Increased serum inhibin B levels in postmenopausal women with altered thyroid function.

Hyper- and hypothyroidism have significant effects on the female reproductive system. However, little in the way of data is available on the relationship between ovarian paracrine control and thyroid function. This study was aimed at characterising the serum levels of inhibin B in relation to altered thyroid function. Serum inhibin B and FSH levels were measured in 91 women (51 regularly cycling and 40 postmenopausal). The mean serum concentration of inhibin B in euthyroid cycling women (0.025 +/- 0.018 microg/l) was similar to that observed in hyper- and hypothyroid patients (0.022 +/- 0.015 and 0.018 +/- 0.014 microg/l, respectively, p=ns). Inhibin B levels were obviously reduced (-72%) in euthyroid postmenopausal women. In contrast, in hyper- and hypothyroid postmenopausal women, inhibin B levels remained substantially at the premenopausal level. So far, serum inhibin B appeared to be significantly increased in both hyperthyroid patients (0.025 +/- 0.014 microg/l; p<0.0001) and in hypothyroid patients (0.016 +/- 0.006 microg/l; p=0.0006). Altered thyroid function did not affect FSH levels at fertile age. However, a significant decrease of FSH levels was observed in hyper- and hypothyroid (-52% and -43%, respectively) postmenopausal women. Nevertheless, these FSH levels remained in the postmenopausal range. These results indicate that an altered thyroid function affects serum inhibin B levels in postmenopausal women.

Reversible increase of serum activin A levels in women with Graves' disease.

The aim of this study was to analyze the serum levels of activin A in hyperthyroid patients with Graves' disease. Serum activin A and FSH levels were measured in a total of 93 females (64 regularly cycling and 29 post-menopausal). Of these, 20 were hyperthyroid patients with Graves disease, 33 were euthyroid goitrous patients (20 had autoimmune thyroiditis AT and 13 only had goiter) representing the internal control group and 40 were healthy subjects representing the external control group. Serum levels of activin A were higher in goitrous patients with AT than in control subjects (p=0.0388). Activin A levels were almost doubled in the cycling and in post-menopausal hyperthyroid women (0.91+/-0.21 vs 0.43+/-0.07 microg/l; p<0.0001 and 0.92+/-0.22 vs 0.48+/-0.24 microg/l; p=0.0001, respectively). In 10 cycling hyperthyroid patients, studied even after methimazole treatment, that increase was substantially reversed, once euthyroidism was attained (p=0.002). These findings indicate that thyroid function and autoimmune processes significantly affect serum levels of activin A in patients with Graves' disease.

Age-related prevalence of platelet-associated immunoglobulins G in nonthrombocytopenic patients with autoimmune thyroid disease and autoimmune polyglandular syndrome.

OBJECTIVE: The prevalence of platelet-associated IgG (paIgG) in nonthrombocytopenic patients with autoimmune thyroid disease (AITD) alone or associated with autoimmune polyglandular syndrome (APS) has been studied. SUBJECTS: A total of 164 individuals were enrolled in this study: 81 patients with AITD alone, 33 patients with APS, and 50 healthy controls. RESULTS: The presence of paIgG was recorded in 41 of 81 patients with AITD (51%) as compared with 2 of 50 control subjects (4%, p < 0.0001). The prevalence of paIgG in patients with APS was higher even when compared with patients with AITD alone (25/33, 76%; p = 0.02). The presence of paIgG was not related to the functional thyroid parameters. The prevalence of paIgG was higher in the older than in the younger patients (75 vs. 47%, p = 0.0037). CONCLUSIONS: The results indicate that the prevalence of paIgG in patients with AITD is higher than previously thought, namely in elderly patients and in patients with APS, and not related to the thyroid function.

Effect of tryptophan on the early tri-iodothyronine uptake in mouse thymocytes.

OBJECTIVE: We have studied the effect of tryptophan on cellular [(125)I]tri-iodothyronine (T3) uptake by mouse thymocytes. MATERIALS AND METHODS: Mouse thymocytes (20 x 10(6 )cells/ml) were suspended in Krebs-Ringer solution buffered by Tris-HCl and incubation (23 degrees C at pH7.45+/-0.6), in the presence or absence of 1mM tryptophan, was started by adding 25 pM [(125)I]T3. At the end of incubation, samples were cooled in ice, centrifuged over a 30% sucrose cushion and the cell-associated radioactivity was measured in the pellet. RESULTS: Tryptophan reduced both the total and the saturable fraction of [(125)I]T3 uptake by 44% (P=0.0009) and 60% (P=0.0006) respectively, following 1 min of incubation. This effect was specific and dose-dependent, being maximal at 5mM concentration (-82%). In contrast, the pre-exposure of cells to tryptophan for up to 2h had no effect on the subsequent uptake of [(125)I]T3, in the absence of tryptophan. The effect of D-tryptophan on saturable T3 uptake was not different from that obtained using the L-stereoisomer. Tryptophan reduced the V(max) of the initial rate of saturable [(125)I]T3 uptake by two-thirds without affecting the apparent K(m) (2.2 nM) of the process, thus indicating the non-competitive nature of the inhibition. In sodium-free medium the saturable [(125)I]T3 uptake was reduced by 43%. The inhibitory effect of tryptophan on [(125)I]T3 uptake was exerted in both the presence and the absence of sodium. In fact, the inhibitory effect of tryptophan on T3 transport was greater and significantly different (P=0.0046) from that obtained by sodium depletion alone. CONCLUSIONS: Tryptophan interferes with both the sodium-dependent and -independent components of [(125)I]T3 uptake by a dose-dependent, non-competitive mechanism which operates in cis-modality at the plasma membrane level of mouse thymocytes.

[The clinical and echographic assessment of thyroid function and structure in patients with a chronic inflammatory intestinal disease]. / Valutazione clinica ed ecografica della funzione e della struttura tiroidee in pazienti con malattia infiammatoria cronica intestinale.

In Crohn's disease (CD) and in ulcerative colitis (UC) data about possible thyroid involvement are lacking. We studied thyroid morphology and function in 41 patients affected by active inflammatory bowel disease (IBD) (14 UC; 27 CD) before (all) and 45 and 90 days after onset of therapy (23/41), and in 60 normal control subjects. At each time, the following tests were performed: thyroid sonography, hormonal and immunological assays. A statistically significant increase of thyroid volume was found in IBD compared to control subjects, more frequently in CD (70.4%) than in UC (14.3%). Parenchymal structure was inhomogeneous (88.4% CD; 15.4% UC) with increased frequency compared to control subjects (12.7%). Hormone assays demonstrated increased FT4 values in UC (64.3%) and decreased T4 values in CD (51.8%). Patients affected with IBD showed an increased frequency of anti-thyroglobulin and anti-thyroid peroxidase antibodies. Such abnormalities subsided only partially after therapy. Our data suggest that in IBD there is a frequent thyroid involvement with morphological, hormonal, and immunological abnormalities.

Diagnostic items and treatment of Plummer's disease: a study on 180 patients.

OBJECTIVE: The aim of this study was to evaluate clinical data of patients who have been undergone to medical, radionuclide, surgical and percutaneous ethanol injection (PEI) treatment of autonomous "hot nodule", to establish the real value of these therapeutical strategies. PATIENTS AND METHODS: The authors analyzed their experience based on 180 Plummer's disease (PD) from January 1990 to December 1997. 49 nodules have been submitted to FNA. RESULTS: The functional stage of PD was partially autonomously in 47 patients, pretoxic nodule in 98 patients and in toxic phase in 35 patients. The more frequent ultrasonographic type has been a solid nodule with abundant intranodular vascularization to color flow duplex Doppler evaluation. The medical therapy has brought to a resolution of the toxic phase in 71.2% of the patients, while 6.4% of the patients developed a recurrent hyperthyroidism. The surgical treatment of the patients with hyperthyroidism has resolved hyperthyroidism symptoms in 87.5% of cases. The therapy with radioactive iodine determined a metabolic normalization in 73.7% of the cases and an hypothyroidism in 89.5% of the cases. Our results, in 12 patients treated with PEI, followed-up through 12 months, have been excellent: total remission in 75% of the patients and no recurrent hyperthyroidism crisis. CONCLUSIONS: It doesn't exist a single therapy to treat the PD. The surgical or radionuclide treatment could be addressed to the big or toxic nodules insensible to pharmacological therapy and the PEI represent a new method to treat the PD because of efficacious, harmless, cheap and practical too.

[Variations in the anatomy and physiology of the thyroid gland in old age]. / Variazioni nell'anatomia e nella fisiologia della ghiandola tiroidea in senescenza.

Recently, the anatomical and physiological modifications of thyroid gland in the elderly have been undergone to many investigations. However, it does not exist an univocal interpretation about the results. Furthermore, non-thyroidal diseases, in the elderly, can modify TSH, FT3 and FT4 serum levels because of an important inhibition of T3 and T4 peripheric conversion; moreover, many drugs have been reported interactions with hypothalamus-hypophysis-thyroid axis in the senescence. At present, the international literature confirm, in the elderly, a reduction of the activity of the hypothalamus-hypophysis-thyroid axis, associated with an adaptation of hormones production; moreover, the thyroid gland undergoes anatomical (weight) and physiological (captation of iodine and hormones synthesis) adaptations, age-related, which witness for a reduction of thyroid function. Furthermore, FT3 and FT4 plasma levels present in old persons are comparable to younger subjects; in fact, in the elderly, it has been proved a reduction of T4 peripheric degradation which equilibrates its low production. So, the progressive reduction of thyroid gland activity in the old men must be explained like an adaptation to the new metabolic rhythm associated with a reduced TSH secretion and with a smaller body mass in the elderly. However, this peculiar new steady-state is not like an hypothyroidism syndrome, because there is not a real hormones reduction.

Reversible increase of intraocular pressure in subclinical hypothyroid patients.

OBJECTIVE: The aim of the study was to analyse the relationship between the ocular parameters, namely intraocular pressure (IOP), and the early forms of subclinical hypothyroidism. DESIGN: Fifty-three subjects (9 male and 44 female) aged from 18 to 45 years (mean 32 +/- 7 years) were selected for this study. Twenty-nine met the criteria of subclinical hypothyroidism and 24 euthyroid subjects, age- and sex-matched, were used as controls. METHODS: All individuals underwent a complete ocular examination, including visual field examination and serial measurement of IOP by means of a Goldmann tonometer. A tonographic examination was also performed. RESULTS: The hypothyroid patients showed a substantially higher pressure in both eyes compared with control subjects (right eye = 17.52 +/- 4.74 vs 13.42 +/- 1.95 mmHg, P < 0.0001; left eye = 17.55 +/- 3.99 vs 13.71 +/- 1.55 mmHg, P < 0.0001). Indeed, the tonometric pressure exceeded 18 mmHg in 11 out of the 29 (38%) patients in the right eye and in 8 out of 29 (27%) patients in the left eye. The outflow index was normal in all subjects except in two hypothyroid patients. After two months of L-thyroxine (L-T4) replacement therapy, only one patient continued to show tonometric values above 18 mmHg and the hypothyroid patients showed a significant reduction in mean IOP in both eyes compared with pre-treatment values (right eye = 14.96 +/- 1.32 mmHg, P < 0.0097; left eye = 15.03 +/- 1.38 mmHg, P < 0.0018). Treatment did not lead to any change in the outflow indices; however, the C value (outflow coefficient at the sclerocorneal corner) returned to normal in the two patients with increased pre-treatment tonographic values. CONCLUSIONS: These findings indicate that the intraocular pressure is increased even in subclinical hypothyroid patients and that, at this early stage, the impairment is fully reversible with L-T4 therapy.

[Graves' disease: ultrasonographic, color Doppler and histological aspects]. / Malattia di Graves. Aspetti ecografici, color-Doppler ed istologici.

The aim of the present work was to study the relationship between thyroid low echogenicity, the thyroid blood flow by color-Doppler (CD) and histological features in patients with Graves' disease (GD). Thyroid ultrasonography and CD was performed on 28 patients with GD. In 5 patients has been compared CD with histology. The thyroid volume was higher in 100% of patients with GD at the onset rather than in euthyroidism. Diffuse hypoechogenicity of the thyroid was discovered in 100% of patients with GD at the onset and it persisted in 57.1% of patients that became euthyroid after therapy. Qualitative CD resulted in different patterns that were classified as follow: pattern A ("thyroid inferno") in 17 patients (60.7%); pattern B (mildly increased of parenchymal blood flow) in 11 patients (39.3%). In the 5 histological proven cases, in the pattern A (3 cases) there was a diffuse microfollicular hyperplasia with functional activation notes. There was lymphocytic infiltration. While in the pattern B (two cases) there were a non-follicular hypercellular nodule with pseudocapsule and rare colloid. We conclude that there are two different histological types with different CD patterns in GD.

[Echotomography and color-Doppler in the diagnosis of thyroid carcinoma]. / Ecotomografia e Color-Doppler nella diagnosi di carcinoma tiroideo.

Ultrasound examination of the thyroid gland is used extensively in the diagnosis of thyroid carcinoma: it is easy and rapid to perform and widely available. Ultrasound enables easy identification of the image of disease foci within the gland, especially when high frequency probes (7.5-10 MHz) are used. Thyroid nodules are subdivided on the basis of their echostructure into hypoechoic solid, isoechoic solid, and hyperechoic solid, mixed, and liquid. In neoplastic pathologies, a hypoechoic echostructure is not pathognomonic of malignancy but must be regarded with suspicion, especially if it is an isolated nodule in a male patient and continues to grow during suppressive therapy. In fact, thyroid neoplasms evidence a hypoechoic echostructure in 60-70% of the cases, while a hyperechoic echostructure is present in only 2-4%. Only 15-25% of neoplasms appear as isoechoic nodules; a mixed echostructure is rarely (5-10% of the cases) seen. Color-Doppler patterns are classified into four types: I) nodules without internal or perinodular vascularization; II) nodules with vascularization confined to extranodular tissue; III) nodules with significant intra- and perinodular vascularization; IV) increased vascularization (or "thyroid inferno"). The vast majority of thyroid carcinoma (90%) presents type III vascularization. We therefore suggest the routine use of ultrasonography and color-Doppler studies in conjunction with fine-needle aspiration cytology for the diagnostic evaluation of thyroid carcinoma.