Biomedical subjects

A Pinchera

Publications and source records attributed to A Pinchera.

At least 145 records · Page 8Linked to original sources

PubMed1998

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.

Adult↗

PubMed1998

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.

Adenoma↗

PubMed1998

Role of conventional ultrasonography and color flow-doppler sonography in predicting malignancy in 'cold' thyroid nodules.

The aim of the present study was to establish the usefulness of conventional thyroid ultrasonography (US) and color flow-doppler (CFD) sonography in the assessment of 'cold' thyroid nodules. One hundred and four consecutive patients with thyroid nodules who were to undergo surgery were examined by US and CFD before thyroidectomy. Conventional US evaluated the presence of a halo sign, hypoechogenicity and microcalcifications. The vascular pattern on CFD was classified as follows: Type I, absence of blood flow; Type II, perinodular blood flow; Type III, marked intranodular blood flow. On histology, 30 nodules were diagnosed as malignant (carcinoma, CA) and 74 as benign nodules (BN). On US, the echographic pattern most predictive for malignancy was absent halo sign, which was found in 20/30 CA and in 17/72 BN (P = 0.0001; specificity 77.0%; sensitivity 66.6%). The most specific combination on US, absent halo sign/microcalcifications, was found in 8/30 CA and in 5/74 BN (P < 0.005; specificity 93.2%, sensitivity 26.6%). The Type III pattern on CFD was found in 20/30 CA and 38/74 BN (not statistically significant). The combination of absent halo sign on US with Type III pattern on CFD was found in 15/30 CA and in 8/74 BN (P < 0.0001; specificity 89.0%, sensitivity 50.0%). The combination of absent halo sign/microcalcifications on US with Type III pattern on CFD was the most specific combination of the two techniques, being found in 5/30 CA and in only 2/74 BN (P < 0.01; specificity 97.2%, sensitivity 16.6%). In conclusion, findings on US and CFD become highly predictive for malignancy only when multiple signs are simultaneously present in a thyroid nodule. Thus the predictive value of these techniques increases at the expense of their sensitivity. Only in a small proportion of patients with thyroid carcinoma is US and CFD information highly predictive of malignancy.

Adolescent↗

PubMed1998

Preoperative localization of suspicious parathyroid adenomas by assay of parathyroid hormone in needle aspirates.

OBJECTIVE: To determine the usefulness of parathyroid hormone (PTH) measurement in needle aspirates of a suspicious neck mass to confirm its parathyroid nature in patients with primary hyperparathyroidism. METHODS: Thirty-three patients with surgically proved primary hyperparathyroidism were submitted to neck ultrasound (US), parathyroid scintigraphy, and assay of PTH in the aspirate (PTHa) of the suspicious cervical mass. RESULTS: Based on the results of neck US and parathyroid scintigraphy, patients were divided into two groups. Group 1: 16 patients (seven with nodular goiter) with concordant positive US and scintigraphic results. In all but one patient, PTHa was detectable and often markedly elevated (> 1000 pg in 12 patients, between 292 pg and 803 pg in three patients and 53 pg in one patient). The patient with undetectable PTHa had a small lower left parathyroid adenoma (8x8x10 mm). Group 2: 17 patients (12 with nodular goiter) with discordant US and scintigraphic results. PTHa established the parathyroid nature of the mass in 13 cases (> 1000 pg in 8 patients, between 501 pg and 953 pg in three patients and 90 and 79 pg in two patients): 11 of these had a suspected lesion by US examination but the scintigraphy results were negative; two had a mass that gave positive scintigraphy results but was of uncertain origin according to US: in both cases an intrathyroidal parathyroid adenoma was found. PTHa was undetectable in four cases (three with nodular goiter): all of these had equivocal US results, and three had positive scans and one a negative scan. CONCLUSIONS: Assay of PTHa is a simple method and should be useful for confirming the parathyroid nature of a cervical mass in patients with discordant or non-diagnostic US and scintigraphic results.

Adenoma↗

PubMed1998

[Physiopathology of iodine deficiency].

The process of goitrogenesis is likely to be the consequence of an increased TSH stimulation linked to an initial reduction of circulating thyroid hormone caused by iodine deficiency (ID). Other growth factors associated to TSH may have a role in the pathogenesis of goiter. Natural history of goiter is the evolution towards nodularity and functional autonomy. This phenomenon is due to the heterogeneity of thyroid follicular cells, some of which, with an intrinsic elevated growth rate, under the stimulation of ID progress to nodule formation and hyperfunction. In multinodular goiter TSH receptor mutations activating adenylate cyclase-cAMP pathway were found. In a recent epidemiological survey it was shown that nodular goiter increased with the age, being about 1% in schoolchildren and 23% in the adults (56-75 years). Also nodular autonomy and hyperthyroidism were more frequent in the 36-75 year age group. Severe ID is also cause of endemic cretinism. In Europe minor neuropsychological impairments and cognitive deficits were described in areas of moderate ID. The exposure to a mild ID during fetal life causes minor neuropsychological damage. In conclusion, ID is responsible of goiter and its evolution towards nodularity and functional autonomy. Severe ID is also cause of endemic cretinism, while cognitive deficits and minor neuropsychological impairments were found in mild to moderate ID.

Adult↗

PubMed1998

[Transient congenital hypothyroidism: physiopathology and clinica].

The fetus and the newborn are more sensitive than adults to a reduced environmental iodine supply, and in iodine-deficient areas, transient neonatal hypothyroidism is frequently observed. This transient thyroid failure may be associated with neonatal goiter and elevated serum thyroglobulin levels at birth. Borderline elevated neonatal serum TSH concentrations frequently occur in newborns in iodine deficient areas, and result in a higher recalling rate at the screening for congenital hypothyroidism. Minor defects in mental performances and neurological development are observed in children living in areas of mild to moderate iodine deficiency, and result from the concomitant effects of iodine deficiency in the mother during pregnancy and transient neonatal hypothyroidism. Endemic cretinism is the severe and irreversible neurological consequence of iodine deficiency during fetal and neonatal life. Iodine prophylaxis is highly effective in preventing the development of iodine deficiency disorders including transient neonatal hypothyroidism. Since iodine prophylaxis in Italy is inadequate, variable degrees of iodine deficiency are still present all-over the country, and are responsible of a higher incidence of transient neonatal hypothyroidism or hyperthyrotropinemia.

Adult↗

PubMed1998

[Efficacy and safety of iodine prophylaxis].

Iodine deficiency and iodine deficiency disorders (IDD) are still present in developing countries as well as in some European areas. It is well known that iodine deficiency correction prevents endemic goiter and other IDD. Iodized oil has been shown to reduce goiter prevalence and cretinism in African countries. In countries where iodine prophylaxis is performed since many years (USA, Switzerland, Scandinavian countries) IDD are dramatically reduced. One example of the efficacy of iodine prophylaxis through iodized salt was reported in a Tuscan village were urinary iodine excretion increased from 47 micrograms/l in 1981 to 130 micrograms/l in 1991. Goiter prevalence in schoolchildren dropped from 60% in 1981 to 8.1% in 1991. In the same children neuropsychological performances were evaluated showing a reduction of motor response to perceptive stimuli assessed by measurement of reaction times in children born before the beginning of iodine prophylaxis. Iodine prophylaxis has no side effects, although a transitory increase of hyperthyroidism has been reported in the past and recently in African countries. A reevaluation by the experts of the International Council for the Control of Iodine Deficiency Disorders (ICCIDD) has pointed out that this phenomenon is not relevant with respect to the efficacy of iodine prophylaxis. In conclusion, universal iodine prophylaxis prevents endemic goiter and other IDD, without side effects.

Child↗

PubMed1998

[Thyroid carcinoma in a thyroglossal duct cyst: tumor resection alone or a total thyroidectomy?].

Tumours arising in a thyroglossal duct cyst are very rare. Most of them develop from ectopic thyroid remnants. Controversies persist concerning th treatment of these neoplasms, some authors preferring local excision (Sistrunk procedure), while others prefer a more radical approach (associated total thyroidectomy). From 1977 to 1996 we observed and treated 10 patients with by a thyroglossal duct tumour: 8 females and 2 males. A mass in the midline of the neck was the presenting complaint in all cases. Each patient was treated by a Sistrunk procedure associated with total thyroidectomy. Histopathology reports showed 7 papillary carcinomas, 1 Hürthle cell carcinoma, 1 follicular carcinoma and 1 insular carcinoma. Systematic examination of the thyroid gland revealed foci of papillary cancer in 4 cases (40%), with only 1 tumour being larger than 1 centimetre. Cervical metastases were found at operation in 1 case. This series suggests that total thyroidectomy for tumours of thyroglossal cysts could be justified by the high incidence of associated papillary carcinomas of the thyroid and by the relatively aggressive nature that some tumors. In these cases, a radical therapeutic attitude allows, better patients management (total scintigraphy, serum thyroglobulin measurement) and allows the possibility of a complementary radioiodine treatment.

Adult↗

PubMed1997

Comparison of the breakpoint regions of ELE1 and RET genes involved in the generation of RET/PTC3 oncogene in sporadic and in radiation-associated papillary thyroid carcinomas.

The RET/PTC3 oncogene is an activated form of the RET protooncogene, which is frequently rearranged in papillary thyroid carcinoma. RET/PTC3 results from a structural rearrangement between the ELE1 and the RET genes, and it has been observed in both sporadic and radiation-associated post-Chernobyl tumors. To understand the molecular basis that predisposes RET and ELE1 genes to be recurrent targets of "illegitimate" recombination, we examined the genomic regions containing the ELE1/RET breakpoints of six sporadic and three post-Chernobyl tumors in two papillary carcinomas of different origins. Our data indicated, in both genes, a clustering of the breakpoints in regions designated ELE1-bcr (1.8 kb) and RET-bcr (1.9 kb). Notably, in all sporadic tumors and in one post-Chernobyl tumor the ELE1/RET recombination corresponded with short sequences of homology (3-7 nt) between the two rearranging genes. In addition, we observed an interesting distribution of the post-Chernobyl breakpoints in ELE1-bcr located within an Alu element, or in between two close Alu elements, and always in A+T-rich regions.

Base Sequence↗

PubMed1997

Somatic in frame deletions not involving juxtamembranous cysteine residues strongly activate the RET proto-oncogene.

Somatic RET mutations have been identified in a variable proportion (about 30-70%) of sporadic Medullary Thyroid Carcinoma (MTC) cases. They are represented by the Met918Thr substitution (exon 16) typical of Multiple Endocrine Neoplasia type 2B (MEN2B) and, to a lesser extent, by nucleotide changes occurring at one of five critical cysteine residues (exons 10 and 11) typical of MEN type 2A (MEN2A). An in vitro transforming activity has already been demonstrated for these mutations. A few different MTC somatic mutations have been reported so far whose biological activity has still to be tested. In this paper we report the identification, in two MTC tumor samples, of two interstitial deletions of 48 bp and 6 bp occurred in exons 10 and 11 respectively. Both were somatic heterozygous in frame mutations, not involving any cysteine residue. Moreover, the expression of a full length RET cDNA carrying one of the two deletions demonstrated a strong transforming capacity in NIH3T3 cells.

3T3 Cells↗

PubMed1997

Polyclonal origin of medullary carcinoma of the thyroid in multiple endocrine neoplasia type 2.

Multiple endocrine neoplasia type 2 (MEN 2) is a dominantly inherited cancer syndrome characterized by medullary thyroid carcinoma (MTC) and other tumors. Since MTC can also occur in a sporadic form and as familial medullary thyroid carcinoma, this neoplasm offers a unique opportunity to investigate the difference of origin, if any, between the sporadic and the hereditary forms of a tumor. While sporadic malignancies have usually been found to result from a mutational event occurring at the single-cell level and are therefore monoclonal, studies on hereditary neoplasms have been scarce and often produced conflicting results. In order to determine the clonal origin of sporadic MTCs and of those occurring in MEN 2 syndromes we used a clonality assay based on a polymorphic trinucleotide repeat of the X-linked human androgen-receptor gene. We found that 10 out of 11 MTCs expressed a polyclonal pattern of X inactivation, including a significant percentage of the cases clinically defined as sporadic.

Adolescent↗

PubMed1997

Thyroid diseases in the elderly.

The ageing thyroid is associated with a number of morphological and functional changes, such as decreased serum T3 and mean thyroid-stimulating hormone concentrations, that are to some extent independent of intercurrent non-thyroidal illnesses. All thyroid diseases, including clinical and subclinical hypo- and hyperthyroidism, non-toxic nodular goitre and thyroid cancer, are encountered in the elderly, but their prevalence and clinical expression differ from those observed in younger patients. In the elderly, autoimmune hypothyroidism is particularly prevalent, hyperthyroidism is mainly characterized by cardiovascular symptoms and is frequently due to toxic nodular goitres, and differentiated thyroid carcinoma is more aggressive. The interpretation of thyroid function tests is difficult in old individuals, because of age-associated changes in thyroid function and frequent alterations secondary to non-thyroidal illnesses and/or drugs. Treatment of thyroid disease deserves special attention in old patients because of the increased risk of complications.

Aged↗

PubMed1997

Treating severe Graves' ophthalmopathy.

Most patients with Graves' disease have some evidence of ocular involvement, but this is commonly mild, requiring only local measures. A minority of patients (3-5%) have severe Graves' ophthalmopathy, for which the three main treatment procedures are represented by high-dose glucocorticoids, orbital radiotherapy and orbital decompression. Favourable results with medical treatment have been reported in approximately 60% of patients, with particular regard to inflammatory changes, newly developed eye muscle dysfunction and optic neuropathy. Orbital decompression is indicated in severe eye disease not responsive to glucocorticoids and/or irradiation, particularly in the presence of marked proptosis and optic neuropathy. Not conclusive or unsatisfactory results have been obtained with other medical treatment procedures, including immunosuppressive drugs, intravenous immunoglobulins and plasmapheresis. Recently favourable responses have been reported with somatostatin analogues. Rehabilitative surgery involving either the eye muscles or the eyelids is not infrequently required after medical treatment or decompression. Permanent control of thyroid hyperfunction by radioiodine or thyroidectomy is advisable when severe ophthalmopathy is present. Exacerbation of ophthalmopathy following radioiodine may occur but can be prevented by concomitant administration of glucocorticoids. Smoking deleteriously influences the course of ophthalmopathy and its response to treatment.

Glucocorticoids↗

PubMed1997

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.

Adult↗

PubMed1997

Mutations in the gene encoding thyroid transcription factor-1 (TTF-1) are not a frequent cause of congenital hypothyroidism (CH) with thyroid dysgenesis.

Permanent congenital hypothyroidism (CH) has an incidence of 1/3000-4000 newborns and is among the most frequent cause of mental retardation and neurological alterations in children. In 80% to 85% of cases CH is associated with thyroid dysgenesis. A group of 61 patients with CH (22 with agenesis, 18 with ectopy, 1 with hypoplasia, and 20 cases with CH without thyroid enlargement but not further characterized) and 30 normal subjects were examined for the presence of mutations in the gene encoding the thyroid transcription factor 1 (TTF-1). The coding-region of the TTF-1 gene was analyzed in all cases by the single stranded conformational polymorphism (SSCP) and no mutations were detected. Direct sequencing also carried out in patients with thyroid agenesis confirmed the absence of mutations or polymorphisms in the TTF-1 gene. The absence of mutations in the TTF-1 gene in our samples indicates that the mutations in the TTF-1 gene are not a frequent cause of CH.

Congenital Hypothyroidism↗

PubMed1997

Post-Chernobyl thyroid carcinoma in Belarus children and adolescents: comparison with naturally occurring thyroid carcinoma in Italy and France.

After the Chernobyl nuclear accident (April 26, 1986), childhood thyroid carcinoma had a great increase in Belarus and Ukraine, as a consequence of the exposure to iodine radioactive fallout. The epidemiological and clinical features of the disease were studied in 472 patients less than 21 yr old at diagnosis, with differentiated thyroid carcinoma, representing 97.7% of all thyroid carcinomas diagnosed in Belarus between May, 1986, and December, 1995. The results were compared with those of 369 subjects of the same age group, with naturally occurring thyroid carcinoma, observed in Italy and France. Between 1986 and 1989, the number of thyroid cancer cases per year ranged from 3-8 and increased to 31 in 1990, to 66 in 1991, to 72 in 1992, to 93 in 1993, to 96 in 1994, and to 90 in 1995. The age at diagnosis was 14 yr or less in 78.8% (children group) and more than 14, but less than 21, yr in the remaining subjects (adolescents group). Mean (+/- SD) age at the time of the accident was 4.4 +/- 3.4 yr (3.2 +/- 2.3 in children and 8.9 +/- 2.7 in adolescents), the majority of the patients (62.9%) being 5 yr old or less. The time interval between the accident and the diagnosis (latency period) decreased progressively from 7.5 +/- 1.6 yr in children 0-2 yr old at the time of the accident to 6.0 +/- 1.6 yr in those 9-11 yr old. Since 1993, the yearly distribution of new cases showed a decrease in the subjects 9 yr old or more at the time of the accident but not in those 5 yr old or less. This could not be accounted for by a shift of exposed subjects to an age group at diagnosis not included in this study, because only subjects less than 12 yr of age at the time of the accident were considered in this analysis. Mean age at diagnosis in Belarus patients was 11.3 +/- 3.1 yr (10.1 +/- 2.3 in children and 15.7 +/- 1.4 in adolescents), whereas, among patients with naturally-occurring thyroid carcinomas from Italy and France, the majority of cases were diagnosed after 14 yr of age (mean age at diagnosis: 14.6 +/- 4.2 yr). The female-to-male ratio was significantly higher in Italy and France (2.5/1), compared with the ratio of patients from Belarus (1.6/1). Most of the tumors were papillary in both series, but a relatively high proportion of follicular carcinomas (P = 0.0001) was found in Italy/France (15.2%), as opposed to 5.3% in Belarus. Extrathyroidal extension and lymph node metastases were more frequent in Belarus (49.1%, P = 0.0001; and 64.6%, P = 0.002, respectively) with respect to Italy/France (24.9% and 53.9%, respectively). Thyroid lymphocytic infiltration and circulating antithyroperoxidase antibody were more frequent in Belarus patients. Our analysis of Belarus thyroid cancer patients less than 21 yr old showed that the post-Chernobyl increase in thyroid carcinomas involved both children and, to a much lesser extent, adolescents. Subjects 5 yr old or less at the time of the accident accounted for the majority of the patients. No evidence of a decrease in the number of new cases was observed in this age group, as opposed to older subjects. These data support the concept that subjects who were younger at the time of radiation exposure had, and continue to have, a greater risk of developing thyroid carcinoma and strongly suggest that this age group should be carefully monitored in the future. When compared with naturally occurring thyroid carcinoma of the same age group observed in Italy and France, the post-Chernobyl Belarus thyroid carcinomas affected younger subjects, were less influenced by gender, were virtually always papillary, had a greater aggressiveness at presentation, and were more frequently associated with thyroid autoimmunity.

Adenocarcinoma, Follicular↗

PubMed1997

Mild clinical expression of myasthenia gravis associated with autoimmune thyroid diseases.

Myasthenia gravis (MG) may occur in association with autoimmune thyroid diseases (AITD). The aim of this study was to evaluate the features of MG associated with AITD compared to those of MG without AITD. A total of 129 MG patients (34 men and 95 women; age range, 11-81 yr) were subdivided into: group A, 56 MG patients with AITD [25 with autoimmune thyroiditis and 31 with Graves' disease (GD)]; group B, 21 MG patients with nonautoimmune thyroid diseases; and group C, 52 MG patients without thyroid disease. The severity of MG was ranked according to the Osserman score. Laboratory evaluation included assays for antithyroid and antiacetylcholine receptor (AchRAb) antibodies. Ocular MG (Osserman's class 1) was more frequent in group A (41.0%) than in group B (14.2%; P < 0.03) or C (21.4%; P < 0.03). Severe generalized MG (classes > or = 2B) was more frequent in groups B (57.1%; P < 0.03) and C (51.9%; P < 0.02) than in group A (28.5%). GD patients with clinical evidence of ophthalmopathy had a higher frequency (P = 0.05) of ocular MG (57.8%) than GD patients without clinical ophthalmopathy (16.6%). Thymic disease was less frequent in group A (26.7%) than in group B (71.4%; P = 0.001) or C (59.7%; P = 0.001). The prevalence of thymic hyperplasia was 17.8%, 38.0%, and 40.3% in groups A, B, and C, respectively; the prevalence of thymoma was 8.9%, 33.4%, and 19.4%. When only patients with generalized MG were considered, thymic disease was less frequent (P < 0.02) in group A (40.6%) than in the remaining groups (69.4%). AchRAb was more frequent in groups B (57.1%) and C (57.6%; P < 0.03) than in group A (35.7%). In conclusion, MG associated with AITD has a mild clinical expression, with preferential ocular involvement and lower frequency of thymic disease and AchRAb. This supports the hypothesis that ocular and generalized MG are separate diseases with different spectra of associated diseases. Nonautoimmune thyroid diseases have no influence on the features of MG. The association of ocular MG and AITD might be due to a common autoimmune mechanism and/or a peculiar genetic background.

Adolescent↗

PubMed1997

Effect of iodized salt on thyroid volume of children living in an area previously characterized by moderate iodine deficiency.

It is well established that an adequate iodine intake prevents iodine deficiency disorders. Prophylaxis through iodized salt is able to correct urinary iodine deficiency and to prevent goiter endemia, but scanty data are available about its effect on decreasing the thyroid size in goitrous children born before prophylaxis. The prevalence of goiter was evaluated by ultrasound in the school-children population of an area of Eastern Tuscany (Tiberina Valley) characterized by moderate iodine deficiency in 1985. At present, after the implementation of voluntary iodized salt consumption, iodine urinary excretion was borderline sufficient (median, 98 micrograms/L). Goiter prevalence was higher at ultrasound (17%) than by palpation (10%). The median thyroid volume ranged from 3.1 mL in 7-yr-old children to 9.2 mL in 14-yr-old children. In the 7-10 yr age class (i.e. in children born after iodine prophylaxis), no statistical difference in thyroid volume was found with respect to controls. In older children (11-14 yr) born before the institution of iodine prophylaxis, the median thyroid volume was significantly higher than that in age-matched controls. Moreover, in this cluster of subjects, the median thyroid volume in nongoitrous children was higher than that in controls. In conclusion, the data of the present study indicate that the iodized salt prophylaxis is able to prevent the development of goiter in children born after the implementation of iodized salt consumption and to further control thyroid enlargement in older children, but is less effective (or rapid) in reducing goiter size in children exposed to iodine deficiency in the first years of life.

Adolescent↗