Demonstration of innate immune responses in the thyroid gland: potential to sense danger and a possible trigger for autoimmune reactions.

BACKGROUND: Autoimmune thyroid disease is an archetypal organ-specific autoimmune disorder that is characterized by the production of thyroid autoantibodies and lymphocytic infiltration into the thyroid. However, the underlying mechanisms by which specific thyroid antibodies are produced are largely unknown. Recent studies have shown that innate immune responses affect both the phenotype and the severity of autoimmune reactions. Moreover, it appears that even non-immune cells, including thyroid cells, have an ability to launch such responses. The aim of this study was to conduct a more detailed analysis of innate immune responses of the thyroid upon stimulation with various "non-self" and "self" factors that might contribute to the initiation of autoimmune reactions. METHODS: We used rat thyroid FRTL-5 cells, human thyroid cells, and mice to investigate the effects of various pathogen-associated molecular patterns (PAMPs), danger-associated molecular patterns (DAMPs), and iodide on gene expression and function that were related to innate immune responses. RESULTS: RT-PCR analysis showed that both rat and human thyroid cells expressed mRNAs for Toll-like receptors (TLRs) that sensed PAMPs. Stimulation of thyrocytes with TLR ligands resulted in activation of the interferon-beta (IFN-ß) promoter and the nuclear factor kappa-light-chain-enhancer of activated B cells (NFκB)-dependent promoter. As a result, pro-inflammatory cytokines, chemokines, and type I interferons were produced. Similar activation was observed when thyroid cells were stimulated with double-stranded DNA, one of the typical DAMPs. In addition to these PAMPs and DAMPs, treatment of thyroid cells with high concentrations of iodide increased mRNA expression of various cytokines. CONCLUSION: We show that thyroid cells express functional sensors for exogenous and endogenous dangers, and that they are capable of launching innate immune responses without the assistance of immune cells. Such responses may relate to the development of thyroiditis, which in turn may trigger autoimmune reactions.

Vitamin D deficiency in two young adults with biochemical findings resembling pseudohypoparathyroidism type I and type II.

We report two patients with vitamin D deficiency due to unbalanced diet. The patients initially presented with severe hypocalcemia, normophosphatemia and markedly elevated serum PTH levels. Although nutritional vitamin D deficiency was suspected from their history of gastrointestinal problems and dietary restriction, we conducted Ellsworth- Howard test to exclude the possibility of pseudohypoparathyroidism (PHP). Both patients showed no incremental response of urinary phosphate excretion. However, the urinary cAMP response to exogenous PTH was different between the two. Case 1 showed a blunted response (5-fold and 1.54 micro mol/h increase) and case 2 showed a normal response (39-fold and 3.04 micro mol/h increase). According to the criteria of Ellsworth-Howard test, the data of case 1 was compatible with PHP type I, and of case 2 with PHP type II. The final diagnosis of vitamin D deficiency was established in both patients based on very low serum 25-hydroxyvitamin D levels (less than 5 ng/mL) and the effect of treatment. After calcium supplementation with or without vitamin D, their biochemical abnormalities disappeared. They maintained normocalcemia without medication after correction of their unbalanced diet. The present study indicated that patients with vitamin D deficiency occasionally showed biochemical findings suggestive of PHP and that such patients could exhibit not only PHP type II pattern of response to exogenous PTH but also of type I pattern. Thus our clinical observation suggests the complexity of PTH resistance in vitamin D deficiency and underscores the importance of diet to prevent the disorder.

Genes up- or down-regulated by high calcium medium in parathyroid tissue explants from patients with primary hyperparathyroidism.

To investigate genes modulated in the parathyroid glands by calcium, expression levels of mRNA for all genes expressed in parathyroid tissue explants (PTEs) obtained from patients with primary hyperparathyroidism (I degrees -HPT) were analyzed by oligo-DNA microarray. PTEs obtained from 4 patients with I degrees -HPT were precultured in normocalcemic medium (Ca(++) 1.0-1.1 mM) for 7 days and then cultured in hypocalcemic medium (Ca(++) 0.60 mM) or hypercalcemic (Ca(++) 1.60 mM) medium containing 4 mg/dl phosphate for an additional 7 days. As expected, expression levels of mRNA for PTH and chromogranin A were decreased to less than 50% in the hypercalcemic medium when compared with those in the hypocalcemic medium. Furthermore, oligo-DNA microarray analyses revealed that 7 genes were up-regulated by more than 2-fold and more than 30 genes were down-regulated by more than 1/2 in PTEs. Interestingly, 9 of these genes (up-regulated genes: chemokine ligand 8, multiple C2 domain and transmembrane region protein 1; down-regulated genes: matrix metallopeptidase-9, B-box and SPRY domain-containing protein, nitric oxide synthase 2A, PTH, cartilage acidic protein 1, chromogranin A, and fibrin 1) were involved in calcium metabolism or calcium-signaling pathways in the parathyroid tissue. However, the expression level of mRNA for alpha-klotho was variable, and it was not constantly decreased in hypercalcemic medium under the present experimental conditions. Although it was not possible to use normal parathyroid tissue, this is the first reported study to have investigated the expression levels of mRNA for all genes in human parathyroid adenomas that are modulated by high calcium concentration in organ culture.

Successful treatment of postsurgical hypoparathyroidism by intramuscular injection of vitamin D3 in a patient associated with malabsorption syndrome due to multiple abdominal surgeries.

A 56-year-old patient with postsurgical hypothyroidism and hypoparathyroidism associated with gastrointestinal malabsorption syndrome was prescribed with L: -thyroxine and 1alpha(OH)D(3) at a massive daily dosage of 600 and 39 mug, respectively. Although the patient became nearly euthyroid, she had been hypocalcemic, requiring frequent intravenous injection of calcium gluconate to prevent tetany. Because the serum level of 1,25(OH)(2)D hardly increased after an oral intake of 21 microg 1alpha(OH)D(3), vitamin D(3) was administered intramuscularly. After stoss therapy (600,000 IU), the patient has been receiving 300,000 IU vitamin D(3) at intervals of 2-4 months so that she remained slightly hypocalcemic (7-8 mg/dl). At 1.5 years later, serum levels of 25(OH)D and 1,25(OH)(2)D were maintained at about 60 ng/ml and 30-50 pg/ml, respectively, and renal function was maintained well. These data suggest that intramuscular injection of 300,000 IU vitamin D(3) at an interval of a few months to maintain a slightly increased serum level of 25(OH)D and a slightly decreased serum level of calcium is a safe and cost-effective treatment in such a parathyroid hormone-deficient hypoparathyroid patient with malabsorption syndrome.

Iodide-induced chemokines and genes related to immunological function in cultured human thyroid follicles in the presence of thyrotropin.

BACKGROUND: It is well known that iodide exacerbates thyroid function in subclinical hypothyroid patients with autoimmune thyroiditis. To investigate the immunological mechanism of iodine-induced thyroid dysfunction, we studied the effect of iodide in cultured human thyroid follicles, which respond to physiological concentrations of human thyrotropin (TSH) (0.3-10 microU/mL) and maintain the Wolff-Chaikoff effect. MATERIALS AND METHODS: Thyroid follicles obtained from Graves' patients at subtotal thyroidectomy were precultured in medium containing 0.5% fetal calf serum and 10(-8) M iodide for 5 days, and then cultured with the medium containing bovine TSH (30 microU/mL) and low (10(-8)M) or high (10(-5)M) concentrations of iodide. After 3-72 hours of culture, the effect of iodide on thyroid cell mRNA expression was analyzed by microarray and reverse transcriptase-polymerase chain reaction. RESULTS: After 48 hours of culture, iodide nearly doubled the mRNA expression levels of the immunity-associated genes (intercellular adhesion molecule-1, transforming growth factor beta 1-induced protein, early growth response gene 1, guanylate-binding protein 1, and annexin A1) and decreased the mRNA expression of sodium-iodide symporter to less than 20%. Further, the mRNA expression levels of chemokines (CCL2, CXCL8, and CXCL14) increased nearly twofold, whereas their receptors did not show any significant response. Real-time polymerase chain reaction analyses confirmed that iodide increased the mRNA expression levels of these genes in a time- and concentration-dependent manner. Immunohistochemical studies revealed that the chemokines were expressed mainly in the thyroid follicular cells in addition to the immune cells. The iodide-induced increase in CCL2 was greater in thyroid follicles obtained from thyroid gland that had been moderately infiltrated with the immunocompetent cells. CONCLUSION: We have demonstrated that iodide stimulates thyroid follicular cells to produce chemokines, particularly CCL2, CXCL8, and CXCL14. These chemokines and intercellular adhesion molecule-1 would attract immunocompetent cells into thyroid gland. These in vitro findings suggest that iodide at high concentrations may induce thyroid dysfunction through not only biochemical but also immunological mechanisms, particularly in patients with autoimmune thyroid disorders.

Novel gain of function mutations of the calcium-sensing receptor in two patients with PTH-deficient hypocalcemia.

Among 15 patients with PTH-deficient idiopathic hypocalcemia, we found two novel missense mutations in the calcium-sensing receptor (CaSR). Patient 1, who developed severe hypocalcemia (5.0 mg/dL) and seizures after birth, had a heterozygous de novo missense mutation in the transmembrane domain (A844P). The patient is currently receiving a minimum dose of 1alpha-OHD(3) (0.5 microg/day) to maintain the serum calcium level at 6 mg/dL and thus prevent seizures. Patient 2 had asymptomatic hypocalcemia (7.5 mg/dL) and also had a heterozygous missense mutation in the extracellular domain (E228G). These findings suggest that gene analysis of CaSR should be performed in patients with idiopathic hypocalcemia, particularly when it occurs in the neonatal period.

[H2O2 oxidation of 1,4-dihydropyridines over Mg2+ ion exchanged clinoptilolite and solventless solid state acid decomposition of ester to 3,5-pyridinedicarboxylic acid].

The acid property of alkali and alkali earth cation exchanged clinoptiolites were observed by micro-calorimetry of NH(3) adsorption at 200 degrees C. The reaction rates on decomposition of tert-butyl acetate (TBA) over clinoptilolites was proportional to the acid strength. 1,4-Dihydropyridines were oxidized to corresponding Pyridines in high yields at room temperature by H(2)O(2) aqueous solution over Mg(2+) ion exchanged clinoptilolte (CZ-Mg) in acetone. Solventless acid ester decomposition of Di-tert-butyl 3,5-pyridinedicarboxylate to 3,5-Pyridinedicarboxylic acid was effected using CZ-Mg at 170 degrees C.

Association of polymorphism at position 49 in exon 1 of the cytotoxic T-lymphocyte-associated factor 4 gene with Graves' disease refractory to medical treatment, but not with amiodarone-associated thyroid dysfunction.

BACKGROUND: Recently, the G allele of the cytotoxic T-lymphocyte-associated factor 4 (CTLA-4) exon 1 single-nucleotide polymorphism (CTLA-4 A/G(49)) has been identified as the most informative marker in patients with Graves' disease. Patients with the G/G genotype are refractory to medical treatment and frequently relapse after discontinuation of antithyroid drugs. Therefore, we analyzed CTLA-4 A/G(49) in patients who had been treated with (131)I. Further, a preliminary report has suggested that amiodarone-associated thyroid dysfunction (AATD) has a relationship with human leukocyte antigen (HLA) class I and class II. METHOD: CTLA-4 genotypes in exon 1 (A/G(49)) and CT60 were analyzed in 415 Japanese patients with Graves' disease and 65 patients with AATD. RESULTS: The frequencies of the G alleles and G/G genotype at the both polymorphisms were significantly higher in Graves' patients compared with normal subjects. Compared with CT60, the frequencies of the G alleles and G/G genotypes at the A/G(49) were more significantly higher in patients with persistently positive thyrotropin receptor antibody despite >5 years of antithyroid drug therapy, compared with those whose thyrotropin receptor antibody became negative in <5 years (p < 0.0001). Consequently, the frequencies of the G/G genotype and G allele at the A/G(49) were also significantly higher in patients with Graves' disease who received (131)I therapy (p < 0.05). However, there was no significant difference in the A/G polymorphisms in the 65 patients with AATD. CONCLUSIONS: The G/G genotype in exon 1 (A/G(49)) is frequently expressed in Graves' disease patients who are refractory to antithyroid drug treatment. Therefore, the G/G genotype in A/G(49) would be a useful predictor of Graves' patients who are suitable for radioiodine therapy. Although the number of analyzed patients was small, our preliminary data suggest that the CTLA-4 gene polymorphisms might be unassociated with AATD.

PTH(7-84) inhibits PTH(1-34)-induced 1,25-(OH)2D3 production in murine renal tubules.

To elucidate whether PTH(7-84), a degradation product of PTH(1-84), which inhibits PTH(1-84)-induced bone resorption, also exerts an antagonistic effect on the kidney, we studied the effect of PTH(7-84) on PTH(1-34)-induced production of 1,25-(OH)2D3 in primary cultured murine renal tubules. Neonatal mouse renal tubules cultured in serum-free MEM for 7 days were treated with PTH(1-34) and/or PTH(7-84). Three hours after addition of 25-OHD(3) (10(-6) M), 1,25-(OH)2D3 was determined. PTH(1-34) stimulated the conversion of 25-OHD3 to 1,25-(OH)2D3, and PTH(7-84) dose-dependently inhibited this process. Real-time PCR revealed that PTH(1-34) increased the expression level of 1alpha-hydroxylase mRNA, whereas PTH(7-84) did not affect the expression level 1alpha or 24-hydroxylase mRNA. These in vitro data suggest that PTH(7-84) elicits an antagonistic effect in renal tubules through receptors different from the type I PTH/PTHrP receptor. This may at least partly account for the decreased serum level of 1,25-(OH)2D in patients with severe primary hyperparathyroidism with renal failure.

Stimulating parathyroid cell proliferation and PTH release with phosphate in organ cultures obtained from patients with primary and secondary hyperparathyroidism for a prolonged period.

The pathogenesis of primary hyperparathyroidism (I degrees -HPT) and secondary hyperparathyroidism (II degrees -HPT) remains to be elucidated. To characterize their pathophysiology, we investigated the effects of calcium and phosphate on cell proliferation and PTH release in an organ culture of parathyroid tissues. Dissected parathyroid tissues obtained from patients with I degrees -HPT (adenoma) or II degrees -HPT (nodular hyperplasia) were precultured on a collagen-coated membrane for 1-4 week. After changing the medium for one containing various concentrations of phosphate, PTH release and [(3)H]thymidine incorporation were studied. In contrast to dispersed parathyroid cells cultured in a monolayer, calcium decreased PTH release in a concentration-dependent manner in parathyroid tissues. Furthermore, when parathyroid tissues obtained from II degrees -HPT were precultured for 1-4 weeks, PTH release and parathyroid cell proliferation were significantly increased in high-phosphate medium. These phosphate effects were also observed to a lesser extent in parathyroid tissues obtained from I degrees -HPT, but there was no significant difference between I degrees -HPT and II degrees -HPT. Microarray analyses revealed that mRNA levels of PTH, CaSR, and VDR were well preserved, and several growth factors (e.g. TGF-beta1-induced protein) were abundantly expressed in II degrees -HPT. Using organ cultures of hyperparathyroid tissues, in which PTH release and CaSR are well preserved for a prolonged period, we have demonstrated that phosphate stimulates parathyroid cell proliferation not only in II degrees -HPT but also in I degrees -HPT. Although the mechanism responsible for phosphate-induced cell proliferation remains to be elucidated, our in vitro findings suggest that both parathyroid tissues preserve to some extent a physiological response system to hyperphosphatemia as observed in normal parathyroid cells.

Increased thyroid blood flow in the hypoechoic lesions in patients with recurrent, painful Hashimoto's thyroiditis at the time of acute exacerbation.

We report two cases with painful Hashimoto's thyroiditis, who developed recurrent fever and painful thyroid. Glucocorticoid treatment was transiently successful but tenderness in the thyroid gland and fever developed when glucocorticoid was tapered. One patient underwent total thyroidectomy uneventfully. As is well known, it is frequently difficult to make differential diagnosis between painful Hashimoto's thyroiditis and subacute thyroiditis particularly at the initial phase. Interestingly, color flow doppler sonography of patient 1 revealed an increased thyroid blood flow in the hypoechoic lesions at the time of acute exacerbation although the serum level of TSH was suppressed. In the other patient, thyroid blood flow was also increased mainly in the hypoechoic lesions when the serum level of TSH was moderately increased, and it disappeared completely after supplementation of prednisolone and L-T4. Since thyroid blood flow in subacute thyroiditis is always decreased, such an increased blood flow in the hypoechoic lesion may be one of clinical characteristics of painful Hashimoto's thyroiditis, and useful for differential diagnosis from subacute thyroiditis.

Hypercalcemia during pregnancy, puerperium, and lactation: review and a case report of hypercalcemic crisis after delivery due to excessive production of PTH-related protein (PTHrP) without malignancy (humoral hypercalcemia of pregnancy).

Hypercalcemia during pregnancy or after delivery is uncommon, and mostly associated with primary hyperparathyroidism (PHPT). If unrecognized, it may increase maternal and fetal morbidity. In a very few patients with PHPT, hypercalcemic crisis develops during pregnancy and particularly after delivery, since calcium transport from the mother to the fetus is abruptly disrupted. Hypercalcemia may also develop in pregnant women due to PTH-related protein (PTHrP)-producing malignant tumors (humoral hypercalcemia of malignancy). Since PTHrP is produced physiologically in fetal and maternal tissues, hypercalcemia may occasionally develop during pregnancy, puerperium, and lactation due to excessive production of PTHrP in the placenta and/or mammary glands. PTHrP may also be involved in milk-alkali syndrome that develops during pregnancy. Although non-malignant hypercalcemia is usually mild, we report a 28-years-old pregnant woman who developed hypercalcemic crisis after normal delivery of an infant. On the first postpartum day, the corrected serum calcium concentration increased to 19.4 mg/dl with a markedly increased serum level of PTHrP (28.4 pmol/L) (normal <1.1 pmol/L). After administration of saline and pamidronate, the serum levels of calcium and PTHrP rapidly normalized. Extensive examination revealed no malignant lesion, suggesting that the placenta may have been producing an excessive amount of PTHrP (humoral hypercalcemia of pregnancy). We review case reports of non-malignant hypercalcemic crisis associated with pregnancy indexed in PubMed in which serum levels of intact PTH and/or PTHrP were described, and stress that rapid control of hypercalcemia is mandatory to save the life of the mother and the infant.

Symptomatic hypercalcemia due to painless thyroiditis after unilateral adrenalectomy in a patient with Cushing's syndrome.

We report a 53-year-old woman with Cushing's syndrome due to an adrenocortical adenoma, who underwent unilateral adrenalectomy and developed symptomatic hypercalcemia during the thyrotoxic period of painless thyroiditis, while tapering off a daily supplemented dose of cortisol. A study of patients with thyrotoxicosis and hypoadrenalism at our institute revealed that mild hypercalcemia was present in 9.9% of those with thyrotoxicosis and 5.0% of those with hypoadrenalism. The present case suggests that the simultaneous occurrence of thyrotoxicosis and hypoadrenalism may lead to overt hypercalcemia due to a synergistic increase in bone resorption and impaired urinary excretion of calcium.

Differential diagnosis and appropriate treatment of four thyrotoxic patients with Graves' disease required to take amiodarone due to life-threatening arrhythmia.

We report the treatment of four thyrotoxic patients. Two were cases of type I amiodarone-induced thyrotoxicosis (AIT) treated with methimazole. The third Graves' disease patient, who became hypothyroid 25 years after subtotal thyroidectomy, developed type II AIT. Furthermore, one case with heart failure and ventricular tachycardia, who developed an adverse reaction to antithyroid agents and was prescribed amiodarone, underwent total thyroidectomy. The clinical course was uneventful, and the patient is doing well. Since amiodarone contains a large amount of iodine, it is frequently difficult to make a differential diagnosis. Surgical treatment of Graves' disease patients is recommended when immediate control of hyperthyroidism and heart failure is required.

Latent hypoparathyroidism in an osteoporotic patient with multiple endocrinopathies and secondary hemochromatosis due to multiple blood transfusions, unmasked by alendronate and glucocorticoid at adrenal crisis.

A 30-year-old normocalcemic man with hypopituitarism, hypogonadism, diabetes mellitus, and secondary hemochromatosis due to multiple blood transfusions was admitted because of adrenal crisis. After intravenous administration of saline and cortisol, the corrected serum level of calcium decreased to 7.3 mg/dl. This osteoporotic patient had been prescribed alendronate for radial bone fracture. Since the increase in intact PTH (68 pg/ml) was impaired compared to that seen in hypocalcemic patients with secondary hyperparathyroidism, we presume that the patient has had latent hypoparathyroidism, which was unmasked by the administration of glucocorticoid and bisphosphonate. With a supplemented dose of 1alpha-OHD3, the patient has been eucalcemic.

Amiodarone reversibly decreases sodium-iodide symporter mRNA expression at therapeutic concentrations and induces antioxidant responses at supraphysiological concentrations in cultured human thyroid follicles.

CONTEXT: Amiodarone, a potent antiarrhythmic, iodine-containing agent, is a highly active oxidant exerting cytotoxic effects on thyrocytes at pharmacological concentrations. Patients receiving amiodarone usually remain euthyroid, but occasionally develop thyroid dysfunction. Although there is a general consensus that amiodarone-associated hypothyroidism is iodine induced, the destructive mechanism of thyroid follicles in amiodarone-induced thyrotoxicosis remains unknown. OBJECTIVE: To elucidate the mechanism by which amiodarone elicits thyroid dysfunction. DESIGN: Human thyroid follicles were cultured with thyroid-stimulating hormone (TSH) and amiodarone at therapeutic (1-2 microM) and pharmacological (10-20 microM) concentrations, and the drug-induced effect on whole human gene expression was analyzed by cDNA microarray. Microarray data were confirmed by real-time PCR and Western blot. MAIN OUTCOMES: Amiodarone at 1-2 muM decreased the expression level of the sodium-iodide symporter (NIS) to nearly half, but did not affect genes participating in thyroid hormonogenesis (thyroid peroxidase, thyroglobulin, pendrin, and NADPH oxidase). Higher concentrations (10-20 microM) decreased the expression of all these genes, accompanied by increased expression of antioxidant proteins such as heme oxygenase 1 and ferritin. When thyroid follicles obtained from a patient with Graves' disease who had been treated with amiodarone were cultured in amiodarone-free medium, TSH-induced thyroid function was intact, suggesting that amiodarone at a maintenance dose did not elicit any cytotoxic effect on thyrocytes. The ultrastructural features of cultured thyroid follicles were compatible with these in vitro findings. CONCLUSION: These in vitro and ex vivo findings suggest that patients taking maintenance doses of amiodarone usually remain euthyroid, probably due to escape from the Wolff-Chaikoff effect mediated by decreased expression of NIS mRNA. Further, amiodarone is not cytotoxic for thyrocytes at therapeutic concentrations but elicits cytotoxicity through oxidant activity at supraphysiological concentrations. We speculate that when amiodarone-induced prooxidant activity somehow exceeds the endogenous antioxidant capacity, the thyroid follicles will be destroyed and amiodarone-induced destructive thyrotoxicosis may develop.

The relationship between serum levels of estradiol and osteoprotegerin in patients with anorexia nervosa.

Osteoporosis is one of the major complications in anorexia nervosa (AN) patients. Receptor activator of nuclear factor kappaB ligand (RANKL) and osteoprotegerin (OPG) have been identified as important regulators of bone turnover. The objective of this study was to clarify the role of RANK-RANKL-OPG system, and their relationship with other regulators for bone metabolism in AN patients. We investigated serum levels of RANKL, OPG, and bone turnover markers of 26 Japanese young female AN patients and 7 age-matched healthy women. We measured serum levels of estradiol (E2), insulin like growth factor-I (IGF-I) and triiodothyronin (T3) from the same samples and studied their relationship with RANKL or OPG. Mean serum levels of E2, IGF-I, T3 and leptin in AN patients were significantly lower than those of controls (p<0.05). Serum levels of OPG in AN patients were significantly higher than those in controls and negatively correlated with body mass index (BMI), E2, IGF-I or leptin. Serum levels of free RANKL could not be detected except for only one healthy control in both groups. These results suggest that serum OPG levels may be increased by a compensatory mechanism for malnutrition and estrogen deficiency which induces an increase in bone resorption.

[Drug-induced osteomalacia].

In our country, calcium- or phosphate-deficient rickets/osteomalacia due to malnutrition are scarcely reported. However, osteomalacia induced by drugs, such as anti-epileptics, etidronate and saccharated ferric oxide (SFO) is occasionally reported. When SFO is repeatedly injected to patients with iron-deficient anemia for a prolonged period, a tiny amount of SFO is excreted into renal tubules, where it exerts toxic effects on renal phosphate reabsorption and 1alpha-hydroxylase activity, leading to hypophosphatemic osteomalacia. Furthermore, Fe accumulates on the calcification front, resulting in impairment of bone formation. Although the SFO-induced osteomalacia is reversible, SFO should be used according to instructions of the package inserts, since it is a very effective parental agent for patients with iron-deficient anemia.

Povidone iodine-induced overt hypothyroidism in a patient with prolonged habitual gargling: urinary excretion of iodine after gargling in normal subjects.

Iodine-induced hypothyroidism that develops in patients who gargle routinely with povidone iodine is well known. Usually the hypothyroidism is mild and resolves spontaneously upon cessation of gargling. Here, we report a 63-year-old patient with overt hypothyroidism that developed due to habitual gargling with povidone iodine for more than 10 years. The urinary excretion of iodine was estimated to be greater than 5 mg/day, based on values obtained from 18 normal subjects who gargled three times a day (4.6+/-2.1 mg, mean+/-SD). After discontinuation of the gargling, the patient has been euthyroid for more than 10 months.