Methimazole Treatment Research Articles

Comparison of survival times of cats with hyperthyroidism treated with thyroidectomy or methimazole at a primary care hospital in Japan.

We identified the associated factors and compared the survival times of feline hyperthyroidism (FHT) between thyroidectomy and methimazole alone. The medical records of 41 cats diagnosed with new-onset hyperthyroidism were retrospectively reviewed. The cats were categorized into the thyroidectomy (n = 15) and methimazole (26) treatment groups. Survival analyses using the Kaplan-Meier method, log-rank test, and Cox proportional hazards models were conducted to compare the time to the selected outcomes. Univariate analysis revealed that survival time was significantly longer with thyroidectomy than with methimazole (P < .001). Multivariate analyses revealed thyroidectomy as an independent prognostic factor for good outcomes (hazard ratio, 0.209; 95% CI, 0.073 to 0.601; P = .004). The recurrence rate was significantly lower in cats that underwent thyroidectomy than in those that received methimazole alone (P = .011). Compared with methimazole alone, thyroidectomy was associated with a longer survival time in FHT and can be considered an irreversible treatment modality in settings where radioisotopes are not available.

8471 A Rare Case of Graves' Disease in a Three-Year-Old

Abstract Disclosure: A. Rajesh: None. A. Ravari: None. L.E. Kimball-Ravari: None. H. Roan: None. Graves’ Disease (GD) is an autoimmune disease that causes hyperfunctioning of the thyroid gland which may be triggered by environmental factors such as infection or stress. Though the leading cause of hyperthyroidism in both adult and pediatric populations is GD, it is extremely rare in children under the age of four years old. Some studies show the incidence to be 1 per 1,000,000 cases[1],2. Detecting GD in children early is very important as untreated GD poses a risk for failure to thrive. There have also been cases of young children suffering from psychomotor delays, craniosynostosis, and language delays because their suspected diagnosis of GD had not been detected for one to two years. In this article, we report the case of a previously healthy three-year-old Caucasian female who presented to the pediatric endocrinologist after collapsing from an episode of hypoglycemia; plasma glucose 47 mg/dL (71-180) . The patient was diagnosed with Graves’ Disease due to her significantly elevated free T3 and T4, decreased TSH, positive thyroid peroxidase (TPO) antibodies, and elevated TSIg. She was started on methimazole treatment; however, she did not respond after six months of ATD and underwent total thyroidectomy. Her hypoglycemia was attributed to abnormal proinsulin processing and glucose metabolism, which has been associated with hyperthyroidism; thyroid hormones can produce increased GLUT2 transporters3. This case report demonstrates the importance of recognizing the signs and symptoms of GD early, as well as discuss the importance of increasing the recognition of autoimmune diseases in the pediatric population.

Effect of methimazole treatment on Th1, Th17, and Th22 lymphocytes in pediatric Graves' disease patients.

Graves' disease is the leading cause of autoimmune hyperthyroidism. Thyroid hormones are an essential element of the endocrine system, playing a pivotal role in the body's development, especially important in children with intensified growth. Disturbance within thyroid tissue certainly affected the whole body. Nowadays, numerous research studies indicate different factors contributing to the onset of the disease; however, the exact pathomechanism of Graves' disease is still not fully understood, especially in the context of immune-related processes. Th1, Th17, and Th22 effector lymphocytes were found to be crucial participants in the disease outcome, as well as in autoimmune diseases. Here, our study aimed at assessing selected effector T lymphocytes, Th1, Th17, and Th22, in newly diagnosed pediatric Graves' disease patients, together with their association with thyroid-related parameters and the potential outcome of disease management. We indicated significant increases in the frequencies and absolute numbers of selected effector lymphocytes in Graves' disease patients. In addition, their mutual ratios, as well as Th1/Th17, Th/Th22, and Th17/Th22, seem to be significant in those diseases. Notably, low Th17/Th22 ratio values were distinguished as potential prognostic factors for normalizing TSH levels in response to methimazole treatment. To sum up, our research determines the crucial contribution of Th1, Th17, and Th22 cells in the pathogenesis of Graves' disease. Moreover, the mentioned subset of T cells is highly likely to play a substantial role in the potential prediction of therapy outcomes.

Efficacy of selenium supplementation for patients with Graves' hyperthyroidism during methimazole treatment: protocol for a systematic review and meta-analysis

IntroductionThe most common cause of hyperthyroidism, Graves' disease is a common organ-specific autoimmune disease. Selenium is an essential trace element of the human body that is mainly concentrated in the...

105 Fetal hypothyroidism dysregulates local hepatic and renal renin-angiotensin systems in a temporal manner

Abstract The renin-angiotensin system (RAS) is an essential endocrine system with roles in electrolyte balance, blood volume, and blood pressure. While the canonical RAS exerts systemic vasoregulatory effects through steps involving hepatic, renal, and pulmonary-derived compounds, there is also evidence of localized, independently acting RAS in organs such as the liver and kidney. Further, modulations in RAS resulting from fetal hypothyroidism have previously been documented, although the temporal specificity of this endocrine interaction is not well-characterized. Thus, the objective of the current study was to examine the time-dependency of modulations in local hepatic and renal RAS in a porcine model of fetal hypothyroidism. To achieve this, pregnant gilts (n = 24) were divided evenly into either a control (CON) or methimazole (MMI) treatment group, with the MMI group receiving 5 mgּ kg-1ּ d-1 of oral MMI treatment and the CON group receiving an equivalent sham carrier. Each group was further divided into four timepoints (n = 3/treatment at each timepoint), with treatment beginning on d 34, 45, 55, or 65 of gestation. After 21 d of treatment, and at d 55, 66, 76, and 86, respectively, the gilts were humanely euthanized, blood samples taken from all fetuses (n = 340), and thyroid, liver (LVR), and kidney (KID) collected from a subset of four fetuses per litter (n = 96). Confirmation of fetal hypothyroidism in the MMI group was accomplished via histological assessment of the thyroid and measurement of circulating thyroxine (T4) concentrations. Each MMI-treated fetus (n = 96) subset showed evidence of goitrous thyroid histology, with the absence of healthy eosinophilic colloid indicating successful disruption of the fetal hypothalamic-pituitary-thyroid axis. T4 assays performed on a similar subset of n = 96 fetuses showed that MMI treatment significantly reduced T4 concentrations within each timepoint relative to CON (P &amp;lt; 0.001 at all timepoints). Following confirmation of hypothyroidism, RNA was extracted from the fetal LVR and KID samples to allow for gene expression analysis by qPCR. Ct values were normalized, fold changes calculated using the 2-∆∆Ct method, and differences within timepoint determined using a Wilcoxon signed-rank test. AGT, the precursor to all bioactive RAS peptides, was significantly downregulated in LVR at d 66 (P = 0.014) and 76 (P &amp;lt; 0.001). ACE was significantly upregulated at d 76 in both LVR (P = 0.037) and KID (P = 0.005). No significant changes were observed for ACE2 in either tissue, or for renal REN. Finally, AGTR1, the receptor that mediates RAS effects, was significantly downregulated at d 55 in KID (P &amp;lt; 0.001) and d 76 in LVR (P = 0.023), while also being upregulated at d 86 in LVR (P = 0.033). Collectively, these results show that fetal hypothyroidism modulates RAS function in a gestational age-dependent manner, which may alter fetal development and subsequent postnatal physiology.

Effects of low-dose methotrexate with MMI in patients with Graves' disease: results of a randomized clinical trial.

Supplemental methotrexate (MTX) may affect the clinical course of Graves' disease (GD). Evaluate efficacy of add-on MTX on medical treatment in GD. Prospective, open-label, randomized supplementation controlled trial. Academic endocrine outpatient clinic. One hundred and fifty-three untreated hyperthyroid patients with GD. Patients received MTX 10 mg/d with methimazole (MMI) or MMI only. MTX and MMI were discontinued at months 12-18 in euthyroid patients. Discontinuation rate at months 18 in each group. In the MTX with MMI group, the discontinuation rate was higher than the MMI group at months 15-18 (50.0 vs. 33.3%, P=0.043, 95% CI 1.020 to 3.922; and 55.6 vs 38.9%, P=0.045, 95%CI 1.011 to 3.815, respectively). The decrease in TRAb levels in the MTX with MMI group was significant from baseline to months 6 compared to the MMI alone group [MTX+MMI 67.22% (43.12-80.32), MMI 54.85% (33.18-73.76), P= 0.039) and became more significant from months 9 [MTX+MMI 77.79% (62.27-88.18), MMI 69.55% (50.50-83.22), P= 0.035] to months 18 (P < 0.01 in 15-18 months). A statistically significant difference between the levels of TRAb in the MTX with MMI group and the MMI group at 9-18 months. There were no significant differences in the levels of FT3, FT4 and TSH between two groups. No serious drug-related adverse events were observed in both groups(P=0.771). Supplemental MTX with MMI resulted in higher discontinuation rate and improvement in decreased TRAb levels to homeostatic levels faster than methimazole treatment alone at months 12-18.

Targeting glioma stem cells with thyroid hormone suppression: Phase 1/2 trial of methimazole in patients with progressive grade 4 gliomas.

2044 Background: Gaseous hydrogen sulfide (H2S), a by-product of cysteine metabolism, inhibits the growth of glioblastoma (GBM) cells and impairs GBM progression in mice. Likewise, H2S generation and sulfhydration are decreased in human GBM specimens as compared to non-tumor controls. Thus, boosting H2S production is a novel strategy for GBM treatment. Suppression of thyroid hormone (TH) signaling increases endogenous production of H2S. We hypothesize that methimazole-induced hypothyroidism will enhance the efficacy of chemotherapy in WHO grade 4 gliomas by boosting H2S production capacity (HPC) within the tumor. The goal of this trial is to provide proof of concept that suppression of TH signaling, via methimazole and subsequent augmentation of H2S synthesis and signaling, is feasible in patients with WHO grade 4 gliomas (G4G). Methods: This modified phase 1/2 study evaluates the safety and efficacy of methimazole + chemotherapy with pharmacodynamic correlates in patients with progressive G4G. The main objective is a 10% increase in HPC and a 1.5-fold increase in peripheral blood sulfhydration signaling (SS). Patients who are planned for a clinically-indicated resection receive pre-op (5-7 days) and post-op methimazole with the addition of investigator’s choice of chemotherapy 1 month after starting post op methimazole. Patients receive methimazole + chemotherapy until progression. Resected tumor will be assayed for HPC and for proteins relevant to H2S production. Peripheral blood lead-acetate assays for HPC and SS are obtained at baseline, pre-op, intra-op, post-op, before the addition of chemotherapy, and before each cycle of methimazole + chemo. Key eligibility criteria: progressive G4G for whom a clinically-indicated resection is planned, and normal thyroid function with no history of thyroid disease. Patients may have had unlimited prior regimens including bevacizumab. Results: To date six patients (4 male) ages 49-59 years have enrolled. At all time points tested post-methimazole treatment relative to baseline age/sex matched no-methimazole control patients, there were significant increases in plasma H2S production capacity (table). Conclusions: In this early cohort, it appears methimazole treatment in recurrent GBM patients enhances HPC on a systemic level. Next steps will be to measure sulfide signaling and sulfhydration alterations in patient tumor samples. The protocol is being modified to allow earlier addition (2 weeks) of post-op chemotherapy. Clinical trial information: NCT05607407 . [Table: see text]

Neutropenia Occurs More Often Under Carbimazole than Under Methimazole Treatment in Pediatric Graves' Disease Patients.

Background: Agranulocytosis is a rare antithyroid drug treatment (ATD) side effect seen in children suffering from Graves' disease (GD). Neutropenia is a recognized adverse event associated with ATD but has also been reported as pre-treatment neutropenia in GD. Methods: We performed a retrospective cohort study to analyze the longitudinal clinical and biochemical data of 161 pediatric patients with GD who received either methimazole (MMI) or carbimazole (CBZ) as ATD. The inclusion criteria were elevated free thyroxine (fT4 >25 pmol/L), suppressed thyrotropin (TSH <0.05 mlU/mL), and elevated thyrotropin receptor antibodies (TSHRAbs >2.5 IU/L). Absolute neutrophil count (ANC) was used to define neutropenia (ANC <1800/µL) and agranulocytosis (ANC <500/µL). Results: Nine of the 161 patients had neutropenia at diagnosis (ANC: 1348/µL ± 250) without further deterioration under ATD. In this subgroup, we found higher levels of free triiodothyronine (fT3: 31.45 pmol/L ± 3.99) at diagnosis in comparison with those who developed neutropenia (26.29 pmol/L ± 12.96; p = 0.07) and those without neutropenia before and during therapy (23.12 pmol/L ± 13.7; p = 0.003). Thirty-eight patients (23.6%) became neutropenic (ANC: 1479/µL ± 262) while receiving ATD. Neutropenia occurred after a mean of 551.8 (range: 10-1376) days, mostly without further deterioration. Two of these 38 patients developed agranulocytosis and underwent emergency thyroidectomy. The patients with neutropenia were significantly younger (p = 0.031). Neutropenia occurred significantly more often in patients receiving CBZ (50%; n = 20/40) than in those receiving MMI (16.5%; n = 18/110; p = 0.001). The minimum ANC was significantly lower in the CBZ (1971/µL ± 1008) than in the MMI group (2546 ± 959); p = 0.004. Conclusions: Neutropenia occurred significantly more often under CBZ than MMI. As this is potentially due to higher immunogenicity, we suggest that children with GD should be treated with MMI. Frequent measurements of ANC may be needed to detect severe agranulocytosis, although low pre-treatment ANC may not necessarily be a contraindication to ATD treatment. Young age may be potentially associated with an increased risk of reduced ANC. Further investigation is necessary to fully understand risk factors for neutropenia in children with GD.

Resistance to thyroid hormone and nonfunctioning pituitary microadenoma in a 13-year-old boy with THRB mutation.

Resistance to thyroid hormone (RTH) is a rare syndrome characterized by elevated serum free iodothyronines levels and non-suppressed thyroid stimulating hormones (TSH). The most common cause of RTH is heterozygous pathogenic mutations in thyroid hormone receptor β gene (THRB). Because of the similarities in biochemical profiles, differential diagnosis between RTHβ and TSH-secreting pituitary adenoma (TSHoma) is important, and accurate RTHβ diagnosis is essential to prevent inappropriate treatment. A 13-year-old boy was referred to our hospital for a microadenoma and uncontrolled hyperthyroidism despite use of methimazole for more than one year. He suffered from thyrotoxic clinical features and elevated serum T3 and fT4, and normal ranges for TSH and other pituitary hormones were noted. TSH receptor antibody was undetectable, and pituitary MRI revealed a 3mm-sized microadenoma. A TRH stimulation test showed normal TSH response, and the TSH-α-subunit level was not elevated, which is consistent with RTH. The patient was diagnosed with RTHβ and coexistent non-functioning pituitary microadenoma based on identification of a heterozygous mutation, c.1021C>G (p.Leu341Val), in THRB. Methimazole treatment was stopped, and a β-adrenergic blocking agent was started, subsequently thyrotoxic symptoms were relieved. Currently, only one pediatric case diagnosed with RTH and TSHoma has been reported so far, and this case is the first to report a pediatric case of coexistence of RTH and non-functioning pituitary microadenoma. Also, this case shows that inappropriate secretion of thyroid hormones requires careful clinical diagnosis to avoid unnecessary and potentially harmful management.

P-79 Graves’ Disease associated with alemtuzumab use for multiple sclerosis

Abstract Introduction Alemtuzumab was the first humanized monoclonal antibody to be created and is directed against CD52, a lymphocyte cell surface marker of unknown function. It has been used to treat leukemia and organ transplant rejection. More recently, alemtuzumab has been demonstrated to be highly effective in treating relapsing-remitting multiple sclerosis (MS) disease. Thyroid disease develops in approximately 20% of patients using alemtuzumab for MS, and Graves’ disease is the most common among them. Graves’ disease has not been reported in the use of alemtuzumab for reasons other than MS. Clinical Case A 28-year-old female patient with a 10 year history of MS had been treated with pulse corticosteroid, β-interferon and fingolimod. She received alemtuzumab in May 2019 due to increased relapse rates. After the first dose of alemtuzumab, she could not continue her treatment program due to the COVID-19 pandemic. Thyrotoxic thyroid functions (TSH: &amp;lt;0.015 uIU/mL, free T4: 24.79 pmol/L) were detected in the laboratory examination of the patient who was admitted to the endocrinology outpatient clinic with the complaint of palpitation in April 2021. The review of the patient's past laboratory test results determined she was euthyroid before alemtuzumab treatment. She had no personal or family history of thyroid disease. She had no signs and symptoms of thyroid ophthalmopathy. Ultrasonographic examination of her thyroid gland revealed normal size gland and pseudonodular appearance in the parenchyma. Subsequent thyroid scintigraphy showed diffuse uptake of the radioisotope and reduced counting time of the examination. These results were consistent with Graves’ disease. The patient was started on 5 mg methimazole twice a day. Since the etiology of Graves’ disease was thought to be primarily related to alemtuzumab, the patient's MS treatment was continued with ocrelizumab. She stopped the methimazole treatment within 3 months and did not regularly show up to her follow-up visit. In November 2022, she was admitted to the outpatient department with palpitation, sweating, and irritability symptoms. Thyrotoxic thyroid functions were detected again (TSH:&amp;lt;0,015 uIU/mL, free T4: 26,82 pmol/L). She was restarted on 5 mg methimazole treatment twice a day. In June 2023, she was euthyroid (TSH: 0,496 uIU/mL, free T4: 5,42 pmol/L, free T4: 10,45 pmol/L) and her TSI level was undetectable. The methimazole was reduced to 5 mg once a day. She continues to her treatment and follow-up in our center. Conclusion Graves’ disease is a common complication of alemtuzumab use in MS. Alemtuzumab-associated Graves’ disease follows an atypical course compared to the classical form of the disease. The spontaneous remission rate is less than in the classical form of the disease, and medical treatment is often required. Thyroidectomy may be necessary in cases that do not respond to antithyroid agents. Close monitoring of thyroid function tests is essential in alemtuzumab-associated Graves’ disease.

Sustained Euthyroidism during Thionamide Antithyroid Drug Treatment: Comparison of Short- and Long-term Methimazole Therapy

Background: Extended low serum thyrotropin (TSH) levels may increase the risk of cardiovascular events in patients with hyperthyroidism. Objectives: This study aimed to compare the time spent with sustained normal TSH concentration following short- and long-term methimazole treatment. Methods: A total of 258 patients with Graves’ hyperthyroidism completed 18 - 24 months of methimazole therapy and were randomized to discontinue treatment (n = 128, short-term group) or continue an additional 36 - 102 months of methimazole therapy (n = 130, long-term group). Clinical and laboratory evaluations were performed every 6 months for 132 months after randomization. Results: There was no difference in serum-free thyroxine, triiodothyronine, and TSH concentrations between the 2 groups at the time of randomization. Of 128 patients in the short-term group, 5 left in follow-up, 2 became hypothyroid, 67 (54%) had a relapse of hyperthyroidism, and only 54 (44%) were euthyroid at the end of the study. Among 130 patients on the long-term methimazole therapy, 4 were left in follow-up, 24 developed hyperthyroidism, 4 developed hypothyroidism, and 98 (78%) were euthyroid 132 months post-randomization. Total time spent on euthyroidism was 90.4% ± 8.1% of the study period in the short-term and 95.8% ± 7.0% in the long-term treatment groups (P &lt; 0.001). The lowest time spent in euthyroidism (74.6% ± 6.4% of the study period) belonged to 29 (24%) patients in the short-term group under levothyroxine therapy because of fluctuation in serum TSH. Patients in both groups with hyperthyroidism relapse who chose methimazole therapy spent &gt;90% of the study time in euthyroidism. Conclusions: In patients with Graves' hyperthyroidism, sustained normal serum TSH levels were more common in the long term as compared to the short-term methimazole treatment.

Risk of recurrence at the time of withdrawal of short- or long-term methimazole therapy in patients with Graves' hyperthyroidism: a randomized trial and a risk-scoring model.

In Graves' disease, administration of low-dose methimazole for more than 60 months induces higher remission rates compared with the conventional duration of 12-18 months. However, the risk of recurrence and its predictors beyond 48 months of drug withdrawal are not known. The aims of this study were to determine the risk of recurrence during 84 months after withdrawal of short- or long-term methimazole therapy and a risk stratification for recurrence of hyperthyroidism. A total of 258 patients were treated with methimazole for a median of 18 months and randomized to discontinuation of the drug(conventional short-term group; n = 128) or continuation of the treatment up to 60-120 months(long-term group; n = 130). Patients were followed for 84 months after methimazole withdrawal. Cox proportional hazards modeling was performed to identify factors associated with relapse and develop a risk-scoring model at the time of discontinuing the treatment. Hyperthyroidism recurred in 67 of 120(56%) of conventionally-treated patients versus 20 of 118(17%) of those who received long-term methimazole treatment, p < 0.001. Age, sex, goiter grade, triiodothyronine, thyrotropin, and thyrotropin receptor antibodies were significant predictors of recurrence in both "conventional" and "long-term" groups but free thyroxine just in the "long-term" group. The risk-scoring model had a good discrimination power (optimism corrected c-index = 0.78,95%CI = 0.73-0.82) with a range of 0-14 and sensitivity of 86% and specificity of 62% at the risk-score of eight. A relapse-free state was achieved in 83% of patients with Graves' hyperthyroidism 84 months after cessation of long-term methimazole treatment which could be predicted by some significant predictors in a simple risk-scoring system.

The association between methimazole tapering and intractable Graves' disease in children.

The aim of this study was to find predictive factors for intractable Graves' disease (GD). Ninety-three GD patients who visited two pediatric endocrinology clinics from March 2009 to August 2019 were involved in this study. Data were collected on the methimazole (MZ) dosages prescribed from their first visits to their fifth visits. The amount of tapered dosage was presented as a "tapering velocity" (dosage difference (mg/m2)/follow-up interval (months)). The relationship between the tapering velocity and the remission rate of GD was analyzed. Remission of GD was defined as having a total period of MZ treatment less than 5 years with no relapse after MZ withdrawal for at least more than a year. Of 93 patients diagnosed with GD, 26 patients (28.0%) were classified as the "remission group" and 67 (72.0%) were classified as the "intractable group." The frequency of goiter was significantly higher in the intractable group (p = 0.031). Multivariate logistic analysis revealed that the tapering velocity change from the first to the fifth visit significantly influenced the risk of intractable GD: odds ratio (OR) = 0.598, 95% confidence interval (CI) 0.413-0.865, p = 0.006. An accompanying goiter at the time of diagnosis (OR = 4.706 95% CI 1.315-16.847, p = 0.017) and thyroid stimulation hormone receptor antibody titer (OR = 1.032 95% CI 1.002-1.062, p = 0.034) were also found to be independent factors associated with intractable progress in GD. Difficulty in tapering the MZ dosage in the first 4 months of treatment was an independent predicting factor for intractable GD.

Different doses of methimazole treatment of children and adolescents with graves’ disease: a clinical study based on 161 cases of outpatients

ObjectiveThis study aimed to evaluate the association between the initial dose of MMI and the clinical course, as well as adverse effects on young people with GD.MethodsOne hundred and sixty-one children and adolescents with newly diagnosed GD were enrolled for this study and categorized into four groups based on initial serum-free T3 and T4 levels and daily MMI doses: Group A (mild, 0.3–0.5 mg/kg/day, n = 78), Group B (moderate, 0.6–0.8 mg/kg/day, n = 37), Group C (severe, 0.6–0.8 mg/kg/day, n = 24), and Group D (severe, 0.8-1.0 mg/kg/day, n = 22). The thyroid function, blood cell analysis and liver function were examined before treatment and at 4, 8 and 12 weeks after treatment. Outcome of long-term follow-up were also observed.ResultsAfter 12 weeks of treatment, 91.0% of the patients in group A and 90.9% of the patients in group D recovered to normalization of FT3, which was slightly higher than the other two groups; 70.8% of the patients in group C recovered to normalization of FT4, which was slightly lower than that in the other three groups. The incidence of minor adverse effects was 12.8% in group A, 13.5% in group B, 16.7% in group C and 40.9% in group D (P < 0.01). Remission was achieved in 38 patients (23.6%).ConclusionsLower doses of MMI (0.3–0.5 mg/kg/day) are suitable for mild GD, and higher doses of MMI (0.6–0.8 mg/kg/day) are advisable for moderate or severe GD. Much higher doses of MMI (0.8-1.0 mg/kg/day) are harmful for initial use in children and adolescents with GD patients.

Rare adverse reactions after methimazole treatment in two children with Graves' disease

Rare adverse reactions after methimazole treatment in two children with Graves' disease

The memory impairment by hypothyroidism in mice is dependent on time-of-day and sex

Hypothyroidism is an endocrine-metabolic disorder, and as such it compromises a wide range of physiological functions. Memory deficits and, the most recently described, circadian rhythm disruption are among the impairments caused by thyroid dysfunctions. However, although highly likely, there is no evidence connecting these two effects of hypothyroidism. Here, we hypothesized the time-of-day interferes with the memory deficit caused by hypothyroidism. C57BL/6 J mice from both sexes were subjected to novel object recognition (NOR) task during the rest and active phases, corresponding to ZT 2–4 and 14–16, respectively (ZT: Zeitgeber time; ZT 0: lights on at 07:00 am). First, we showed that neither sex nor ZT altered object recognition memory (ORM) in euthyroid mice. Next, animals were divided into control (euthyroid) and hypothyroid [induced with methimazole (0.01%) and perchlorate (0.1%) treatment in the drinking water for 21 days] groups. Under euthyroid conditions, male and female mice recognized the novel object regardless of the time-of-day. However, hypothyroidism impaired ORM at rest phase (ZT 2–4) in both sexes. Surprisingly, in the active phase (ZT 14–16), the hypothyroid males performed the NOR, though a longer time to execute the task was required. In contrast, female hypothyroid mice showed a greater impairment in ORM. Our results suggest that hypothyroidism may disrupt the circadian rhythm in brain areas related to mnemonic processes since in euthyroid condition ORM is not affected by the time-of-day. Furthermore, our findings in an animal model indicate a pronounced deleterious effect of hypothyroidism in women.

Short- and long-term outcomes of patients with hyper or hypothyroidism following COVID vaccine.

Since the beginning of the wide-scale anti-Coronavirus disease 2019 (COVID-19) vaccination program, sporadic cases of thyroid disease following vaccination have been reported. We describe 19 consecutive cases of COVID vaccine-related thyroid disease. Medical records were reviewed for 9 patients with Graves' disease (GD) and 10 with Thyroiditis, all of whom were diagnosed following COVID-19 vaccination. In the GD group, the median age was 45.5 years, female/male(F/M) ratio 5:4, thyroid-stimulating immunoglobulins were elevated in seven patients. The median time from vaccination to diagnosis was 3 months. Methimazole treatment was given to all but one patient. At a median follow-up of 8.5 months from vaccination, three patients were still on methimazole, five went into remission (data were missing for one). In the Thyroiditis group, the median age was 47 years, the F/M ratio 7:3. Thyroiditis was diagnosed after the first, second, and third doses in one, two, and seven patients, respectively. The median time from vaccination to diagnosis was 2 months. TPO antibodies were positive in three patients. All patients were euthyroid off medication at the last visit. Six patients were diagnosed in the hypothyroid phase at 2.5 months from vaccination. Four resolved spontaneously at 3, 6, 4, and 8 months; the other two were treated with thyroxine at 1.5 and 2 months from vaccination and remained on treatment at their last visit, at 11.5 and 8.5 months, respectively. Thyroid disease should be included among possible complications of COVID-19 vaccine and either a late onset or delayed diagnosis should be considered.

Abstract #1411962: Methimazole Induced Agranulocytosis: A Treatment Dilemma

Agranulocytosis is a phrase often used to indicate severe neutropenia. It is a rare, but serious adverse effect of anti-thyroid medications with prevalence of less than one percent. Diagnosis warrants immediate termination of the offending agent, in addition to prompt evaluation for definitive treatment options. Due to low prevalence, the presentation can pose a diagnostic and treatment challenge. We present a case of a 21-year-old female with Graves’ disease who was initiated on methimazole, and was subsequently hospitalized for methimazole induced agranulocytosis. Patient was a 21-year-old female without any significant prior medical history who initially presented to the hospital with symptoms of weight loss and heart palpitations. She was diagnosed with Graves’ disease on the basis of laboratory and imaging data. She was initiated on high doses of methimazole thirty milligrams twice daily. Her baseline white blood cell count at the time of treatment initiation was normal. She was on treatment therapy for four weeks, before she presented back to the hospital at the request of her outpatient endocrinologist with symptoms of fever, sore throat, vomiting, and diarrhea. Based on laboratory data and clinical presentation, she was diagnosed with neutropenic fever and was initiated on prophylactic antibiotics. The methimazole treatment was terminated on admission due to concern for drug induced agranulocytosis. Subsequently, her infectious work up was negative and antibiotics were stopped. The patient received granulocyte stimulating colony factor with normalization of her neutrophil counts and resolution of her fever. Unfortunately, her thyroid hormones began to rise once methimazole was stopped. Therefore, the patient promptly underwent a total thyroidectomy for definitive treatment of Graves’ disease during the admission. She was successfully discharged home on levothyroxine therapy with appropriate follow up. Anti-thyroid drugs are the cornerstone of management of hyperthyroidism. Treatment with these agents carries a less than one percent risk of developing agranulocytosis. This adverse effect is thought to be related to direct toxicity and immune mediated process. The use of high doses of anti-thyroid medications is a risk factor for development of agranulocytosis. The clinical presentation varies, but the most common symptoms include fever and sore throat. The use of granulocyte stimulating colony factor may shorten the length of hospital stay and improve the neutrophil recovery time, but it has not been linked to improved mortality rates. Ultimately, both surgery and radioactive iodine therapy are effective alternative treatments when medical therapy is terminated. Clinical suspicion and patient education regarding potential adverse effects of anti-thyroid medications are the cornerstones of responsible patient care.

Immunomodulatory role of vitamin D and selenium supplementation in newly diagnosed Graves' disease patients during methimazole treatment.

Methimazole (MMI) represents the conventional therapeutic agent for Graves' disease (GD) hyperthyroidism, but MMI efficacy is limited since it marginally affects the underlying autoimmune process. In a previous study, we randomly assigned 42 newly diagnosed GD patients with insufficient vitamin D (VitD) and selenium (Se) levels to treatment with MMI alone (standard) or combined with selenomethionine and cholecalciferol (intervention) and observed a prompter resolution of hyperthyroidism in the intervention group. In the present study, we aimed to explore changes in peripheral T regulatory (Treg) and circulating natural killer (NK) cell frequency, circulating NK cell subset distribution and function, during treatment. At baseline, circulating total CD3-CD56+NK cells and CD56bright NK cells were significantly higher in GD patients than in healthy controls (HC) (15.7 ± 9.6% vs 9.9 ± 5.6%, p=0.001; 12.2 ± 10.3% vs 7.3 ± 4.1%, p=0.02, respectively); no differences emerged in Treg cell frequency. Frequencies of total NK cells and CD56bright NK cells expressing the activation marker CD69 were significantly higher in GD patients than in HC, while total NK cells and CD56dim NK cells expressing CD161 (inhibitory receptor) were significantly lower. When co-cultured with the K562 target cell, NK cells from GD patients had a significantly lower degranulation ability compared to HC (p<0.001). Following 6 months of treatment, NK cells decreased in both the intervention and MMI-alone groups, but significantly more in the intervention group (total NK: -10.3%, CI 95% -15.8; -4.8% vs -3.6%, CI 95% -9; 1.8%, p=0.09 and CD56bright NK cells: -6.5%, CI 95% -10.1; -3 vs -0.9%, CI 95% -4.4; 2%, p=0.03). Compared to baseline, CD69+ NK cells significantly decreased, while degranulation ability slightly improved, although no differences emerged between the two treatment groups. Compared to baseline, Treg cell frequency increased exclusively in the intervention group (+1.1%, CI 95% 0.4; 1.7%). This pilot study suggested that VitD and Se supplementation, in GD patients receiving MMI treatment, modulates Treg and NK cell frequency, favoring a more pronounced reduction of NK cells and the increase of Treg cells, compared to MMI alone. Even if further studies are needed, it is possible to speculate that this immunomodulatory action might have facilitated the prompter and better control of hyperthyroidism in the supplemented group observed in the previous study.

Long-Term, Low-Dose Methimazole Therapy Is Effective in Protecting against Relapses in Graves’ Disease

Clinical ThyroidologyVol. 35, No. 02 HyperthyroidismFree AccessLong-Term, Low-Dose Methimazole Therapy Is Effective in Protecting against Relapses in Graves’ DiseaseGiuseppe BarbesinoGiuseppe BarbesinoThyroid Unit, Division of Endocrinology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, U.S.A.Search for more papers by this authorPublished Online:8 Feb 2023https://doi.org/10.1089/ct.2023;35.54-56AboutSectionsPDF/EPUB Permissions & CitationsPermissionsDownload CitationsTrack CitationsAdd to favorites Back To Publication ShareShare onFacebookTwitterLinked InRedditEmail Review of: Lertwattanarak R, Kunavisarut T, Sriussadaporn S 2022 Benefits of Long-term continuation of low-dose methimazole therapy in the prevention of recurrent hyperthyroidism in Graves' hyperthyroid patients: A randomized prospective controlled study. Int J Endocrinol 2022:1705740. PMID: 36267362.SUMMARYBackgroundThe management of Graves’ disease (GD) hyperthyroidism has been evolving over the past two decades. The traditional standard of care suggested treatment with methimazole for 12 to18 months followed by radioactive iodine (RAI) treatment or surgery (1) in patients not achieving remission, where remission is defined as the ability to maintain euthyroidism after discontinuation of methimazole. This recommendation is supported by the recognition that longer courses of antithyroid drugs do not increase the rate of lasting remissions after discontinuation (2). This strategy has become less attractive owing to increasing evidence that RAI can cause or worsen thyroid eye disease (3) on the one hand and on the other to concerns about quality of life with hypothyroidism, even when thyroid hormone is optimally replaced (4). This study (5) was conducted to understand whether long-term therapy with low-dose methimazole could protect GD patients from relapses of hyperthyroidism.MethodsThis was a randomized controlled study in adult GD patients who had been euthyroid while taking methimazole for at least 6 months prior to randomization. The patients were randomly assigned to either continue methimazole at low doses (2.5–5 mg daily) or discontinue methimazole. The subjects’ thyroid function was then monitored every 6 months for 36 months. Standard diagnostic criteria for GD were adopted for inclusion. Patients who had already experienced a relapse were excluded. The primary outcome measured was the cumulative incidence of relapsing hyperthyroidism in the two groups.ResultsNinety-two patients were randomly assigned to the discontinuation group and 92 to the low-dose treatment group. Except for minor differences, the two groups were very similar for most epidemiologic parameters (86% female vs. 84% and mean [±SD] age, 39.9±10.9 vs. 42.2±14.9 years), indicating a reliable randomization process. The average duration of methimazole therapy prior to randomization was 37 months in the discontinuation group and 32 months in the low-dose group (not statistically different). In the discontinuation group, the number of relapses increased progressively and uniformly during the study time, reaching 41.2% at 36 months. In the low-dose group, the rate of relapse was 11%, and it was reached 18 months after randomization, with no additional relapses after that time. There were no recorded side effects during the study period.ConclusionsIn patients with GD, long-term treatment with 2.5 to 5 mg of methimazole daily is safe and effective in preventing the relapse of hyperthyroidism. This strategy is a valid alternative to RAI therapy and thyroidectomy in patients who want neither and yet worry about relapses of hyperthyroidism.COMMENTARYGraves’ disease, like many other autoimmune diseases, is often characterized by flares and remissions (6). Patients taking methimazole are typically treated for 12 to 18 months, after which a discontinuation trial is performed, in the hope of a lasting remission. Measuring serum TSH receptor antibodies (TRAbs) before antithyroid drug discontinuation helps to identify patients who are at high risk for early relapses in the 3 to 6 months after discontinuation (7). However, 20 to 30% of patients negative for TRAbs will still relapse months to years after the discontinuation (8,9). This observation, and mounting diffidence towards RAI therapy and surgery, has led to increased interest for long-term methimazole treatment. The data so far available have been mostly retrospective, or have addressed only select patient groups (for example, patients who already have experienced a relapse) (10). Like other endocrinologists, I have been advising some of my patients with GD who appear to be “currently” in remission, to continue methimazole indefinitely at very low doses, typically 2.5 mg daily. This article provides good-quality evidence to support such a practice, which I will continue to apply, especially to older patients and patients who had experienced particularly intense symptoms from the hyperthyroidism at the time of its first presentation.Disclosures: The author has no relevant conflicts of interest to declare.