Methimazole-induced agranulocytosis in patients with Graves' disease is more frequent with an initial dose of 30 mg daily than with 15 mg daily

Dose-dependent incidence of agranulocytosis in patients treated with methimazole and propylthiouracil

Agranulocytosis is a serious adverse effect of methimazole (MMI) and propylthiouracil (PTU), and although there have been reports suggesting a dose-dependent incidence in relation to both drugs, the evidence has not been conclusive. The objective of our study was to determine whether the incidences of agranulocytosis induced by MMI and PTU exhibit dose-dependency. The subjects were 27,784 patients with untreated Graves' disease, 22,993 of whom were on an antithyroid drug treatment regimen for more than 90 days. Within this subset, 18,259 patients had been treated with MMI, and 4,734 had been treated with PTU. The incidence of agranulocytosis according to dose in the MMI group was 0.13% at 10 mg/day, 0.20% at 15 mg/day, 0.32% at 20 mg/day, and 0.47% at 30 mg/day, revealing a significant dose-dependent increase. In the PTU group, there were 0 cases of agranulocytosis at doses of 125 mg/day and below, 0.33% at 150 mg/day, 0.31% at 200 mg/day, and 0.81% at 300 mg/day, also revealing a significant dose-dependent increase. The incidence of agranulocytosis at MMI 15 mg and PTU 300 mg, i.e., at the same potency in terms of hormone synthesis inhibition, was 0.20% and 0.81%, respectively, and significantly higher in the PTU group. Our findings confirm a dose-dependent increase in the incidence of agranulocytosis with both drugs, but that at comparable thyroid hormone synthesis inhibitory doses PTU has a considerably higher propensity to induce agranulocytosis than MMI does.

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.

Hyperthyroidism

Thyrotoxicosis causes a variety of symptoms and adverse health outcomes. Hyperthyroidism refers to increased thyroid hormone synthesis and secretion, most commonly from Graves' disease or toxic nodular goitre, whereas thyroiditis (typically autoimmune, viral, or drug induced) causes thyrotoxicosis without hyperthyroidism. The diagnosis is based on suppressed serum concentrations of thyroid-stimulating hormone (TSH), accompanied by free thyroxine and total or free tri-iodothyronine concentrations, which are raised (overt hyperthyroidism) or within range (subclinical hyperthyroidism). The underlying cause is determined by clinical assessment, detection of TSH-receptor antibodies and, if necessary, radionuclide thyroid scintigraphy. Treatment options for hyperthyroidism include antithyroid drugs, radioactive iodine, and thyroidectomy, whereas thyroiditis is managed symptomatically or with glucocorticoid therapy. In Graves' disease, first-line treatment is a 12-18-month course of antithyroid drugs, whereas for goitre, radioactive iodine or surgery are preferred for toxic nodules or goitres. Evidence also supports long-term treatment with antithyroid drugs as an option for patients with Graves' disease and toxic nodular goitre.

NADPH Oxidase 3: Beyond the Inner Ear

Reactive oxygen species (ROS) were formerly known as mere byproducts of metabolism with damaging effects on cellular structures. The discovery and description of NADPH oxidases (Nox) as a whole enzyme family that only produce this harmful group of molecules was surprising. After intensive research, seven Nox isoforms were discovered, described and extensively studied. Among them, the NADPH oxidase 3 is the perhaps most underrated Nox isoform, since it was firstly discovered in the inner ear. This stigma of Nox3 as "being only expressed in the inner ear" was also used by me several times. Therefore, the question arose whether this sentence is still valid or even usable. To this end, this review solely focuses on Nox3 and summarizes its discovery, the structural components, the activating and regulating factors, the expression in cells, tissues and organs, as well as the beneficial and detrimental effects of Nox3-mediated ROS production on body functions. Furthermore, the involvement of Nox3-derived ROS in diseases progression and, accordingly, as a potential target for disease treatment, will be discussed.

Antithyroid drug-induced leukopenia and G-CSF administration: a long-term cohort study

Although antithyroid drug (ATD)-induced agranulocytosis is a significant concern, its risks associated with long-term use and re-administration are not fully elucidated. Therefore, we performed this study to determine the incidence of ATD-induced leukopenia and G-CSF administration using administrative claims database. Retrospective cohort study. This study was performed using the DeSC Japanese administrative claims database. A total of 12,491 patients with newly diagnosed Graves' disease (GD) who received methimazole or propylthiouracil between April 2014, and February 2021 among 3.44 million patients in the database were included in the study. We measured the six-year incidence of leukopenia and granulocyte colony-stimulating factor (G-CSF) administration. The incidence of leukopenia and G-CSF administration was 1.34% (168 patients) and 0.30% (38 patients), respectively. Leukopenia had a dose-dependent and biphasic incidence. The incidence of leukopenia and G-CSF administration was 37.2 (0.7%) and 8.0 (0.2%) per 1000 person-years during the first 72 days of ATD initiation, whereas it was 3.1 and 0.7 per 1000 person-years during the subsequent 6 years, respectively. The incidence of both outcomes was comparable between first administration and re-administration of ATD. The incidence of ATD-induced leukopenia and G-CSF administration was high in the first 72 days, with a reduced risk for at least 6 years thereafter. The incidence was similar between first administration and re-administration. ATD, a standard therapy, is often administered for a long period; therefore, our findings can guide the treatment of GD.

Therapeutic Management and Long-Term Outcome of Hyperthyroidism in Patients with Antithyroid-Induced Agranulocytosis: A Retrospective, Multicenter Study

BACKGROUND

Antithyroid drug-induced agranulocytosis (AIA) (neutrophils <500/µL) is a rare but serious complication in the treatment of hyperthyroidism.

METHODOLOGY

Adult patients with AIA who were followed up at 12 hospitals in Spain were retrospectively studied. A total of 29 patients were studied. The etiology of hyperthyroidism was distributed as follows: Graves' disease (n = 21), amiodarone-induced thyrotoxicosis (n = 7), and hyperfunctioning multinodular goiter (n = 1). Twenty-one patients were treated with methimazole, as well as six patients with carbimazole and two patients with propylthiouracil.

RESULTS

The median (IQR) time to development of agranulocytosis was 6.0 (4.0-11.5) weeks. The most common presenting sign was fever accompanied by odynophagia. All of the patients required admission, reverse isolation, and broad-spectrum antibiotics; moreover, G-CSF was administered to 26 patients (89.7%). Twenty-one patients received definitive treatment, thirteen patients received surgery, nine patients received radioiodine, and one of the patients required both treatments. Spontaneous normalization of thyroid hormone values occurred in six patients (four patients with amiodarone-induced thyrotoxicosis and two patients with Graves' disease), and two patients died of septic shock secondary to AIA.

CONCLUSIONS

AIA is a potentially lethal complication that usually appears around 6 weeks after the initiation of antithyroid therapy. Multiple drugs are required to control hyperthyroidism before definitive treatment; additionally, in a significant percentage of patients (mainly in those treated with amiodarone), hyperthyroidism resolved spontaneously.

Evaluation of the therapeutic effect of Descurainia sophia (L.) Webb ex Prantl seed extract on hyperthyroidism: A double-blind placebo-controlled pilot clinical trial

The seeds of Descurainia sophia (L.) Webb ex Prantl contain goitrogenic glucosinolates, such as gluconapin (3-butenyl glucosinolate). Because of the important role of iodine in the synthesis of thyroid hormones and the inhibitory activity of D. sophia on iodine uptake by the thyroid gland, this study aimed to determine the effects of D. sophia syrup on clinical and biochemical variables of thyrotoxicosis in hyperthyroid patients. In this randomized, double-blind trial, 10 newly diagnosed hyperthyroid female patients were randomly assigned to treatment with (1) methimazole (MMI) plus D. sophia capsules (350 mg/d) or (2) MMI plus placebo capsules. The primary outcomes were clinical and biochemical manifestations of hyperthyroidism after 60 days. Serum levels of FT3 and FT4 significantly decreased (5.9 ± 2.5 vs. 9.4 ± 5.9 and 29.1 ± 3.1 vs. 31.77 ± 3.7, respectively) and the serum thyroid-stimulating hormone (TSH) concentration significantly increased in the D. sophia group contrasted to the placebo group (4.7 ± 0.1 vs. 0.05 ± 0.02). Significant improvement in the thyrotoxicosis clinical symptoms was reported in the D. sophia group contrasted to the placebo group (p < .05). D. sophia can suppress plasma levels of FT3 and FT4 and may be useful as adjunctive therapy for hyperthyroidism.

Clinical characteristics of neutropenic patients under antithyroid drug: Twelve-year experience in a medical center

BACKGROUND

Thionamide-induced agranulocytosis (TiA) is a rare adverse event with a reported incidence of approximately 0.1% to 1.75%. Prompt recognition of TiA is critical to reduce the mortality rate. However, the differential diagnosis between cases of TiA and non-TiA neutropenia can be challenging due to the potential simultaneous involvement of other causes of neutropenia, such as concomitant chemotherapy, liver dysfunction, or infection. The aim of the present study was to investigate the possible factors associated with the development of TiA.

METHODS

This was a retrospective cohort study of patients treated with antithyroid drugs (ATDs) in Taipei Veterans General Hospital, Taipei, Taiwan, from 2006 to 2018. Patients who developed a neutropenic event during treatment with ATDs were identified from their medical records. The diagnosis of TiA was based on the following: (1) development of neutropenia during treatment or within 7 days after previous exposure to the same ATDs; (2) complete resolution of neutropenia within 1 month after discontinuation of the culprit drug with an absolute neutrophil count (ANC) >1500/μL; and (3) exclusion of other causes of neutropenia. The incidence and risk factors of TiA were analyzed and compared with those of non-TiA neutropenia.

RESULTS

Among 6644 patients treated with ATDs, 66 (mean age: 53 ± 15 years; 16.2% men) developed a neutropenic event and 20 were diagnosed with TiA (incidence: 0.3%). In the univariate analysis, compared with non-TiA neutropenia, TiA was associated with a lower Charlson Comorbidity Index, shorter treatment duration, lower cumulative ATD dosage, higher ATD dosage, higher ANC, and higher levels of free T4 at the time of the neutropenic event. In the multivariate logistic regression analysis, after adjusting for age, gender and the time to neutropenia, the cumulative ATD dose to neutropenia and ATD dosage at the time of the neutropenic event, Charlson Comorbidity Index, free T4 levels (odds ratio [OR], 4.44; 95% CI, 1.48-13.25), and ANC (OR, 1.00; 95% CI, 1.00-1.01) remained independently associated with TiA.

CONCLUSION

Patients with TiA were more likely to have higher levels of free T4 and ANC at the time of the neutropenic event vs those with non-TiA neutropenia.

Therapeutic Plasma Exchange for the Treatment of Hyperthyroidism: Approach to the Patient with Thyrotoxicosis or Antithyroid-Drugs Induced Agranulocytosis

Primary hyperthyroidism is an endocrine disorder characterized by excessive thyroid hormone synthesis and secretion by the thyroid gland. Clinical manifestations of hyperthyroidism can vary from subclinical to overt forms. In rare cases, hyperthyroidism may represent a clinical emergency, requiring admission to an intensive care unit due to an acute and severe exacerbation of thyrotoxicosis, known as a thyroid storm. First-line treatment of hyperthyroidism is almost always based on medical therapy (with thioamides, beta-adrenergic blocking agents, glucocorticoids), radioactive iodine or total thyroidectomy, tailored to the patient’s diagnosis. In cases of failure/intolerance/adverse events or contraindication to these therapies, as well as in life-threatening situations, including a thyroid storm, it is necessary to consider an alternative treatment with extracorporeal systems, such as therapeutic plasma exchange (TPE). This approach can promptly resolve severe conditions by removing circulating thyroid hormones. Here we described two different applications of TPE in clinical practice: the first case is an example of thyrotoxicosis due to amiodarone treatment, while the second one is an example of a severe adverse event to antithyroid drugs (agranulocytosis induced by methimazole).

Approach to the Patient: Management and the Long-term Consequences of Graves' Disease in Children

In children, Graves' disease (GD) is the most common cause of hyperthyroidism. Most pediatric patients with GD will not go into lasting remission, even following many years of antidrug therapy. Thus, most pediatric patients will require radioactive iodine (RAI) or surgery. When antithyroid drugs are used, methimazole is the drug of choice. When methimazole is used in children, up to 20% will have minor adverse reactions and serious adverse events occur in up to 1%. RAI is an effective form of therapy when the thyroid size is less than 80 g. Because of concerns of whole-body radiation exposure, it is recommended that RAI be avoided in children under 5 years of age, and dosages less than 10 mCi be used between 5 and 10 years of age. Surgery is an effective treatment in children if performed by a high-volume thyroid surgeon. Because of the scarcity of high-volume pediatric thyroid surgeons, a multidisciplinary approach using pediatric surgeons and endocrine surgeons can be considered. Whereas there is a trend toward long-term antithyroid drug therapy in adults, for several reasons, this approach may not be practical for children. Determining the optimal treatment for the pediatric patient with GD, requires consideration of the risks and benefits relating to age and likelihood of remission.

Evaluating thyroid function in pregnant women

Thyroid hormones are primarily responsible for regulating the basal metabolic rate but also make important contributions to reproductive function and fetal development. Both hyper- and hypothyroidism in pregnancy have been associated with increased risks of complications that include preeclampsia and low birth weight, among others. Furthermore, thyroid hormone deficiency in the developing fetus results in neurodevelopmental delay. As the fetus is exclusively reliant on maternal thyroid hormone for most of the first trimester and requires continued maternal supply until birth, identifying maternal thyroid dysfunction is critically important. However, evaluating thyroid function in pregnancy is challenging because of the many physiological changes that affect concentrations of thyroid-related analytes. Increasing plasma human chorionic gonadotropin (hCG) concentrations in the second half of the first trimester elicit a corresponding transient decrease in thyroid-stimulating hormone (TSH), and continually increasing estradiol concentrations throughout pregnancy cause substantial increases in thyroxine-binding globulin (TBG) and total thyroxine (T4) relative to the nonpregnant state. Lastly, free T4 concentrations gradually decrease with increasing gestational age. For these reasons, it is essential to interpret thyroid function test results in the context of trimester-specific reference intervals to avoid misclassification of thyroid status. This review summarizes the effects of thyroid dysfunction prior to conception and during pregnancy and describes considerations for the laboratory assessment of thyroid function in pregnant women.

Management of Graves' hyperthyroidism: present and future

INTRODUCTION

Graves' disease (GD) is an autoimmune disorder due to loss of tolerance to the thyrotropin receptor (TSHR) and ultimately caused by stimulatory TSHR antibodies (TSHR-Ab). GD may be associated with extrathyroidal manifestations, mainly Graves' orbitopathy. Treatment of GD relies on antithyroid drugs (ATDs), radioactive iodine (RAI), thyroidectomy. The major ATD limitation is the high recurrence rate after treatment. The major drawback of RAI and thyroidectomy is the inevitable development of permanent hypothyroidism.

AREAS COVERED

Original articles, clinical trials, systematic reviews, meta-analyses from 1980 to 2021 were searched using the following terms: Graves' disease, management of Graves' disease, antithyroid drugs, radioactive iodine, thyroidectomy, Graves' orbitopathy, thyroid-eye disease.

EXPERT OPINION

ATDs are the first-line treatment worldwide, are overall safe and usually given for 18-24 months, long-term treatment may decrease relapses. RAI is safe, although associated with a low risk of GO progression, particularly in smokers. Thyroidectomy requires skilled and high-volume surgeons. Patients play a central role in the choice of treatment within a shared decision-making process. Results from targeted therapies acting on different steps of the autoimmune process, including iscalimab, ATX-GD-59, rituximab, blocking TSHR-Ab, small molecules acting as antagonists of the TSHR, are preliminary or preclinical, but promising in medium-to-long perspective.

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.

Pre-treatment Neutropenia in Children and Adolescents with Autoimmune Hyperthyroidism

OBJECTIVE

Neutropenia can occur in untreated autoimmune hyperthyroidism (AIH) or in association with treatment with the anti-thyroid drug, methimazole (MMI). Starting MMI in children and adolescents with AIH and pre-existing neutropenia could thus be worrisome. The aim was to describe the prevalence of neutropenia in pediatric AIH, prior to antithyroid drug therapy and to assess the effect of antithyroid drugs on neutrophil count.

METHODS

Patients with AIH attending a pediatric endocrinology clinic were retrospectively reviewed. Absolute neutrophil count (ANC) data at presentation and during anti-thyroid treatment for up to 24 weeks was collected. AIH was defined as elevated free thyroxine (fT4) or free tri-iodothyronine (fT3), suppressed thyroid stimulating hormone, and positive thyroid autoantibodies. Neutropenia was defined as ANC <1500 cells/μL.

RESULTS

Thirty-one patients (71% female) were included with a median interquartile range (IQR) age of 14.71 (11.89-17.10) years. Neither fT4 nor fT3 levels correlated with ANC at presentation (r_s=0.22, p=0.24 and r_s=0.13, p=0.54, respectively). 26/31 (84%) had normal baseline ANC. None developed neutropenia with thionamides. 5/31 (16%) had baseline neutropenia (median ANC 1,200/μL; IQR 874-1200). Four of these five started MMI at diagnosis while one was started on propranolol only but MMI was started one week later. All five normalized ANC within 24 weeks.

CONCLUSION

In this cohort, 16% of AIH patients had neutropenia at presentation, but this resolved in the short term and did not worsen with thionamides. Thionamides may be used with caution in these patients with close monitoring of blood counts.

Efficacy and adverse events related to the initial dose of methimazole in children and adolescents with Graves' disease

PURPOSE

The first-line antithyroid drug for children and adolescents with Graves' disease (GD) is methimazole (MMI). This study evaluated the relationship between the initial MMI dose and the clinical course of GD after treatment.

METHODS

We studied the efficacy of the initial MMI dose and the relationship between the initial MMI dose and adverse events (AEs). We retrospectively enrolled 22 males and 77 females and divided those subjects into 3 groups according to the initial dose of MMI: &lt;0.4 mg/kg/day (group A; n=32); 0.4-0.7 mg/kg/day (group B; n=39); and &gt;0.7 mg/kg/day (group C; n=28).

RESULTS

The mean time to the normalization of free thyroxine (fT4) levels upon initial treatment was 5.64, 8.61, and 7.98 weeks in groups A, B, and C, respectively (P=0.116). The incidence of liver dysfunction, neutropenia, and skin rash was 12.5%, 20.5%, and 42.9% in groups A, B, and C, respectively (P=0.018). Neutropenia, as a severe AE, was absent in group A, but its prevalence was 7.7% in group B and 21.4% in group C (P=0.015). When comparing only groups B and C, the incidences of liver dysfunction and neutropenia were higher in group C (P=0.04 and P=0.021, respectively).

CONCLUSION

The mean time to the normalization of fT4 levels did not differ among the 3 groups, but the incidence of AEs was higher in the groups that received high MMI doses. High doses of MMI (&gt;0.7 mg/kg/day) should be reconsidered as an initial treatment for children and adolescents with GD.

Clinical efficacy of thyroid-stimulating immunoglobulin detection for diagnosing Graves' disease and predictors of responsiveness to methimazole

BACKGROUND

As thyroid-stimulating immunoglobulins (TSI) are a sign of Graves' disease (GD), measuring TSI titers is becoming increasingly important for GD diagnosis. This study evaluated the diagnostic accuracy of a new fully automated TSI immunoassay (Immulite™ TSI assay) in GD patients and compared it to the third generation thyroid-stimulating hormone receptor antibody (TRAb) electrochemiluminescence assay (Elecsys Anti-TSHR assay). Additionally, clinical characteristics associated with responsiveness to methimazole in patients with newly diagnosed GD were preliminarily explored.

METHODS

This study involved 324 subjects, comprising patients with untreated GD (GD-UT), Graves' ophthalmopathy (GO) patients, GD patients who had been treated for > 12 months (GD-T), autoimmune thyroiditis (AIT) patients, and healthy subjects (HS). The Immulite™ TSI and Elecsys Anti-TSHR assay were performed on all samples. According to their responsiveness to methimazole, the GD-UT patients were divided into rapid and slow responder groups, and their clinical characteristics were compared.

RESULTS

A receiver operating characteristic (ROC) curve analysis of GD-UT patients showed that the optimal TSI cut-off value was 0.57 IU/L. Logistic regression revealed that age and initial FT4 and TSI levels in the middle-dose methimazole group were related to a rapid response, while the initial FT4 level, but not TSI, in the high-dose group was also associated with a rapid response.

CONCLUSIONS

The clinical diagnostic performance of the Immulite™ TSI assay for diagnosing GD was comparable to that of the Elecsys Anti-TSHR assay. The initial FT4 and TSI levels can be used as predictors of the responsiveness to methimazole in patients with newly diagnosed GD.

Very rare case of Graves' disease with resistance to methimazole: a case report and literature review

BACKGROUND

Methimazole (MMI) is used to treat hyperthyroidism in Graves' disease. It is rare to encounter patients in whom hyperthyroidism cannot be controlled using high doses of MMI.Case presentation: A 21-year-old woman was referred to our hospital because of MMI-resistant Graves' disease. Although her MMI dose had been increased to 120 mg/day, her serum thyroid hormone concentration was too high to be measured. Additional therapy with lithium carbonate, and then with dexamethasone and inorganic iodine, was initiated. After 14 days, the patient's serum thyroid hormone concentration normalized, while she was taking 150 mg/day MMI, 800 mg/day lithium carbonate, 6 mg/day dexamethasone and 306 mg/day inorganic iodine, and total thyroidectomy was then performed. The patient was discharged 8 days after the thyroidectomy and experienced no major complications.

CONCLUSIONS

We have presented a rare case of Graves' disease that was resistant to high-dose MMI. Combination therapy of MMI with lithium carbonate, dexamethasone and inorganic iodine may represent a therapeutic option for the preoperative preparation of patients with MMI-resistant Graves' disease.

Management of Graves Thyroidal and Extrathyroidal Disease: An Update

CONTEXT

Invited update on the management of systemic autoimmune Graves disease (GD) and associated Graves orbitopathy (GO).

EVIDENCE ACQUISITION

Guidelines, pertinent original articles, systemic reviews, and meta-analyses.

EVIDENCE SYNTHESIS

Thyrotropin receptor antibodies (TSH-R-Abs), foremost the stimulatory TSH-R-Abs, are a specific biomarker for GD. Their measurement assists in the differential diagnosis of hyperthyroidism and offers accurate and rapid diagnosis of GD. Thyroid ultrasound is a sensitive imaging tool for GD. Worldwide, thionamides are the favored treatment (12-18 months) of newly diagnosed GD, with methimazole (MMI) as the preferred drug. Patients with persistently high TSH-R-Abs and/or persistent hyperthyroidism at 18 months, or with a relapse after completing a course of MMI, can opt for a definitive therapy with radioactive iodine (RAI) or total thyroidectomy (TX). Continued long-term, low-dose MMI administration is a valuable and safe alternative. Patient choice, both at initial presentation of GD and at recurrence, should be emphasized. Propylthiouracil is preferred to MMI during the first trimester of pregnancy. TX is best performed by a high-volume thyroid surgeon. RAI should be avoided in GD patients with active GO, especially in smokers. Recently, a promising therapy with an anti-insulin-like growth factor-1 monoclonal antibody for patients with active/severe GO was approved by the Food and Drug Administration. COVID-19 infection is a risk factor for poorly controlled hyperthyroidism, which contributes to the infection-related mortality risk. If GO is not severe, systemic steroid treatment should be postponed during COVID-19 while local treatment and preventive measures are offered.

CONCLUSIONS

A clear trend towards serological diagnosis and medical treatment of GD has emerged.

Clinical experience of treating Graves' hyperthyroidism complicated with malignancy-The possible role of potassium iodide for avoiding the risk of thionamide-associated neutropenia

The treatment of Graves' hyperthyroidism (GD) complicated with malignancy is challenging, as anti-thyroid thionamide drugs (ATDs) and anti-cancer chemotherapy are both associated with a risk of neutropenia. Treatment with conventional ATDs, radioactive iodine (RAI) or potassium iodide (KI) was attempted in 8 patients with malignancy (34-80 years of age; 2 males and 6 females) in whom GD had been fortuitously diagnosed during a detailed systematic examination. Three patients requiring surgery were initially treated conventionally with methylmercaptoimidazole (MMI), MMI and KI or RAI (group A; one patient each). The patients became euthyroid on days 17-31 and underwent surgery on days 25-47. RAI therapy was administered to one patient after surgery. The patients were then treated with KI during chemotherapy. Five other patients who did not require surgery were initially treated with 100 mg KI monotherapy (group B). The serum free T₄ level declined immediately in all of these patients, and they became euthyroid on days 7-18, remaining almost entirely euthyroid for more than 120 days. Anti-cancer chemotherapy was successfully completed for three of the patients while taking KI, despite the patients experiencing repeated episodes of anti-cancer chemotherapy-induced neutropenia. Our present findings suggest that, in patients with GD and malignancy, MMI + KI or RAI may be required if immediate surgery is scheduled, but KI monotherapy may be worth trying, if anti-cancer chemotherapy is scheduled, thus avoiding the possibility of thionamide-induced neutropenia.

Safety of antithyroid drugs in pregnancy: update and therapy implications

Introduction: The thionamide antithyroid drugs, methimazole (MMI), its pro-drug derivative carbimazole (CMZ), and propylthiouracil (PTU) are the mainstay of treatment for hyperthyroidism in pregnancy. However, antithyroid drugs carry risks of adverse effects that can affect fetal and maternal well-being.Areas covered: This review provides an update on the safety of antithyroid drugs in pregnancy, focusing on the most serious concerns of severe liver disease and congenital anomalies.Expert opinion: PTU-induced liver disease is uncommon but can run a catastrophic course in pregnancy with a risk of liver failure and threats to maternal or fetal survival. Acute pancreatitis is a relatively rare occurrence that has been linked to thionamide use in a handful of reports in non-pregnant individuals. Observational studies on the risk of birth defects with antithyroid drug exposure in pregnancy overall show an increase in birth defect risk with exposure to CMZ/MMI, and to a lesser extent, PTU. Further studies are required to determine whether the currently recommended approach of switching between thionamide drugs in pregnancy improves outcomes. Ultimately, a preventative strategy of offering definitive therapy to hyperthyroid women of childbearing potential offers the best approach to truly reduce the risks of antithyroid drug adverse effects in pregnancy.

Graves' disease: developments in first-line antithyroid drugs in the young

Introduction: First-line treatment for most young people with Graves' disease (GD) will include the administration of a thionamide antithyroid medication (ATD); Carbimazole (CBZ), Methimazole (MMZ), or rarely, propylthiouracil (PTU). GD is a challenge for families and clinicians because the likelihood of remission following a course of ATD is lower in young people when compared to adults, yet the risk of adverse events is higher. An overall consensus regarding the optimal ATD treatment regimen is lacking; how ATD are prescribed, for how long and how the associated risk of adverse events is managed varies between clinicians, units and nations. This partly reflects clinician and family uncertainty regarding outcomes.Areas covered: This review will focus on some of the key articles published in the field of thionamide ATD in children. It will highlight key issues that need to be discussed with families as well as addressing the approach and controversies in the treatment of GD. This article does not reflect a formal systematic review of the literature.Expert opinion: New strategies in areas such as immunomodulation may see the development of new antithyroid drug treatments that, either in isolation or in combination with thionamide therapy, may increase the likelihood of long-term remission.

Pharmacodynamic Response to Anti-thyroid Drugs in Graves' Hyperthyroidism

Objective: Graves' disease is the commonest cause of hyperthyroidism in populations with sufficient dietary iodine intake. Anti-thyroid drugs (ATD) are often used as the initial treatment for Graves' hyperthyroidism, however there is a paucity of data relating the dose of ATD therapy to the effect on thyroid hormone levels, increasing the risk of both over- and under-treatment. We aimed to determine the pharmacodynamic response to the ATD carbimazole. Design: Retrospective cohort study. Methods: Participants were patients (n = 441) diagnosed with Graves' disease at Imperial College Healthcare NHS Trust between 2009 and 2018. The main outcome measure was change in thyroid hormone levels in response to ATD. Results: Baseline thyroid hormone levels were positively associated with TSH receptor antibody titres (P < 0.0001). Baseline free triiodothyronine (fT3) were linearly related to free thyroxine (fT4) levels in the hyperthyroid state (fT3 = fT4^*0.97-11), and fell proportionately with carbimazole. The percentage falls in fT4 and fT3 per day were associated with carbimazole dose (P < 0.0001). The magnitude of fall in thyroid hormones after the same dose of carbimazole was lower during follow up than at the initiation visit. The fall in thyroid hormone levels approximated to a linear response if assessed at least 3 weeks after commencement of carbimazole. Following withdrawal of antithyroid drug treatment, the risk of relapse was greater in patients with higher initial fT4, initial TSH receptor antibody titre, males, smokers, and British Caucasian ethnicity. Conclusion: We identify a dose-response relationship for fall in thyroid hormones in response to carbimazole to aid in the selection of dose for Graves' hyperthyroidism.

Safety of long-term antithyroid drug treatment? A systematic review

Continued low-dose MMI treatment for longer than 12-18 months may be considered in patients not in remission. However, ATDs are not free from adverse effects. We undertook a systematic review to clarify safety of long-term ATD treatment. Medline and the Cochrane Library for trials published between 1950 and Nov 2018 were systematically searched. We included original studies containing data for long-term (> 18 months) ATD treatment. Two reviewers independently extracted data from included trials and any disagreement was adjudicated by consensus. Of 615 related articles found, 12 fulfilled the criteria. Six articles had data for adults, five for non-adults and one article had data for both groups. The sample sizes ranged between 20 and 249 individuals, and the mean duration of ATD treatment ranged between 2.1 and 14.2 years. Considering all data from 1660 patients treated with ATD for a mean duration of 5.8 years (around 10,000 patient-years), major complications occurred only in 14 patients: 7 severe agranulocytosis, 5 severe liver damage, one ANCA-associated glomerulonephritis and one vasculitis with small cutaneous ulcerations. Minor complications rates were between 2 and 36%, while more complications were in higher doses and in the children. The most reported AE was cutaneous reaction; the other adverse events were elevated liver enzymes, leukocytopenia, arthritis, arthralgia, myalgia, thrombocytopenia, fever, nausea and oral aphthous. Long-term ATD treatment is safe, especially in low dose and in adults, indicating that it should be considered as an earnest alternative treatment for GD.

Exome sequencing in routine diagnostics: a generic test for 254 patients with primary immunodeficiencies

BACKGROUND

Diagnosis of primary immunodeficiencies (PIDs) is complex and cumbersome yet important for the clinical management of the disease. Exome sequencing may provide a genetic diagnosis in a significant number of patients in a single genetic test.

METHODS

In May 2013, we implemented exome sequencing in routine diagnostics for patients suffering from PIDs. This study reports the clinical utility and diagnostic yield for a heterogeneous group of 254 consecutively referred PID patients from 249 families. For the majority of patients, the clinical diagnosis was based on clinical criteria including rare and/or unusual severe bacterial, viral, or fungal infections, sometimes accompanied by autoimmune manifestations. Functional immune defects were interpreted in the context of aberrant immune cell populations, aberrant antibody levels, or combinations of these factors.

RESULTS

For 62 patients (24%), exome sequencing identified pathogenic variants in well-established PID genes. An exome-wide analysis diagnosed 10 additional patients (4%), providing diagnoses for 72 patients (28%) from 68 families altogether. The genetic diagnosis directly indicated novel treatment options for 25 patients that received a diagnosis (34%).

CONCLUSION

Exome sequencing as a first-tier test for PIDs granted a diagnosis for 28% of patients. Importantly, molecularly defined diagnoses indicated altered therapeutic options in 34% of cases. In addition, exome sequencing harbors advantages over gene panels as a truly generic test for all genetic diseases, including in silico extension of existing gene lists and re-analysis of existing data.

Increased Risk of Antithyroid Drug Agranulocytosis Associated with Amiodarone-Induced Thyrotoxicosis: A Population-Based Cohort Study

BACKGROUND

Agranulocytosis occurs in 0.2-0.5% of patients treated with the antithyroid drugs (ATDs) methimazole and propylthiouracil. The objectives of this study were to evaluate the risk of ATD-related agranulocytosis in patients with amiodarone-induced thyrotoxicosis (AIT), and to compare it with the agranulocytosis risk in patients with thyrotoxicosis due to other etiologies treated with ATDs.

METHODS

This was a retrospective cohort study. Participants were 14,781 adult patients with thyrotoxicosis, newly treated with an ATD between January 1, 2002, and December 31, 2015. Among them were 593 patients treated by ATDs due to AIT. The main outcome measures were incidence rates and crude and adjusted hazard ratios using univariate and multivariable Cox regression models for ATD-related agranulocytosis within one year of treatment initiation, in association with AIT.

RESULTS

Agranulocytosis occurred in 28 (0.19%) of patients newly treated with methimazole or propylthiouracil during the first year of follow-up. Of these 28 patients, 8/593 (1.35%) were AIT patients and 20/14,188 (0.14%) were thyrotoxic patients that was not AIT related (p < 0.001). Incidence rates were 22 (9.47-43.36) cases/1000 person-years of follow-up in AIT, and 1.79 (1.09-2.76)/1000 person-years of follow-up in non-AIT thyrotoxicosis (p < 0.0001). In univariate Cox regression analysis, risk for ATD agranulocytosis associated with AIT was 9.71 (4.28-22.05) compared to the risk in non-AIT thyrotoxicosis. In a multivariable model, adjusting for age, sex, body mass index, smoking history, year of cohort entry, diabetes mellitus, hypertension, renal failure, beta blockers, calcium channel blockers, anti-aggregants, and dose of ATDs, the risk associated with AIT was 5.70 (2.14-15.21). In a model adjusted for a propensity score to receive amiodarone, risk for ATD agranulocytosis associated with AIT was 6.32 (1.22-32.70).

CONCLUSIONS

ATD use is associated with a higher risk for agranulocytosis in patients with AIT.

Thyroid function and thyroid disorders during pregnancy: a review and care pathway

PURPOSE

To review the literature on thyroid function and thyroid disorders during pregnancy.

METHODS

A detailed literature research on MEDLINE, Cochrane library, EMBASE, NLH, ClinicalTrials.gov, and Google Scholar databases was done up to January 2018 with restriction to English language about articles regarding thyroid diseases and pregnancy.

RESULTS

Thyroid hormone deficiencies are known to be detrimental for the development of the fetus. In particular, the function of the central nervous system might be impaired, causing low intelligence quotient, and mental retardation. Overt and subclinical dysfunctions of the thyroid disease should be treated appropriately in pregnancy, aiming to maintain euthyroidism. Thyroxine (T4) replacement therapy should reduce thyrotropin (TSH) concentration to the recently suggested fixed upper limits of 2.5 mU/l (first and second trimester) and 3.0 mU/l (third trimester). Overt hyperthyroidism during pregnancy is relatively uncommon but needs prompt treatment due to the increased risk of preterm delivery, congenital malformations, and fetal death. The use of antithyroid drug (methimazole, propylthiouracil, carbimazole) is the first choice for treating overt hyperthyroidism, although they are not free of side effects. Subclinical hyperthyroidism tends to be asymptomatic and no pharmacological treatment is usually needed. Gestational transient hyperthyroidism is a self-limited non-autoimmune form of hyperthyroidism with negative antibody against TSH receptors, that is related to hCG-induced thyroid hormone secretion. The vast majority of these patients does not require antithyroid therapy, although administration of low doses of β-blocker may by useful in very symptomatic patients.

CONCLUSIONS

Normal maternal thyroid function is essential in pregnancy to avoid adverse maternal and fetal outcomes.

ANNIVERSARY REVIEW: Antithyroid drug therapy: 70 years later

The thionamide antithyroid drugs were discovered in large part following serendipitous observations by a number of investigators in the 1940s who found that sulfhydryl-containing compounds were goitrogenic in animals. This prompted Prof. Edwin B Astwood to pioneer the use of these compounds to treat hyperthyroidism in the early 1940s and to develop the more potent and less toxic drugs that are used today. Despite their simple molecular structure and ease of use, many uncertainties remain, including their mechanism(s) of action, clinical role, optimal use in pregnancy and the prediction and prevention of rare but potentially life-threatening adverse reactions. In this review, we summarize the history of the development of these drugs and outline their current role in the clinical management of patients with hyperthyroidism.

Thyroid disease in pregnancy: new insights in diagnosis and clinical management

Adequate thyroid hormone availability is important for an uncomplicated pregnancy and optimal fetal growth and development. Overt thyroid disease is associated with a wide range of adverse obstetric and child development outcomes. An increasing number of studies now indicate that milder forms of thyroid dysfunction are also associated with these adverse pregnancy outcomes. The definitions of both overt and subclinical thyroid dysfunction have changed considerably over the past few years, as new data indicate that the commonly used fixed upper limits of 2.5 mU/l or 3.0 mU/l for thyroid-stimulating hormone (TSH) are too low to define an abnormal thyroid function. Furthermore, some studies now show that the reference ranges are not necessarily the best cut-off for identifying pregnancies at high risk of adverse outcomes. In addition, data suggest that thyroid peroxidase autoantibody positivity and high or low concentrations of human chorionic gonadotropin seem to have a more prominent role in the interpretation of thyroid dysfunction than previously thought. Data on the effects of thyroid disease treatment are lacking, but some studies indicate that clinicians should be aware of the potential for overtreatment with levothyroxine. Here, we put studies from the past decade on reference ranges for TSH, determinants of thyroid dysfunction, risks of adverse outcomes and options for treatment into perspective. In addition, we provide an overview of the current views on thyroid physiology during pregnancy and discuss strategies to identify high-risk individuals who might benefit from levothyroxine treatment.

Association of HLA-B and HLA-DRB1 polymorphisms with antithyroid drug-induced agranulocytosis in a Han population from northern China

Antithyroid drug (ATD)-induced agranulocytosis is associated with human leukocyte antigen (HLA) and nearby genes in Southeast Asian and European populations. The susceptibility of the Han population from northern China to ATD-induced agranulocytosis has not been reported. We evaluated the associations of genetic variants at the HLA-B and HLA-DRB1 loci and 32 candidate single nucleotide polymorphisms (SNPs) with agranulocytosis in 29 patients with ATD-induced agranulocytosis and in 140 patients with Graves’ disease (GD) as controls. All subjects were of Han descent from northern China. HLA-B*27:05 (P = 1.10 × 10⁻⁴), HLA-B*38:02 (P = 2.41 × 10⁻⁴) and HLA-DRB1*08:03 (P = 1.57 × 10⁻³) were susceptibility HLA variants for ATD-induced agranulocytosis. All subjects carrying the HLA-B*27:05 allele had agranulocytosis. The odds ratios (ORs) comparing allele carriers to non-carriers were 66.24 (95% confidence interval (CI): 3.54–1239.66) for HLA-B*27:05, 7.525 (95% CI: 2.294–24.68) for HLA-B*38:02 and 4.316 (95% CI: 1.56–11.93) for HLA-DRB1*08:03. Two SNPs, rs2596487 (OR = 4.196, 95% CI = 2.086–8.441, P = 2.08 × 10⁻⁵) and rs2228391 (OR = 3.621, 95% CI = 1.596–8.217, P = 1.2 × 10⁻³), were independently associated with ATD-induced agranulocytosis. Subjects carrying the ‘A’ allele of rs1811197 or HLA-B*38:02 showed lower minimum granulocyte counts than non-carriers (P = 4.74 × 10⁻⁴ and P = 7.39 × 10⁻⁴, respectively). Our findings support the association between genetic variations of HLA-B and HLA-DRB1 with ATD-induced agranulocytosis in a Han population from northern China.

Increased risk for thionamide-induced agranulocytosis in elderly patients: a case presentation and literature review

Thionamides, such as methimazole and propylthiouracil, are used for the management of hyperthyroidism. Agranulocytosis is a rare adverse effect of thionamides and elderly patients are especially vulnerable. Here we discuss a case of an 80-year-old woman who developed agranulocytosis and pneumonia approximately 4 weeks after starting low dose methimazole therapy. Despite aggressive treatment with broad-spectrum antibiotics and granulocyte colony stimulating factor, she developed multiorgan failure and died. Our goals are to identify risk factors common to elderly patients and hopefully improve outcomes in this population when prescribed thionamides.

Rare NOX3 Variants Confer Susceptibility to Agranulocytosis During Thyrostatic Treatment of Graves' Disease

Agranulocytosis is a rare and serious adverse effect of antithyroid drugs, with unknown etiology. The present study aimed to uncover genetic susceptibility and underlying mechanisms of antithyroid drug-induced agranulocytosis (ATDAC). We studied two independent families with familial Graves' disease, of which several members developed ATDAC. In addition, six sporadic ATDAC patients with Graves' disease were investigated. Whole exome sequencing analysis of affected and unaffected family members was performed to identify genetic susceptibility variants for ATDAC, followed by functional characterization of primary granulocytes from patients and unrelated healthy controls. Whole exome sequencing, cosegregation analysis, and stringent selection criteria of candidate gene variants identified NOX3 as a genetic factor related to ATDAC. Functional studies revealed increased apoptosis of methimazole-treated granulocytes from patients carrying NOX3 variants. In conclusion, genetic variants in NOX3 may confer susceptibility to antithyroid drug-induced apoptosis of granulocytes. These findings contribute to the understanding of the mechanisms underlying ATDAC.

Emphasis on the early diagnosis of antithyroid drug-induced agranulocytosis: retrospective analysis over 16 years at one Chinese center

PURPOSE

Antithyroid drug (ATD)-induced agranulocytosis is a rare but life-threatening adverse drug reaction that occurs in patients during the treatment of Graves' disease. We aimed to comprehensively examine data for patients with this rare complication and to improve the clinical safety of ATDs.

METHODS

We retrospectively reviewed the medical records of 64 hospitalized patients diagnosed with ATD-induced agranulocytosis between 2000 and 2015.

RESULTS

Agranulocytosis occurred in 52 (81.3%) patients within the first 3 months after initiation of ATD therapy. Fever (84.4%) and sore throat (82.8%) were the most common symptoms. Although they experienced symptoms, 30 (46.9%) patients did not seek treatment immediately and delayed their diagnosis of agranulocytosis. The minimum granulocyte count was lower in the patients diagnosed after the appearance of symptoms than in those diagnosed before the appearance of symptoms (0.01 × 10⁹/L (0 × 10⁹/L - 0.06 × 10⁹/L) versus 0.26 × 10⁹/L (0.05 × 10⁹/L - 0.40 × 10⁹/L), P < 0.001). The interval days from the appearance of symptoms to the diagnosis of agranulocytosis were negatively correlated with the minimum granulocyte count (r = -0.348, P = 0.005). In addition, a lower minimum granulocyte count was associated with a longer recovery time (β = -11.899, 95% CI -15.304 to -8.496).

CONCLUSIONS

Our findings have demonstrated that delayed diagnosis of ATD-induced agranulocytosis is common in our population. Delayed diagnosis is associated with severe agranulocytosis and may prolong the recovery time from agranulocytosis. Monitoring of the white blood cell and granulocyte counts may be an effective way to establish an early diagnosis and prevent progression to severe agranulocytosis.

Free Thyroxine, Anti-Thyroid Stimulating Hormone Receptor Antibody Titers, and Absence of Goiter Were Associated with Responsiveness to Methimazole in Patients with New Onset Graves' Disease

BACKGROUND

Anti-thyroid drug therapy is considered a treatment of choice for Graves' disease; however, treatment response varies among individuals. Although several studies have reported risk factors for relapse after initial treatment, few have assessed responsiveness during the early treatment period. Our study aimed to identify the clinical characteristics for responsiveness to methimazole.

METHODS

We included 99 patients diagnosed with Graves' disease for the first time. Drug responsiveness was defined as the correlation coefficients between decreasing rates of free thyroxine level per month and methimazole exposure dose. According to their responsiveness to treatment, the patients were classified into rapid or slow responder groups, and age, sex, free thyroxine level, and thyrotropin binding inhibiting immunoglobulin (TBII) titers were compared between groups.

RESULTS

The mean patient age was 44.0±13.5 years and 40 patients were male (40%). The mean TBII titer was 36.6±74.4 IU/L, and the mean free thyroxine concentration was 48.9±21.9 pmol/L. The rapid responder group showed higher TBII titer and free thyroxine level at diagnosis, while age, sex, smoking, and presence of goiter did not differ between the two groups. Logistic regression analyses revealed that high level of serum thyroxine, high titer of TBII, and absence of goiter were significantly associated with a rapid response, while age, sex, and smoking were not significant factors for the prediction of responsiveness.

CONCLUSION

In patients with new onset Graves' disease, high level of free thyroxine, high titer of TBII, and absence of goiter were associated with rapid responsiveness to methimazole treatment.

Epidemiology, management and outcomes of Graves' disease-real life data

PURPOSE

Treatment options in Graves' disease are clearly defined, but management practices and the perceptions of success are varied. The outcomes of treatment in large consecutive cohorts of Graves' disease have not been well characterised. The study describes the epidemiology, management strategies and medium term outcomes following anti-thyroid drug treatment, radio-iodine ablation and surgery in Graves' disease.

METHODS

All patients (n = 659) who received treatment for a new diagnosis of Graves' disease in secondary care over a 5 year period were included with a median (interquartile range) follow-up of 42.9 (29-57.5) months.

RESULTS

The age adjusted incidence of adult onset Graves' disease in Sheffield, UK was 24.8 per 100,000 per year. Excluding 35 patients lost to follow-up, 93.1% (n = 581) were controlled on anti-thyroid drug treatment. Of these, 73.6% went into remission following withdrawal of anti-thyroid drugs; 5.2% were still undergoing initial therapy; 13.3% lost control whilst on anti-thyroid drugs; and 7.9% went on to have either surgery or radio-iodine ablation whilst controlled on anti-thyroid drugs. Of the 428 patients who achieved remission, 36.7% relapsed. Of 144 patients who had radio-iodine ablation treatment, 5.6% relapsed and needed further treatment. Of 119 patients having surgery, 5.2% had long-term hypoparathyroidism and none had documented long-term recurrent laryngeal nerve palsy.

CONCLUSIONS

In the follow-up, 39.9% of patients underwent surgery or radio-iodine ablation with little morbidity. Up to two-thirds of patients who achieved remission did not relapse. Data on effectiveness and risks of treatments for Graves' disease presented in this study will help clinicians and patients in decision making.

Guidelines for the treatment of childhood-onset Graves' disease in Japan, 2016

Purpose behind developing these guidelines: Over one decade ago, the “Guidelines for the Treatment of Graves’ Disease with Antithyroid Drug, 2006” (Japan Thyroid Association (JTA)) were published as the standard drug therapy protocol for Graves’ disease. The “Guidelines for the Treatment of Childhood-Onset Graves’ Disease with Antithyroid Drug in Japan, 2008” were published to provide guidance on the treatment of pediatric patients. Based on new evidence, a revised version of the “Guidelines for the Treatment of Graves’ Disease with Antithyroid Drug, 2006” (JTA) was published in 2011, combined with the “Handbook of Radioiodine Therapy for Graves’ Disease 2007” (JTA). Subsequently, newer findings on pediatric Graves’ disease have been reported. Propylthiouracil (PTU)-induced serious hepatopathy is an important problem in pediatric patients. The American Thyroid Association’s guidelines suggest that, in principle, physicians must not administer PTU to children. On the other hand, the “Guidelines for the Treatment of Graves’ Disease with Antithyroid Drug, 2011” (JTA) state that radioiodine therapy is no longer considered a “fundamental contraindication” in children. Therefore, the “Guidelines for the Treatment of Childhood-Onset Graves’ Disease with Antithyroid Drug in Japan, 2008” required revision.

Relationship between dose of antithyroid drugs and adverse events in pediatric patients with Graves' disease

Graves’ disease (GD) accounts for a large proportion of pediatric hyperthyroidism, and the first-line treatment is antithyroid drug (ATD) therapy. Methimazole (MMI) is effective in most patients but is associated with significant adverse events (AEs). We reviewed the medical records of GD patients (n = 56) with onset age of <15 yr and investigated the relationship between MMI dose and AEs. The study population comprised 11 male and 45 female patients and the median age at diagnosis was 11 yr. All patients were initially treated with ATDs. Among the 52 patients initially treated with MMI, 20 received a low dose, and 32 received a high dose of MMI (< 0.7 vs ≥ 0.7 mg/kg/day, respectively). AEs occurred in 20% of the patients in the low-dose MMI group, and in 50% patients in the high-dose MMI group (p = 0.031). A greater variety of AEs was observed in the high-dose group. Neutropenia and rash were observed in both groups. With treatment transition to low-dose MMI according to the Japanese Society for Pediatric Endocrinology guidelines, we expect a decrease in the incidence of AEs in future. However, we should be careful as neutropenia and rash can occur independently of the MMI dose.

Periodic Granulocyte Count Measuring Is Useful for Detecting Asymptomatic Agranulocytosis in Antithyroid Drug-Treated Patients with Graves' Disease

OBJECTIVE

Finding agranulocytosis (AG) at an early stage is important to improve outcome, but periodic granulocyte count monitoring is not generally recommended for patients with Graves' disease, because AG develops suddenly.

METHOD

At the Kuma Hospital, Graves' patients under antithyroid drug (ATD) treatment in an outpatient clinic have a granulocyte count examination during each visit, and if it is <1,000/μl, a warning is immediately sent to the patient's physician. We evaluated the usefulness of this system.

RESULTS

We investigated 25 AG and 33 granulocytopenia (GP) cases over a recent 5-year period, excluding patients who developed AG or GP at another hospital and were referred to us for treatment. Among the 25 AG patients, 16 patients (64%; 9 asymptomatic and 7 very mild symptomatic cases) were discovered by the periodic granulocyte count examination at an outpatient clinic. The remaining 9 patients visited the Kuma Hospital or other hospitals because of infection symptoms. Most of the AG patients were given granulocyte colony-stimulating factor injections immediately and were admitted if a prompt increase in granulocytes could not be obtained. The final treatments for Graves' disease were ¹³¹I-radioisotope therapy (19 patients), thyroidectomy (2 patients), inorganic iodine (1 patient), or another ATD (1 patient). Among the 33 GP patients, 31 (94%), including 20 asymptomatic cases, were discovered during periodic granulocyte count monitoring. Most of them stopped ATD, and other treatments for Graves' disease were selected.

CONCLUSION

Periodic monitoring of granulocyte counts is useful for identifying AG and GP patients with no or minimum infection symptoms.

Delayed methimazole-induced agranulocytosis in a 6-year old patient with Graves’ disease

Background

Agranulocytosis is regarded as a rare side effect of methimazole (MMI) therapy that occurs in a dose dependent manner and that usually develops within the first 3–6 months of treatment. Although delayed development beyond this timeline has been documented in adults, very few children have been reported with this presentation.

Case presentation

We present a 6-year old patient who developed agranulocytosis 18 months after the start of MMI therapy.

Conclusions

This is an unusual case of a 6-year old patient who developed this serious side effect on stable MMI therapy well beyond the typical timeline. Our review of the literature revealed that there really is inconclusive data on the incidence, time, and dose-dependency of MMI-induced agranulocytosis in the pediatric Graves’ disease population.

Management of hyperthyroidism due to Graves' disease: frequently asked questions and answers (if any)

Graves' disease is the most common cause of hyperthyroidism in iodine-replete areas. Although progress has been made in our understanding of the pathogenesis of the disease, no treatment targeting pathogenic mechanisms of the disease is presently available. Therapies for Graves' hyperthyroidism are largely imperfect because they are bound to either a high rate of relapsing hyperthyroidism (antithyroid drugs) or lifelong hypothyroidism (radioiodine treatment or thyroidectomy). Aim of the present article is to offer a practical guidance to the reader by providing evidence-based answers to frequently asked questions in clinical practice.

2016 American Thyroid Association Guidelines for Diagnosis and Management of Hyperthyroidism and Other Causes of Thyrotoxicosis

BACKGROUND

Thyrotoxicosis has multiple etiologies, manifestations, and potential therapies. Appropriate treatment requires an accurate diagnosis and is influenced by coexisting medical conditions and patient preference. This document describes evidence-based clinical guidelines for the management of thyrotoxicosis that would be useful to generalist and subspecialty physicians and others providing care for patients with this condition.

METHODS

The American Thyroid Association (ATA) previously cosponsored guidelines for the management of thyrotoxicosis that were published in 2011. Considerable new literature has been published since then, and the ATA felt updated evidence-based guidelines were needed. The association assembled a task force of expert clinicians who authored this report. They examined relevant literature using a systematic PubMed search supplemented with additional published materials. An evidence-based medicine approach that incorporated the knowledge and experience of the panel was used to update the 2011 text and recommendations. The strength of the recommendations and the quality of evidence supporting them were rated according to the approach recommended by the Grading of Recommendations, Assessment, Development, and Evaluation Group.

RESULTS

Clinical topics addressed include the initial evaluation and management of thyrotoxicosis; management of Graves' hyperthyroidism using radioactive iodine, antithyroid drugs, or surgery; management of toxic multinodular goiter or toxic adenoma using radioactive iodine or surgery; Graves' disease in children, adolescents, or pregnant patients; subclinical hyperthyroidism; hyperthyroidism in patients with Graves' orbitopathy; and management of other miscellaneous causes of thyrotoxicosis. New paradigms since publication of the 2011 guidelines are presented for the evaluation of the etiology of thyrotoxicosis, the management of Graves' hyperthyroidism with antithyroid drugs, the management of pregnant hyperthyroid patients, and the preparation of patients for thyroid surgery. The sections on less common causes of thyrotoxicosis have been expanded.

CONCLUSIONS

One hundred twenty-four evidence-based recommendations were developed to aid in the care of patients with thyrotoxicosis and to share what the task force believes is current, rational, and optimal medical practice.

Cholestyramine Use for Rapid Reversion to Euthyroid States in Patients with Thyrotoxicosis

Cholestyramine (CS) is an ion exchange resin, which binds to iodothyronines and would lower serum thyroid hormone level. The use of CS added to conventional antithyroid drugs to control thyrotoxicosis has been applied since 1980's, and several studies indicate that using CS in combination with methimazole (MZ) produces a more rapid decline in serum thyroid hormones than with only MZ treatment. Our recent retrospective review of five patients taking high dose MZ and CS, compared to age-, gender-, initial free thyroxine (T4) level-, and MZ dose-matched 12 patients with MZ use only, showed more rapid decline of both free T4 and triiodothyronine levels without more adverse events. CS could be safely applicable short-term adjunctive therapy when first-line antithyroid medications are not enough to adequately control severe thyrotoxicosis or side effects of antithyroid drug would be of great concern.

Methimazole Induced Total Myeloid Aplasia with Delayed Recovery Despite Granulocyte Colony Stimulating Factor (G-CSF): Marrow Progenitor Recovery Kinetics

An eighteen-year-old female with Graves thyrotoxicosis presented with methimazole-induced agranulocytosis and total myeloid aplasia. The bone marrow at presentation showed complete absence of myeloid precursors and striking plasmacytosis. 16 days later, myeloid precursors were still absent morphologically; however bone marrow flow cytometry and cell culture detected an improvement in myelogenesis, which was soon followed by clinical recovery of agranulocytosis. Neutrophil recovery was delayed until day 22 after cessation of methimazole despite G-CSF use, consistent with a direct toxic effect on committed myeloid cells. Our findings suggest that cell culture and flow cytometric evaluation of bone marrow myeloid progenitors can be used as a guide to anticipate neutrophil recovery.

Antithyroid drug induced a granulocytosis: what still we need to learn?

Antithyroid drugs (ATDs) induced agranulocytosis is a rare but life threatening condition. We report a 29 years Filipino female diagnosed as having hyperthyroidism with normal base line blood counts, liver and renal profile. She was started on maximum 60mg (20mg TID) oral dose of carbimazole since one month by her treating physician. Exactly after one month of treatment she presented to emergency room (ER) with fever, sore throat and generalized weakness for several days.

Characteristics of Antithyroid Drug-Induced Agranulocytosis in Patients with Hyperthyroidism: A Retrospective Analysis of 114 Cases in a Single Institution in China Involving 9690 Patients Referred for Radioiodine Treatment Over 15 Years

BACKGROUND

Antithyroid drug (ATD)-induced agranulocytosis is a rare but life-threatening disease. Clinical features of ATD-induced agranulocytosis and outcomes remain incompletely understood.

METHOD

Patients with clinically diagnosed ATD-induced agranulocytosis were retrospectively studied, involving 9690 patients who were referred for radioiodine treatment during a 15-year period (2000-2015) in China. There were 114 cases of agranulocytosis attributable to ATD included, and their clinical characteristics and therapy outcomes were analyzed.

RESULTS

The female-to-male ratio of ATD-induced agranulocytosis was 10.4:1. The mean age (±standard deviation) of the patients with ATD-induced agranulocytosis was 41.7 ± 12.3 years. The methimazole and propylthiouracil doses given at the onset were 22.9 ± 8.0 mg/day and 253.6 ± 177.5 mg/day, respectively. ATD-induced agranulocytosis occurred in 45.1%, 74.3%, and 88.5% of patients within 4, 8, and 12 weeks of the onset of ATD therapy, respectively. Fever (78.9%) and sore throat (72.8%) were the most common symptoms when agranulocytosis was diagnosed. The mean recovery time of agranulocytosis was 13.41 ± 7.14 days. Recovery time in the granulocyte colony-stimulating factor (G-CSF)-treated group (12.7 ± 6.0 days) did not differ from that in the group not treated with G-CSF (16.4 ± 10.6 days; p = 0.144). Treatment with (131)I was successful in 87/98 patients (88.8%). The success rate of (131)I was equivalent (p = 1.000) between the groups receiving methimazole (88.2%, 75/85) and propylthiouracil (92.3%, 12/13).

CONCLUSIONS

This largest single-institution study in China shows that ATD-induced agranulocytosis tends to occur within the first 12 weeks after the onset of ATD therapy. For patients with ATD-induced agranulocytosis, G-CSF does not improve the recovery time of agranulocytosis, and (131)I is an optimal treatment approach.

Successful Re-administration of Low-dose of Methimazole (MMI) in Graves' Disease Patients Who Experienced Allergic Cutaneous Reactions to MMI at Initial Treatment and Had Received Long-term Propylthiouracil (PTU)

Objective When patients with Graves' disease show severe allergic cutaneous reactions, physicians often suggest that they undergo radioiodine therapy instead of receiving propylthiouracil (PTU), another antithyroid drug, because anti-neutrophil cytoplasmic antibody (ANCA) -related vasculitis can occur with PTU, especially with long-term use. However, some patients refuse radioiodine therapy and chose PTU. Sometimes PTU treatment may be prolonged. Since the frequency of adverse effects of methimazole (MMI) is dose-related, there is a possibility that we can re-administer a low dose without adverse effects to patients well-controlled with PTU who once experienced an allergic reaction to MMI. Methods I prospectively re-administered a low dose of MMI to patients who previously experienced an allergic reaction to MMI at initial treatment. The dose of re-administered MMI ranged from 5 mg twice a week to 5 mg daily. Patients Nine patients with Graves' disease who developed urticaria at initial treatment with MMI and had been treated with PTU for 6 to 21 years were recruited. Results Eight of the 9 patients were successfully controlled with MMI without allergic cutaneous reactions. Only one patient felt itchiness 2 days after switching to MMI. However, skin change was not observed. Conclusion If the patients show allergic cutaneous reactions as a side effect of MMI at the initial treatment for Graves' disease, then there is a strong possibility that such patients can tolerate a low dose of MMI without adverse effects after the disease activity has subsided.

Characteristics of Korean Patients with Antithyroid Drug-Induced Agranulocytosis: A Multicenter Study in Korea

BACKGROUND

Antithyroid drugs (ATDs) can lead to the development of agranulocytosis, which is the most serious adverse effect. Characteristics of ATD-induced agranulocytosis (AIA) have seldom been reported due to the rarity. In this study, we characterized the clinical features for AIA in Korean patients.

METHODS

We retrospectively reviewed data from patients with AIA diagnosed between 1997 and 2014 at four tertiary hospitals. Agranulocytosis was defined as an absolute neutrophil count (ANC) below 500/mm³.

RESULTS

The mean age of the patients (11 males, 43 females) was 38.2±14.9 years. Forty-eight patients (88.9%) with AIA had fever and sore throat on initial presentation, 20.4% of patients developed AIA during the second course of treatment, and 75.9% of patients suffered AIA within 3 months after initiation of ATD. The patients taking methimazole (n=39) showed lower levels of ANC and more frequent use of granulocyte-macrophage colony-stimulating factor than propylthiouracil (n=15) users. The median duration of agranulocytosis was 5.5 days (range, 1 to 20). No differences were observed between the long (≥6 days) and short recovery time (≤5 days) groups in terms of age, gender, ATDs, duration of ATDs, or initial ANC levels. Four patients (7.4%) who were taking ATDs for less than 2 months died of sepsis on the first or second day of hospitalization.

CONCLUSION

The majority of AIA incidents occur in the early treatment period. Considering the high fatality rate of AIA, an early aggressive therapeutic approach is critical and patients should be well informed regarding the warning symptoms of the disease.

Necrotizing gingivostomatitis and osteonecrosis associated with antithyroid drug propylthiouracil therapy

A 43-year-old Chinese female had been diagnosed with hyperthyroidism 15 years ago. She was recently administered 150 mg/day propylthiouracil (PTU). After 3 weeks of PTU administration, she developed necrotizing stomatitis and osteonecrosis, most likely due to secondary effects from the PTU treatment. Her neutrophil count was reduced below normal to 0.24×10(9)/L but normalized after withdrawal of PTU therapy. About 1 month after onset, the patient came to our hospital and began to receive intravenous treatments of metronidazole and amoxicillin. Following review of her medical history and a series of clinical and laboratory examinations, the patient was diagnosed with secondary necrotizing gingivostomatitis and osteonecrosis possibly associated with PTU-induced agranulocytosis. One-year after treatment, the patient's oral manifestations remained unchanged. This case demonstrates the need for dental practitioners to more closely monitor oral symptoms in patients with hyperthyroidism treated with antithyroid drugs.

Comparison of efficacy and adverse effects between methimazole 15 mg+inorganic iodine 38 mg/day and methimazole 30 mg/day as initial therapy for Graves' disease patients with moderate to severe hyperthyroidism

BACKGROUND

Methimazole (MMI) is usually used at an initial dose of 30 mg/day for severe Graves' disease (GD) hyperthyroidism, but adverse effects are more frequent at this dose than at MMI 15 mg/day.

OBJECTIVES

We designed a regimen to address the lack of a primary therapeutic effect of the MMI 15 mg/day by combining it with inorganic iodine at 38.2 mg/day. Our aim was to compare the two regimens (MMI 15 mg+inorganic iodine at 38.2 mg/day (M15+I) vs. MMI 30 mg/day (M30)) in terms of therapeutic effect, adverse effects, and remission rate.

DESIGN AND PATIENTS

In a prospective study, 310 patients with untreated GD (serum free thyroxine (fT4) ≥5 ng/dL) were assigned to one of the two regimens. Potassium iodide was discontinued in the M15+I group as soon as the serum fT4 level was within the reference range (0.8-1.6 ng/dL).

RESULTS

Percentages of patients achieving an fT4 level within reference range in ≤30, ≤60, or 90 days on the study treatment regimens were 45.3%, 73.9%, and 82.0% respectively for the M15+I group, and 24.8%, 63.1%, and 75.2% respectively for the M30 group. Hence, the proportions of patients achieving this goal in ≤30 or ≤60 days were significantly larger in the M15+I group. Adverse effects that required discontinuation of MMI were more frequent in the M30-treated than in the M15+I-treated group (14.8% vs. 7.5%; p=0.0387). The remission rates in the M15+I and M30 groups were 19.9% and 14.8%-higher in the former, but the difference did not reach statistical significance.

CONCLUSION

The results of this study raise the possibility that M15+I is superior to M30 as a primary treatment for moderate to severe hyperthyroidism caused by GD.

Lithium Carbonate in the Treatment of Graves' Disease with ATD-Induced Hepatic Injury or Leukopenia

Objective. GD with ATD-induced hepatic injury or leukopenia occurs frequently in clinical practice. The purpose of the present study was to observe the clinical effect of lithium carbonate on hyperthyroidism in patients with GD with hepatic injury or leukopenia. Methods. Fifty-one patients with GD with hepatic injury or leukopenia participated in the study. All patients were treated with lithium carbonate, in addition to hepatoprotective drugs or drugs that increase white blood cell count. Thyroid function, liver function, and white blood cells were measured. Clinical outcomes were observed after a 1-year follow-up. Results. After treatment for 36 weeks, symptoms of hyperthyroidism and the level of thyroid hormones were improved and liver function, and white blood cells returned to a normal level. Twelve patients (23.5%) obtained clinical remission, 6 patients (11.8%) relapsed after withdrawal, 25 patients (49.0%) received radioiodine therapy, and 8 patients (15.7%) underwent surgical procedures after lithium carbonate treatment. Conclusion. Lithium carbonate has effects on the treatment of mild-to-moderate hyperthyroidism caused by GD, and it is particularly suitable for patients with ATD-induced hepatic injury or leukopenia.