Propylthiouracil and carbimazole associated-antineutrophil cytoplasmic antibodies (ANCA) in patients with Graves' disease

Serum syndecan1 has the potential to reflect activity at diagnosis and predict death during follow-up in patients with ANCA-associated vasculitis

OBJECTIVES

This study investigated whether serum syndecan1 at diagnosis reflects activity at diagnosis and predicts poor outcomes during follow-up in patients with antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV).

METHODS

The study included 79 patients with AAV from the cohort of Korean patients diagnosed with AAV. AAV-specific indices, including the Birmingham vasculitis activity score (BVAS), five-factor score (FFS), 36-item short-form survey (SF-36) physical and mental component summary (PCS and MCS), and vasculitis damage index (VDI), were assessed. Laboratory data including erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) levels were also collected. The highest tertile and upper half of the BVAS were tentatively defined as having high AAV activity. Serum syndecan1 levels were measured in sera stored at diagnosis.

RESULTS

Serum syndecan1 at diagnosis was significantly correlated with AAV activity and functional status, as assessed by BVAS, FFS, SF-36 PCS, MCS, and acute-phase reactants, including ESR and CRP. Patients with serum syndecan1 ≥ 76.1 ng/mL at diagnosis, and those with serum syndecan1 ≥ 60.0 ng/mL at diagnosis showed significantly higher risks for the highest tertile and the upper half of BVAS at diagnosis than those without, respectively. Patients with serum syndecan1 ≥ 120.1 ng/mL at diagnosis had a significantly higher risk for all-cause mortality during follow-up than those without, and further, exhibited a significantly lower cumulative patients' survival rate than those without.

CONCLUSION

Serum syndecan1 at diagnosis may not only reflect AAV activity at diagnosis but may also be associated with all-cause mortality during follow-up.

ANCA-Positive Small-Vessel Vasculitis Following SARS-CoV-2 Vaccination-A Systematic Review

As vaccinations against the SARS-CoV-2 virus have become a crucial tool in controlling the spread of the disease, reports of rare health complications have emerged, including new-onset antineutrophil cytoplasmic autoantibodies (ANCA)-associated vasculitis (AAV). We systematically reviewed new-onset AAV following COVID-19 vaccination case reports and case series published in three databases before January 2024 following PRISMA guidelines to understand the characteristics of possible causal relationships or coincidences. In total, 404 articles were screened respectively by title, abstracts, and full-texts. Thirty-four papers fulfilled the inclusion criteria and have been analyzed, covering 44 patients with new-onset AAV after COVID-19 vaccination with no prior history of COVID-19 infection. Data regarding patients' metrics, comorbidities, vaccination characteristics, symptoms, diagnostics, treatment, and outcomes were investigated and summarized. The cohort consisted predominantly of females. AAV diagnosis was confirmed via biopsy, with renal dysfunction as a prevailing manifestation. In most cases, the first symptoms of AAV developed after the second dose; moreover, Pfizer-BioNTech was the most frequently administered vaccine among the analyzed cohort. Primary treatment involved glucocorticoid therapy, with a mostly favourable response. This systematic review aims to raise awareness among clinicians in the field regarding this rare but possible complication, to promote the prompt recognition and diagnosis of de novo ANCA-positive small-vessel vasculitis in timely association with SARS-CoV-2 vaccination.

Characteristics and outcome of ANCA-associated vasculitides induced by anti-thyroid drugs: a multicentre retrospective case-control study

OBJECTIVE

Data on ANCA-associated vasculitis (AAV) induced by anti-thyroid drugs (ATD) are scarce. We aimed to describe the characteristics and outcome of these patients in comparison to primary AAV.

METHODS

We performed a retrospective multicentre study including patients with ATD-induced AAV. We focused on ATD-induced microscopic polyangiitis (MPA) and compared them with primary MPA by matching each case with four controls by gender and year of diagnosis.

RESULTS

Forty-five patients with ATD-induced AAV of whom 24 MPA were included. ANCA were positive in 44 patients (98%), including myeloperoxidase (MPO)-ANCA in 21 (47%), proteinase 3 (PR3)-ANCA in six (13%), and double positive MPO- and PR3-ANCA in 15 (33%). Main clinical manifestations were skin involvement (64%), arthralgia (51%) and glomerulonephritis (20%). ATD was discontinued in 98% of cases, allowing vasculitis remission in seven (16%). All the remaining patients achieved remission after glucocorticoids, in combination with rituximab in 11 (30%) or cyclophosphamide in four (11%). ATD were reintroduced in seven cases (16%) without any subsequent relapse. Compared with 96 matched primary MPA, ATD-induced MPA were younger at diagnosis (48 vs 65 years, P < 0.001), had more frequent cutaneous involvement (54 vs 25%, P = 0.007), but less frequent kidney (38 vs 73%, P = 0.02), and a lower risk of relapse (adjusted HR 0.07; 95% CI 0.01, 0.65, P = 0.019).

CONCLUSION

ATD-induced AAV were mainly MPA with MPO-ANCA, but double MPO- and PR3-ANCA positivity was frequent. The most common manifestations were skin and musculoskeletal manifestations. ATD-induced MPA were less severe and showed a lower risk of relapse than primary MPA.

Urinary loss of thyroid hormones: An issue to remember

A 45-year-old woman suffering from primary hypothyroidism, previously well substituted with levothyroxine, was urgently referred from Primary Care to Endocrinology due to very elevated thyrotropin, free thyroxine at low limit of normality, very high cholesterol and generalised oedema. Hypothyroidism was suspected as the main aetiology of this clinical condition. A detailed examination showed nephrotic range proteinuria and the patient was finally diagnosed with lupus nephritis. Urinary loss of thyroid hormones, fundamentally linked to their transport proteins, in patients affected by nephrotic syndrome is sometimes a forgotten phenomenon and one which should be considered in patients with increased levothyroxine requirements. In this report, we present the details of this case and a brief review of the literature on this topic.

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.

Comorbidities and health-related quality of life in Patients with Antineutrophil Cytoplasmic Antibody (ANCA) - associated vasculitis

BACKGROUND AND OBJECTIVES

The optimization of immunosuppressive therapies has led to a marked improvement in the survival of ANCA-associated vasculitides (AAV). The main issue now appears to be the management of comorbidities and the improvement of quality of life. The objective of this review was to investigate the incidence and the impact of AAV-associated comorbidities, as well as the determinants of health-related quality of life (HRQoL).

METHODS

We performed a systematic literature review of articles published in Medline from 2001 to 04/28/2020. We selected relevant articles about AAV-associated comorbidities as well as HRQoL and fatigue. For each selected article, data on the incidence of comorbidity were extracted, and factors associated with the Mental component score (MCS) and the Physical component score (PCS) were identified.

RESULTS

Among the 10,993 references identified, 103 were retained for the final analysis. A significant increase in cardiovascular risk was evidenced, particularly for coronary artery disease and thromboembolic events, especially during the active phase of the disease. AAV was also associated with bronchiectasis, thyroid diseases and osteoporosis. A marked decrease in HRQoL and an increase in fatigue and anxiety were reported. Decrease in PCS and MCS was associated with fatigue, mood disorders, sleep disturbance, and/or unemployment.

CONCLUSION

The excess mortality of AAV is still a concern, partly in connection with cardiovascular and thromboembolic comorbidities. AAV patients also experiment a reduction in their HRQoL that requires integrated management. Patients with AAV need comorbidity management strategies to improve their quality of life and 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.

Treatment of adult Graves' disease

Treatment strategy in Graves' disease firstly requires recovery of euthyroid status by antithyroid therapy. Treatment modalities, precautions, advantages and side-effects are to be discussed with the patient. No particular treatment modality has demonstrated superiority. Pregnancy or pregnancy project affects choice of treatment and monitoring. Graves' orbitopathy is liable to be aggravated by iodine-131 treatment and requires pre-treatment assessment. Iodine-131 treatment aims at achieving hypothyroidism. Thyroid surgery for Graves' disease should preferably be performed by an expert team. In case of recurrence of hyperthyroidism, the various treatment options should be discussed with the patient. Empiric treatment of thyroid dermopathy uses local corticosteroids in occlusive dressing.

Diagnosis and management of hyperthyroidism from prenatal life to adolescence

Hyperthyroidism in children is a rare heterogeneous syndrome characterized by excessive thyroid hormone production. Its manifestations differ according to disease severity. For all forms of hyperthyroidism, treatment aims to restore a euthyroid state, enabling the child to demonstrate appropriate metabolism, growth, and neurocognitive development. Graves' disease is the most frequent cause of hyperthyroidism in children. Treatment modalities include antithyroid drugs, with the advantage that prolonged treatment for several years can be followed by freedom from medical intervention in about 40-50% of cases. It may also be treated with radioactive iodine or, less frequently, thyroidectomy, these more radical treatments both necessitating subsequent lifelong levothyroxine treatment. Particular care is required in the management of pregnant women with Graves' disease. Fetal and neonatal forms of hyperthyroidism are transient and rare, but nevertheless serious. Here, we provide an overview of the best approach to hyperthyroidism diagnosis and management, from fetal development to adolescence.

Increased Prevalence of Thyroid Disease in Patients with Antineutrophil Cytoplasmic Antibodies–associated Vasculitis

Objective.

Antineutrophil cytoplasmic antibodies (ANCA)–associated vasculitis (AAV) has been linked with thyroid disease as a result of antithyroid medications. We assessed the prevalence of thyroid disease in our patients with AAV.

Methods.

Clinical records of 279 patients with AAV diagnosed between 1991 and 2014 were analyzed.

Results.

Thyroid disease was identified in 21.5% of patients, but only 2 had previously received propylthiouracil. There was a greater proportion of female patients, patients with antimyeloperoxidase antibodies, and patients with renal disease in the group with thyroid disease.

Conclusion.

Our data show a higher prevalence of thyroid disease in patients with AAV than the general population. This was not attributable to antithyroid drugs.

MANAGEMENT OF ENDOCRINE DISEASE: Arguments for the prolonged use of antithyroid drugs in children with Graves' disease

Graves' disease is an autoimmune disorder. It is the leading cause of hyperthyroidism, but is rare in children. Patients are initially managed with antithyroid drugs (ATDs), such as methimazole/carbimazole. A major disadvantage of treatment with ATD is the high risk of relapse, exceeding 70% of children treated for duration of 2 years, and the potential major side effects of the drug reported in exceptional cases. The major advantage of ATD treatment is that normal homeostasis of the hypothalamus-pituitary-thyroid axis may be restored, with periods of drug treatment followed by freedom from medical intervention achieved in approximately 40-50% of cases after prolonged treatment with ATD, for several years, in recent studies. Alternative ablative treatments such as radioactive iodine and, less frequently and mostly in cases of very high volume goiters or in children under the age of 5 years, thyroidectomy, performed by pediatric surgeons with extensive experience should be proposed in cases of non-compliance, intolerance to medical treatment or relapse after prolonged medical treatment. Ablative treatments are effective against hyperthyroidism, but they require the subsequent administration of levothyroxine throughout the patient's life. This review considers data relating to the prognosis for Graves' disease remission in children and explores the limitations of study designs and results; and the emerging proposal for management through the prolonged use of ATD drugs.

Thiocarbonyl Surrogate via Combination of Sulfur and Chloroform for Thiocarbamide and Oxazolidinethione Construction

An efficient and practical thiocarbonyl surrogate via combination of sulfur and chloroform has been developed. A variety of thiocarbamides and oxazolidinethiones have been established, including chiral thiourea catalysts and chiral oxazolidinethione auxiliaries with high selectivity. Meanwhile, pesticides Diafenthiuron (an acaricide), ANTU (a rodenticide), and Chloromethiuron (an insecticide) were practically synthesized through this method in gram scale. Dicholorocarbene, as the key intermediate, was further confirmed via a carbene-trapping control experiment.

Radioiodine therapy of thyrotoxicosis in children and adolescents. Indications, efficacy and safety. Literature review

Болезнь Грейвса (БГ) – основная причина тиреотоксикоза у детей. В современной клинической практике применяется три метода лечения БГ: тиреостатики, радиоактивный йод и операция. Все эти методы лечения применяются давно, и в мире накоплен огромный опыт применения каждого из методов лечения. Лечение начинают практически всегда с тиреостатиков, непереносимость или неэффективность которых становится показанием к выбору альтернативных методов лечения. Для осознанного выбора метода лечения необходимо понимать его потенциальные параметры эффективности и безопасности, а также влияющие на них факторы. Цель обзора – критический анализ эффективности и безопасности радиойодтерапии в лечении тиреотоксикоза у детей и подростков в сравнении с аналогичными показателями других методов лечения, а также показания и противопоказания к данному виду лечения в современной клинической практике эндокринологов, радиологов и эндокринных хирургов. Выбор тактики лечения БГ у ребенка на каждом этапе осуществляется согласованно с ним и его родителями/опекунами путем информирования лечащим врачом об объективных преимуществах и недостатках методов лечения на основе имеющейся доказательной базы. Также приведены основные рекомендации эффективной и безопасной терапии радиоактивным йодом БГ у детей и подростков.

Controversies in the management of Graves' disease in children

Graves' disease (GD) is the most prevalent cause of thyrotoxicosis in children. Because spontaneous and lasting resolution of this condition occurs in only a minority of patients, most pediatric patients with GD will need radioactive iodine treatment (¹³¹I) or thyroidectomy. Whereas the medication propylthiouracil (PTU) had been used in the past, only methimazole (MMI) should be now used in children, as PTU is associated with an unacceptable risk of liver failure. However, MMI may be associated minor and major side effects, which may be minimized using lower doses. An area of controversy involves the optimal duration of antithyroid drug (ATD) therapy. For some children, the prolonged use of antithyroid drugs is a valid approach, but for most, this will not increase the chance of remission. When ¹³¹I is administered, dosages should be greater than 150 uCi/gm of thyroid tissue, with higher dosages needed for larger glands. Considering that there will be low-level whole body radiation exposure associated with ¹³¹I, this treatment is viewed as controversial by some and should be avoided in young children. When surgery is performed, near-total or total thyroidectomy is the recommended procedure. Complications for thyroidectomy in children are considerably higher than in adults. Thus, an experienced thyroid surgeon is needed when children have surgery. Overall, when different treatment options for GD are considered, the benefits, risks and viewpoints of the family need to be considered and discussed in full.

Antineutrophil Cytoplasmic Antibody-Positive Small-Vessel Vasculitis Associated with Antithyroid Drug Therapy: How Significant Is the Clinical Problem?

BACKGROUND

The aim of this review was to delineate the characteristics of antineutrophil cytoplasmic antibody (ANCA)-associated small-vessel vasculitis associated with antithyroid drugs (ATD). A PubMed search was made for English language articles using the search terms antithyroid drugs AND ANCA OR ANCA-associated vasculitis.

SUMMARY

The literature includes approximately 260 case reports of ANCA-associated small-vessel vasculitis related to ATD, with 75% of these associated with thiouracil derivatives (propylthiouracil [PTU]) and 25% with methyl-mercapto-imidazole derivatives (MMI/TMZ). The prevalence of ANCA-positive cases caused by ATD varied between 4% and 64% with PTU (median 30%), and 0% and 16% with MMI/TMZ (median 6%). Young age and the duration of ATD therapy were the main factors contributing to the emergence of ANCA positivity. Before ATD therapy initiation, the prevalence of ANCA-positive patients was 0-13%. During ATD administration, 20% of patients were found to be positive for ANCA. Only 15% of ANCA-positive patients treated with ATD exhibited clinical evidence of vasculitis, corresponding to 3% of all patients who received ATD. Clinical manifestations of ANCA-associated vasculitis related to ATD were extremely heterogeneous. When vasculitis occurred, ATD withdrawal was usually followed by rapid clinical improvement and a favorable prognosis.

CONCLUSIONS

ANCA screening is not systematically recommended for individuals on ATD therapy, particularly given the decreasing use of PTU in favor of TMZ/MMI. Particular attention should be given to the pediatric population with Graves' disease who receive ATD, as well as patients treated with thiouracil derivatives and those on long-term ATD therapy.

Rheumatic and autoimmune thyroid disorders: a causal or casual relationship?

A number of dysfunctions may affect the thyroid gland leading either to hyper- or hypothyroidism which are mediated by autoimmune mechanisms. Thyroid abnormalities may represent an isolated alteration or they may be the harbinger of forthcoming disorders as is the case of well-characterized polyendocrine syndromes. Also, they may precede or follow the appearance of rheumatic manifestations in patients affected with connective tissue diseases or rheumatoid arthritis. The mechanisms by which autoimmune thyroid disorders may be linked to systemic autoimmune diseases have not been fully unraveled yet, however alterations of common pathways are suggested by shared genetic variants affecting autoantigen presentation and regulation of the immune response. On the other hand, the higher prevalence of autoimmune thyroid disorders over rheumatic diseases compels the chance of a mere causal concomitancy in the same patient. The aim of our paper is to provide an overview of available data on thyroid involvement in different rheumatic diseases and to go over the main rheumatic manifestations in the context of autoimmune thyroid diseases.

Relationship between Leukopenia and Intercellular Adhesion Molecules in Graves' Disease

OBJECTIVE

Changes in soluble intercellular adhesion molecule-1 (sICAM-1) and E-selectin levels as well as leukocyte count were examined in this study to explore the relationship between leukopenia and ICAMs in Graves' disease (GD).

METHODS

Fasting blood samples were obtained from 37 GD patients with normal leukocytes and 32 GD patients with leukopenia. Enzyme-linked immunosorbent assay (ELISA) was performed to determine serum sICAM-1 and E-selectin levels for comparison. The same analyses were repeated for the GD patients with leukopenia after glucocorticoid treatment (15 mg/day to 30 mg/day prednisone).

RESULTS

The ELISA results showed that E-selectin levels were higher in GD patients with leukopenia than those with normal leukocytes (p < 0.05), but these levels decreased after glucocorticoid (prednisone) treatment (p < 0.05). No significant change in sICAM-1 levels was observed (p = 0.12). Correlation analysis showed that leukocyte count and E-selectin were negatively correlated (r = -0.778; p < 0.05).

CONCLUSION

E-selectin may have an important function in GD with leukopenia, and glucocorticoids (prednisone) could decrease E-selectin level, which may be a new therapy target for GD with leukopenia.

A patient with agranulocytosis following the discontinuation of methimazole treatment for 4 months: A case report

Agranulocytosis is a rare and serious adverse effect of antithyroid drugs (ATD), in particular methimazole (MMI), and usually develops within 3 months following the start of uninterrupted ATD treatment. Agranulocytosis may also develop for the first time following interruption and subsequent resumption of the same ATD treatment. In this case report, a 27-year-old female, who was treated for thyrotoxicosis with MMI, developed agranulocytosis following the discontinuation of MMI treatment for four months. To the best of our knowledge, this is the first study to report this. The aim of this report is to increase the awareness of physicians of the onset of agranulocytosis when MMI is discontinued, and to demonstrate that MMI should be used with caution.

Pediatric Graves' disease: management in the post-propylthiouracil Era

The most prevalent cause of thyrotoxicosis in children is Graves’ disease (GD), and remission occurs only in a modest proportion of patients. Thus most pediatric patients with GD will need treatment with radioactive iodine (RAI; ¹³¹I) or surgical thyroidectomy. When antithyroid drugs (ATDs) are prescribed, only methimazole (MMI) should be administered, as PTU is associated with an unacceptable risk of severe liver injury. If remission does not occur following ATD therapy, ¹³¹I or surgery should be contemplated. When ¹³¹I is administered, dosages should be greater than 150 uCi/gm of thyroid tissue, with higher dosages needed for large glands. Considering that there will be low-level whole body radiation exposure associated with ¹³¹I, this treatment should be avoided in young children. When surgery is performed near total or total-thyroidectomy is the recommended procedure. Complications for thyroidectomy in children are considerably higher than in adults, thus an experienced thyroid surgeon is needed when children are operated on. Most importantly, the care of children with GD can be complicated and requires physicians with expertise in the area.

The relationship between bone marrow characteristics and the clinical prognosis of antithyroid drug-induced agranulocytosis

This study is aimed to explore the relationship between bone marrow characteristics and clinical prognosis of antithyroid drug (ATD) induced agranulocytosis. A retrospective study was conducted in the first affiliated hospital of the University of South China. A total of 33 hospitalized patients diagnosed with ATD-induced agranulocytosis were analyzed. The bone marrow characteristics were classified into two types. Type I was characterized by reduction or absence of granulocytic precursors and type II was recognized as hypercellular bone marrow with dysmaturity of granulocytic cells. Bone marrow of 20 cases (61%) were characterized with type I whereas 13 cases (39%) with type II. The median duration of neutrophil recovery and high-grade fever were 4.7 ± 1.0 days and 3.6 ± 2.5 days respectively for type II, compared to 8.0 ± 2.8 days and 8.6 ± 3.1 days for type I (p < 0.01 in both compared groups). However, there was no significant difference between the two types in terms of age, median duration of drug administration before the diagnosis of agranulocytosis, the amount of neutrophil count on admission and the total administration dose of granulocyte-colony stimulating factor (G-CSF) before bone marrow examination. Two cases of type I died of complications from infection. This study showed that the bone marrow characteristics of ATD-induced agranulocytosis could be classifed into two types. Also, the clinical prognosis was closely related to the bone marrow features. Type I is the dominant type which is usually associated with worse clinical prognosis compared to type II.

Propylthiouracil-induced antineutrophil cytoplasmic antibody-associated vasculitis

Antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) refers to a group of potentially life-threatening autoimmune diseases. A recent development in this field is the recognition that certain drugs can induce AAV. Among these agents, the drug most often implicated in causing disease is the commonly used antithyroid agent propylthiouracil (PTU). This Review provides an update on PTU-induced AAV. Clinical characteristics of PTU-induced AAV are similar to that of primary AAV, but usually have a milder course and better prognosis, provided early cessation of the disease-causing drug. PTU-induced ANCAs usually react to several components of myeloid granules, which is helpful in differentiating PTU-induced AAV from primary AAV. Early cessation of PTU is crucial in the treatment of PTU-induced AAV. The duration of immunosuppressive therapy might be shorter than in primary AAV, depending on the severity of organ damage, and maintenance therapy is not always necessary.

Thyrotoxicosis

Thyrotoxicosis is a common disorder, especially in women. The most frequent cause is Graves' disease (autoimmune hyperthyroidism). Other important causes include toxic nodular hyperthyroidism, due to the presence of one or more autonomously functioning thyroid nodules, and thyroiditis caused by inflammation, which results in release of stored hormones. Antithyroid drugs are the usual initial treatment (thionamides such as carbimazole or its active metabolite methimazole are the drugs of choice). A prolonged course leads to remission of Graves' hyperthyroidism in about a third of cases. Because of the low remission rate in Graves' disease and the inability to cure toxic nodular hyperthyroidism with antithyroid drugs alone, radioiodine is increasingly used as first line therapy, and is the preferred choice for relapsed Graves' hyperthyroidism. Total thyroidectomy is an option in selected cases. Future efforts are likely to concentrate on novel and safe ways to modulate the underlying disease process rather than stopping excess thyroid hormone production.

Carbimazole-induced agranulocytosis: does antineutrophil cytoplasmic antibody have a role?

Carbimazole is a drug that is widely used for hyperthyroid disorders, such as Graves' disease. Agranulocytosis is a rare idiosyncratic adverse reaction to the drug which is potentially fatal. This report describes a patient with a history of successfully treated pyoderma gangrenosum, who developed agranulocytosis 3 weeks after commencement of carbimazole for Graves' disease. It may give credence to the theory that implicates antineutrophil cytoplasmic antibodies in the pathogenesis of agranulocytosis induced by antithyroid drugs.

Toxicological considerations for antithyroid drugs in children

INTRODUCTION

Propylthiouracil (PTU), methimazole (MMI) and carbimazole are indicated for the treatment of hyperthyroidism in adult and pediatric patients. The aim of this review is to present all the relevant information regarding the use of antithyroid drugs (ATD) in pediatric thyrotoxic cases, the pediatric toxicology of ATD and the warning which has recently been issued for PTU by the FDA.

AREAS COVERED

Epidemiology, diagnosis and treatment of pediatric thyrotoxicosis are all presented in this article. The authors also extensively discuss the details regarding the pharmacology, bioactivation, biodisposition, bioavailability and pharmacokinetic properties of the two main ATD (MMI and PTU).

EXPERT OPINION

The FDA recently reported that use of PTU is associated with a higher risk for clinically serious or fatal liver injury compared to MMI in both adult and pediatric patients. They also found that congenital malformations were reported approximately three times more often with prenatal exposure to MMI compared with PTU and especially with the use of MMI during the first trimester of pregnancy. The authors believe that PTU should not be used in pediatric patients unless the patient is allergic to or intolerant of MMI, and there are no other treatment options available. That being said, PTU may be the treatment of choice during, and just before, the first trimester of pregnancy.

Medical management of thyroid eye disease

Thyroid eye disease (TED) is the most common cause of orbital disease in adults. The immunologic pathogenesis of TED has been an area of active research and considerable progress has resulted in an expansion of therapeutic options. Although surgical intervention may be required, a majority of TED patients can be managed with medical therapies. Of medical therapies, glucocorticoids remain the agent of choice in the control of TED activity. The objective of this review is to discuss the paradigm and options in medical management of TED.

A comparison of antineutrophil cytoplasmic antibody prevalence in patients treated and untreated for hyperthyroidism

We aimed to compare the prevalence of antineutrophil cytoplasmic antibody (ANCA) and its subgroups between on-treatment (with anti-thyroid drugs; propylthiouracil, methimazole) and untreated patients with hyperthyroidism in our unit. Overall 78 consecutive patients were enrolled in the study; 45 patients were on-treatment (female/male 31:14) and 33 were newly diagnosed (female/male 20:13). We have studied ANCA, perinuclear-ANCA (p-ANCA), cytoplasmic-ANCA (c-ANCA), myeloperoxidase-ANCA (mpo-ANCA), and proteinase 3-ANCA (pr3-ANCA) in sera of all the patients. The data about clinical status, laboratory tests, and physical examination and mean duration of treatment in treated group were recorded. There was no statistically significant difference between the two groups for ANCA, c-ANCA, and pr3-ANCA (P=0.13, P=0.07, and P=0.63 respectively). p-ANCA and mpo-ANCA prevalences were significantly higher in on-treatment group than in untreated group (P=0.04 and P=0.01, respectively). The mean duration of treatment was 17 months in on-treatment group. The use of antithyroid drugs (propylthiouracil, methimazole) seems to be correlated with increased prevalence of ANCA. These drugs may especially increase p-ANCA and mpo-ANCA positivity.

Current and emerging treatment options for Graves' hyperthyroidism

Radioiodine, antithyroid drugs and surgery have been well established therapies for Graves' hyperthyroidism for several decades. However there remain large variations in practice among physicians in the preferred modality and the method of administration. Patient choice and perceptions also play a big role in the choice of treatment. Radioiodine may be given using fixed high doses or by calculated doses following uptake studies. The risks of radioiodine including eye disease and the role of prophylactic steroid therapy are discussed. The commonly used antithyroid drugs include carbimazole, methimazole and propylthiouracil; however a number of other agents have been tried in special situations or in combination with these drugs. The antithyroid drugs may be given in high (using additional levothyroxine in a block-replace regimen) or low doses (in a titration regimen). This review examines the current evidence and relative benefits for these options as well as looking at emerging therapies including immunomodulatory treatments such as rituximab which have come into early clinical trials. The use of antithyroid therapies in special situations is also discussed as well as clinical practice issues which may influence the choices.

A long-term follow-up of serum myeloperoxidase antineutrophil cytoplasmic antibodies (MPO-ANCA) in patients with Graves disease treated with propylthiouracil

Propylthiouracil (PTU) is known to induce myeloperoxidase antineutrophil cytoplasmic antibodies (MPO-ANCA) in patients with Graves disease (GD). Previously, we showed that serum MPO-ANCA were frequently seen in patients with GD treated with PTU. In this study, we analyzed 13 patients with positive MPO-ANCA examining a long-term clinical consequence of these patients as well as antibody titers during 5.6 +/- 3.0 years. PTU therapy was continued in 8 patients and discontinued in 5 patients. Antibody titers decreased in 7 of 8 patients who discontinued PTU therapy but remained positive in 5 patients 5 years after PTU withdrawal. The initial MPO-ANCA levels were significantly higher in those antibody titers remained positive for longer than 5 years (n=5) than in those titers turned to be negative within 5 years after PTU withdrawal (n=3) (203 +/- 256 EU and 22 +/- 2 EU, respectively, P=0.04), but there were no significant differences in age, gender, duration of PTU therapy or dosage of PTU. Among 5 patients who continued PTU therapy, 2 patients with initially low MPO-ANCA titers turned to having negative antibody. No patients had new symptoms or signs of vasculitis throughout the follow-up periods. The long-term follow-up study suggests that higher MPO-ANCA levels remain positive for years after PTU withdrawal but are rarely associated with vasculitis.

Partial characterization of feline myeloperoxidase and investigation of its potential role as an autoantigen in hyperthyroid cats

OBJECTIVE

To partially characterize the cDNA, amino acid sequence, and tertiary structure of feline myeloperoxidase, describe its cellular location in mature granulocytes, and determine whether hyperthyroid cats have anti-myeloperoxidase antibody.

SAMPLE POPULATION

Bone marrow RNA and whole blood from cats of various sources and feline serum samples submitted for measurement of total thyroxine concentration from September 2006 to July 2007.

PROCEDURES

Feline myeloperoxidase cDNA was amplified from bone marrow RNA; presumptive splice sites were determined by comparison with human sequences. Intracellular localization of myeloperoxidase in granulocytes was determined by use of immunofluorescence and electron microscopy, and molecular weight and partial tertiary structure were determined by use of immunoblotting of granulocyte lysates. Anti-human myeloperoxidase (hMPO) antibody was detected via ELISA.

RESULTS

A 2,493-bp sequence encompassing the 2,160-bp cDNA with presumably the same number and size of exons as hMPO was generated. Translation predicted 85% homology with hMPO. Feline myeloperoxidase was localized to neutrophil primary granules, and immunoblotting revealed heavy and light bands with molecular weights similar to those of hMPO. The prevalence of anti-hMPO antibody did not differ between nonhyperthyroid and hyperthyroid cats or among hyperthyroid cats subclassified by treatment modality.

CONCLUSIONS AND CLINICAL RELEVANCE

Moderate homology existed between feline myeloperoxidase and hMPO cDNA and protein. Although findings suggested a similar tertiary structure and function for the 2 proteins, they also suggested that inability to detect a high prevalence of anti-hMPO antibody in hyperthyroid cats may be attributable to antigenic differences between the human and feline proteins rather than a lack of autoantibody.

Treatment of Graves' hyperthyroidism: evidence-based and emerging modalities

Currently there are three well-established treatment options for hyperthyroid Graves' disease (GD): antithyroid drug therapy with thionamides (ATD), radioactive iodine treatment with (131)I, and thyroid surgery. This article reviews the current evidence so the reader can evaluate advantages and disadvantages of these treatment modalities. Surgery is rarely used, except for patients who have a large goiter or ophthalmopathy. Fewer than 50% of patients treated with ATD remain in long-term remission. Therefore, radioactive iodine is used increasingly. No data as yet support the routine use of biologic therapies (eg, rituximab). Prospective, randomized studies comparing available and any novel therapeutic options for GD are needed. The focus of these studies should include, but not be limited to, cost and quality of life.

Churg-Strauss Syndrome following PTU Treatment

Propylthiouracil (PTU) is a frequently prescribed drug in the treatment of hyperthyroidism. The use of PTU is, however, accompanied by numerous potentially serious side effects including vasculitis. PTU-related vasculitides can present as haematuria, pulmonary haemorrhage, or cutaneous lesion together with aspecific symptoms such as fever, myalgia, arthralgia, and fatigue. Cerebral involvement is seldom observed. We present a 49-year-old female with Graves' disease and asthma, who developed paresis of the proximal extremities, eosinophilia, pulmonary, and cutaneous lesions following treatment with PTU. A cerebral vasculitis consistent with Churg-Strauss syndrome (CSS) was suspected. Although cerebral involvement is seldom observed with PTU treatment, cerebral vasculitis should be considered in patients developing CNS symptoms.

Prevalence and clinical significance of antineutrophil cytoplasmic antibody in Graves' patients treated with propylthiouracil

Development of antineutrophil cytoplasmic antibody (ANCA) during therapy with propylthiouracil (PTU) is not uncommon and PTU-induced ANCA-positive vasculitis is also reported. The aim of this study was to assess the presence and clinical significance of ANCA positivity in Graves' patients treated with PTU. Newly diagnosed Graves' disease patients (prospective group, n = 58) were evaluated before and during therapy with PTU to investigate the development of ANCA positivity. ANCA positivity is also investigated in previously diagnosed Graves' patients who had already been receiving PTU treatment (cross-sectional group, n = 51). Comparisons with Hashimoto thyroiditis (n = 55) and toxic nodular goitre (n = 20) patients, and healthy control subjects (n = 20) were carried out to define the possible influence of hyperthyroidism and/or thyroid autoimmunity on ANCA positivity. At baseline evaluation, ANCA was negative in all newly diagnosed Graves' patients. Only 28 of the 58 patients in prospective group completed 2 years of follow-up which occurred at 3-month intervals. ANCA positivity was detected 32.1% (n = 9) in a mean period of 11.7 +/- 6.1 months in prospective group. Only two (3.9%) patients in a cross-sectional group had ANCA positivity in a mean treatment period of 7.6 +/- 4.6 months. None of the patients with ANCA positivity developed symptoms and signs related to vasculitis. None of the patients with Hashimoto thyroiditis and toxic nodular goitre, and healthy control subjects had ANCA positivity. PTU therapy is associated with asymptomatic production of ANCA in a time-dependent manner, which mostly disappears after discontinuation of therapy. Hyperthyroidism or autoimmunity per se does not appear to have effect on development of ANCA positivity.

Central nervous system vasculitis after starting methimazole in a woman with Graves' disease

BACKGROUND

Graves' disease (GD), a prototypical autoimmune disorder, is associated with other autoimmune diseases, including vasculitis. Antithyroid drugs, despite their postulated immunosuppressive effects, may cause several autoimmune disorders. Here we describe the first patient with central nervous system (CNS) vasculitis that developed shortly after the start of methimazole (MMI) treatment for GD.

PATIENT FINDINGS

CNS vasculitis was suspected on the basis of the clinical features and neurologic examination, showing a reinforcement of deep reflexes, especially of the left knee and Achilles reflexes. The diagnosis was confirmed by a brain magnetic resonance imaging (MRI), which showed some hyperintensive spots in the subcortical substantia alba and in the parietal area bilaterally, and by a single-photon emission computed tomography (SPECT) imaging, which showed a nonhomogenous distribution of the blood flow in the brain, with a reduced perfusion on the left side of the frontotemporal and parietal regions, and on the right side of the frontotemporal area. MMI was stopped before total thyroidectomy, and symptoms resolved in the next 5 weeks. Six months after MMI was stopped, the brain MRI and SPECT had become normal.

SUMMARY

To our knowledge, this is the first report of CNS vasculitis related to MMI therapy.

[Antineutrophil cytoplasmic antibody (Anca)-associated autoimmune disease induced by propylthiouracil]

Antithyroid drugs sometimes cause severe complications. Propylthiouracil (PTU) can be associated to ANCA positive vasculitis, most often related to myeloperoxidase subtype (ANCA-MPO). Our objective is to describe a female patient with Graves' disease, who developed PTU induced-autoimmune disease, with cutaneous, pulmonary, and renal lesions, associated with ANCA. Histopathological examination revealed diffuse pulmonary hemorrhage, and focal segmental glomerulosclerosis at the kidney biopsy. She was treated with systemic corticosteroid therapy and cyclophosphamide, with clinical improvement. This case highlights the need for greater awareness of this relatively rare adverse effect of propylthiouracil.

Clinical and Pathological Features of Renal Involvement in Propylthiouracil-Associated ANCA-Positive Vasculitis

BACKGROUND

The kidney is one of the organs affected in patients with propylthiouracil (PTU)-associated antineutrophil cytoplasmic antibody (ANCA)-positive vasculitis. We present a series of Chinese patients with renal involvement in PTU-associated ANCA-positive vasculitis and describe their clinical and pathological characteristics.

METHODS

Clinical and pathological data from patients with PTU-associated ANCA-positive vasculitis with renal involvement, diagnosed in Peking University First Hospital, were collected and analyzed retrospectively.

RESULTS

Nineteen patients with PTU-associated ANCA-positive vasculitis were treated at Peking University First Hospital between December 1999 and December 2005, and 15 of them had renal involvement. Of the 15 patients, 13 were female and 2 were male, with an average age of 26.3 +/- 11.8 years. All 15 patients were perinuclear ANCA positive with specificities to myeloperoxidase (15 of 15), cathepsin G (9 of 15), human leukocyte elastase (8 of 15), lactoferrin (7 of 15), azurocidin (5 of 15), and proteinase 3 (4 of 15). Duration of PTU administration was 43.0 +/- 31.2 months. All 15 patients had clinical markers of renal involvement, including hematuria (100%), proteinuria (100%), and renal function abnormality (47%). All 15 patients underwent percutaneous renal biopsy. Ten patients had necrotizing crescentic glomerulonephritis, and 7 of these 10 patients had immune complex deposition. Three patients had minimal involvement, 2 patients had immunoglobulin A nephropathy, and 2 patients had membranous nephropathy. PTU treatment was discontinued in all 15 patients. All except 2 patients with minimal renal involvement received immunosuppressive treatment. Eleven of 15 patients achieved complete clinical remission.

CONCLUSION

Renal involvement in our case series of patients with PTU-associated ANCA-positive vasculitis was heterogeneous, and nearly half our patients had renal immune complex deposition.

Follow-up of avidity and titre of anti-myeloperoxidase antibodies in sera from patients with propylthiouracil-induced vasculitis

OBJECTIVE

Propylthiouracil (PTU) has been known to induce myeloperoxidase-antineutrophil cytoplasmic antibody (MPO-ANCA) positive vasculitis. Our previous study indicated that the increase of avidity of MPO-ANCA might be associated with the occurrence of clinical vasculitis in patients with PTU-induced ANCA. The current study aimed to follow-up the avidity and titre of anti-MPO antibodies in sequential sera from patients with PTU-induced ANCA-associated systemic vasculitis (AASV).

METHODS

Six patients with PTU-induced vasculitis were enrolled in the current study. Serial sera in both active phase and in remission were collected. MPO-ANCA avidity was assessed by antigen-inhibition enzyme-linked immunosorbent assays (ELISAs), and avidity constant (aK) was determined as the reciprocal value of the MPO molar concentration in the liquid phase resulting in 50% inhibition of anti-MPO antibody binding to MPO in solid phase ELISA. Titres of MPO-ANCA were determined by using serial serum dilutions in MPO-ELISA.

RESULTS

After cessation of PTU and initiation of immunosuppressive therapy, the avidity and titre of MPO-ANCA decreased significantly during follow-up in sera from all the patients, and the avidity decreased much more quickly than the titres.

CONCLUSION

Our study indicates that avidity of anti-MPO antibodies might be more closely associated with clinical vasculitis than titre.

[New insights into the pathogenesis of ANCA-positive vasculitides]

Recent studies provided new insights into the pathogenesis of vasculitides associated with antineutrophil cytoplasm antibodies (ANCA). They yield more information about the pathogenic role of ANCA, the initiation of the immune response against proteinase 3, the expression of ANCA target antigens on neutrophil surfaces, endothelial damage and the mechanisms of vasculitis associated with propylthiouracil. The pathogenic role of antimyeloperoxidase antibodies has been established in vitro and in vivo in animal models and in human. A pathogenic role for antiproteinase 3 antibodies has not yet been clearly established in vivo although it is well documented in vitro.

The target antigens of antineutrophil cytoplasmic antibodies (ANCA) induced by propylthiouracil

OBJECTIVE

Antineutrophil cytoplasmic antibody (ANCA) has been well documented in association with propylthiouracil (PTU), and some patients with PTU-induced ANCA also develop clinical vasculitis. The aim of the current study was to detect ANCA specificities in sera from patients with PTU-induced ANCA with and without clinical vasculitis.

METHODS

Sera from 65 patients with PTU-induced ANCA were collected, and 27 of these patients were diagnosed with PTU-induced ANCA associated systemic vasculitis (AASV). Indirect immunofluorescence assay and antigen-specific ELISAs were used to detect ANCA and their antigen specificities. The seven known target antigens included myeloperoxidase (MPO), proteinase 3, human leukocyte elastase, lactoferrin, cathepsin G, azurocidin and bactericidal/permeability-increasing protein (BPI).

RESULTS

In IIF assay, P-ANCA was found in 58/65 (89.2%) sera, C-ANCA in two, both P-ANCA and C-ANCA in five, respectively. MPO (60%) and lactoferrin (63.1%) were the two most common target antigens detected in sera from all the patients. 25/27 sera from patients with PTU-induced AASV recognized multiple target antigens, which was significantly higher than those (13/38) from patients without (P<0.001). Except anti-BPI antibodies, the prevalence of antibodies against the other six target antigens was significantly higher in patients with clinical vasculitis than that in patients without (P<0.05, respectively).

CONCLUSION

Antibodies against multiple ANCA specific antigens, especially the antigens rather than MPO and PR3, might be the characteristic of PTU-induced ANCA. Patients with antibodies against more ANCA specific antigens might be at increased risk of developing overt clinical vasculitis. The mechanism of ANCA production in PTU-induced cases was different from that in primary AASV.

The treatment of Graves' disease in children

Graves' disease is the most common form of hyperthyroidism in childhood. Current treatment options include antithyroid medications, surgery, and radioactive iodine. Medical therapy is generally associated with long-term remission rates of less than 25% and a small risk of serious adverse reactions that include hepatic failure and bone marrow suppression. Total thyroidectomy is associated with very high cure rates and a small risk of hypoparathyroidism and recurrent laryngeal nerve damage. When radioactive iodine is used at appropriate doses, there is a very high cure rate without increased risks of thyroid cancer or genetic damage. Clinicians caring for the child or adolescent with Graves' disease are thus faced with using medications with potential short-term and long-term toxicity, for a condition in which spontaneous remission occurs in the minority of pediatric patients. Definitive therapy in the form of surgery or radioactive iodine is necessary and unavoidable for the majority of pediatric patients with Graves' disease.

Titre and affinity of propylthiouracil-induced anti-myeloperoxidase antibodies are closely associated with the development of clinical vasculitis

Substantial evidences suggested that propylthiouracil (PTU) could induced anti-myeloperoxidase (MPO) antibodies in sera from patients with hyperthyroidism, however, only a subgroup of the PTU-induced anti-MPO antibody positive patients developed clinical evident vasculitis. The aim of this study is to compare the titres and affinities of PTU induced anti-MPO antibodies in sera from patients with hyperthyroidism with and without clinical vasculitis. Anti-MPO antibody positive sera from patients diagnosed hyperthyroidism with (n = 13) and without (n = 14) clinical evident vasculitis were collected. The titre was determined by MPO-ELISA and expressed as logarithm value (lgT). The affinity constant (aK) of anti-MPO IgG was measured by antigen inhibition assay. The titre and aK values were compared between patients with and without vasculitis. In patients with vasculitis, the mean lgT of anti-MPO antibodies was 3.62 +/- 0.66; the median aK was 4.47 x 10(7)M(-1). In patients without vasculitis, the mean lgT was 2.54 +/- 0.29; the median aK was 0.14 x 10(7)M(-1), and both were significant lower than those in patients with vasculitis (t = 5.464; P = 0.000 & z = -4.373; P = 0.000, respectively). We concluded that the titre and affinity of anti-MPO antibodies might be associated with the development of clinical vasculitis in patients with PTU-induced ANCA.

The onset of Graves’ disease during the clinical course of myeloperoxidase antineutrophil cytoplasmic antibody (MPO-ANCA)-associated glomerulonephritis

A 47-year old man presented with atrial fibrillation, weight loss, hand tremor, and hyperperspiration concurrent with the reactivation of the disease activity of myeloperoxidase antineutrophil cytoplasmic antibody (MPO-ANCA)-associated glomerulonephritis. Laboratory findings indicated that the hyperthyroidism had already existed when glomerulonephritis was detected, and Graves' disease became evident while decreasing the dose of prednisolone. Although the levels of thyroid-stimulating hormone receptor antibody, antithyroid peroxidase antibody, and myeloperoxidase antibody increased, both disease activities were suppressed by increasing the dose of prednisolone. This case indicates that MPO-ANCA-associated glomerulonephritis and Graves' disease may share a common pathogenesis.