Radioiodine uptake after monotherapy with potassium iodide in patients with Graves' disease

The effect of potassium iodide (KI) on radioiodine uptake (RAIU) before radioisotope therapy in Graves' disease (GD) patients was investigated. A total of 82 patients who had been treated with KI monotherapy before 24-hour RAIU (24 h RAIU) were evaluated and 354 of those who had been treated with thiamazole (MMI) monotherapy were extracted from the 1,130 GD patients who were identified as having had appropriate iodine restriction based on urinary iodine excretion. Urinary iodine excretion (UIE) <200 μg/day was confirmed in all subjects. Propensity score-matching was performed to identify the difference in 24 h RAIU between the KI group and the MMI group. In addition, multiple regression analysis was performed to evaluate related to 24 h RAIU. Propensity score-matching resulted in 57 matched patients in each group. After matching, 24 h RAIU was still significantly lower in the KI group than in the MMI group (median 53% (interquartile range 47-61%) vs. 63% (56-66%); p = 0.001). In addition, KI monotherapy was weakly negatively correlated with 24 h RAIU, whereas the female sex and FT3 were very weakly positively correlated on multiple regression analysis. The results suggest that KI monotherapy likely suppressed 24 h RAIU more than MMI monotherapy in GD patients with appropriate iodine restriction, given the difference in the mechanism of hormone suppression.

Survey of the actual administration of thiamazole for hyperthyroidism in Japan by the Japan Thyroid Association

To clarify the actual administration of thiamazole (MMI), the first choice of antithyroid drugs, the actual therapy provided by the Japan Thyroid Association (JTA) members for the following conditions was surveyed. The subjects included adult patients, pregnant women, and pediatric patients with Graves' disease who visited each medical institution from September 2019 to February 2020. Initial doses, frequency of administration, maintenance doses, maximum doses, consultation intervals for pregnant women, and dosages administrated to breastfeeding mothers were surveyed. The total number of cases collected was 11,663. Administration of 15 mg once a day was the most common initial therapy, constituted 74.4% (2,526/3,397 cases) of adults, 33.8% (44/130) of pregnant women, and 50.8% (61/120) of children. The maintenance dose before discontinuation was equivalent to 2.5 mg/day in 52.3% (3,147/6,015). The most common maximum dose for adults and children was 30 mg/day, administrated to 57.5% of adults (223/388) and 59.6% (28/47) of children; for pregnant women, it was 15 mg/day, administrated to 71.1% (27/38). The most common consultation interval for pregnant women was every four weeks (32.1%, 341/1,063). In lactating mothers, the dose was 10 mg/day or less in 366 of 465 cases (78.7%). Breastfeeding was also allowed 4-6 hours after the administration of 15-20 mg/day in 69 patients (14.8%). Breastfeeding was prohibited in 26 patients (5.6%). In conclusion, initial MMI therapy was started with 15 mg once a day in most patients, and MMI was also administrated to lactating mothers following the Graves' disease treatment guidelines by the JTA.

A case of membranous nephropathy secondary to asymptomatic Graves' disease

Although cases of secondary membranous nephropathy associated with autoimmune thyroid disease (AITD) have been reported, most of them, if not all, present with symptomatic thyroid disease. Here we report an asymptomatic case of AITD complicated with secondary membranous nephropathy. A 16-year-old girl was referred to our institute because of proteinuria found by an annual medical checkup. Urinalysis showed a urinary protein creatinine ratio (UPCR) of 3.0 g/gCre. Blood examination revealed that she had Graves' disease, although she did not have any symptoms of hyperthyroidism such as weight loss, anxiety, tremor, tachycardia, or eye symptoms. In a kidney biopsy, periodic acid silver-methenamine staining showed spike formation in the basement membrane. Electron microscopy showed electron-dense deposits on the epithelial side of the glomerular basement membrane. Immunofluorescent staining showed co-localization of thyroid peroxidase and IgG deposition along the glomerular capillary walls. A diagnosis of membranous nephropathy secondary to asymptomatic Graves' disease was made on the basis of results of the examinations. Treatment with thiamazole added to enalapril improved proteinuria (reduction of UPCR to 0.83 g/gCr) and hypoalbuminemia. Consideration should be given to the possibility of AITD in differential diagnosis of etiologies of membranous nephropathy even when typical symptoms of AITD are lacking.

Prevention of Iodinated Contrast Media-Induced Hyperthyroidism in Patients with Euthyroid Goiter

INTRODUCTION

Iodinated contrast media (ICM)-induced hyperthyroidism is an underestimated, potentially severe condition; however, its prevention has not been sufficiently investigated. The aim of this study was to evaluate the influence of ICM on thyroid status, the advantages of prophylactic therapy for iodine-induced hyperthyroidism (IIH) in patients with euthyroid goiter and cardiovascular comorbidities, and the association between the incidence of IIH and thyroid volume.

METHODS

Thirty-six euthyroid patients undergoing procedures involving ICM administration were divided into 2 groups: the first group (n = 13) received prophylactic treatment with thiamazole or thiamazole combined with sodium perchlorate during ICM exposure; the second group (n = 23) did not receive prophylaxis. Thyroid-stimulating hormone levels were evaluated before and after ICM, and thyroid hormone levels were assessed after ICM at different points in time. The morphology of the thyroid was evaluated by ultrasonography.

RESULTS

Twenty-one patients (58%) developed hyperthyroidism after ICM. Hyperthyroidism was observed more frequently in the group without prophylactic treatment than in the group with prophylaxis (65 vs. 15%, respectively; p = 0.006). No cases of overt hyperthyroidism were observed in the group receiving thiamazole with sodium perchlorate. IIH persisted for a median time of 52.5 days. Larger thyroid volume was associated with a significantly higher occurrence of ICM-induced hyperthyroidism (p = 0.04).

CONCLUSIONS

Patients with euthyroid goiter receiving ICM are at risk of developing hyperthyroidism. The occurrence of hyperthyroidism after ICM in euthyroid patients with goiter is higher in those with larger thyroid volume. The frequency of ICM-induced hyperthyroidism in euthyroid patients with goiter is lower in those receiving prophylactic therapy with thiamazole in monotherapy or in combination with sodium perchlorate than in those not receiving prophylactic treatment.

Effect of thiamazole on kainic acid-induced seizures in mice

Kainic acid (KA) induced epileptic seizures in mice is a commonly used experimental model of epilepsy. Previous studies have suggested the roles of various neurotransmitters and oxidative stress in KA-induced seizures. An important role of hypothyroidism has also been suggested in epilepsy. Thiamazole (TZ) is an anti-hyperthyroid drug with antioxidant property. This study reports the effect of TZ on KA-induced epileptic seizures in mice, produced by intraperitoneal (IP) injection of KA (18 mg/kg). Prior to KA injection, the animals were treated with TZ (12.5, 25 and 50 mg/kg IP). Our results showed that in KA alone group, about half of the animals developed seizures. Pre-treatment of mice with TZ significantly increased the frequency of seizures in dose-dependent manner. Administration of TZ significantly reduced the latency time and aggravated the severity of seizures. TZ also increased the mortality in KA-treated mice. Striatal dopamine and serotonin levels were markedly increased in KA alone treated mice, which were not significantly affected by TZ treatment. Among the indices of oxidative stress, we observed a significant reduction in cerebral vitamin E whereas the levels of cerebral malondialdehyde and conjugated dienes were significantly increased in animals with high severity of seizures. In conclusion, TZ potentiated the frequency and severity of experimental seizure in mice. There is a possibility of altered metabolism of KA in presence of TZ that might have potentiated the toxicity of KA. These findings suggest a caution while administering anti-hyperthyroid drugs in epileptic seizures.

Detection of Ag+ ions via an anti-aggregation mechanism using unmodified gold nanoparticles in the presence of thiamazole

The present study proposed a novel and highly selective and sensitive method for Ag⁺ ion detection based on gold nanoparticles (AuNPs) anti-aggregation. Thiamazole can induce AuNPs aggregation due to electrostatic interactions, which result in color transitions in the AuNPs solution from red to blue. However, the presence of Ag⁺ ions results in the preferential combination of the pyridinic nitrogen of thiamazole with the Ag⁺ ions. In addition, the Ag⁺ ions oxidize the sulfhydryl groups(-SH), which inhibit AuNPs aggregation and prompt a color change from blue to red. As a result, the present study established a method for Ag⁺ ion determination by AuNPs-thiamazole colorimetric probe based on the aforementioned anti-aggregation mechanism. The probe dynamic range was easily tuned via adjustments of the thiamazole amount. The relationship between the Ag⁺ concentration and AuNPs aggregation was monitored by ultraviolet-visible light (UV-Vis) spectroscopy at a dynamic range of 0.1 nM-9 μM and at a detection limit of 0.042 nM. The river water and tap water recovery analysis validated the successful operation of this colorimetric sensor in environmental monitoring.

[Thiamazole-induced arthritis]

Wir berichten über den Fall eines 42-jährigen Patienten mit akuter asymmetrischer Polyarthritis der großen und mittelgroßen Gelenke sowie Fieber und erhöhten serologischen Entzündungszeichen. Die Symptomatik begann kurz nach Beginn einer Thiamazol-Therapie bei neu diagnostiziertem Morbus Basedow. Eine durch Thionamide ausgelöste Arthritis wird auch als „antithyroid arthritis syndrome“ (AAS) bezeichnet und ist eine seltene unerwünschte medikamentöse Nebenwirkung. Klinisch kann sich das Krankheitsbild mit Myalgien, Arthralgien, Fieber, Hautausschlag und Polyarthritis präsentieren. Bei Verdacht auf ein AAS sollte die Thionamid-Medikation in Rücksprache mit dem Endokrinologen nach Möglichkeit zeitnah abgesetzt oder umgestellt werden. In einigen Fällen ist eine antiinflammatorische Therapie mit NSAR oder Glukokortikoiden zur Symptomkontrolle nötig.

[Iodine-induced thyroid dysfunction]

BACKGROUND

Iodine-induced thyroid dysfunctions are, despite their rare occurrence, important clinical syndromes. Their immediate recognition can avoid serious consequences. Important triggers can be iodine-containing contrast agents, amiodarone or iodine-containing disinfectants. Iodine-induced hypothyroidism and hyperthyroidism need to be distinguished, whereby the former is usually self-limiting.

OBJECTIVES

The aim of this article is to present current knowledge on the pathogenesis, therapy, and prophylaxis of iodine-induced thyroid dysfunction.

MATERIALS AND METHODS

We performed a literature search of current publications and linked them to daily clinical experience.

RESULTS AND CONCLUSION

In iodine-induced hyperthyroidism, antithyroid drugs and perchlorate are primarily used to decrease thyroid hormone synthesis and further iodine uptake into the thyroid. For the prophylaxis of x‑ray contrast agent-induced hyperthyroidism, perchlorate can be administered in high-risk settings in combination with antithyroid drugs, if possible starting one day before the iodine exposure.

Graves' disease in children

R1 The diagnosis of Graves' disease in children is based on detecting a suppression of serum TSH concentrations and the presence of anti-TSH receptor antibodies. 1/+++. R2 Thyroid ultrasound is unnecessary for diagnosis, but can be useful for assessing the size and homogeneity of the goiter. 2/+. R3. Thyroid scintigraphy is not required for the diagnosis of Graves' disease. 1/+++. R4. The measurement of T4L and T3L levels is not necessary for the diagnosis of Graves' disease in children but can be useful for the management and assessment of prognosis. 1/++. R5. In the absence of TSH receptor autoantibodies, the possibility of genetically inherited hyperthyroidism must be considered. 1/++. R6. Drug therapy is the primary line of treatment for children and consists of imidazole, carbimazole or thiamazole, with an initial dosage of 0.4 to 0.8mg/kg/day (0.3 to 0.6mg/kg/day for thiamazole) depending on the initial severity, up to maximum of 30mg. 1/++. R7. Propylthiouracil is contraindicated for children with Grave's disease. 1/+++. R8. Before starting treatment, it may be useful to perform a CBC in order to assess the degree of neutropenia caused by hyperthyroidism. It is not necessary to perform systematic CBCs during follow-up. 2/+. R9. An emergency CBC should be performed if symptoms include fever or angina. If neutrophil counts are <1000/mm³, synthetic antithyroid therapy should be discontinued or decreased and may be permanently contraindicated in severe (<500) and persistent neutropenia. Otherwise treatment may be resumed. 1/++. R10. Transaminases levels should be measured before initiating treatment. Systematic monitoring of liver function is not consensually validated. 2/+. R11. In cases of jaundice, digestive disorders or pruritus, measuring liver enzymes (AST, ALT), total and conjugated bilirubin and alkaline phosphatases is indicated. 1/++. R12. Patients and parents should be informed of the possible side effects of antithyroid agents. 1/+. R13. Therapeutic education of parents and children is important in ensuring the best possible treatment compliance. 2/++. R14. Given the specificities involved in the treatment of Graves' disease in children, medical care should be provided by a specialist accustomed to treating endocrinopathies in pediatric patients. 2/+. R15. Depending on patient age, the severity of the disease at diagnosis and the persistence of anti-TSH receptor antibodies, the initial course of treatment must take place over an extended period of 3 to 6 years. R16.The anticipated success rates of medical treatment (50% of patients in remission following several years of treatment) should be explained to the family and the child. The possibility that radical treatment may be required in case of failure or intolerance of medical treatment should also be discussed. 1/++. R17.In females with Graves' disease, it is important to explain that they must undergo an assessment by an endocrinologist before planning future pregnancies, from the start of pregnancy and during the course of pregnancy. This is true in all female patients, even those in remission after medical treatment, or those who have undergone radical treatment. R18.Indications for a radical treatment can arise in cases of: 1/+: contraindication to antithyroid agents; poorly controlled hyperthyroidism due to lack of compliance; relapse despite prolonged medical treatment; a request made by the family and child for personal reasons. R19.Surgery is the radical method of treatment used in children under 5 years of age, or in cases of very large, nodular, or compressive goiters. 2/++. R20. The surgeon's experience in dealing with thyroidectomies in children is likely to be the most significant determining factor in limiting the morbidity of the procedure (alongside any collaboration between a pediatric surgeon and an adult surgeon). 1/++. R21 When radical treatment is indicated, I-131 treatment may be discussed after 5 years (but more often after puberty), if the goiter is not too large. Experience from monitoring Graves' disease in North American children is reassuring. 1/++.

Iodine-enhanced ultrasound degradation of sulfamethazine in water

This study investigated sulfamethazine (SMT) ultrasound degradation, enhanced by iodine radicals, generated by potassium iodide (KI) and hydrogen peroxide (H₂O₂) in situ. The results showed that the ultrasound/H₂O₂/KI (US/H₂O₂/KI) combination treatment achieved an 85.10 ± 0.45% SMT removal (%) in 60 min under the following conditions: pH = 3.2, ultrasound power of 195 W, initial SMT concentration of 0.04 mmol·L^-1, H₂O₂ concentration of 120 mmol·L^-1, and KI concentration of 2.4 mmol·L^-1. UV-Vis spectrophotometric monitoring of molecular iodine (I₂) and triiodide (I₃^-) revealed a correlation between the SMT degradation and the iodine change in the solution. Quenching experiments using methanol, t-butanol and thiamazole as radical scavengers indicated that iodine radicals, such as I and I₂^-, were more important than hydroxyl radicals (HO) for SMT degradation. SMT degradation under the US/H₂O₂/KI treatment followed pseudo-first order reaction kinetics. The activation energy (E_a) of SMT degradation was 7.75 ± 0.61 kJ·mol^-1, which suggested the reaction was controlled by the diffusion step. Moreover, TOC removal was monitored, and the obtained results revealed that it was not as effective as SMT degradation under the US/H₂O₂/KI system.