Evaluating adherence, tolerability and safety of oral calcium citrate in elderly osteopenic subjects: a real-life non-interventional, prospective, multicenter study

BACKGROUND

Osteoporosis is a common concern in the elderly that leads to fragile bones. Calcium supplementation plays a crucial role in improving bone health, reducing fracture risk, and supporting overall skeletal strength in this vulnerable population. However, there is conflicting evidence on the safety of calcium supplements in elderly individuals.

AIM

The aim of this study was to evaluate the adherence, safety and tolerability of calcium citrate supplementation in elderly osteopenic subjects.

METHODS

In this non-interventional, prospective, multicenter study, subjects received daily 500 mg calcium citrate supplementation for up to one year. Adherence was calculated based on compliance and persistence. Safety was assessed through adverse reactions (ARs), deaths, and clinical laboratory evaluations.

RESULTS

A total of 268 Caucasian subjects (91.4% female, mean age 70 ± 4.5 years) participated in the study. Mean adherence to treatment was 76.6 ± 29.5% and half of subjects had an adherence of 91% and ~ 33% of participants achieved complete (100%) adherence. ARs were reported by nine (3.9%) subjects, primarily gastrointestinal disorders, with no serious ARs. The frequency of all adverse events (including ARs) was significantly higher in subjects with adherence of < 80% (41.6%; 32/77) vs. those with adherence ≥ 80% (11%; 16/145, p < 0.0001). Both systolic and diastolic blood pressure decreased from baseline to follow-up visit (change of -2.8 ± 13.9 mmHg, p = 0.0102 and -2.1 ± 10.4 mmHg, p = 0.0116, respectively).

CONCLUSION

This study demonstrated favorable adherence to calcium citrate supplementation in elderly osteopenic subjects. The occurrence of ARs, though generally mild, were associated with lower adherence to calcium supplementation.

False-positive radioiodine uptake after radioiodine treatment in differentiated thyroid cancer

BACKGROUND AND PURPOSE

False-positive radioiodine uptake can sometimes be observed with post-radioiodine treatment (RIT) whole body scanning. Radioiodine pitfall has often been reported as being caused by benign or inflammatory disease, or, in some cases, by tumor lesions. This paper reviews the possible causes of such false-positive imaging, and suggests possible reasons for suspecting these pitfalls.

METHODS AND RESULTS

Online databases, including MEDLINE (via PubMed), Embase, ISI Web of Science, Google Scholar, and Scopus, were systematically examined, using different keyword combinations: "radioiodine false-positive imaging", "131 I false-positive imaging" and " RAI false-positive imaging". An illustrative case was described. Excluding cases in which SPECT/CT was not performed, a total of 18 papers was found: 17 case reports and one series regarding false-positive iodine-131 uptake after RIT.

CONCLUSIONS

The prevalence of radioiodine pitfall was significantly reduced through the use of SPECT/CT imaging, though its possible presence has always to be taken into account. Inflammation, passive iodine accumulation, other tumors, and, sometimes, unknown causes can all potentially generate false-positive imaging. Missing detection of false-positive imaging could result in over-staging and inappropriate RIT or it could lead to the non-detection of other cancers. We examine the reasons for these possible pitfalls.

Low-intermediate dose of lenvatinib in anaplastic thyroid cancer is highly effective and safe

We report two cases of anaplastic thyroid cancer (ATC) which had a very good response to a treatment with lenvatinib at 14 mg. A 73-year-old man with ATC stage IVB was operated on, undergoing a near-total thyroidectomy, and the pathological remnant tissue showed a quick and partial response to treatment with the drug. The patient had a single metastasis in the brain after 9 months, but then died due to bronchopneumonia after undergoing a neurosurgical intervention for the complete removal of the lesion. A 74-year-old woman with ATC stage IV was operated on, undergoing a near-total thyroidectomy after a neoadjuvant treatment with the drug, that was continued after surgical treatment. She had a partial remission of the local disease and of distant metastasis, which lasted for 14 months. She then died 4 months later due to cancer progression. Lenvatinib at 14 mg appears to be effective, fast and well tolerated.

The BRAF V600E mutation in papillary thyroid cancer with positive or suspected pre-surgical cytological finding is not associated with advanced stages or worse prognosis

The mutation BRAF V600E is thought to be a putative prognostic marker of the aggressiveness of several cancers among which is also papillary thyroid cancer. Our study aimed to evaluate whether this mutation is associated with advanced stages of disease or with a worse prognosis in a series of patients with cytological findings of Thyr 4 and Thyr 5 and who were undergoing total thyroidectomy and routine central compartment lymph-node dissection. 110 patients were consecutively enrolled over an 18-month period from September 2010 to March 2012. All patients had cytological findings that were either indicative of, or positive for papillary thyroid cancer, Thyr 4 or Thyr 5. Detection of BRAF mutation was made on fine-needle aspiration specimen by pyrosequencing after microdissection and DNA extraction of neoplastic cells. After surgical intervention, the patients underwent radioiodine ablation according to our protocol, and follow-up was performed after 8 months. The BRAF V600E mutation was found in 79 % of our cases: 85.7 % of these cases represented the classical variant, 57.8 % the follicular variant, 89.6 % the tall cell variant, and 33.3 % the solid variant. All patients had confirmation of papillary thyroid cancer after histology, with no differences being seen in pTNM presentation between patients with BRAF wild-type and patients with BRAF V600E mutation. Ninety-nine patients underwent radioiodine ablation. Results at follow-up 8 months after radioiodine ablation showed no differences in the rate of ablation between patients harboring BRAF V600E mutation and those having BRAF wild-type. The BRAF V600E mutation doesn't appear to be a reliable risk factor for the aggressiveness of a tumor. BRAF analysis should neither be the only guide for pre-surgical decisions regarding the extent of surgery nor for post-surgical decisions regarding the aggressiveness of the treatment.

Thyroid disease prevalence in carabineers deployed in a war theater

The problem of morbidity in deployed military personnel represents a much-debated topic. Because there have been two cases of thyroid cancer in the Tuscania regiment, the aim of the present study was to investigate the prevalence of all types of thyroid disease in a cohort of carabineers. A total of 673 carabineers, including 501 deployed carbineers (DCs) (29-48 years of age) and 172 nondeployed carabineers (NDCs) (29-51 years of age), of the Tuscania regiment were involved in the study. Thyroid volume, percentages of single nodules and multinodular goiter, percentage of autoimmune thyroid disease, and percentages and histological types of thyroid cancer were all measured. No statistical difference between DCs and NDCs was found for any of the data. Furthermore, when we divided DCs into subgroups according to time spent on deployment and time elapsed since the first deployment, we found no differences. However, a high prevalence of thyroid cancer was found in our cohort (2.0% in DCs and 2.5% in NDCs; not significant), and the prevalence of thyroid cancer in nodules in the cohort of carabineers was higher (10.0%) than the prevalence of thyroid cancer in nodules in the civilian population (5.6%, p < 0.001). No differences regarding the prevalence of thyroid diseases were observed when we compared DCs and NDCs, which suggests that no significant difference in exposure to toxic or carcinogenic substances that could have affected the thyroid occurred during deployments. The high prevalence of thyroid cancer in carabineers may merely reflect an increase of this cancer in the general population, or it may suggest the presence of some carcinogenic event in this specific cohort.

Foot bone mass and analysis of calcium metabolism in diabetic patients affected by severe neuropathy

AIM

Charcot neuro osteoarthropathy (NAC) is a devastating foot complication which is associated to peripheral neuropathy. The aim of this study was to investigate the changes in foot bone mass in patients with peripheral neuropathy and to correlate this with calcium metabolism in diabetes.

METHODS

The study included three groups of patients enrolled consecutively: group 1 consisted of 28 diabetic patients, affected by both peripheral neuropathy and autonomic neuropathy as well as monolateral foot ulcer; group 2 consisted of 10 diabetic patients without neuropathy and without foot ulcerations; group 3 consisted of 10 healthy people. In all patients we studied calcium and bone metabolism and quantitative ultrasonography (QUS) of calcaneal bone was performed in both feet in each subject. Calcium and bone metabolism were assessed by the assay of serum parathyroid hormone (PTH), serum calcium, serum phosphorus, serum magnesium, serum bone alkaline phosphatase isoenzyme and urinary excretion of deoxypyridinoline DPD.

RESULTS

In patients with neuropathic ulceration, QUS showed a decrease in bone density in the affected foot: mean T score in the normal foot was -0.54+/-0,26 (mean+/-ESM) while mean T score in the foot with the ulcer was -1.23+/-0.31 (mean+/-ESM) (P=0.004). In diabetic patients without neuropathy the authors did not find any difference in T score between the two feet. Moreover, the T score in the feet in these patients didn't show any differences in comparison to the T score of the healthy foot in neuropathic patients. The T-score in the feet of normal subjects didn't show any difference in respect to the healthy feet in diabetic patients. No difference of serum parameters of calcium metabolism was seen among the groups, while, among the parameters of bone metabolism, B-ALP was elevated in patients with foot ulcer.

CONCLUSION

These data suggest that bone demineralization is associated to peripheral neuropathy with foot ulceration. MOC can represent a way to personalized therapy of patients who are prone to fractures and to the development of NAC.

Percutaneous Laser Ablation in the Treatment of Toxic and Pretoxic Nodular Goiter

OBJECTIVE

To report data regarding treatment with use of percutaneous laser ablation (PLA) in autonomously functioning thyroid nodules (AFTN).

METHODS

We treated 18 patients (10 women and 8 men, 31 to 80 years old) who presented with a single hyperfunctioning thyroid nodule (8 patients) or a multi-nodular goiter (10 patients) with clearly hyperfunctioning areas on a thyroid scintiscan. In 5 cases, free thyroxine (FT4) and free triiodothyronine (FT3) levels were high, and in these patients and a further 9 patients with cardiovascular symptoms, methimazole therapy was initiated to restore euthyroidism. The total number of PLA sessions ranged from 1 to 5 (median, 3). Thyroid-stimulating hormone, FT4, FT3, thyroglobulin, and antithyroglobulin and anti-thyroid peroxidase antibodies were measured by a commercial kit the day after PLA treatment, then weekly during the first month, and monthly thereafter. The Student t test was used for statistical analyses, and data are reported as mean values +/- SE.

RESULTS

After each PLA session, there was a transient and mild increase in FT4 and FT3-5.2% to 18.1% (mean, 11.1 +/- 0.69%) (P<0.001) in patients not treated with methimazole and 4.0% to 8.3% (mean, 5.9 +/- 0.31%) (P<0.001) in patients treated with methimazole-relative to values before treatment; however, these values never reached the range of hyperthyroidism. In addition, thyroglobulin showed a remarkable increase after 24 hours- 115% to 390% (mean, 266.0 +/- 12.7%) (P<0.001). Thyroid-stimulating hormone increased in all cases and reached normal values in all patients with single AFTN and in 5 patients (50%) with multinodular goiter within 3 months after PLA. At 1-year follow-up, the decrease in nodular volume was 24% to 72% (mean, 59.3 +/- 8.2%; P<0.001).

CONCLUSION

Our data show that PLA can be a useful treatment in AFTN and particularly in single toxic nodules. Possible elective indications are patients who refuse surgical or radioiodine treatment and patients with cardiovascular comorbidity who need rapid restoration of the euthyroid state and who cannot tolerate the discontinuation of antithyroid drugs for radioiodine treatment.

Recombinant human thyroid-stimulating hormone is effective for radioiodine ablation of post-surgical thyroid remnants

OBJECTIVE

To investigate whether recombinant human thyroid-stimulating factor (rhTSH) is effective for the radiometabolic ablation of post-surgery thyroid remnants, using low doses of (131)I.

PATIENTS AND METHODS

The study included two groups of patients enrolled consecutively: group 1 consisted of 52 patients with papillary cancer or minimally invasive follicular cancer (stage I and II), and group 2 consisted of 41 patients with the same stage of disease. All patients underwent a total thyroidectomy. Group 1 received 1.11 GBq (30 mCi) (131)I for post-surgical remnants ablation with the aid of rhTSH, while group 2, in the hypothyroid state, received the same amount of radioiodine. To minimize iodine interference, all patients remained on a low iodine diet for 2 weeks and L-thyroxine (L-T4) was stopped for 4 days in the group of patients treated with the aid of rhTSH. To investigate (131)I uptake in this group, a tracer dose was administered 3 h after the second injection of rhTSH and the uptake was evaluated at 24 h just before administration of the therapeutic dose. I was also measured in the patients treated in the hypothyroid state just before the therapeutic dose was given.

RESULTS

After 1 year both groups were studied by using whole-body scintigraphy (WBS) and measuring thyroglobulin after rhTSH. In group 1, WBS was negative in 76.9% (40 patients), while thyroglobulin-stimulated levels were <1.0 ng . ml(-1) in 86.5% (45 patients). In Group 2, WBS was negative in 75.6% (31 patients), while thyroglobulin-stimulated levels were <1 ng . ml(-1) in 78.0% (32 patients). (131)I uptake was 2.29+/-0.45 in the group treated with the aid of rhTSH, and 3.30+/-0.7 in the group treated in the hypothyroid state (P=0.2). No patients treated with the aid of rhTSH and with the short stoppage of L-T4 experienced symptoms of hypothyroidism, and free thyroxine (FT4) and thyroid-stimulating hormone levels remained normal.

CONCLUSIONS

Our data confirm that, when the interference of iodine is minimized, rhTSH is highly effective for the treatment of post-surgical thyroid remnants using a low dose of (131)I.

Thyroid papillary cancers: microcarcinoma and carcinoma, incidental cancers and non-incidental cancers - are they different diseases?

OBJECTIVE

Tumour size represents a much-debated prognostic factor in papillary cancer, and the necessity to perform a fine-needle aspiration (FNA) on small nodules is a frequent matter of discussion. We compared some prognostic histological features for various sizes of papillary cancers (PCs) and, with regard to these prognostic features, we compared non-incidental with incidental PCs. We also considered the possibility that ultrasonography could detect nodules harbouring the most aggressive cancers.

DESIGN AND PATIENTS

We have studied patients with a histological diagnosis of PC from 1999 to 2003. FNA was performed on all nodules > 1.0 cm and on hypoechoic nodules with irregular margins or microcalcification when the size was < 1.0 cm (3321 FNAs in total). We were able to consider several different types of patients: those with PC diagnosed by FNA before surgery; those with large goitre and PC of small size diagnosed after histological examination and in whom a careful examination of the presurgical ultrasonography could show a distinct highly suspicious nodule that was not subjected to FNA, and patients with real incidental PC (that is, those with nodular goitre who correctly underwent FNA on suspicious nodules but in whom thyroid cancer was discovered only at histological examination). We considered two groups of patients with PC. Group 1 PCs were diagnosed before surgery with FNA (128 cases); in this group we also considered the two cases that were not correctly diagnosed before surgery. Group 2 real incidental PCs (12 cases) were found in goitres at histological examination after thyroidectomy for goitre (282 thyroidectomies). Group 1 was divided into three subgroups according to the maximum size of the PC at histological examination: (a) 44 PCs with maximum size < 10 mm, (b) 47 PCs with maximum size between 10 mm and 20 mm, and (c) 39 PCs with maximum size 20 mm. In all subgroups 1 as well as in group 2, the following four histological features were considered separately: multifocality, extracapsular extension, lymph-node involvement and its extent, and special aggressive features (dedifferentiation and/or insular aspects, tall and columnar variants).

RESULTS

In subgroups 1a, 1b and 1c the results were, respectively: multifocality 56.8, 57.4 and 51.2%; extracapsular extension 27.2, 23.4 and 46.3% (P = 0.01, subgroups 1a and 1b vs. subgroup 1c); lymph-node metastasis 13.5, 23.3 and 46.1% (P = 0.003 subgroup 1a vs. 1c; P = 0.04, subgroup 1b vs. 1c); special aggressive features 11.3, 25.5 and 28.2% (P = ns). Group 2 showed one case of multifocality (8.3%) in a patient with prior exposure to radiotherapy in childhood, while no case was found of extracapsular invasion or lymph-node involvement, and only one patient had a PC with features of dedifferentiation.

CONCLUSIONS

Non-incidental cancer, apart from multifocality, showed a classical progression for all prognostic factors from microcarcinoma to larger cancers. However, real incidental PC seemed to be different from non-incidental PC microcarcinoma regarding the main prognostic features. We conclude that ultrasonography is useful not only in terms of revealing the presence of cancer but also in identifying the most aggressive cancers.

Genetic analysis of TTF-2 gene in children with congenital hypothyroidism and cleft palate, congenital hypothyroidism, or isolated cleft palate

Homozygous null mice for thyroid transcription factor (TTF)-2 gene exhibit cleft palate and thyroid malformation. We performed a genetic analysis of the TTF-2 gene in 2 children with congenital hypothyroidism (CH) and cleft palate, 45 children with thyroid dysgenesis, 19 children with isolated cleft palate or cleft lip, 4 patients with thyroid hemiagenesis. The entire coding-region of the TTF-2 gene was analyzed by direct sequencing. Direct sequencing of the TTF-2 gene revealed polymorphisms in the length of the polyalanine tract. The most frequent stretch length was 14 residues and it was found in 50 of 70 (71%) and in 45 of 53 (85%) normal healthy controls. A polyalanine tract of 16 residues in the heterozygous state was seen in 18 of 70 (26%) cases and in 4 of 53 (7%) normal subjects. In 1 of 4 (25%) case of hemiagenesis a polyalanine tract of 16 residues in the homozygous state was observed. In 1 of 26 agenesis the polyalanine tract consisted of 12 residues in the heterozygous state. Direct sequencing also revealed the presence of two silent polymorphisms. No mutations were identified in the TTF-2 gene. In conclusion, our results show that no genetic alteration was present in the TTF-2 gene of these patients, suggesting that defects in the TTF-2 gene are a rare event.

Assay of Free Thyroxine and Free Triiodothyronine in Fine-Needle Aspiration of Thyroid Nodules: a Useful and Low-Cost Assessment

OBJECTIVE

To evaluate whether analysis of thyroid hormones in fine-needle aspiration (FNA) of thyroid nodules can provide information about the functional status and the nature of the nodules.

METHODS

We studied 4 groups of patients: group 1, 17 patients with autonomous hyperfunctioning thyroid nodules; group 2, 52 patients with cold nonfunctioning thyroid nodules; group 3, 12 patients with malignant thyroid nodules; and group 4 (control group), 10 patients with nonthyroid nodular lesions (enlarged parathyroid glands or lymph nodes). The assay of thyroid hormones was performed in FNA after the washing of needles and, with patient consent, also in normal thyroid parenchyma.

RESULTS

The free thyroxine (FT(4)) and free triiodothyronine (FT(3)) values were remarkably high in group 1 (mean, 5.5 +/- 0.53 ng/dL and 27.6 +/- 3.1 pg/mL, respectively; P<0.05 versus group 2 and group 4, the control group). The levels of FT(4) and FT(3) were very low in group 3 (<0.2 ng/dL and <1.0 pg/mL, respectively; P<0.05 versus group 2). Thyroglobulin values in FNA specimens were much higher than the normal range in human serum, but no significant differences were found between the various groups. The control group had low levels of FT(4) and FT(3) (<0.2 ng/dL and <1.0 pg/mL, respectively) in conjunction with low levels of thyroglobulin, whereas parathyroid hormone levels were high in parathyroid nodules.

CONCLUSION

These results show that assay of FT(4) and FT(3) in FNA can yield information about the functional status of thyroid nodules and, indirectly, about the nature of nodules. In this era of sophisticated new molecular markers in FNA cytology, this low-cost diagnostic method can be readily performed in every laboratory.

Radioiodine treatment with 30 mCi after recombinant human thyrotropin stimulation in thyroid cancer: effectiveness for postsurgical remnants ablation and possible role of iodine content in L-thyroxine in the outcome of ablation

The main steps in the management of differentiated thyroid cancer are thyroidectomy, treatment with iodine-131 ((131)I), and follow-up with whole-body scanning (WBS) and serum thyroglobulin (Tg) determination. Both (131)I treatment and follow-up require maximum stimulation of normal or pathological thyroid remnants by TSH. The use of recombinant human TSH (rhTSH) has been shown to be useful for follow-up, whereas previous reports are not univocal regarding the use of (131)I postsurgical ablation of thyroid remnants, at least when low doses (30 mCi) of (131)I are administered. A possible explanation for the diminished effectiveness of (131)I treatment after rhTSH may be the interference of iodine content of L-thyroxine (L-T4) therapy during the protocol of administration of rhTSH. We have evaluated the effectiveness of stimulation by rhTSH for radioiodine ablation of postsurgical remnants, stopping L-T4 the day before the first injection of rhTSH and restarting L-T4 the day after (131)I. The study included two groups of patients: group 1 included 16 patients with differentiated thyroid cancer (15 papillary cancers and 1 follicular cancer, stages I and II), who were treated with 30 mCi (131)I with the aid of rhTSH, using the standard protocol but stopping L-T4 as stated previously; and group 2 included 24 patients with the same features (histology and stage) of disease treated with 30 mCi in the hypothyroid state after L-T4 withdrawal. In both groups, serum TSH reached a very good stimulation level [76-210 U/liter (mean, 112 +/- 11 SE) and 38-82 U/liter (mean, 51 +/- 3 SE), respectively]. At the first WBS (after (131)I treatment), all patients showed thyroid remnants. Furthermore, two patients of the first group and three patients of the second group showed lymph node metastases. After 1 yr, all patients were studied again and underwent WBS with a tracer dose of (131)I and serum Tg measurement using rhTSH with the same protocol in both groups. The percentage of ablation (undetectable Tg and a negative WBS) was higher, although not reaching statistical significance, in patients treated with rhTSH: 81.2% in patients treated by rhTSH withdrawal and 75.0% in patients treated by L-T4 withdrawal, respectively. No patient experienced symptoms of hypothyroidism during the 4 d of L-T4 interruption, and serum T4 remained in the normal range. Urinary iodine was analyzed in both groups and compared with a control group of patients who received, for diagnostic purposes, rhTSH without stopping L-T4. In the first group, urinary iodine was 47.2 +/- 4.0 microg/liter (mean +/- SE; P = 0.21 vs. the second group, P = 0.019 vs. control group). In the second group, urinary iodine was 38.6 +/- 4.0 microg/liter (mean +/- SE; P < 0.001 vs. control group); urinary iodine in the control group was 76.4 +/- 9.3 microg/liter (mean +/- SE). Our data show that rhTSH, as administered in the protocol stated previously, allows at least the same rate of ablation of thyroid remnants when low doses (30 mCi) of (131)I are used. The possible role of interference of iodine content in L-T4 is not surprising if we consider that the amount of iodine in 30 mCi is negligible (5 microg) compared with the amount of iodine content in a daily dose of T(4) ( approximately 50 microg). The cost of rhTSH seems modest compared with the high cost of complex therapeutic regimens in other areas of oncology and in consideration of the well-being of patients and of the high level of effectiveness of the treatment.

Cloning, chromosomal localization and identification of polymorphisms in the human thyroid transcription factor 2 gene (TITF2)

The human gene encoding the thyroid transcription factor 2 (TTF-2) was cloned and mapped to human chromosome 9q22. Three polymorphisms were identified in the gene by SSCP and direct sequencing: two consist of a third base substitution in the triplet encoding Leu129 and Ser273, and the third is an alanine stretch that varies from 12 to 17 residues. TTF-2 plays a critical role during thyroid morphogenesis in mice, and in man the TITF2 gene is associated with congenital hypothyroidism and cleft palate with thyroid dysgenesis. The polymorphisms identified in this study can be used as markers to study the role of the TITF2 gene in other cases of thyroid dysgenesis, especially in familial cases.

Serum iodothyronines in the human fetus and the newborn: evidence for an important role of placenta in fetal thyroid hormone homeostasis

The pattern of circulating iodothyronines in the fetus differs from that in the adult, being characterized by low levels of serum T3. In this study, concentrations of various iodothyronines were measured in sera from neonates of various postconceptional age (PA). Results obtained in cord sera at birth (PA, 24-40 weeks), reflecting the fetal pattern, were compared with those found during extrauterine life in newborns of 5 days or more of postnatal life (PA, 27-46 weeks). The main findings are: Starting at 30 weeks of PA, serum levels increase linearly during extrauterine life; and at 40 weeks, they are more than 200% of those measured in cord sera from newborns of equivalent PA. Serum reverse T3 (rT3) levels during fetal life are higher than those measured during extrauterine life; but they significantly decrease, starting at 30 weeks of PA. Serum T3 sulfate (T3S) does not significantly differ between the two groups, showing the highest values at 28-30 weeks of PA, and significantly decreasing at 30-40 weeks. T3S levels are directly correlated with rT3, both in fetal and extrauterine life, whereas a significant negative correlation between T3S and T3 is found only during extrauterine life.

IN CONCLUSION

1) changes in serum concentrations of iodothyronines in umbilical cord and during postnatal life indicate that maturation of extrathyroidal type I-iodothyronine monodeiodinase (MD) accelerates, starting at 30 weeks of PA; 2) high levels of type III-MD activity in fetal tissues prevent the rise of serum T3, whereas they maintain high levels of rT3 during intrauterine life; 3) an important mechanism leading to the transition from the fetal to the postnatal thyroid hormone balance is a sudden decrease in type III-MD activity; iv) because placenta contains a high amount of type III-MD, it is conceivable that placenta contributes to maintain low T3 and high rT3 serum concentrations during fetal life and that its removal at birth is responsible for most changes in iodothyronine metabolism occurring afterwards.

Chronic recurrent stress due to panic disorder does not precipitate Graves' disease

A role of psychic stress in precipitating hyperthyroid Graves' disease has been suggested, but the evidence in support of this pathogenetic mechanism is conflicting. In this study we investigated the possible occurrence of Graves' disease in patients with panic disorder, a psychiatric condition characterized by recurrent endogenous stress. The study group included 87 consecutive patients suffering from panic disorder since 1 to 30 years: 17 males (mean age 31.3, range 26-43 years) and 70 females (mean age 37.6, range 15-73 years). Two hundred and sixty-two normal subjects with no present or past history of psychiatric disorder served as controls. Patients were submitted to a full evaluation of the thyroid that included physical examination, assays for free thyroid hormones, TSH, thyroglobulin (TgAb), thyroperoxidase (TPOAb) and TSH receptor (TRAb) antibodies, and thyroid echography. The prevalence of circulating TgAb and/or TPOAb in patients with panic disorder did not differ from that in the control group. Twelve patients with panic disorder (13.7%) had circulating TgAb and/or TPOAb, but none had TRAb. Three out of 12 patients with thyroid antibodies, indicating a genetic susceptibility to autoimmune thyroid disease, had a family history of clinical thyroid autoimmunity, and 4 of them had a hypoechogenic pattern of the thyroid at ultrasound suggesting autoimmune thyroiditis. None of the patients with panic disorder had a previous history of hyperthyroidism. On examination, clinical hyperthyroidism or endocrine ophthalmopathy were not found in any of them. A small goiter was appreciated by palpation in 16 patients (18.3%). Free thyroid hormones and TSH were within the normal range in all patients but one: a 55-year old lady with normal serum free thyroid hormones and undetectable TSH. During an 18-month follow-up she did not develop hyperthyroidism and her TSH spontaneously returned in the normal range. Considering the individual duration of panic disorder, evidence for previous or present Graves' hyperthyroidism was not found for a total of 478 patient-years of exposure to recurrent endogenous stress in the whole study group, and for a total of 39 patient-years in patients with a genetic susceptibility to autoimmune thyroid disease. In conclusion, we found that recurrent endogenous stress did not precipitate Graves' hyperthyroidism in a series of 87 patients with panic disorder, encompassing a total of 478 patient-years of exposure to stress. Failure to activate the hypothalamic-pituitary-adrenal axis by endogenous stress due to panic disorder as opposed to exogenous stress due to life-events might explain why panic disorder does not precipitate Graves' hyperthyroidism.

PAX8 mutations associated with congenital hypothyroidism caused by thyroid dysgenesis

Permanent congenital hypothyroidism (CH) is a common disease that occurs in 1 of 3,000-4,000 newborns. Except in rare cases due to hypothalamic or pituitary defects, CH is characterized by elevated levels of thyroid-stimulating hormone (TSH) resulting from reduced thyroid function. When thyroid hormone therapy is not initiated within the first two months of life, CH can cause severe neurological, mental and motor damage. In 80-85% of cases, CH is associated with and presumably is a consequence of thyroid dysgenesis (TD). In these cases, the thyroid gland can be absent (agenesis, 35-40%), ectopically located (30-45%) and/or severely reduced in size (hypoplasia, 5%). Familial cases of TD are rare, even though ectopic or absent thyroid has been occasionally observed in siblings. The pathogenesis of TD is still largely unknown. Although a genetic component has been suggested, mutations in the gene encoding the receptor for the thyroid-stimulating hormone (TSHR) have been identified in only two cases of TD with hypoplasia. We report mutations in the coding region of PAX8 in two sporadic patients and one familial case of TD. All three point mutations are located in the paired domain of PAX8 and result in severe reduction of the DNA-binding activity of this transcription factor. These genetic alterations implicate PAX8 in the pathogenesis of TD and in normal thyroid development.

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.

Study of serum 3,5,3'-triiodothyronine sulfate concentration in patients with systemic non-thyroidal illness

Sulfation is an important pathway of triiodothyronine (T3) metabolism. Increased serum T3 sulfate (T3S) values have been observed during fetal life and in pathological conditions such as hyperthyroidism and selenium deficiency. Similar variations have also been reported in a small number of patients with systemic non-thyroidal illness, but the underlying mechanisms have not been elucidated. In this study, serum T3S concentrations have been measured by a specific radioimmunoassay in 28 patients with end-stage neoplastic disease (ESND) and in 44 patients with chronic renal failure (CRF); 41 normal subjects served as controls. Both ESND and CRF patients had lower serum total T4 (TT4) and total T3 (TT3) than normal controls, while serum reverse T3 (rT3) was increased significantly in ESND (0.7 +/- 0.5 nmol/l; p < 0.001 vs. controls) but not in CRF (0.3 +/- 0.1 nmol/l). The TT3/rT3 ratio, an index of type I iodothyronine monodeiodinase (type I MD) activity, was reduced significantly in both groups of patients. Serum T4-binding globulin (TBG) was decreased in CRF but not in ESND patients. Serum T3S was significantly higher both in ESND (71 +/- 32 pmol/l) and CRF (100 +/- 24 pmol/l) than in controls (50 +/- 16 pmol/l, p < 0.001). Serum T3S values showed a positive correlation with rT3 values and a negative correlation with both TT3 and FT3 values in ESND, but not in CRF. In the latter group a positive correlation was observed between T3S and TBG values. The T3S/FT3 ratio was higher both in CRF (18 +/- 5) and in ESND (23 +/- 18) as compared to controls (10 +/- 4). Serum inorganic sulfate was increased and correlated positively with T3S values in CRF patients. In conclusion, the results of this study in a large series of patients confirm that patients with systemic non-thyroidal illness have increased serum T3S levels. The mechanisms responsible for these changes appear to be different in ESND and CRF patients. In ESND the increase in serum T3S levels is mainly related to reduced degradation of the hormone by type I MD, whereas in CRF it might be driven by the enhanced sulfate ion concentration, and could be partially dependent on the impaired renal excretion of T3S. Because T3S can be reconverted to T3, it is possible that increased T3S concentrations contribute to maintenance of the euthyroid state in systemic non-thyroidal disease.

The location and the regulation of the type I-iodothyronine 5'-monodeiodinase (type I-MD) in the rat thyroid: studies using a specific anti-type I-MD antibody

Type I-iodothyronine monodeiodinase (type I-MD) is abundant in thyroid tissue and contributes to the generation of T3 secreted by the gland. The availability of a specific antibody against rat type I-MD (type I-MD Ab) allowed us to directly identify this enzyme in rat thyroid glands, and in a differentiated strain of rat thyroid cells maintained in continuous culture (FRTL-5 cells). FRTL-5 cells maintain many differentiated functions of thyroid cells, including the expression of TSH receptor and thyroid peroxidase. Using an immunohistochemical technique on rat thyroid sections, a clear staining for type I-MD was demonstrated in follicular cells. The degree of immunoreactivity was greater in small follicles containing little amounts of colloid compared to large follicles lined by functionally inactive cells. Using immunofluorescence (IFL), a strong staining for type I-MD was observed in FRTL-5 cells grown in medium containing TSH. Both in vivo and in culture the staining for type I-MD was localised in the cytoplasm of thyroid cells, while nuclei were negative. Interestingly, no surface staining was shown when viable FRTL-5 cells were submitted to the same IFL procedure. TSH deprivation for 7 days was followed by the disappearance of type I-MD. Immunoreactivity for type I-MD was recovered by addition of TSH, forskolin or thyroid stimulating antibody (TSAb) to TSH-deprived FRTL-5 cells. The effect of TSH was prevented by cycloheximide. There was no induction of type I-MD when IGF-I was added to FRTL-5 cells.(ABSTRACT TRUNCATED AT 250 WORDS)

Simultaneous expression of thyroid peroxidase and human leukocyte antigen-DR by human thyroid cells: modulation by thyrotropin, thyroid-stimulating antibody, and interferon-gamma

Major histocompatibility class II molecules human leukocyte antigen-DR (HLA-DR) are abnormally expressed by human thyroid cells (HTC) in autoimmune thyroid glands. The simultaneous expression of HLA-DR and organ-specific autoantigens such as thyroid peroxidase (TPO) by HTC might enable these cells to function as antigen-presenting cells, thus perpetuating the autoimmune process. The aim of the present study was to clarify the interplay of endocrine (TSH) and immune [TSab or interferon-gamma (IFN gamma)] factors on the expression of HLA-DR and TPO in HTC. Thyrocytes were cultured with supernatants of T-cells cloned from the infiltrate of Hashimoto's glands, human recombinant IFN gamma, TSab, or TSH. These factors were added either alone or in different combinations and sequences. HLA-DR and TPO were identified in HTC by a double indirect immunofluorescence technique, using a monoclonal anti-HLA-DR antibody and human serum containing anti-TPO antibody, respectively. IFN gamma, either recombinant or produced by T-cell clones, induced HLA-DR appearance in thyrocytes, whereas TSH or TSab stimulated TPO expression. The appearance of HLA-DR induced by IFN gamma was accompanied by a progressive reduction of TPO despite stimulation by TSH or TSab. This decline reached a nadir after 9-10 days in different primary cultures. During this period, a percentage of cells ranging from 10-40% simultaneously expressed HLA-DR and TPO on their surface and in the cytoplasm. The inhibition of TPO expression and the appearance of HLA-DR induced by IFN gamma were rapidly reverted when TSH or TSab was substituted for interleukin in the culture medium and vice versa. We conclude that 1) the expression of TPO or HLA-DR in thyroid cells is a dynamic phenomenon that is differently influenced by TSH, TSab, and IFN gamma. It is the interplay of these factors in different follicles and during different periods of time that determines the expression of TPO alone, HLA-DR alone, or both molecules together in the same thyroid cell; 2) during exposure to TSH (or TSab) and IFN gamma, TPO and HLA-DR can be expressed simultaneously by thyroid cells for up to 7 days; and 3) the modulation of HLA-DR and TPO by supernatants of T-cells cloned from Hashimoto's glands is reproduced by IFN gamma alone.

Studies on the in vitro cytotoxic effect of amiodarone

Amiodarone, a potent antiarrhythmic drug, contains 37.2% iodine by weight and may induce either hypo- or hyperthyroidism. The high iodine content of amiodarone may be responsible for both complications, but a cytotoxic effect of the drug on the thyroid resulting in thyroiditis has been reported. In the present study the cytotoxic effect of amiodarone was evaluated in three culture systems with different biological properties: 1) a strain of rat thyroid cells (FRTL-5 cells) that maintains most differentiated functions of normal thyroid cells, including an active iodide pump, but an inability to organify iodide; 2) a line of Chinese hamster ovary (CHO) fibroblasts; and 3) freshly prepared primary cultures of human thyroid follicles (hTF) that trap and organify iodide. Cells were radiolabeled with 51Cr and incubated for 24 h with medium alone, medium plus amiodarone (3.75-200 microM), medium plus an iodinated radiographic contrast agent (sodium diatrizoate; 7.5-200 microM), or medium plus potassium iodide (7.5-300 microM). At concentrations ranging from 75-200 microM, amiodarone induced a significant and dose-dependent release of 51Cr in FRTL-5 cells. In contrast, diatrizoate or KI had no cytotoxic effect on FRTL-5 cells. In the same molar concentrations, amiodarone was also cytotoxic in CHO cells. In hTF, the release of 51Cr produced by amiodarone occurred at a lower concentration (37.5 vs. 75 microM) and was significantly greater than that in FRTL-5 cells. The cytotoxic effect of amiodarone in hTF was partially, but significantly, reduced by methimazole, an inhibitor of iodide organification. In the FRTL-5 cell culture system, amiodarone also produced a dramatic inhibition of TSH-stimulated cell growth. This growth-inhibiting effect of amiodarone was evident at low concentrations (3.75-7.5 mumol/liter) of the drug, which did not produce significant cytotoxicity. In conclusion, 1) amiodarone had a cytotoxic effect in CHO fibroblasts, a nonthyroid cell line; 2) this cytotoxic effect occurred in thyroid cells independent of their ability to organify iodide; 3) however, the toxic effect of amiodarone was greater and occurred at a lower molar concentration in freshly prepared human thyroid follicles that trap and organify iodide; and 4) in the latter culture system, methimazole, an inhibitor of iodide organification, partially, but significantly, reduced the cytotoxic effect of amiodarone. These data suggest that thyroid cytotoxicity produced by amiodarone is mainly due to a direct effect of the drug on thyroid cells, but excess iodide released from the drug may contribute to its toxic action.

Antibodies producing complement-mediated thyroid cytotoxicity in patients with atrophic or goitrous autoimmune thyroiditis

Thyroid-cytotoxic antibodies (thyroid-cytotoxic Abs) have been described in patients with autoimmune thyroiditis, but their role in the development of hypothyroidism remains to be clarified. In this study, we evaluated the pathogenetic role of thyroid-cytotoxic Abs in 20 patients with atrophic thyroiditis (idiopathic myxedema; AT) and 94 patients with goitrous Hashimoto's thyroiditis (HT). Among patients with HT, 27 were euthyroid (HT-E), 27 had subclinical hypothyroidism (HT-SH), and 40 had overt hypothyroidism (HT-H). Seventeen normal subjects and 8 patients with nonthyroidal illnesses were used as controls (C). To detect thyroid-cytotoxic Abs, human thyroid cells expressing thyroid peroxidase (TPO) were labeled with 51Cr and challenged with the immunoglobulin G (IgG) fraction of serum plus rabbit complement. The cytotoxic effect of IgGs was calculated as the percent specific lysis (% SL), taking into account the lytic effect of complement alone and the maximal lysis produced by a detergent. Most C-IgGs decreased the cytotoxic effect of complement (median % SL, -3.3). IgGs from hypothyroid patients with thyroiditis had a greater cytotoxic effect than C-IgGs, either as a whole group (P < 0.001), or when subdivided according to clinical diagnosis: HT-SH (median % SL, 4.8; P < 0.005), HT-H (%SL, 2.2; P < 0.0001), or AT (%SL, 0.9; P < 0.01). Among patients with HT, the lytic activity of IgGs from patients with subclinical and overt hypothyroidism was higher than that of IgGs from euthyroid patients (P < 0.05). The results of IgGs from euthyroid patients with HT (median % SL, -0.9) did not significantly differ from those of C-IgGs. By taking a cut-off over the upper range of % SL produced by C-IgGs (> 2), the prevalence of thyroid-cytotoxic Abs was 30% in AT, 59% in HT-SH, and 55% in HT-H. However, 37% of euthyroid patients with HT also had thyroid-cytotoxic Abs. No IgG containing TPO antibodies (TPOAb) at low titer (< 40(2)) was cytotoxic. However, the levels of thyroid-cytotoxic Abs did not correlate with TPOAb titers, and preabsorption with TPO only partially abolished the lytic effect of some HT-IgG. These findings suggest that TPO is a target of thyroid-cytotoxic Abs, but other thyroid antigens are also involved in the cytotoxic reaction.(ABSTRACT TRUNCATED AT 400 WORDS)

Thyroid autoimmunity and female gender

Sexual dimorphism exists in regard to the immune response between women and men, and it accounts for the greater prevalence of thyroid autoimmunity in women. Similarly to the human situation a sex-related susceptibility to autoimmune thyroiditis is evident in animal models. A direct influence of genes on sex chromosomes (X or Y) on the immune response has been postulated in some models of autoimmune thyroiditis in rats. On the other hand sex hormones have been implicated to explain the majority of sex differences in the autoimmune response against the thyroid. A state of immune suppression during pregnancy influences the clinical course of autoimmune thyroid diseases, in that a typical amelioration during pregnancy is accompanied by aggravation following delivery. This immunologic rebound phenomenon may also underly the post partum thyroid dysfunction in otherwise healthy women with a genetic predisposition to autoimmune thyroid disease. Thyroid autoimmunity also interferes with the female reproductive function. Hypothyroidism and less frequently hyperthyroidism due to thyroid autoimmune disorders may produce menstrual dysfunction, anovulation and eventually infertility. Maternal hyper- or hypothyroidism can affect the outcome of pregnancy, producing a higher incidence of miscarriages, maternal complications, and congenital malformations. Untreated maternal hypothyroidism produced by Hashimoto's disease during pregnancy can impair the neurological development of the fetus due to a reduced availability of maternal thyroxine during early gestation.2+ More specifically, fetal and/or neonatal hypo- or hyperthyroidism produced by the transplacental passage of maternal thyroid autoantibodies can impair growth and neuropsychological development of affected children.

Evaluation of L-thyroxine replacement therapy in children with congenital hypothyroidism

The outcome of L-thyroxine (L-T4) replacement therapy in children with congenital hypothyroidism (CH) remains to be completely evaluated. In this paper the overall pattern of response to L-T4 replacement therapy was studied in a group of 19 children with CH diagnosed by neonatal screening (10 with hypoplastic/aplastic thyroid disease, group H/A; 9 with gland ectopy, group E) who were followed-up for 60 +/- 27 months (mean +/- SD). With 1 exception serum T4 at diagnosis was greater than 2 micrograms/dl in children of group E and less than 2 micrograms/dl in those of group H/A. The initial dose of L-T4 (8-10 micrograms/kg BW/day) was modified in relation to age and weight in order to maintain serum TSH less than or equal to 5 microU/ml and FT3 in the normal range. A general inverse correlation between serum TSH and FT4 or FT3 concentrations was found, and the mean levels of serum FT4 and FT3 were significantly higher according to the following order of TSH results: low TSH (0-0.5 microU/ml) greater than normal (greater than 0.5-5 microU/ml) greater than elevated TSH (greater than 5 microU/ml). TSH levels less than or equal to 5 microU/ml were associated with FT4 values in the upper half of the normal range (54% of observations) or even higher (46%). Elevation of serum FT4 alone with FT3 values in the normal range did not result in clinical thyrotoxicosis, alteration of growth or premature craniosynostosis.(ABSTRACT TRUNCATED AT 250 WORDS)