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ObjectiveThe objective of this study was to re-evaluate the adult CT reference values determined by five different immunoassays and by introducing criteria for selecting control subjects.DesignA prospective multicenter study.PatientsThree hundred and seventy-five clinically euthyroid subjects.MethodsWe used five different CT immunoassays. Sera were assayed for the concentration of TSH, gastrin, procalcitonin, urea, calcium, and anti-thyroperoxidase antibodies.ResultsScreening for the various potential causes of hypercalcitoninemia led to the exclusion of 23% of the sera. Our reference value analysis dealt with 287 subjects (142 men and 145 women). The proportion of samples in which no CT was detected varied from 56% (for assay D) to 88% (for assay C). We observed significant correlations (whose magnitude depended on the assay used) between CT levels and age or body mass index (BMI) (primarily in men). The distribution of CT levels showed that 4.7, 9.8, 2.5, 6.5, and 8.0% of the values were over 10 pg/ml respectively. These values corresponded essentially to samples from 11 male subjects (median age: 55 years), most of whom were smokers. The highest CT values were around twice as high in men than women, and were higher in smokers than non-smokers.ConclusionIn clinical practice (and after having excluded the usual causes of raised CT levels), the interpretation of CT assay results must take into account i) the method used; ii) the patient's gender, age, and weight; and iii) the potential influence of cigarette smoking.

Familial medullary thyroid carcinoma only is related to germline mutations in the protooncogene RET, mainly in exons 10, whereas noncysteine mutations (exons 13-15) are considered infrequent. We analyzed 148 patients from 47 familial medullary thyroid carcinoma only families, and we found noncysteine RET mutations in 59.5% of these families. Of the index cases with noncysteine mutations, 43.4% presented with a multinodular goiter and high basal calcitonin; they were older at diagnosis than those with mutation in exon 10 and had more multifocal medullary thyroid carcinoma, but no difference in size, bilaterality, presence of C cell hyperplasia, or nodal metastases was found. Gene carriers with noncysteine RET mutations had a lower incidence of medullary thyroid carcinoma (78.2% vs. 94.1%) than those with mutation in exon 10; 20.2% had C cell hyperplasia only, although thyroidectomized at an older age. In conclusion, familial medullary thyroid carcinoma with noncysteine RET mutations are not infrequent and are overrepresented in presumed sporadic medullary thyroid carcinoma, suggesting that RET analysis should routinely be extended to exons 13, 14, and 15. The phenotype is characterized by a late onset of the disease, suggesting a delayed appearance of C cell disease rather than a less aggressive form. In familial medullary thyroid carcinoma gene carriers, the optimal timing for thyroidectomy remains controversial. Based on these data, we propose that surgery should be performed before elevation of the basal calcitonin level, potentially as soon as the pentagastrin test becomes abnormal.

OBJECTIVE We studied the influence of TSH suppressive therapy combined with carbimazole (CBZ) on treatment outcome in Graves' disease. DESIGN Open non-randomized prospective study. SETTING University Hospital of Montpellier, France. SUBJECTS Sixty-six consecutive patients without prior treatment were included. All the patients were treated initially with 30 mg of CBZ. After 1 month of treatment, one group continued CBZ alone (n = 23), another group received a combination of CBZ plus T3 (n = 19) and a third group received CBZ and 3,5,3′-triiodothyroacetic acid (Triac, n = 24). Therapy was stopped when remission was obtained based on clinical euthyroidism, normalization of FT4 and of early radioiodine uptake. Nine patients with medical treatment failure or major side effects requiring to stop antithyroid drugs underwent surgery or radioiodine therapy. Nine patients were lost to follow-up. The remaining 48 patients were available for analysis of both remission and relapse. RESULTS The median duration of therapy was 18 months (range, 4–41 months). Based on clinical examination, goitre size at 4 months decreased more in the CBZ + T3 and CBZ + Triac groups than in the CBZ group (P = 0.02). The overall remission rate tended to be higher in the groups treated with CBZ + T3 and CBZ + Triac than in the group treated with CBZ alone, but the difference did not reach statistical significance (P = 0.17). No difference in the relapse rate was observed between the three groups. CONCLUSION TSH suppression combined with CBZ has little or no effect on remission and relapse rates in Graves' disease patients.

In order to know how thyroid nodules and differentiated thyroid cancers are investigated and treated in 1988, an international inquiry was performed by mean of a questionnaire based on a well-defined case report of a 35-year-old female with a solitary small thyroid nodule. Clinicians were asked to indicate their diagnostic and therapeutic approaches to the reported case and to some variations. Analysis of the 157 responses from thyroid experts showed that three in vitro tests (sensitive-TSH, free T4 and total T4) and three in vivo tests (99mTc or radioiodide scintiscan, fine needle aspiration and ultrasonography) were performed most frequently. In the case of a solid and cold nodule and in the absence of fine needle aspiration results, 19% of respondents advocated suppressive therapy and 81% surgery. In the same clinical case, but whom fine needle aspiration had been performed and cytology was benign, surgery was advocated by 24%, suppressive therapy by 48% and a regular follow-up without treatment by 28% of respondents. When surgery was performed and the diagnosis was a differentiated thyroid cancer, (near) total thyroidectomy was more frequently chosen than partial thyroidectomy in both papillary (60 and 40%, respectively, of respondents) and follicular (74 and 26%, respectively, of respondents) cancers; 80% of clinicians did not change their surgical technique in relation to histological type of the tumour. Total thyroidectomy was more often recommended in most of the clinical or anatomical variations compared with the basic case report. Pre- or postoperative hormonal therapy was initiated with L-T4 and TSH suppression was controlled by sensitive-TSH and thyroglobulin determinations. After total thyroidectomy, 131I was used with similar modalities for papillary and follicular cancers to ablate a thyroid remnant.

In an attempt to explore the natural variable heavy and light chain (VH/VL) pairing of autoantibodies involved in Graves’ disease, we constructed a phage-displayed Ab library obtained by in-cell PCR of thyroid-infiltrating cells. We report here the molecular cloning and characterization of human single-chain fragment variable regions (scFv) specific for thyroid peroxidase (TPO) generated from this library. On the basis of the nucleotide sequences, three different scFvs were obtained (ICA1, ICB7, and ICA5). All were encoded by genes derived from the VH1 and Vλ1 gene families. Using BIACORE for epitope mapping and kinetic analysis, we showed that these scFvs exhibited high affinity (Kd = 1 nM) for TPO and recognized three different epitopes. The biological relevance of these scFvs as compared with serum anti-TPO autoantibodies was assessed by competition studies. Sera from all the 29 Graves’ disease patients tested were able to strongly inhibit (60–100%) the binding of the 3 scFvs to TPO. These data demonstrate that the in-cell PCR library generated human anti-TPO scFvs that retained the VH/VL pairing found in vivo and that the different epitope specificities defined by these scFvs overlapped with those found in the sera of patients with autoimmune thyroid disease.

THE ASSOCIATION of Graves' disease and hypothyroidism with chronic lymphocytic thyroiditis has long been recognized. In some cases, hypothyroidism seems to be the final outcome of Graves' thyrotoxicosis. 1 Many reports are not completely substantiated, however, and none, to our knowledge, reports on the histological appearance of the thyroid gland at both stages of the disease in the same patient. Report of a Case A 39-year-old woman (height, 159 cm; weight, 55 kg) was seen in 1972 with thyrotoxicosis, unilateral exophthalmos, and a large, smooth goiter. The six-hour sodium iodide uptake was raised at 68% (normal, 25% to 35% dose), and the scan was homogenous. The patient was euthyroid during antithyroid drug therapy (carbimazole, 30 mg/day), as confirmed at repeated checkups during 1972 and 1973. Treatment was discontinued voluntarily by the patient from 1973 to January 1977. At that time, the patient was again found to be thyrotoxic with a