) and in 1 TT (1.7%) patients; hypoparathyroidism occurred in three ST (3.8%) and in two (3.3%) TT patients. CONCLUSIONS: Total thyroidectomy does not present more complications with respect to subtotal thyroidectomy, but it avoids the worsening of thyroid humoral autoimmunity and the relapse of hyperthyroidism. Thus it could represent the treatment of choice in Graves' disease.

Use of cells expressing the human thyrotropin (TSH) receptor for the measurement of thyroid stimulating and TSH-blocking antibodies.

A clone of Chinese hamster ovary cells (CHO) transfected with the cDNA of the human thyrotropin (TSH) receptor (CHO-R) was used to optimise assays for TSH receptor antibodies with either thyroid stimulating (TSAb) or TSH blocking (TSH-blocking Ab) activity. The study group included 89 patients with Graves' disease, 38 patients with goitrous Hashimoto's thyroiditis (HT) and 47 subjects with atrophic thyroiditis (AT). In the HT group, 8 patients had subclinical hypothyroidism (HT-SH) and 30 had overt hypothyroidism (HT-H). In the assay for TSAb, CHO-R cells were incubated with 1mg/ml of the immunoglobulin G (IgG) from patients with Grave's disease, while in the assay for TSH-blocking Ab cells were incubated with IgGs from patients with HT or AT alone (1mg/ml), or IgGs plus TSH (10 mU/L). After 2 h of incubation the extracellular cAMP was measured by a RIA. In these conditions a significant stimulation by Graves' IgG was obtained in patients with active hyperthyroidism (33/35, 94% untreated; 21/23, 91% relapsed after a course of medical treatment), in 12/20 (60%) patients euthyroid under methimazole and in 4/11 (36%) euthyroid after a course of antithyroid drugs. TSH-blocking Ab were detected in 1/8 (12.5%) patients with HT-SH, in 7/30 (23.3%) with HT-H and in 16/47 (34.0%) patients with AT. TSAb and TSH-blocking Ab coexisted in 4 IgGs that belonged to patients in whom spontaneous hypothyroidism developed after hyperthyroidism, or viceversa. TSAb and TSH-blocking Ab were also tested on FTRL-5 cells. TSAb were positive in both assays in 43/58 (74%) patients with active Graves' disease, negative in both assays in 3 (5%), negative in FRTL-5 and positive in CHO-R in 11 (19%), negative in CHO-R and positive in FRTL-5 in 1 (1.7%). In FTRL-5 cells TSH-blocking Ab were detected in 1/8 (12.5%) patients with HT-SH, in 5/30 (16.6%) with HT-H and in 15/47 (31.9%) with AT. The results of cAMP stimulation in FRTL-5 and CHO-R showed a fairly good correlation in TSAb (r = 0.60, p < 0.0001) and in TSH-blocking Ab (r = 0.74, p < 0.0001) assays. In conclusion, CHO cells transfected with the cloned human TSH receptor are suitable for the clinical assay of TSAb and TSH-blocking Ab. The sensitivity of this assay is higher than that obtained using FRTL-5 cells, having the additional advantages of expressing the human TSH receptor and requiring less cumbersome procedures for cell culture.