Distinct clinical, serological, and sonographic characteristics of hashimoto's thyroiditis based with and without IgG4-positive plasma cells

Are sonographic characteristics of Hashimoto's thyroiditis related with immunologic parameters? A cross-sectional study

BACKGROUND

The clinical, laboratory, and imaging characteristics of Hashimoto's thyroiditis are widely recognized. However, there is a dearth of information concerning the relationship between these aspects. The primary objective of this study was to investigate the correlation between sonographic features and immunologic parameters in individuals with Hashimoto's thyroiditis.

METHODS

This cross-sectional study enrolled a cohort of 100 consecutive patients diagnosed with Hashimoto's thyroiditis. Ultrasonography was performed to classify thyroid gland characteristics, including parenchymal heterogeneity (mild/moderate-to-high), extent of fibrosis (none-to-mild/moderate-to-high), and volume (atrophic/non-atrophic). As for immunologic parameters, thyroid autoantibodies (TOA; anti-TPO and anti-Tg), along with IG (immunoglobulin) G4 levels and lymphocyte subsets, were assessed.

RESULTS

Of the 100 patients evaluated, 88 were female (88%) and 12 were male (12%). IgG4/IgG ratio and weekly levothyroxine (LT4) dose were significantly higher in the group with moderate-to-high heterogeneity than the group with mild parenchymal heterogeneity (p = 0.043 and p < 0.001, respectively). Compared to the group with none-to-mild fibrosis, the anti-TPO, IgG4, IgG4/IgG ratio and LT4 dose were significantly higher in the moderate-to-high fibrosis group. Anti-TPO and IgG levels were significantly lower in the atrophic thyroid group compared to the non-atrophic thyroid group. Although not reaching statistical significance, the proportion of plasma cells in the moderate/high fibrosis group was higher than in the non-fibrosis/mild fibrosis group. There was a moderate positive correlation between fibrosis with Anti-TPO, and a low positive correlation between anti-Tg, IgG4 levels with IgG4/IgG ratio.

CONCLUSION

TOA, Ig G4 levels and severity of hypothyroidism were associated with ultrasonographic features such as parenchymal heterogeneity and fibrosis in Hashimoto's thyroiditis.

IgG4 serum levels in Graves' orbitopathy

OBJECTIVE

IgG4-related disease (IgG4-RD) can involve many organs, including thyroid and orbital tissues. A link between IgG4, Graves' disease (GD) and Graves' orbitopathy (GO) has been proposed, but results are conflicting. Here we investigated the possible association between IgG4 and GO.

METHODS

Retrospective investigation in 297 patients with Graves' disease (GD), 152 with GO.

PRIMARY OUTCOME

prevalence of IgG4 ≥ 135 mg/dL (cut-off for IgG4-RD).

SECONDARY OBJECTIVES

(1) serum IgG4 concentrations; (2) IgG4/IgG ratio; (3) prevalence of IgG4/IgG ratio ≥ 8.0%; (4) relationship between IgG4 and eye features; (5) relationship between IgG4 and anti-TSH receptor antibodies (TRAbs).

RESULTS

Because GO patients had lower FT3 concentrations, we evaluated the main objectives in the second and third FT3 quartiles subpopulation, in which there were no relevant differences between patients with (n = 81) or without GO (n = 67) for baseline parameters. Within this population, the prevalence of IgG4 levels ≥ 135 mg/dL did not differ between patients without and with GO (17.9% vs 17.3%). No difference was observed concerning IgG4 concentrations, prevalence of IgG4/IgG ≥ 8.0%, and IgG4/IgG ratio. There was no relationship between IgG4 and eye features and no correlation between IgG4 levels and TRAb was found.

CONCLUSIONS

Our results suggest that, within GD, there is no relationship between serum IgG4 and GO.

A machine learning-based diagnosis modeling of IgG4 Hashimoto's thyroiditis

PURPOSE

This study aims to develop a non-invasive diagnosis model using machine learning (ML) for identifying high-risk IgG4 Hashimoto's thyroiditis (HT) patients.

METHODS

A retrospective cohort of 93 HT patients and a prospective cohort of 179 HT patients were collected. According to the immunohistochemical and pathological results, the patients were divided into IgG4 HT group and non-IgG4 HT group. Serum TgAb IgG4 and TPOAb IgG4 were detected by ELISAs. A logistic regression model, support vector machine (SVM) and random forest (RF) were used to establish a clinical diagnosis model for IgG4 HT.

RESULTS

Among these 272 patients, 40 (14.7%) were diagnosed with IgG4 HT. Patients with IgG4 HT were younger than those with non-IgG4 HT (P < 0.05). Serum levels of TgAb IgG4 and TPOAb IgG4 in IgG4 HT group were significantly higher than those in non-IgG4 HT group (P < 0.05). There were no significant differences in gender, disease duration, goiter, preoperative thyroid function status, preoperative TgAb or TPOAb levels, and thyroid ultrasound characteristics between the two groups (all P > 0.05). The accuracy, sensitivity, and specificity were 57%, 78%, and 79% for logistic regression model of IgG4 HT, 80 ± 7%, 84.7% ± 2.6%, and 75.4% ± 9.6% for the RF model and 78 ± 5%, 89.8% ± 5.7%, and 64.7% ± 5.7% for the SVM model. The RF model works better than SVM. The area under the ROC curve of RF ranged 0.87 to 0.92.

CONCLUSION

A clinical diagnosis model for IgG4 HT established by RF model might help the early recognition of the high-risk patients of IgG4 HT.

IgG4-related disease: an update on pathology and diagnostic criteria with a focus on salivary gland manifestations

Immunoglobulin G4-related disease (IgG4-RD) is a multi-organ disorder characterized by a highly variable clinical presentation depending on the affected organ/s, extent of tumefactive fibroinflammatory lesions, and associated functional impairment. The disease pursues a chronic, relapsing, often asymptomatic course and hence may pose a significant diagnostic challenge. Diagnostic delay can lead to progressive fibrosis and irreversible organ damage resulting into significant morbidity and even mortality. Given its broad clinical spectrum, physicians of all specialties may be the first clinicians facing this diagnostic challenge. Outside the pancreatobiliary system, the head and neck represents the major site of IgG4-RD with variable organ-specific diffuse or mass-forming lesions. In up to 75% of cases, elevated serum IgG4 levels are observed, but this figure possibly underestimates the fraction of seronegative cases, as the disease manifestations may present metachronously with significant intervals. Together with negative serology, this can lead to misdiagnosis of seronegative cases. A standardized nomenclature and diagnostic criteria for IgG4-RD were established in 2012 and revised in 2020 facilitating scientific research and expanding the range of diseases associated with IgG4 abnormalities. In addition to orbital pseudotumor, dacryoadenitis, Riedel thyroiditis, sinonasal manifestations, and rare miscellaneous conditions, IgG4-related sialadenitis is one of the most frequent presentations in the head and neck region. However, controversy still exists regarding the relationship between sialadenitis and IgG4-RD. This review focuses on the clinicopathological features of IgG4-related sialadenitis and its contemporary diagnostic criteria.

Immunoglobulin G4-related thyroiditis associated with Graves' disease: A case report

We report a case of immunoglobulin (ig)-g4-related thyroiditis associated with graves' disease. a 45-year-old man was diagnosed with graves' disease due to asymptomatic enlarged thyroid gland and high serum levels of thyrotropin receptor antibodies and thyroid hormones. surgical resection of the thyroid gland was performed because of further thyroid gland enlargement and severe fluctuations in the thyroid hormonal levels, despite medical therapy with a combination of an antithyroid drug and a thyroid hormone preparation. macroscopic examination of the resected thyroid gland revealed a grayish-white diffuse swelling, and histopathological findings revealed follicular destruction, chronic inflammatory cell infiltration with diffuse igg4-positive plasma cells (IgG4/IgG >40%), storiform fibrosis, and phlebitis obliterans throughout the thyroid tissue. Additionally, there were small foci of high columnar follicular components with scalloping, resembling Graves' disease. We propose that all patients with Graves' disease should be evaluated for coexisting IgG4-related thyroiditis to detect ophthalmopathies as soon as possible.

Inflammatory and Infectious Disorders in Endocrine Pathology

A variety of inflammatory conditions may directly involve the endocrine glands, leading to endocrine dysfunction that can cause severe consequences on patients' health, if left untreated. Inflammation of the endocrine system may be caused by either infectious agents or other mechanisms, including autoimmune and other immune-mediated processes. Not infrequently, inflammatory and infectious diseases may appear as tumor-like lesions of endocrine organs and simulate neoplastic processes. These diseases may be clinically under-recognized and not infrequently the diagnosis is suggested on pathological samples. Thus, the pathologist should be aware of the basic principles of their pathogenesis, as well as of their morphological features, clinicopathological correlates, and differential diagnosis. Interestingly, several systemic inflammatory conditions show a peculiar tropism to the endocrine system as a whole. In turn, organ-specific inflammatory disorders are observed in endocrine glands. This review will focus on the morphological aspects and clinicopathological features of infectious diseases, autoimmune disorders, drug-induced inflammatory reactions, IgG4-related disease, and other inflammatory disorders involving the endocrine system. A mixed entity-based and organ-based approach will be used, with the aim to provide the practicing pathologist with a comprehensive and practical guide to the diagnosis of infectious and inflammatory disorders of the endocrine system.

Attention Deficit Hyperactivity Disorder Misdiagnosis: Why Medical Evaluation Should Be a Part of ADHD Assessment

INTRODUCTION

Attention deficit hyperactivity disorder (ADHD) is a neurodevelopmental disorder that interferes with multiple aspects of daily functioning and is associated with impairments in several domains. It may affect academic, educational, vocational, social, emotional, interpersonal, and health domains, and worsen risks to health outcomes.

OBJECTIVE

To identify and discuss medical conditions that commonly present with symptoms resembling ADHD.

METHOD

This review is selective and not systematic. It is conducted through a focused literature search through PubMed, Google Scholar, and EMBASE. Search term included "ADHD misdiagnosis", "medical conditions with ADHD like symptoms", "ADHD AND medical problems".

EXCLUSION

giftedness, high IQ, and any article that does not list medical conditions. The limits applied were the following: the work must have been published in the past 20 years, be on humans, and be in the English language.

RESULTS

There are several medical conditions that can be misdiagnosed as ADHD and may show a similar presentation to ADHD, particularly with inattentive symptoms. Examples include, but are not limited to, absence seizure disorder, diabetes, thyroid dysfunction, sleep deprivation, post-concussion states, inflammatory bowel disease, iron deficiency states and anemia, and disordered breathing.

CONCLUSIONS

Our review suggests that a thorough medical evaluation should be conducted prior to the diagnosis of ADHD. Allied health professionals and psychologists who diagnose ADHD should seek medical clearance from a physician prior to making the ADHD diagnosis in order to reduce misdiagnosis rates and improve patient outcomes. ADHD diagnosis should follow guidelines and be carried out under a systematic standardized approach. A full medical evaluation should be conducted to assess for medical conditions that may look like ADHD or be associated with ADHD.

Morphological Study of Hashimoto Thyroiditis in Fine Needle Aspiration Cytology Specimens

Background

Hashimoto thyroiditis is an autoimmune disease which is diagnosed based on well-defined clinical and cytological criteria.

Purpose

The objective of this research is to study cytomorphological features in patients of Hashimoto thyroiditis and compare the findings with other studies. Literature on morphology of multinucleated giant cells was found to be lacking, and this study has focused on the number and morphology of these cells in this study.

Material and Methods

FNAC was done in patients who met the clinical diagnostic criteria of Hashimoto thyroiditis formulated by "Japan Thyroid Association" and smears were analyzed by light microscopy. Data analysis was done by XLSTAT in Microsoft Excel 2010. The Wilcoxon Signed Rank Test was done to analyze the data on multinucleated giant cells. The null hypothesis was that the median of the population of differences between the paired data of small and large giant cells is zero.

Results

A total of 26 patients were included in a period of one year. Contrary to observations in other studies, multinucleated giant cells were found in most participants. The Wilcoxon Signed Rank Test proved that small multinucleated giant cells were significantly more common than large multinucleated giant cells in Hashimoto thyroiditis; P value (two-tailed) being <0.0001 at significance alpha of 0.05. This study has also revealed that a few patients with Hashimoto thyroiditis can have large and very large multinucleated giant cells in a small number. Data on other cytomorphological features were no different than in other studies.

Conclusion

The presence of multinucleated giant cells in 92.3% of patients in this study is far higher than in other studies which can have important diagnostic implications. Few large multinucleated giant cells can be present in a small number in a few patients as in Hashimoto thyroiditis.

A nomogram based on the risk factors of cervical lymph node metastasis in papillary thyroid carcinoma coexistent with Hashimoto's thyroiditis

OBJECTIVE

The purpose of this study was to explore the risk factors of cervical lymph node metastasis(LNM) in papillary thyroid carcinoma(PTC) coexistent with Hashimoto's thyroiditis(HT).

METHODS

The clinical data of patients who underwent thyroid operation between November 2016 and January 2020 in our hospital were analyzed retrospectively. The association between sonographic features and the risk factors of cervical LNM in PTC coexistent with HT was analyzed and a nomogram based on the risk factors was built.

RESULTS

Age, US features as calcification, blood flow type, distance between thyroid nodule and fibrous capsule were risk factors of cervical LNM(P < 0.05).Size, SWVmax and SWVmean of thyroid nodule, SWVratio between thyroid nodule and thyroid gland were higher in PTCs with LNM than those without LNM(P < 0.05). The ROC curve showed that the cutoff value of SWVratio for predicting LNM was 1.29 (Sensitivity = 0.806, Specificity = 0.775, AUC = 0.823, P < 0.001). Based on the risk factors above, a relevant nomogram prediction model was established. The model verification showed that the C-index of the modeling set was 0.814, indicating that the nomogram model had good predicted accuracy.

CONCLUSION

Based on the risk factors above, a relevant nomogram prediction model was established. The model verification showed that the C-index of the modeling set was 0.814, indicating that the nomogram model had good predicted accuracy. The nomogram based on the risk factors above had good prediction ability, which could optimize thyroidectomy and cervical lymph node dissection and improving prognosis.

IgG4-positive Hashimoto thyroiditis and its association with IgG4-related sclerosing disease

A woman in her 50s was referred with suspected thyroid malignancy and underwent total thyroidectomy. Immunohistochemical analysis revealed IgG4-positive Hashimoto's thyroiditis. IgG4-related thyroid disease is poorly understood, and thought to encompass various entities including IgG4-positive Hashimoto's thyroiditis, Fibrosing Variant of Hashimoto's thyroiditis, Reidel's thyroiditis and Graves' disease with elevated IgG4 levels. Furthermore, it may be associated with a systemic fibrosing condition called 'IgG4-related sclerosing disease'. The clinical significance of IgG4-positive thyroid disease, however, remains unclear.

Clinical differences between IgG4 Hashimoto's thyroiditis and primary thyroid lymphoma

Background

Hashimoto's thyroiditis (HT) can be divided into IgG4 HT and non-IgG4 HT based on IgG4 and IgG immunohistochemical staining. In clinical practice, it is often necessary to identify diseases such as primary thyroid lymphoma (PTL) and IgG4 HT when a patient presents with a rapidly enlarged thyroid. The aim of our study was to uncover the differential points between the two diseases.

Methods

Clinical information from 19 IgG4 HT and 10 PTL patients was obtained from the patients' medical records, including age, sex, main clinical manifestation, thyroid functional status, the presence of serum anti-thyroid peroxidase antibodies, anti-thyroglobulin antibodies, and thyroid ultrasonography results. Thyroid sections from all patients were collected to detect IgG4 and IgG expression by immunohistochemical staining.

Results

The IgG4 HT patients were significantly younger than those in the PTL group (39.68 ± 10.95 vs 66.20 ± 10.23 years, P < 0.001). There were no significant differences in the sex distribution or TgAb- or TPOAb-positive rates. The PTL group had a higher prevalence of clinical hypothyroidism than the IgG4 HT group (P = 0.016). In the PTL group, thyroid lesions were more likely to exhibit hypoechogenicity (6/6 vs 1/19, P < 0.001) on ultrasound images. In the PTL group, two patients met the immunohistochemical cut-off value of the criteria for IgG4 HT.

Conclusions

Simply relying on immunohistochemistry for IgG4 cannot diagnose IgG4 HT correctly when a patient presents with rapid thyroid enlargement. A combination of clinical and pathological analyses will help distinguish IgG4 HT from PTL which may be with abundant IgG4-positive plasma cells.

Immunoglobulin G4-Related Thyroid Disease: A Single-Center Experience and Literature Review

BACKGROUND

Immunoglobulin G4 (IgG4)-related disease is an entity that can involve the thyroid gland. The spectrum of IgG4-related thyroid disease (IgG4-RTD) includes Hashimoto thyroiditis (HT) and its fibrotic variant, Riedel thyroiditis, as well as Graves' disease. The early diagnosis of IgG4-RTD is important because it is a medically treatable disease, and a delay in the diagnosis might result in unnecessary surgery. We present a case series of IgG4-RTD with a review of the literature.

METHODS

We retrospectively reviewed the clinical presentation and the radiological and pathological findings of patients diagnosed with IgG4-RTD between 2017 and 2021 at a tertiary medical center in Korea. We also conducted a literature review of IgG4-RTD.

RESULTS

Five patients were diagnosed with IgG4-RTD during the study period. The patients' age ranged from 31 to 76 years, and three patients were men. Most patients visited the clinic for a neck mass, and hypoechogenic nodular lesions were observed on neck ultrasonography. Three patients had IgG4 HT, and two patients had IgG4 Riedel thyroiditis. All patients developed hypothyroidism that necessitated L-thyroxine replacement. The diagnosis of IgG4-RTD was confirmed after a pathological examination of the surgical specimen in the first two cases. However, the early diagnosis was possible after a core needle biopsy in three clinically suspected patients.

CONCLUSION

The diagnosis of IgG4-RTD requires clinical suspicion combined with serology and histological analyses using IgG4 immunostaining. The early diagnosis of IgG4-RTD is difficult; thus, biopsy with IgG4 immunostaining and serum IgG4 measurements will help diagnose patients suspected of having IgG4-RTD.

Review of IgG4-related Hashimoto Thyroiditis With Best Practice Recommendations for Diagnosis and Reporting

Found in virtually any organ system, immunoglobulin (Ig) G4-related disease (RD) is a recently recognized immune-mediated, systemic, a fibroinflammatory disease characterized histologically by storiform fibrosis, obliterative phlebitis, and lymphoplasmacytic infiltrate with IgG4-positive plasma cells (PCs). IgG4-related Hashimoto thyroiditis (IgG4-RHT), also called IgG4-related thyroiditis, shares many features with IgG4-RD but is distinct in several ways. A case of IgG4-RHT in a 51-year-old African American female is assembled together with a literature review which uncovered 82 cases of IgG4-RHT. The findings and criteria which the respective authors used to reach their diagnoses are analyzed. Findings common to all studies are lymphoplasmacytic infiltration and IgG4-positive staining, while most describe follicular atrophy (95.2%, 79/83). Stromal fibrosis involving >33% of thyroid architecture was reported in 74% (58/78) of cases. While few reports observed storiform fibrosis, all describe lack of obliterative phlebitis or systemic involvement. Discrepancies between reports exist in immunostaining thresholds, as well as grading systems for stromal fibrosis. Based on our review of the literature and experience, we propose a set of best practice recommendations for the diagnosis of IgG4-RHT. Our diagnostic criteria are (1) lack of extrathyroidal IgG4-RD, (2) the fibroinflammatory process should not extend beyond the thyroid capsule, (3) stromal fibrosis comprises at least 30% of the involved tissue, (4) >30% IgG4/IgG ratio, with absolute immunostaining cutoffs varying by the degree of stromal fibrosis: for >50% stromal fibrosis use >20 IgG4+PCs/HPF, for 30% to 50% fibrosis use >30 IgG4+PCs/HPF, (5) fibrosis infiltrates the interlobular/interfollicular space, (6) features of follicle injury, and (7) obliterative phlebitis is not required.

Update on classification, diagnosis, and management of immunoglobulin G4-related disease

Immunoglobulin G4-related disease (IgG4-RD) is a newly recognized chronic fibro-inflammatory autoimmune disease, and its recognition has been constantly increasing worldwide over the last few years. A correct and timely recognition, as well as appropriate intervention, is crucial for the treatment of IgG4-RD. For certain subtypes of IgG4-RD, organ-specific criteria are formulated to make the diagnosis more accurate. New biomarkers have emerged in the recent years to aid the disease diagnosis, its prognosis prediction, as well as therapy response monitoring. Although recurrence is very common in IgG4-RD, glucocorticoid is still the first-line treatment for the majority of patients. The factors that affect the likelihood of disease relapse are multifaceted. The selection strategy of various steroid-sparing agents is still being explored. Besides, when patients have special sites involvement leading to severe clinical conditions, surgical operation or interventional therapy should also be considered. An update on classification, diagnosis, and management of IgG4-RD is provided in the current study to fully elucidate the recommended clinical practice of this mysterious disease.

Clinical relevance of serum immunoglobulin G4 in glucocorticoid therapy of Graves' ophthalmopathy

OBJECTIVE

Previous study suggested IgG4 levels were associated with the development of Graves' ophthalmopathy (GO). The aims of the present study were to investigate the role of IgG4 levels in glucocorticoid (GC) treatment in GO patients.

DESIGN

69 GO patients were enrolled. Serum thyroid hormones, thyroid antibodies, IgG, IgG4, ophthalmological examinations and orbital MRI were performed. Furthermore, the clinical outcomes (a composite response endpoint including the clinical activity score (CAS), proptosis, vision, intraocular pressure, diplopia and lid width) after high-dose intravenous GC treatment in 32 active moderate-to-severe GO patients were compared.

PATIENTS

69 consecutive patients with GO were asked to participate in the study. 32 of 69 GO patients were treated with high-dose intravenous GCs.

MEASUREMENTS

Measurement of serum IgG and IgG4, serum thyroid hormones and thyroid autoantibodies. An overall ophthalmic assessment was performed pretherapy (week 0) and post-therapy (week 12).

RESULTS

33.3% of GO patients (23/69) had elevated IgG4 levels. IgG4 levels were positively correlated with the severity and activity of GO. After GC therapy, IgG4, IgG4/IgG, vision and CAS were significantly improved in GO patients. Patients with high IgG4 levels had a significantly reduced extraocular muscle area (EOMs) and better clinical outcomes than patients with normal IgG4 levels.

CONCLUSIONS

Our results suggest a possible subgroup of elevated IgG4 GO patients, with more severe ophthalmopathy and better response to GCs treatment compare with normal IgG4 GO patients.

Clinical features and treatment efficacy for IgG4-related thyroiditis

PURPOSE

This study aimed to clarify the clinical features of and evaluate the treatment efficacy for IgG4-related thyroiditis.

METHODS

Fourteen IgG4-related thyroiditis patients and 42 randomly matched IgG4-related disease (IgG4-RD) patients without thyroiditis in a prospective cohort at the Peking Union Medical College Hospital (PUMCH) were enrolled from 2011 to 2019. Patient demographics, clinical characteristics, laboratory parameters and treatment efficacy were analysed.

RESULTS

The prevalence of IgG4-related thyroiditis in our cohort was 2.0%. The average patient age was 42.8 ± 14.9 years, and the male: female ratio was 1:1. Goiter (14, 100.0%), hard thyroid (14, 100.0%) and neck compression (5, 35.7%) were the most prevalent onset symptoms observed. IgG4-related thyroiditis was characterized by asymmetric diffuse thyroid enlargement on ultrasound. Thirteen (92.9%) patients had hypothyroidism, and all patients had significantly elevated circulating thyroid antibodies. Compared with patients without thyroiditis, patients with IgG4-related thyroiditis had less submandibular gland involvement and lacrimal gland involvement and lower serum IgG4 and T-IgE levels (P = 0.019, P = 0.022, P = 0.004, and P = 0.006, respectively) and more single-organ involvement (P = 0.011). After treatment, the symptoms were relieved, while the size of the thyroid gland did not change significantly, and levothyroxine as a supplemental therapy was still needed.

CONCLUSIONS

IgG4-related thyroiditis is a distinct subtype of IgG4-RD characterized by positive circulating thyroid antibodies and a high rate of hypothyroidism. Although compression symptoms could be relieved with treatment, the thyroid size did not change significantly, and the damage to thyroid function was often irreversible.

[Clinical practice guidelines for acute and chronic thyroiditis (excluding autoimmune thyroiditis)]

Острые и хронические заболевания щитовидной железы занимают второе место по выявляемости после сахарного диабета. Всемирная организация здравоохранения отмечает ежегодную тенденцию к увеличению числа заболеваний щитовидной железы. В настоящих клинических рекомендациях будут рассмотрены вопросы этиологии, клинического течения, диагностики и лечения острых и хронических (за исключением аутоиммунного) воспалительных заболеваний щитовидной железы.Клинические рекомендации — это основной рабочий инструмент практикующего врача, как специалиста, так и врача узкой практики. Лаконичность, структурированность сведений об определенной нозологии, методов ее диагностики и лечения, базирующихся на принципах доказательной медицины, позволяют в короткий срок дать тот или иной ответ на интересующий вопрос специалисту, добиваться максимальной эффективности и персонализации лечения.Клинические рекомендации составлены профессиональным сообществом узких специалистов, одобрены экспертным советом Министерства здравоохранения РФ. Представленные рекомендации содержат максимально полную информацию, которая требуется на этапе диагностики острых и хронических тиреоидитов, этапе выбора тактики ведения пациентов с тиреоидитом, а также на этапе лечения пациента.Рабочая группа представляет этот проект в профессиональном журнале, посвященном актуальным проблемам эндокринологии, с целью повышения качества оказываемой медицинской помощи, повышения эффективности лечения острых и хронических тиреоидитов путем ознакомления с полным тестом клинических рекомендаций по острым и хроническим тиреоидитам (исключая аутоиммунный тиреоидит) максимально возможного количества специалистов в области не только эндокринологии, но и медицины общей (семейной) практики.

Long-term Observation of Thyroid Volume Changes in Hashimoto's Thyroiditis in a Series of Women on or off Levo-Thyroxine Treatment in an Area of Moderate Iodine Sufficiency

CONTEXT

Large variations in thyroid volume (TV) have been reported in Hashimoto's thyroiditis (HT). The need for long-term levo-thyroxine (L-T4) administration in order to control TV, as well as to normalise thyroid function, has not been well defined.

SUBJECTS AND METHODS

Retrospective data on TV in 94 adult women with HT were analysed in an ambulatory setting in Liguria, an area of moderate iodine sufficiency. TV was evaluated by means of ultrasonography (US). Thyroid function, anthropometric data, smoking habits and pharmaceutical drugs were registered at each examination.

RESULTS

At the baseline, an atrophic gland was noted in 16% of the women, and goitre in 13%. The women were evaluated 56 and 102 months after the baseline examination. At the time of each examination, 50%, 78% and 83% of women, respectively, were on L-T4 treatment. Baseline TV was not significantly different in women on/off L-T4 treatment. However, in those on L-T4, TV decreased significantly over the period of follow-up, while in those without L-T4 treatment, it did not change. By the end of the study, the percentage of L-T4-treated women with an atrophic gland had increased to 27%, and that of women with goitre had dropped to 6%; in untreated women, only minor changes were noted. There was a significant negative correlation between TV% change and baseline TSH levels in HT women on L-T4 treatment.

CONCLUSION

The majority of HT women living in an area of moderate iodine sufficiency have normal TV. Moreover, long-term L-T4 treatment can be used to control TV, as well as to maintain normal thyroid parameters.

IgG4-related disease of the thyroid gland

IgG4-thyroid-related disease (TRD) represents an uncommon spectrum of diseases, with four subcategories established so far, IgG4-related Hashimoto's thyroiditis, fibrosing variant of Hashimoto's thyroiditis, Riedel's thyroiditis and Graves disease with elevated IgG4 levels. We report the case of a 59-year-old woman presenting with painless cervical swelling and hypothyroidism. Thyroid gland was enlarged and distinctively very hard, with reduced mobility. Neck ultrasonography showed multiple nodularity and diffuse thyroid enlargement, which on CT scan conditioned slight deviation of the airway. Fine-needle aspiration of the biggest nodule was suggestive of lymphocytic thyroiditis. She developed compressive symptoms and was submitted to total thyroidectomy. Histology of the thyroid revealed extensive areas of fibrosis, oncocytic cells and lymphoplasmacytic infiltrates. Immunohistochemistry confirmed the predominance of IgG4-secreting plasma cells. IgG4-TRD is characterised by a rapidly progressive and destructive thyroiditis process. Typical presentation can often mimic malignancy; hence, an opportune recognition of IgG4-TRD may avoid unnecessary burdens.

Proposal of diagnostic criteria for IgG4-related thyroid disease

Patients with IgG4-related disease (IgG4-RD) are diagnosed in Japan by comprehensive or organ-specific diagnostic criteria. To date, organ-specific criteria have been established for several organs, but not for the thyroid. We attempted to establish diagnostic criteria for IgG4-related thyroid disease (IgG4-RTD) based on IgG4-RD research by The Research Program on Intractable Diseases from the Ministry of Health, Labour and Welfare of Japan. These criteria have been publicly reported to members of both the Japan Endocrine Society and the Japan Thyroid Association. Thyroid diseases associated with IgG4 include Hashimoto's thyroiditis, Graves' disease and Riedel's thyroiditis. As a comprehensive definition that includes both systematic and organ-specific forms, we use the broad term 'IgG4-related thyroid disease'. Diagnostic criteria for IgG4-RTD comprise the following five items: I) enlargement of the thyroid, II) hypoechoic lesions in the thyroid by ultrasonography, III) elevated serum IgG4 levels, IV) histopathological findings in the thyroid lesion (IgG4⁺ plasma cells >20/HPF and IgG4⁺/IgG⁺ plasma cell ratio >30%) and V) involvement of other organs. "Definitive" diagnosis of IgG4-RTD is made when I, II, III and IV are all fulfilled, while "probable" diagnosis of IgG4-RTD is when I, II, and IV or V are fulfilled. Patients who fulfill I, II and III criteria are considered as "possible" IgG4-RTD. We believe that the proposed diagnostic criteria contribute to more accurate diagnosis of IgG4-RTD as well as exclusion of mimicry. Furthermore, they may lead to better understanding of the clinical implications and underlying pathogenesis of IgG4-RTD.

Imaging of IgG4-Related Disease in the Head and Neck: A Systematic Review, Case Series, and Pathophysiology Update

This systematic review aims to clarify and comprehensively detail the sometimes variable published imaging features as well as the pathogenesis, clinical diagnostic criteria, and treatment options of IgG4-Related Diseases (IgG4-RD) in the head and neck to aid the radiologist in diagnosing relapse and new sites of disease. A literature search in PubMed and EMBASE for reported cases of IgG4-RD was performed in December 2019. Case reports or series of IgG4-RD in the head and neck in adults that included sufficient imaging and pathology findings were included. This yielded 50 reports. IgG4-RD locations included the orbits, thyroid, pituitary gland, paranasal sinuses, salivary and parotid glands, larynx, pharynx, cervical lymph nodes, meninges, and skull base. Most lesions demonstrated non-specific homogenous CT attenuation, diffuse enhancement, isointense/low T2 signal intensity, and low T1 signal intensity. 6 cases from our institution followed previously reported imaging patterns.

Identification of Markers Predicting Clinical Course in Patients with IgG4-Related Ophthalmic Disease by Unbiased Clustering Analysis

Purpose: To describe the clinical features of patients with immunoglobulin G4 (IgG4)-related ophthalmic disease (IgG4-ROD) grouped by unbiased cluster analysis using peripheral blood test data and to find novel biomarkers for predicting clinical features. Methods: One hundred and seven patients diagnosed with IgG4-ROD were divided into four groups by unsupervised hierarchical cluster analysis using peripheral blood test data. The clinical features of the four groups were compared and novel markers for prediction of clinical course were explored. Results: Unbiased cluster analysis divided patients into four groups. Group B had a significantly higher frequency of extraocular muscle enlargement (p < 0.001). The frequency of patients with decreased best corrected visual acuity (BCVA) was significantly higher in group D (p = 0.002). Receiver operating characteristic (ROC) curves for the prediction of extraocular muscle enlargement and worsened BCVA using a panel consisting of important blood test data identified by machine learning yielded areas under the curve of 0.78 and 0.86, respectively. Clinical features were compared between patients divided into two groups by the cutoff serum IgE or IgG4 level obtained from ROC curves. Patients with serum IgE above 425 IU/mL had a higher frequency of extraocular muscle enlargement (25% versus 6%, p = 0.004). Patients with serum IgG4 above 712 mg/dL had a higher frequency of decreased BCVA (37% versus 5%, p ≤ 0.001). Conclusion: Unsupervised hierarchical clustering analysis using routine blood test data differentiates four distinct clinical phenotypes of IgG4-ROD, which suggest differences in pathophysiologic mechanisms. High serum IgG4 is a potential predictor of worsened BCVA, and high serum IgE is a potential predictor of extraocular muscle enlargement in IgG4-ROD patients.

IgG4 thyroiditis in the Asian population

Immunoglobulin G4-related disease (IgG4-RD) is an immune-mediated fibro-inflammatory condition that often causes the formation of tumefactive lesions. The discovery of IgG4-RD linked many well-known isolated conditions as a distinct multi-organ disease, and started an era of promoting investigation and treatment in relevant fields. In the thyroid gland, a subcategory of Hashimoto thyroiditis (HT) with IgG4-rich inflammation was first discovered and named IgG4 thyroiditis by our group. This subtype of HT presents with rapidly progressive clinical manifestations and destructive histopathological features underlying thyroid dysfunction, which are significantly different from the common type of HT. Moreover, other IgG4-rich thyroid conditions in patients with Graves' disease and systemic IgG4-RD have been described. These observations are most frequently reported in the Asian population for unknown reasons. Although recent studies demonstrated that IgG4 thyroiditis is a specific entity independent from IgG4-RD, recognition of this unique subset of thyroid disease has yielded important insights into understanding its pathogenesis and the development of novel therapeutic approaches.

RECURRENT PAINFUL HASHIMOTO THYROIDITIS SUCCESSFULLY TREATED BY THYROIDECTOMY

Objective

Painful Hashimoto thyroiditis (HT) is a rare HT variant characterized by neck pain. The clinical differentiation between painful HT and subacute thyroiditis is challenging, as the diagnosis cannot be confirmed without histopathological evidence. Here we present a patient who had anterior neck pain who was diagnosed with HT.

Methods

We present the patient's clinical examinations and laboratory findings (white blood cell count, thyroid-stimulating hormone, free thyroxine, thyroid peroxidase antibody, and erythrocyte sedimentation rate). Ultrasound images of the thyroid gland and pathology images representative of marked HT with positive IgG4 immunohistochemical stain after thyroidectomy are also presented.

Results

A 42-year-old female with a 3-year history of HT developed recurrent anterior neck pain with bilateral radiation to the ears as well as a tender, enlarging thyroid goiter. She had no signs of fever or a preceding infection of the upper respiratory tract. Her pain was only temporarily alleviated by oral corticosteroids. According to the serial ultrasound records, both thyroid lobes decreased in size after 2 pain episodes. She eventually underwent total thyroidectomy and remained pain-free for 1.5 years, up to the last office follow-up visit. Histopathology confirmed the diagnosis of HT.

Conclusion

In patients with HT, recurrent thyroid pain despite steroid treatment is the clinical hallmark of diagnosis of painful HT. The reference standard of diagnosis is pathology. Thyroidectomy may be considered after recurrent painful episodes.

IgG4-positive plasma cells in Hashimoto thyroiditis: IgG4-related disease or inflammation-related IgG4-positivity?

Despite the interest of researchers in IgG4-related disease (IgG4-RD), many questions still remain unanswered regarding the thyroid gland. We aimed to clarify the relationship between IgG4-positive plasma cells and the histopathological pattern in the Hashimoto thyroiditis (HT) in a Finnish series. HT specimens (n = 280) were retrieved from the Department of Pathology, Fimlab Laboratories. After re-evaluation, 82 (29%) cases (72 females and 10 males, 52 ± 17 years) with significant fibrosis were selected. CD38, IgG and IgG4 positivity in plasma cells was evaluated by immunohistochemistry. Adjusted IgG4-positive plasma cells per HPF > 20 and IgG4- to IgG-positive plasma cell ratio > 30% were adopted as threshold criteria and related to other morphological features. IgG4-positive HT group included 13 cases (15% from fibrotic HT, 4.6% from all HT, 50 ± 15 years, 11 females) with adjusted HPF count 30 ± 5 (23-40) IgG4-positive cells. IgG4-positivity significantly correlated with the presence of lobulation, oncocytic metaplasia and certain type of fibrosis, fibrosis spread outside the gland, lymphocytes/plasma cells epithelial penetration, the predominance of microfollicles and follicular atrophy in the present study. Despite the persisting uncertainty whether HT is IgG4-RD, HT with IgG4-positive plasma cells is histopathologically distinct entity with some geographic variability.

Hashimoto's Thyroiditis with Increased IgG4-Positive Plasma Cells: Using Thyroid-Specific Diagnostic Criteria May Identify Early Phase IgG4 Thyroiditis

Background: A subset of Hashimoto's thyroiditis (HT), reported as immunoglobulin G4 (IgG4) thyroiditis, is characterized by IgG4+ plasma cell-rich inflammation and marked sclerotic changes, which suggests a close relationship with immunoglobulin G4-related disease (IgG4-RD). However, to date, there is no consensus regarding the cutoff values used to define a significant IgG4+ plasma cell count in thyroid inflammation. We, therefore, sought to validate both the cutoff value of the comprehensive diagnostic criteria (CVC) and the cutoff value of thyroid-specific diagnostic criteria (CVT) for diagnosing IgG4 thyroiditis. Methods: One hundred twenty cases of HT were retrospectively reviewed. According to the CVC (IgG4+ plasma cells >10/HPF (high-power field) and IgG4+/IgG+ plasma cell ratio >40%) and the CVT (IgG4+ plasma cells >20/HPF and IgG4+/IgG+ plasma cell ratio >30%), cases were subclassified as IgG4 thyroiditis or non-IgG4 thyroiditis. Clinical, serological, sonographic, and histopathological characteristics of the two subsets, and the cases diagnosed as IgG4 thyroiditis using different thresholds were compared. Results: Both the CVC and CVT identified the same set of distinct clinical, laboratory, and sonographic features of the cases diagnosed as IgG4 thyroiditis. All 120 cases of HT were able to be divided into four distinct groups. Group A included the 25 cases who were assigned as IgG4 thyroiditis by both the CVC and CVT, whereas Group D included the 85 cases who did not meet either of the cutoff values. Group B and Group C comprised the borderline cases who only met one of the two thresholds. Based on histological evaluation, the cases in Group B who met the CVT demonstrated similar histological features of IgG4 thyroiditis. Conclusions: Although both of the cutoff values can efficiently distinguish IgG4 thyroiditis from its non-IgG4 counterpart, the thyroid-specific cutoff value (CVT, IgG4+ plasma cells >20/HPF, and IgG4+/IgG+ plasma cell ratio >30%) can better identify borderline cases of HT with more fibrotic changes, which may represent an early phase lesion of IgG4 thyroiditis. We propose a new series of clinical and pathological diagnostic clues for both endocrinologists and pathologists to improve the early recognition of IgG4 thyroiditis.

A Literature Review of Painful Hashimoto Thyroiditis: 70 Published Cases in the Past 70 Years

Painful Hashimoto thyroiditis (pHT) is a rare diagnosis, and optimal treatment remains unclear. To better characterize pHT, PubMed, Embase, Scopus, and Web of Science indexes were searched for case reports or case series reporting pHT, published between 1951 and February 2019. Seventy cases reported in 24 publications were identified. Female predominance (91.4%) and a median age of 39.00 years (interquartile range, 32.50-49.75 years) were observed. Among reported cases, 50.8% had known thyroid disease (including Hashimoto thyroiditis, Graves disease, and seronegative goiters), 83.3% had positive antithyroid peroxidase antibodies, and 71.2% had antithyroglobulin antibodies. Most cases did not have preceding upper respiratory tract symptoms or leukocytosis. Ultrasound features were consistent with Hashimoto thyroiditis. Thyroid function at initial presentation was hypothyroid (35.9%), euthyroid (28.1%), or thyrotoxic (35.9%). Cases evolved into hypothyroidism (55.3%) and euthyroidism (44.7%), whereas none became hyperthyroid after medical treatment. Thyroid size usually decreased after medical treatment. Most cases were empirically treated as subacute thyroiditis with corticosteroids, levothyroxine, or nonsteroidal anti-inflammatory drugs. However, no therapy provided sustained pain resolution. In subgroup analysis, low-dose oral prednisone (<25 mg/d) and intrathyroidal corticosteroid injection showed more favorable outcomes. Total thyroidectomy yielded 100% sustained pain resolution. Diagnosis of pHT is based on clinical evidence of Hashimoto thyroiditis and recurrent thyroid pain after medical treatment. The reference standard of diagnosis is pathology. Total thyroidectomy or intrathyroidal glucocorticoid injection should be considered if low-dose oral prednisone fails to achieve pain control.

Comprehensive research on thyroid diseases associated with autoimmunity: autoimmune thyroid diseases, thyroid diseases during immune-checkpoint inhibitors therapy, and immunoglobulin-G4-associated thyroid diseases

Various thyroid diseases are associated with autoimmunity. Major autoimmune thyroid diseases are Graves' disease (GD) and Hashimoto's thyroiditis (HT). Thyrotropin receptor is an autoantigen in GD, and its immunogenicity has been examined. Immune-checkpoint inhibitor (ICI) is recently widely used for treatment of malignant tumors, but cases of thyroid diseases during ICI treatment have been increasing. Thyroid diseases during ICI therapy have been investigated in immunological and clinical aspects, and their Japanese official diagnostic guidelines were established. In addition, serum and tissue immunoglobulin-G4 levels have been examined in association with clinicopathological characteristics in GD, HT, and Riedel's thyroiditis. We review these diseases associated with thyroid autoimmunity and comprehensively discuss their potential application in future research and therapeutic options.

DIAGNOSIS OF ENDOCRINE DISEASE: IgG4-related thyroid autoimmune disease

IgG4-related disease (IgG4-RD) is fibro-inflammatory, immune-mediated, systemic disease recognized as a defined clinical condition only in 2001. The prevalence of IgG4-RD is 6/100 000, but it is likely to be underestimated due to insufficient awareness of the disease. The diagnostic approach is complex because of the heterogeneity of clinical presentation and because of rather variable diagnostic criteria. Indeed, high concentrations of IgG4 in tissue and serum are not a reliable diagnostic marker. The spectrum of IgG4-RD also includes well-known thyroid diseases including Riedel's thyroiditis, Hashimoto's thyroiditis and its fibrotic variant, Graves' disease and Graves' orbitopathy. Results from clinical studies indicate that a small subset of patients with the above-mentioned thyroid conditions present some features suggestive for IgG4-RD. However, according to more recent views, the use of the term thyroid disease with an elevation of IgG4 rather than IgG4-related thyroid diseases would appear more appropriate. Nevertheless, the occurrence of high IgG4 levels in patients with thyroid disease is relevant due to peculiarities of their clinical course.

IgG4-related disease in endocrine practice

IgG4-related disease is a set of symptoms resulting from a chronic, usually multiple organ inflammatory condition which affects various organs. It consists of lymphoplasmacytic infiltrations with attendant fibrosis and deep vein thrombosis. Frequently observed tissue lesions are accompanied by elevated IgG4 levels in serum. The etiopathogenesis of the lesions is of multifactor character and the clinical manifestation of the disease is highly diverse. The diagnostic process is based on the patient's medical history, clinical examination and additional tests, including a histopathological examination of the infected organ's tissues. Almost forty different locations of the disease have been reported, including disorders of the endocrine system. IgG4-related endocrinopathies are quite rare. However, it is likely that the diagnosis is under-reported due to lack of awareness of this clinical entity. Despite increasing interest in the subject, there are not enough reliable studies evaluating the link between IgG4-RD and endocrine disorders.

Epstein-Barr Virus Lytic Reactivation Induces IgG4 Production by Host B Lymphocytes in Graves' Disease Patients and Controls: A Subset of Graves' Disease Is an IgG4-Related Disease-Like Condition

Immunoglobulin (Ig) G4-related disease (IgG4-RD) is a newly recognized systemic fibroinflammatory disease with characteristic histological findings and high serum IgG4 levels. Epstein–Barr virus (EBV) is a persistent herpesvirus in B lymphocytes, and we previously reported EBV reactivation-induced Ig production. We showed that EBV reactivation induced the production of thyrotropin receptor antibodies, the causative antibodies of Graves' disease. In the present study, we investigated whether EBV reactivation induced IgG4 production and if EBV-positive B cells or IgG4-positive plasma cells are present in the thyroid tissues of Graves' disease patients with lymphoplasmacytic infiltration. EBV-encoded small RNA1 (EBER1) in situ hybridization and immunohistochemistry for IgG and IgG4 were performed on seven resected thyroid tissues with lymphoplasmacytic infiltration collected from the thyroids of 11 Graves' disease patients. We then cultured the lymphocytes of 13 Graves' disease patients and 14 controls and induced EBV reactivation to measure IgG4 levels in culture fluids. We detected EBER1-positive cells and IgG4-positive plasma cells in the same area of thyroid tissues. EBV-reactivated cells with IgG4 on their surface were observed in culture cells, and IgG4 production was detected in culture fluids. The IgG4/IgG percentage was higher than that in normal serum level. A subset of Graves' disease is an IgG4-RD-like condition, not an IgG4-RD. EBV reactivation stimulates IgG4 production, which may result in high serum IgG4 levels and promote IgG4-positive plasma cell infiltration. EBER1 needs to be examined when an increase in IgG4-positive plasma cell numbers is noted.

Hashimoto's thyroiditis with elevated serum IgG4 concentrations is not equivalent to IgG4 Hashimoto's thyroiditis

BACKGROUND

Hashimoto's thyroiditis (HT) with serum IgG4 concentrations greater than 135 mg/dL can be diagnosed as elevated serum IgG4 HT. HT can also be classified into IgG4 HT and non-IgG4 HT based on an immunohistochemistry analysis of IgG4. The aim of our study was to determine the relationship between elevated serum IgG4 HT and IgG4 HT.

METHOD

Both thyroid tissues and serum samples stored before pathological examination from 93 patients with HT were collected. The serum levels of IgG, IgG4, TgAb IgG, TgAb IgG4, TPOAb IgG and TPOAb IgG4 were measured by ELISAs. The expression levels of IgG4, IgG and TGF-β1 in thyroid tissues were detected by immunohistochemistry.

RESULTS

Patients with HT were divided into two groups: elevated serum IgG4 HT (n = 12) and nonelevated serum IgG4 HT (n = 81). Hypothyroidism was found in 5 of 12 cases (41.7%) in the elevated serum IgG4 HT group and 10 of 81 cases (12.3%) in the nonelevated serum IgG4 HT group (P = .023). Serologically, there were no significant differences in the levels of TgAb IgG, TPOAb IgG, TgAb IgG4 and TPOAb IgG4 between the two groups, and the expression of TGF-β1 in thyroid tissues was not significantly different between the groups. Most importantly, the frequency of patients who satisfied the criteria for IgG4 HT diagnosis was comparable (25% vs 20.9%, P = .756).

CONCLUSIONS

The measurement of serum IgG4 allows the identification of patients with HT closely associated with hypothyroidism. However, our study demonstrated that elevated serum IgG4 HT is not equivalent to IgG4 HT.

IgG4-Related Disease of the Thyroid Gland Requiring Emergent Total Thyroidectomy: A Case Report

IgG4-related disease of the thyroid gland is a recently recognized subtype of thyroiditis, often with rapid progression requiring surgical treatment. It is considered as a spectrum of disease varying from early IgG4-related Hashimoto's thyroiditis (HT) pattern to late fibrosing HT or Riedel's thyroiditis patterns. Here, we report a 47-year-old Malay woman presenting with progressively painless neck swelling over 3 years and subclinical hypothyroidism. Computed tomography (CT) scan revealed diffuse thyroid enlargement (up to 13 cm) with retrosternal extension and without regional lymphadenopathy. Fine needle aspiration of the thyroid showed a limited number of follicular epithelial cell groups with widespread Hurthle cell change and scanty background colloid, but no evidence of lymphocytosis. The cytologic features fell into the category of 'atypia of undetermined significance'. Subsequently, the patient developed hypercapnic respiratory failure secondary to extrinsic upper airway compression by the thyroid mass and underwent emergent total thyroidectomy. Histology of the thyroid showed diffuse dense lymphoplasmacytic infiltrate and fibrosis. Follicular cells exhibited reactive nuclear features and some Hurthle cell change. IgG4+ plasma cells were over 40/high power field while overall IgG4/IgG ratio was above 50%. The overall features suggest the diagnosis of IgG4-related disease of the thyroid gland in the form of IgG4-related HT. Post-surgery, the patient was found to have markedly elevated serum IgG4 concentration but PET/CT did not show significant increased fludeoxyglucose uptake in other areas. Her recovery was complicated by a ventilator-associated pneumonia with empyema, limiting early use of corticosteroids for treatment of IgG4-related disease.

Hypothyroidism in patients with autoimmune pancreatitis

AIM

To examine thyroid function and clinical features of hypothyroidism in autoimmune pancreatitis (AIP) patients.

METHODS

We examined thyroid function in 77 patients with type 1 AIP (50 males, 27 females; median age 68 years, range 33-85) diagnosed according to the Japanese diagnostic criteria for AIP 2011. We compared clinical and serological findings between patients with and without various categories of hypothyroidism. The change in hypothyroidism after steroid therapy was also examined.

RESULTS

Eight patients (10%) had hypothyroidism of 6 patients had subclinical hypothyroidism with a normal serum free thyroxine (FT4) and high thyroid stimulating hormone (TSH) level, and 2 patients had central hypothyroidism with low serum free triiodothyronine (FT3), FT4 and TSH levels. A significant goiter of the thyroid was not observed in any patient. There were no significant differences in age; male to female ratio; serum concentrations of IgG and IgG4-related disease (IgG4-RD); presence of anti-thyroglobulin antibody, antinuclear antigen or rheumatoid factor; or presence of extrapancreatic lesions between the 6 patients with subclinical hypothyroidism and patients with euthyroidism. After steroid therapy, both subclinical and central hypothyroidism improved with improvement of the AIP.

CONCLUSION

Hypothyroidism was observed in 8 (10%) of 77 AIP patients and was subclinical in 6 patients and central in 2 patients. Further studies are necessary to clarify whether this subclinical hypothyroidism is another manifestation of IgG4-RD.

IgG4-related Disease - A Systemic Disease that Deserves Attention Regardless of One's Subspecialty

IgG4-related disease (IgG4-RD) is an inflammatory condition characterized by a high serum IgG4 concentration and the abundant infiltration of lymphocytes and IgG4-positive plasma cells in the tissue, as well as spatial (diverse clinical manifestations) and temporal (the possibility of recurrence) multiplicities. Since the initial documentation of IgG4-related disease in patients with autoimmune pancreatitis in 2001, a growing body of evidence has been accumulating to suggest that various-virtually all-organs can be affected by IgG4-RD. In general, steroid therapy is effective and is considered to be the first-line treatment for IgG4-RD. The precise mechanism underlying this systemic disorder has remained unknown. Considering that IgG4-RD was specified as being an intractable disease in 2015, further studies are needed to clarify whether IgG4-RD is indeed a distinct disease entity or a complex of disorders of different etiologies and clinical conditions.

Immunoglobulin G4-Related Disease: An Update

Immunoglobulin G4-related disease (IgG4-RD) is an increasingly recognized immune-mediated condition comprised of a collection of disorders that share specific pathological, serological, and clinical features. IgG4-RD is a fibroinflammatory condition with a tendency to form tumors with inflammatory infiltrate with IgG4 rich plasma cells and elevation of serum IgG4, which may affect virtually every organ and tissue. IgG4-related ophthalmic disease may present as dacryoadenitis, myositis, or involvement of other orbital tissue. Hypophysitis or pachymeningitis may manifest as cranial neuropathies. The diagnosis of IgG4-RD is based on a typical clinical scenario, supportive laboratory test, expected radiological characteristics, and distinct histopathological and immunohistochemical features. Corticosteroids and immunosuppressives form the mainline treatment.

Warthin-like papillary thyroid carcinoma with immunoglobulin G4-positive plasma cells possibly related to Hashimoto's thyroiditis

Hashimoto's thyroiditis with heavy lymphoplasmacytic infiltration is a common comorbidity of immunoglobulin G4 (IgG4)-related thyroiditis and Warthin-like papillary thyroid carcinoma (WL-PTC). We hypothesized that WL-PTC may have a strong association with IgG4-related thyroiditis. To validate this hypothesis, we clinically and immunohistochemically studied 17 WL-PTC cases. Fourteen patients (82.4%) had anti-thyroglobulin antibody and were confirmed to have Hashimoto's thyroiditis through microscopic analysis. Among them, five (29.4%) had disease consistent with IgG4-related thyroiditis but did not exhibit a "storiform" pattern or obliterative phlebitis. IgG4-related diseases were not found in other organs. No cases with serum IgG4 level of >135 mg/dL were noted. A total of 94.1% of WL-PTC cases had IgG4-positive plasma cells (⁺PCs) in the stroma, and cases with rich IgG4⁺PCs were more frequently associated with Hashimoto's thyroiditis than those with poor IgG4⁺PCs. In this study, all three cases without Hashimoto's thyroiditis had poor IgG4⁺PCs, and one of them did not exhibit IgG4⁺PCs in the stroma of WL-PTC and Hashimoto's thyroiditis. Nodal metastatic lesions were seen in eight cases, all of which were not WL-PTC. As such, we should consider that the Hashimoto's disease with rich IgG4⁺PCs seen in our cases is representative of non-IgG4-related disease and not IgG4-related disease involving multiple organs. This study is the first to demonstrate the presence of IgG4⁺PCs in the stroma of WL-PTC. We concluded that the appearance of IgG4⁺PCs in the stroma of WL-PTC may be related to Hashimoto's thyroiditis with rich IgG4⁺PC.

Case report: IgG4-related mass-forming thyroiditis accompanied by regional lymphadenopathy

Background

It has been recently accepted that IgG4-related thyroiditis is comparable to the Hashimoto and Riedel thyroiditis and Graves disease which are rich in IgG4-secreting plasma cells. Many physicians believe that in IgG4-related thyroiditis, the thyroid is entirely enlarged and diffusely affected, which is similar to conventional thyroiditis, but rarely ever accompanied by pseudoneoplastic mass formation as in IgG4-related disease in the other organs. This report introduces another pattern of IgG4-related thyroiditis as mass-forming thyroiditis and presents the occurrence of IgG4-related regional lymphadenopathy as an unusual accompanying symptom.

Case presentation

A 66-year-old woman presented with an approximately 2.5-cm mass in the right thyroidal lobe and regional lymph node swelling, which were preoperatively misinterpreted as thyroidal carcinoma. After lobectomy, histological examination was performed, revealing that the mass showed dense stromal fibrosis, lymphoplasmacytic infiltration, and effacement of thyroid follicles, while the background thyroidal tissue seemed to mimic lymphocytic thyroiditis without fibrosis. Immunohistochemistry revealed predominance of IgG4-secreting plasma cells among infiltrating lymphocytes independent of mass lesion or background tissue. In addition, the regional Delphian and paratracheal lymph nodes were swollen, histologically showing numerous IgG4-secreting plasma cell infiltrations in the interfollicular zone.

Conclusions

IgG4-related mass-forming thyroiditis, which may be an extremely rare but recognizable pattern of IgG4-related thyroiditis, may be distinguishable from Hashimoto and Riedel thyroiditis, Graves disease, and thyroidal carcinoma. In addition, the regional IgG4-related lymphadenopathy, also possibly misdiagnosed as metastatic thyroidal carcinoma, may be a newly recognized manifestation of IgG4-related thyroiditis.

A study of serum IgG4 levels in the clinical metamorphosis of autoimmune thyroid disease

Background

Measurement of serum IgG4 had been suggested to distinguish the unique subtypes of autoimmune thyroid disease (AITD) which demonstrated patterns of fluctuating between hyperthyroidism and hypothyroidism. However, the clinical utility of serum IgG4 measurement is inconclusive due to few studies having addressed these unusual patients compared with the specificity of serum IgG4 in healthy patients.

Aim

To investigate whether elevated serum IgG4 levels could be used as a marker to identify fluctuating AITD patients.

Materials and Methods

20 AITD patients who evolved from hyperthyroid Graves’ disease to spontaneous hypothyroidism or vice versa were compared with 40 healthy subjects, 40 patients with hyperthyroid Graves’ disease (GD) and 40 patients with subclinical or overt hypothyroid Hashimoto’s thyroiditis (HT). Serum levels of total IgG and IgG4 were measured and the proportion of elevated serum IgG4 levels (defined by serum IgG4 levels ≥ 135 mg/dL) was compared with control patients.

Results

A series of 20 Thai patients with clinical evolution of AITD was analyzed with a median follow-up at 92 months (range 3–380 months). Elevated serum IgG4 levels were not found in fluctuating AITD patients but were found in 5% of the control GD patients, 2.5% of the control HT, and 2.5% of healthy subjects which were not statistically significant between each group.

Conclusion

Our results contrasted with those of previous studies from Japan which reported elevated serum IgG4 as a marker to identify subset of AITD patients. At present, the clinical utility of serum IgG4 measurements in AITD is inconclusive and requires further investigation.

IgG4-related orbital disease masquerading as thyroid eye disease, vice versa, or both?

A 40 year-old male presented after one year of unilateral, progressive, steroid-responsive, orbital inflammatory disease causing proptosis, extraocular muscle (EOM) restriction, and compressive optic neuropathy. The development of anti-thyroidal antibodies prompted the diagnosis of thyroid eye disease (TED); however, the prolonged active phase, remarkable reversibility of ophthalmic features with high-dose corticosteroids, unilaterally of disease, uncharacteristic EOM involvement (including both obliques), and the absence of autoimmune thyroid disease provoked consideration of alternative diagnoses. Inferior oblique biopsy stained positive for IgG4 with histologic features atypical of TED. The patient received rituximab for presumed IgG4-related orbital disease (IgG4-ROD) with subsequent reversal of compressive optic neuropathy, near complete resolution of EOM restriction, and improved proptosis, the latter two of which are not routinely anticipated in advanced TED. The possible role for B-cell depletion in both TED and IgG4-ROD suggests a degree of overlap in the underlying immune-related pathophysiology that is yet to be defined.

IgG4 Staining in Thyroid Eye Disease

IgG4-related ophthalmic disease is increasingly widely recognized. Moreover, IgG4 staining can occur in other inflammatory diseases. The authors report a case of IgG4 staining of an enlarged, inflamed levator palpebrae superioris in a patient with a past history of thyroid eye disease. A 78-year-old woman with quiescent hyperthyroidism had clinical and radiological evidence of levator palpebrae superioris inflammation without superior rectus involvement. A biopsy was consistent with IgG4-related ophthalmic disease. There was a marked but incomplete response to an orbital injection of triamcinolone. The authors discuss the association between thyroid eye disease and IgG4 staining and the diagnostic issues that arise when IgG4-related ophthalmic disease criteria are fulfilled in patients with other orbital inflammatory conditions.

Clinical Implications of Immunoglobulin G4 to Graves' Ophthalmopathy

BACKGROUND

This study aimed to explore the relation of immunoglobulin G4 (IgG4) to clinical and laboratory characteristics of patients newly diagnosed with Graves' disease (GD) without or with Graves' ophthalmopathy (GO) and to analyze association of IgG4 with development and grade of GO in GD patients.

METHODS

Sixty-four GD patients and 64 sex- and age-matched euthyroid subjects were enrolled. Serum levels of thyroid hormones, thyroid autoantibodies, immunoglobulin G (IgG), and IgG4 were measured, and ophthalmological and ultrasonographical evaluation was performed.

RESULTS

In GD patients compared with euthyroid subjects, levels of thyroid hormones, thyroid autoantibodies and IgG4 as well as the IgG4/IgG ratio were elevated. GD patients having GO in comparison to not having GO were characterized by a female predominance; a high incidence of smoking history; high levels of T3, free T4, TSH receptor autoantibody (TRAb) and IgG4; and a high IgG4/IgG ratio after adjusting for sex. In GD patients, the IgG4 level was the independent factor associated with GO development on multivariate analysis. When severity and activity of GO were classified using the European Group on Graves' Orbitopathy criteria in GD patients with GO, IgG4 levels and IgG4/IgG ratio were elevated in the moderate-to-severe group compared with the mild group and in the active group compared with the inactive group. IgG4 levels and IgG4/IgG ratio became elevated as clinical activity score increased. IgG4 levels were positively correlated with TRAb levels. The high IgG4 group in comparison to the normal IgG4 group had a high incidence of family history of autoimmune thyroid disease, high levels of free T4, TRAb and IgG4, a high IgG4/IgG ratio and extensive hypoechogenicity.

CONCLUSIONS

These results suggest that IgG4 levels are elevated in newly diagnosed GD patients compared with euthyroid subjects and in the presence of GO compared with the absence of GO. Moreover, our findings suggest that IgG4 levels are associated with the development and grade of GO in GD patients.

Imaging of IgG4-related disease of the head and neck

IgG4-related disease is a systemic, inflammatory disorder typically involving multiple organ systems. Several eponymous conditions described previously in the clinical and radiology literature are now recognised to be part of the IgG4-related disease spectrum. This includes multiple manifestations in the head and neck region, which are the subject of this review. Imaging can occasionally suggest the specific diagnosis of IgG4 disease. More commonly, it will be included in a limited differential diagnosis that requires clarification with the aid of image-guided biopsy. There are strict histopathological criteria for the diagnosis of IgG4-related disease.

Thyroid Autoimmunity: Role of Anti-thyroid Antibodies in Thyroid and Extra-Thyroidal Diseases

Autoimmune diseases have a high prevalence in the population, and autoimmune thyroid disease (AITD) is one of the most common representatives. Thyroid autoantibodies are not only frequently detected in patients with AITD but also in subjects without manifest thyroid dysfunction. The high prevalence raises questions regarding a potential role in extra-thyroidal diseases. This review summarizes the etiology and mechanism of AITD and addresses prevalence of antibodies against thyroid peroxidase, thyroid-stimulating hormone receptor (TSHR), and anti-thyroglobulin and their action outside the thyroid. The main issues limiting the reliability of the conclusions drawn here include problems with different specificities and sensitivities of the antibody detection assays employed, as well as potential confounding effects of altered thyroid hormone levels, and lack of prospective studies. In addition to the well-known effects of TSHR antibodies on fibroblasts in Graves' disease (GD), studies speculate on a role of anti-thyroid antibodies in cancer. All antibodies may have a tumor-promoting role in breast cancer carcinogenesis despite anti-thyroid peroxidase antibodies having a positive prognostic effect in patients with overt disease. Cross-reactivity with lactoperoxidase leading to induction of chronic inflammation might promote breast cancer, while anti-thyroid antibodies in manifest breast cancer might be an indication for a more active immune system. A better general health condition in older women with anti-thyroid peroxidase antibodies might support this hypothesis. The different actions of the anti-thyroid antibodies correspond to differences in cellular location of the antigens, titers of the circulating antibodies, duration of antibody exposure, and immunological mechanisms in GD and Hashimoto's thyroiditis.

IgG4-Related Hashimoto's Thyroiditis of the Thyroid Gland

Immunoglobulin (Ig) G4-related Hashimoto's thyroiditis is a newly discovered subtype of Hashimoto's thyroiditis and characterized by thyroid inflammation and marked fibrosis. IgG4-related Hashimoto's thyroiditis is very rare and there has been relatively little information available to date. A 46-year-old woman with a past history of thyroid dysfunction visited our outpatient clinic for severe anterior neck swelling. She complained of swallowing discomfort and pain due to severe goiter and was successfully treated with total thyroidectomy. Immunohistochemistry showed thyroid invasion by IgG4-positive cells and an IgG4/IgG ratio over 40%. The patient was diagnosed with IgG4-related Hashimoto's thyroiditis. We report a very rare case of IgG4-related Hashimoto's thyroiditis with severe goiter. A more comprehensive understanding of the IgG4-related Hashimoto's thyroiditis may help physicians to allow proper diagnosis and treatment of patients with severe goiter.