DIAGNOSIS OF ENDOCRINE DISEASE: IgG4-related thyroid autoimmune disease

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.

Efficacy of rituximab in treating steroid-resistant Graves' orbitopathy in active moderate-to-severe and sight-threatening forms: A retrospective observation from China

Background and objectives

The efficacy of rituximab (RTX) in treating steroid-resistant Graves' orbitopathy (GO) has been limitedly studied in Asians. Moreover, RTX has been considered even less for patients with steroid-resistant dysthyroid optic neuropathy (DON) who failed to undergo orbital decompression surgery for physical or financial reasons, or who responded poorly to the procedure. This study aimed to investigate the efficacy of RTX in treating steroid-resistant active moderate-to-severe and sight-threatening GO in a Chinese population.

Methods

Data from 28 patients with steroid-resistant GO prescribed a single dose of 500 mg RTX were retrospectively retrieved. Treatment responses and contributing factors were analyzed.

Results

The median follow-up time was 22 (8-34) weeks. 23 (82.1 %) patients had a positive objective outcome recommended by the European Group on Graves' Orbitopathy (EUGOGO), while 25 (92.6 %) had a decrease in 7-item clinical activity score (CAS) by at least 2. Diplopia, visual dysfunction, and MRI-detected T2 relaxation time of the involved extraocular muscles improved significantly at the last follow-up compared to baseline (81.0 % vs. 47.6 %, 38.9 % vs. 16.7 %, and 87.8 (8.64) vs. 75.8 (10.9) ms, respectively; all p values < 0.05). No significant improvement was seen in terms of proptosis and eye muscle duction. Notably, a higher baseline IgG4 to IgG ratio was a predictor for RTX-induced positive EUGOGO outcomes. After RTX treatment, all 8 patients with DON demonstrated inactivation, and 4 improved in visual acuity by ≥ 1 line. No patient with DON experienced obvious deterioration.

Conclusion

A single dose of 500 mg RTX seemed to be an effective and tolerable treatment for steroid-resistant GO. However, larger-scale studies with a control group are required for a more solid conclusion. The role of RTX in steroid-resistant DON management where surgery is unavailable or ineffective should be further explored.

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.

Autoimmune Polyglandular Syndrome Type 3 Complicated with IgG4-related Disease

A 52-year-old Japanese woman developed type 1 diabetes mellitus (type 1 DM) at 41 years old. She became complicated with Hashimoto's disease and showed swelling of both submandibular glands, which was diagnosed as IgG4-related disease (IgG4-RD). This is a rare case of a Japanese patient with autoimmune polyglandular syndrome type 3A (APS-3A) coexisting with autoimmune thyroid disease (AITD) and type 1 DM complicated by IgG4-RD. Bilateral submandibular gland resection was successfully performed without steroid therapy. We discuss the possibility that the immunological pathogenic mechanisms of APS-3A and IgG4-RD are related.

Clinical Significance of IgG4 Serum Concentration in Graves' Disease

Elevated immunoglobulin G4 (IgG4) serum antibodies are an important feature of IgG4-related disease. However, IgG4 antibodies can play a role in autoimmune thyroid disorders. In this study, we aimed to evaluate the impact of serum IgG4 levels on clinical features of Graves' disease (GD). We recruited 60 patients with GD (48 patients without thyroid eye disease, 12 patients with moderate-to-severe Graves' orbitopathy [GO], and 25 healthy control subjects). The prevalence of high IgG4 serum concentration was 4.2% among GD patients without GO and 33.33% in patients with moderate-to-severe GO. The group with GO had significantly higher median IgG4 levels (87.9 mg/dL) than the control group (41.2 mg/dL, P = 0.034) and the GD without GO group (30.75 mg/dL, P < 0.001). Patients with thyroid nodules had lower IgG4 levels than patients without thyroid nodules, but the difference was not statistically significant (35.7 [24.8; 41.53] mg/dL vs. 43 [30.1; 92.7] mg/dL, P = 0.064). IgG4 as a diagnostic tool for moderate-to-severe GO had the following parameters: area under the curve (AUC): 0.851 (P < 0.001), at the cut-off value of 49 mg/dL, negative predictive value: 100%, positive predictive value: 48%, sensitivity: 100%, specificity: 73%. There were no significant differences between the high and normal IgG4 groups in thyroid hormones, antithyroid antibodies, and ultrasound features. Serum IgG4 levels are associated with some of the clinical features of GD and can help in the diagnostic process of the disease. More research is needed to better understand the pathophysiology of IgG4 involvement in GD.

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.

Value of High-Frequency Ultrasonography in the Qualitative and Semi-Quantitative Assessment of Immunoglobulin G4-Related Submandibular Sialadenitis

OBJECTIVE

To assess the value of high-frequency ultrasonography in the evaluation of immunoglobulin G4-related submandibular sialadenitis (IgG4-SS).

METHODS

Thirty-four submandibular glands in 17 patients with IgG4-SS were retrospectively enrolled, as well as 34 submandibular glands in 17 healthy control subjects. Qualitative ultrasonic features including submandibular gland size, border, echogenicity, and vascularity were reviewed. Two different scoring systems (0-16 and 0-48, respectively) were used for semi-quantitative analysis of imaging features. Comparison of both qualitative and semi-quantitative ultrasonic analysis were made between patients with IgG4-SS and healthy controls. Spearman correlation was used to explore relationships between variables.

RESULTS

The submandibular glands with IgG4-SS presented with enlarged size, rough border, increased vascularity, and abnormal echogenicity (All P < .05). The most common echogenicity pattern for IgG-SS was diffuse hypoechoic foci pattern (44.1%), followed by superficial hypoechoic pattern (20.6%), tumor-like pattern (14.7%), and diffuse hypoechogenicity pattern (11.8%). Most IgG4-SS glands presented linear hyperechogenicity in parenchyma (91.2%). Based on both scoring system, scores of IgG4-SS were significantly higher than those of the controls (All P < .05). Association analysis of both scoring systems showed positive correlation of scores with vascularity in the gland parenchyma (All P < .05).

CONCLUSION

The ultrasonic features of IgG4-SS comprise enlarged gland, rough border, increased vascularity, and abnormal echogenicity, which correlate with its pathological characteristics. The most common echogenicity pattern for IgG4-SS was diffuse hypoechoic foci pattern. Semi-quantitative analysis systems could be useful in the assessment of IgG4-SS. Ultrasound is a potential, valuable, and non-invasive tool for the diagnosis and evaluation of IgG4-SS.

Reshaping the Concept of Riedel's Thyroiditis into the Larger Frame of IgG4-Related Disease (Spectrum of IgG4-Related Thyroid Disease)

Recently, Riedel's thyroiditis (RT) was assimilated into the larger spectrum of immunoglobulin IgG4-related disease (IgG4-RD) in addition to a particular frame of IgG4-related thyroid disease (IgG4-RTD), underlying IgG4-RT, IgG4-associated Hashimoto's thyroiditis (and its fibrotic variant), and IgG4-related Graves's disease. Our objective was to overview recent data on RT, particularly IgG4-RD and IgG4-RTD. The case and study- sample analysis (2019-2023) included 293 articles and selected 18 original studies: nine single case reports (N = 9, female/male = 2/1, aged: 34-79 years, 5/9 patients with serum IgG4 available data, 2/5 with high serum IgG4) and four case series (N = 21; 4/5 series provided data on IgG4 profile, 3/21 had serum IgG4 assays, and 2/3 had abnormally high values). IgG4-RD and thyroid findings were analyzed in three cohorts (N = 25). Another two studies (N = 11) specifically addressed IgG4-RTD components. On presentation, the patients may have hypothyroidism, transitory thyrotoxicosis, goiter, long-term history of positive anti-thyroid antibodies, and hypoechoic ultrasound thyroid pattern. The 5-year analysis (N = 66) showed the rate of serum IgG4 evaluation remained low; normal values do not exclude RT. Mandatory histological and immunohistochemistry reports point out a high content of IgG4-carrying plasma cells and IgG4/IgG ratio. Unless clinically evident, histological confirmation provides a prompt indication of starting corticoid therapy since this is the first-line option. Surgery, if feasible, is selective (non-responders to medical therapy, emergency tracheal intervention, and open/core needle biopsy). Current open issues are identifying the role of serum IgG4 assays in patients with IgG4-RD, finding out if all cases of RT are IgG4-mediated, applying IgG4-RTD criteria of differentiation among four entities, and providing an RT/IgG4-RTD guideline from diagnosis to therapy. It remains that the central aim of approaching RT in daily practice is the early index of suspicion in order to select patients referred for further procedures that provide enough histological/immunohistochemistry material to confirm RT and its high IgG4 burden.

Association of Pro-Inflammatory Cytokines with Vitamin D in Hashimoto's Thyroid Autoimmune Disease

Background and objectives: Hashimoto's thyroiditis is an important autoimmune thyroid condition. It is characterized by lymphocytic congestion of the thyroid gland followed by progressive deterioration and fibrous substitution of the thyroid in the parenchymal structure. This study has provided insight into the variations of blood pro-inflammatory cytokine levels in patients with Hashimoto's disease and the key role of vitamin D levels among selected patients. Materials and Methods: A total of 144 participants including healthy controls and patients were studied in the current study in which 118 were female and 26 were male. The thyroid profile was evaluated in patients with Hashimoto's thyroiditis and healthy controls. Results: The mean ± SD Free T4 in the patients was recorded as 14.0 ± 4.9 pg/mL, and TSH was 7.6 ± 2.5 IU/L, whereas the median ± IQR thyroglobulin antibodies (anti-TG) were 285 ± 142. Thyroid peroxidase antibodies (anti-TPO) were 160 ± 63.5, whereas in the healthy controls, the mean ± SD Free T4 was recorded as 17.2 ± 2.1 pg/mL, and TSH was 2.1 ± 1.4 IU/L, whereas the median ± IQR anti-TGs were 56.30 ± 46.06, and anti-TPO was 5.6 ± 5.12. The assessment of pro-inflammatory cytokines (pg/mL) and total Vitamin D levels (nmol/L) in patients with Hashimoto's thyroiditis was recorded with values IL-1B 6.2 ± 0.8, IL-6 9.4 ± 0.4, IL-8 7.5 ± 0.5, IL-10 4.3 ± 0.1, IL-12 3.8 ± 0.5, TNF-α 7.6 ± 1.1, and total vitamin D 21.89 ± 3.5, whereas in healthy controls the mean ± SD IL-1B was 0.6 ± 0.1, IL-6 2.6 ± 0.5, IL-8 3.0 ± 1.2, IL-10 3.3 ± 1.3, IL-12 3.4 ± 0.4, TNF-α 1.4 ± 0.3 and total vitamin D was 42.26 ± 5.5. Conclusions: It was found that individuals with Hashimoto's thyroiditis had raised serum levels of IL-1B, IL-6, IL-8, IL-10, IL-12, and TNF-α as compared to the healthy controls, whereas the total vitamin D levels were remarkably low as compared to health controls. Serum TSH, anti-TG, and anti-TPO levels were typically lower in controls and much higher in individuals with Hashimoto's thyroiditis. The current study's findings might aid in future studies and in the diagnosis and management of autoimmune thyroid disease.

Anatomic and Functional Imaging of Immunoglobulin G4-related Disease and Its Mimics

Immunoglobulin G4 (IgG4)-related disease (IgG4-RD) is an immune-mediated fibrosclerosing disease with tumefactive lesions infiltrated by IgG4-positive plasma cells. Initially described as autoimmune pancreatitis, IgG4-RD is now recognized as a discrete entity and is found to affect virtually any organ in the body. Common extrapancreatic sites include the biliary tree, salivary glands, periorbital tissue, lungs, kidneys, lymph nodes, aorta, retroperitoneum, and thyroid gland. Diagnosis-which relies on histopathologic, serologic, and radiologic features-can be challenging with the disease underdiagnosed, as IgG4-RD often mimics malignancy, infectious processes, or other immune-mediated conditions. Patients may present with signs of compression of nearby structures due to mass effect or with organ failure when the disease is left untreated. The clinical course is complex, with single- or multiorgan involvement and metachronous or synchronous occurrence of lesions. IgG4-RD responds well to glucocorticoid therapy, disease-modifying antirheumatic drugs, and B-cell-depleting biologic agents; prompt diagnosis is important to avoid delay in treatment and unnecessary pharmacologic or surgical intervention. While imaging features may not be specific for IgG4-RD, functional whole-body imaging with fluorine 18-fluorodeoxyglucose PET/CT is a useful adjunct for localizing extrapancreatic sites for biopsy, monitoring therapeutic response, and demonstrating disease relapse. The authors describe the pancreatic and extrapancreatic sites of involvement in IgG4-RD, with imaging features and patterns to aid in distinguishing IgG4-RD from its mimics through a multimodality approach with emphasis on functional imaging evaluation. ^©RSNA, 2023 Quiz questions in the supplemental material and the slide presentation from the RSNA Annual Meeting are available for this article.

High IgG4 serum concentration is associated with active Graves orbitopathy

BACKGROUND

The aim of the study was to evaluate the differences in clinical profile, laboratory parameters, and ophthalmological signs, and symptoms between patients with high IgG4 Graves orbitopathy and patients with normal IgG4 Graves orbitopathy.

METHODS

This was a prospective observational study. We recruited adult patients with Graves Orbitopathy(GO) referred to our clinic for further diagnostics and treatment. Eventually, 60 patients with GO were enrolled in the study. All patients underwent ophthalmological assessment, magnetic resonance imaging (MRI) of the orbits, and laboratory tests, including IgG4 serum concentration measurement. High IgG4 GO was diagnosed if the IgG4 concentration exceeded 135 mg/dl. We used both the clinical activity score (CAS) and magnetic resonance imaging (MRI) to assess the activity of GO. Eventually, active GO was defined according to MRI results.

RESULTS

Among 60 GO patients, 15 (25%) patients had elevated IgG4 levels. Patients in the high IgG4 group had a higher prevalence of active GO by MRI than patients with normal IgG4 (100% vs. 64.44%, P=0.006). They also had a higher eosinophile count in peripheral blood, a lower bilirubin level, a more frequent lower eyelid retraction, and a lower prevalence of glaucoma. There were no statistically significant differences between the groups in CAS. Patients with active GO, had higher median IgG4 level [89.95 (55.48; 171.1) vs 43.45 (32.48; 49.68) mg/dl, P<0.001]. The receiver operating characteristic (ROC) analysis for IgG4 as a marker of active GO revealed the following results: AUC 0.848 for the cut-off value of 54.2 mg/dl, sensitivity 79.5%, specificity 87.5%, positive predictive value 94.6%, negative predictive value 59.1%.

CONCLUSIONS

We demonstrated that IgG4 is a marker of GO activity. Certain differences in the clinical profile of patients with high IgG4 GO, and normal IgG4 GO were observed. More data is needed to establish whether patients with high IgG4 GO are GO patients with particularly active disease or actually represent a distinct clinical entity related to IgG4-Related Disease.

Study on Clinicopathological Features and Risk Factors of Patients with Multiple Primary Breast Cancers and Thyroid Disease

Objective

To explore the clinicopathological features and risk factors of patients with multiple primary breast cancers and thyroid disease.

Method

An analytic approach of the reviewing method was adopted to analyze the clinical data of 80 breast cancer patients who were admitted to our hospital from January 2020 to January 2022. They were divided into an observation group (breast cancer with thyroid lesions) and a control group (simple breast cancer) according to whether the clinical data were accompanied with thyroid lesions to compare the clinical characteristics, pathological types, staging characteristics, and molecular biological characteristics of the two groups and to research the risk factors of the two groups.

Result

(1) In the comparison of clinical data, the number of people aged ≥60 in the observation group was higher than that in the control group, and there was significant difference between the groups in the menopausal status data (P < 0.05). There was no statistical difference between the observation group and the control group in the comparison of clinical data of the body mass index, pregnancy frequency, labor frequency, and abortion history (P > 0.05). (2) In the comparison of pathological type and staging data, there was no statistical difference in the comparison of data on the pathological type, histological grade, T staging, N staging, and TNM staging between the observation group and the control group (P > 0.05). (3) In the comparison of data on molecular biology characteristics, there was a statistical difference in the nuclear proliferation antigen data between the observation group and the control group (P < 0.05). There was no statistical difference in the comparison of data on the estrogen receptor, progesterone receptor, human epidermal growth factor receptor-2, and molecular typing between the observation group and the control group (P > 0.05). (4) Logistic regression analysis showed that age, menopausal status, and nuclear proliferation antigen index were the high-risk inflammatory factors for combined thyroid lesions (P < 0.05).

Conclusion

For patients with simple breast cancer, age, menopausal status, and nuclear proliferation antigen index are risk factors for combined thyroid lesions. Therefore, clinical attention should be paid to the above factors in the process of clinical treatment, and early-risk screening should be performed to achieve the purpose of improving the prognosis to the greatest extent.

[Differential diagnosis of IgG4-related disease]

IgG4-related disease is a chronic autoimmune fibro-inflammatory disease characterized by the presence of lymphoplasmacytic infiltrate, storiform fibrosis, obliterating phlebitis, increased number of IgG4+ cells in tissue, and, in most cases, an elevated serum IgG4 level. This disease often affects the pancreas, salivary glands and lymph nodes, but can involve almost any tissue. Its etiology is still unclear, the central role in the pathogenesis belongs to B-lymphocytes, T2-helpers, interleukins 1-β, 4, 5, 10, 13 and tumor growth factor 1-β. The ambiguous clinical picture and frequent simultaneous involvement of several organs make it difficult to diagnose, so biopsy plays a leading role in making a diagnosis. The characteristic microscopic picture, the presence of certain populations of lymphocytes are key criteria in establishing the correct diagnosis.

The Role of TPOAb in Thyroid-Associated Orbitopathy: A Systematic Review

INTRODUCTION

Thyroid-associated orbitopathy (TAO) is one of the most common autoimmune inflammatory disorders of the orbit. The presence of anti-thyroid antibodies is believed to play a role in the pathogenesis and clinical status of the TAO patients. Herein, we review the usefulness of TPOAb as a biomarker for TAO.

METHODS

A systematic search in MEDLINE library was conducted. Results: Twenty studies were included. TPO is expressed in orbital tissues, and the polymorphism rs11675434 SNP has proven to be associated with clinically evident TAO. Studies in pediatric patients have shown a positive correlation between high TPOAb levels and TAO. In contrast, results in adults are inconsistent. Some studies imply a protective role of TPOAb, yet the majority did not find any association. Some authors have suggested an implication of TPOAb in the pathophysiology of TAO in TRAb-negative patients.

CONCLUSIONS

The role of TPOAb in TAO remains unclear and controversial.

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.

Autoimmune polyglandular syndrome type 3: A case report of an unusual presentation and literature review

Autoimmune polyglandular syndromes (APS) are rare disorders characterized by auto-destruction of endocrine and non-endocrine organs by organ-specific antibody-directed T-lymphocytic infiltration. This case highlights a 29-year-old Caucasian man with vitiligo found to have significant neurological abnormalities in the setting of newly diagnosed pernicious anemia and thyroid autoimmune disease.

Prediction models constructed for Hashimoto's thyroiditis risk based on clinical and laboratory factors

BACKGROUND

Hashimoto's thyroiditis (HT) frequently occurs among autoimmune diseases and may simultaneously appear with thyroid cancer. However, it is difficult to diagnose HT at an early stage just by clinical symptoms. Thus, it is urgent to integrate multiple clinical and laboratory factors for the early diagnosis and risk prediction of HT.

METHODS

We recruited 1,303 participants, including 866 non-HT controls and 437 diagnosed HT patients. 44 HT patients also had thyroid cancer. Firstly, we compared the difference in thyroid goiter degrees between controls and patients. Secondly, we collected 15 factors and analyzed their significant differences between controls and HT patients, including age, body mass index, gender, history of diabetes, degrees of thyroid goiter, UIC, 25-(OH)D, FT3, FT4, TSH, TAG, TC, FPG, low-density lipoprotein cholesterol, and high-density lipoprotein cholesterol. Thirdly, logistic regression analysis demonstrated the risk factors for HT. For machine learning modeling of HT and thyroid cancer, we conducted the establishment and evaluation of six models in training and test sets.

RESULTS

The degrees of thyroid goiter were significantly different among controls, HT patients without cancer (HT-C), and HT patients with thyroid cancer (HT+C). Most factors had significant differences between controls and patients. Logistic regression analysis confirmed diabetes, UIC, FT3, and TSH as important risk factors for HT. The AUC scores of XGBoost, LR, SVM, and MLP models indicated appropriate predictive power for HT. The features were arranged by their importance, among which, 25-(OH)D, FT4, and TSH were the top three high-ranking factors.

CONCLUSIONS

We firstly analyzed comprehensive factors of HT patients. The proposed machine learning modeling, combined with multiple factors, are efficient for thyroid diagnosis. These discoveries will extensively promote precise diagnosis, personalized therapies, and reduce unnecessary cost for thyroid diseases.

IgG4-related disease. Clinical manifestation differential diagnosis and recent International Diagnostic Criteria for IgG4-related disease

Immunoglobulin G4- related disease (IgG4-RD) is a rare systemic fibro-inflammatory disorder. Autoimmune pancreatitis is the most frequent manifestation of IgG4-RD. However, IgG4-RD can affect any organ such as salivary glands, orbits, retroperitoneum, prostate and many others. Recent research enabled a clear clinical and histopathological description of IgG4-RD and in 2019 four Clinical phenotypes of IgG4-related disease were described. Diagnosis is based on morphological examination with typical findings of lymphoplasmocellular inflammation, storiform fibrosis and obliterative phlebitis in IgG4-RD biopsies and the tissue invading plasma cells largely produce IgG4. Elevated serum IgG4 levels are found in many but not all patients. New diagnostic criteria for IgG4-RD have been published recently in 2019 and 2021. This review summarizes current knowledge on pathophysiology, clinical manifestations, diagnosis and differential diagnosis of IgG4-RD from the point of view 2022 and in next article brings overview of the IgG4-RD therapy.

IgG4-related autoimmune manifestations in Alemtuzumab-treated multiple sclerosis patients

We aimed to determine whether Alemtuzumab-induced immune reconstitution affects immunoglobulin and complement levels in the serum of Relapsing-Remitting Multiple Sclerosis (RRMS) patients. IgG4-levels were increased 24-months after treatment initiation compared to baseline levels in twenty-nine patients. Alemtuzumab-treated patients with the highest IgG4-levels were more prone to thyroid-related autoimmune manifestations and specific autoimmune adverse events such as Crohn's disease, Graves' disease, and hemolytic anemia. Compared to baseline, total IgG-levels showed a trend towards reduced levels following two-courses of Alemtuzumab, but no significant change of C3 and/or C4-levels was observed. In conclusion, monitoring of IgG4-levels can serve as a marker for secondary autoimmunity risk in multiple sclerosis patients treated with Alemtuzumab.

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.

IgG4 as a Biomarker in Graves' Orbitopathy

Immunoglobulin G4-related disease (IgG4-RD) is a chronic inflammatory disorder associated with fibrosis and abundant tissue lymphoplasmacytic infiltrations. It typically affects the pancreas, the salivary glands, and the retroperitoneal space. However, it might also involve multiple other organs, including the orbit and the thyroid. Recent studies have suggested that IgG4 plays a role in the pathophysiology of autoimmune thyroid diseases. This ultimately led to the establishment of new clinical entities called IgG4-related thyroid disease and thyroid disease with an elevation of IgG4. The aim of this paper is to describe the pathophysiological, histopathological, and clinical features of Graves' Disease (GD) and Graves' Orbitopathy (GO) with elevated IgG4 levels. Multiple studies have demonstrated higher IgG4 serum concentrations in GD patients than in healthy euthyroid controls. Depending on the studied population, elevated serum IgG4 levels occur in 6.4-23% (average: 10.3%) of all patients with GD, 8.3-37.5% (average: 17.6%) of patients with GO, and 0-9.8% (average: 5.4%) of patients with GD without GO, while GO patients comprise 37.5-100% (average: 65.8%) of all GD patients with elevated IgG4 levels. Characteristic features of GD with elevated IgG4 levels include lower echogenicity of the thyroid gland on ultrasound examination, peripheral blood eosinophilia, higher prevalence of orbitopathy, and better response to antithyroid drugs with a tendency to develop hypothyroidism when compared to patients with GD and normal levels of IgG4. Typical signs of GO accompanied by increased concentration of IgG4 include younger age at diagnosis, and more severe course of the disease with a higher Clinical Activity Score (CAS).. We strongly recommend considering the diagnosis of GO with elevated IgG4 in patients with an established diagnosis of GD, elevated serum IgG4 levels, and clinical features of ophthalmic disease overlapping with those of IgG4-related orbital disease.

Long-Term Outcomes of Tamoxifen Citrate Therapy and Histo- and Immunopathological Properties in Riedel Thyroiditis

BACKGROUND

Riedel thyroiditis (RT) is a rare form of thyroiditis; thus, data about the disease course and treatment options are limited. Therefore, we aimed to assess the clinical, serological, radiological, and histopathological features, as well as short- and long-term follow-up of RT patients under glucocorticoid (GC) and tamoxifen citrate (TMX). Parameters related to IgG4-related diseases (IgG4-RD) were also investigated.

METHODS

Eight patients with RT diagnosed between 2000 and 2019 were enrolled. Data were collected in a retrospective and prospective manner. The diagnosis was confirmed with histopathological features in all patients. Results of the treatment with GCs on short- to mid-term, followed by TMX in the long term, were evaluated.

RESULTS

The mean age at diagnosis was 40.5 ± 6.8 years; female predominance was observed (F/M:7/1). Parameters related to IgG4-RD, like increase in IgG4 serum levels, total plasmablast counts, and IgG4+ plasmablasts, were negative in most of our patients in both active and inactive states of the disease. Likewise, an increased ratio of IgG4/IgG-positive plasma cells >40% could only be observed in 2 cases. GCs followed by TMX were given to the patients with an over-all median follow-up time of 67 (8-216) months. All the patients considerably improved clinically and had a reduction in the size of the mass lesion on GCs, followed by TMX therapy. None of the patients had a recurrence under TMX therapy for a median period of 18.5 (7-96) months.

CONCLUSION

Even though RT is suggested to be a member of IgG4-RD, serologic or histological evidence of IgG4 elevation or positivity is only useful for diagnosis and follow-up of RT. The diagnosis should be based on clinical and radiological evidence and confirmed by histopathology. GCs are effective for initial treatment, and TMX is a successful and safe therapeutic option for long-term maintenance therapy.

IgG4 immunohistochemistry in Riedel's thyroiditis and the recommended criteria for diagnosis: A case series and literature review

OBJECTIVE

Riedel's thyroiditis (RT) is a very rare chronic fibrosing thyroiditis that is often associated with multifocal fibrosclerosis. Although the relationship of RT and IgG4-related disease (IgG4-RD) has been suggested, the expression of IgG and IgG4 in thyroid tissues of patients with RT has seldom been studied.

DESIGN

A case series and literature review.

PATIENTS AND MEASUREMENTS

We searched our hospital's pathology database and identified five cases of RT between 2000 and 2019. The expression levels of IgG4 and IgG in thyroid tissues were detected by immunohistochemistry. We also performed a literature search of the electronic databases PubMed/MEDLINE, Web of Science and China National Knowledge Internet (CNKI). Eight papers were included in this study.

RESULTS

According to immunohistochemistry, the numbers of IgG4+ plasma cells per high-power field (HPF) of the five RT patients at our hospital were 80, 8, 50, 10 and 22, and the respective IgG4+/IgG+ ratios were 76%, 80%, 43%, 19% and 28%. In the literature, 15 RT patients with confirmed IgG4 and IgG immunohistochemical findings were identified. Only seven of them fulfilled the IgG4-RD diagnostic criteria in terms of immunohistochemistry (IgG4+ > 10/HPF, IgG4+/IgG+ > 40%). In order to ensure that most RT cases can meet the IgG4 immunohistochemical criteria, an organ-specific cut-off value (≥10 IgG4+ plasma cells/HPF and ≥ an IgG4+/IgG ratio of 20%) was finally selected in our study.

CONCLUSION

Our findings of IgG4 expression in patients with RT suggest that a cut-off of 10 IgG4+ plasma cells/HPF and an IgG4+/IgG ratio of 20% are more suitable diagnostic criteria for RT in IgG4-RD.

IgG4-Related Disease: A Retrospective Chinese Study of Features and Treatment Response of 98 Patients Including 4 Rare Cases

The features and treatment of 98 Chinese patients with immunoglobulin G4 (IgG4)-related disease (IgG4-RD) referred to a single tertiary referring centre were reviewed. Patients diagnosed with IgG4-RD according to the comprehensive diagnostic criteria (CDC) were included in the retrospective study from May 2012 to March 2019. We collected data on clinical, laboratory, imaging, histological features and treatment. Totally, 98 patients with IgG4-RD were enrolled. The common clinical manifestations included abdominal pain, salivary gland swelling and lymphadenopathy. 51% of the patients had multiple organs involvement. Lymph nodes, pancreas and salivary glands were most commonly involved. Four rare sites including ulna, cerebellum, scalp, and mammary gland were found. The serum IgG4 level was increased by 85.7%. The serum IgG4 level was positively correlated with the number of involved organs, IgG and IgG4/IgG. Low C3 and C4 levels were observed in 37.5% and 12.2% patients respectively, and all patients with kidney involvement had hypocomplementemia. A total of 54 patients underwent tissue biopsies, and 55.6%, 31.5% and 11.1% cases were diagnosed as definite, probable and possible IgG4-RD, respectively. Eighty-eight patients received glucocorticoids (GCs) therapy. Five patients underwent radical surgery to remove the lesion. 73% of them presented a complete or partial remission. IgG4-RD is a systemic fibroinflammatory disease with involvement of multiple organs throughout the body including some rare sites. Most IgG4-RD patients had increased serum IgG4 levels and patients with kidney involvement showed hypocomplementemia. GCs therapy is effective. More research is needed to provide a more reliable basis for the diagnosis and treatment of patients.

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.

[Autoantibodies, immunoglobulins and cytokine profile in patients with graves' disease and Graves' orbitopathy]

BACKGROUND

Graves' Orbitopathy (GO) - also known as Thyroid Eye Disease (TED) - is an autoimmune condition in the modern sense. It is closely associated with autoimmune thyroid diseases. Cytokine-mediated mechanisms play a critical part in immunopathogenesis of autoimmune thyroid diseases including GO. Investigating cytokine profiles as well as antibodies to tissue-specific antigens is essential for explaining GO pathogenesis and developing future therapeutic strategies.

AIMS

The study examines serum levels of cytokines, autoantibodies and immunoglobulins IgG and IgG4 as mediators of autoimmune inflammation in patients with GO and Graves' Disease (GD).

MATERIALS AND METHODS

The study included 52 patients (104 orbits) aged 25-70 years (mean age 48,8±12,3) in the active phase of GO and GD verified with the international diagnostic standards. These patients did not get any treatment for GO before. The control group consisted of 14 individuals (28 orbits) aged 30-68 years without known autoimmune disease.Serum levels of IgG, IgG4,TNFα, IL-1α, IL-1β, IL-2, IL-4, IL-6, IL-8, IL-10, IL-17A, IL-13, sIL-6R, sTNFα- RI и TNFα- R2 IL-2R, TGFβ1, TGF β3, antibodies to TSH-receptor, free T4, free T3 and TSH were measured. A diagnostic ultrasound exam of thyroid gland, multislice computed tomography (MSCT) / magnetic resonance imaging (MRI) of orbits were performed.

RESULTS

Mean duration of GO prior to being admitted to the centre was 8,8±1,5 months (range: 1 - 48 months). According to the degree of thyrotoxicosis compensation: 24 patients were clinically euthyroid, TSH 3,3±0,7 mU/L, free T4 11,9±0,59 pmol/L, free T3 3,97±0,1 pmol/L; 28 patients were considered to have subclinical thyrotoxicosis: TSH 0,03±0,01 mU/L, free T4 14,2±1,0 pmol/L, free T3 5,77±0,49 pmol/L. Serum levels of sTNFα-R2 (p=0,041, p≤0,05), sIL-2R (p=0,020, p≤0,05), TGFβ1 (p=0,000, p≤0,001) were significantly higher in patients with GO compared to the control group. Serum levels of sTNFRα2 (p=0,038, p&lt;0,05) and TGFβ1 (P=0,011, p≤0,05) were positively correlated with the duration of GO. The positive correlations between the serum level of sIL-6R (p=0,034, p≤0,05) and the severity of GO as well as between the serum level of sTNFα- R 1 (P=0,012, p≤0,05) and activity of GO were observed. 54% of patients had elevated concentration level of IgG4 in IgG ( &gt;5%).

CONCLUSION

High levels of soluble cytokine receptors sTNFα-R2 and sIL-2R and cytokine TGFβ1 in patients with long-standing untreated GO and GD being euthyroid or having subclinical thyrotoxicosis indicate activation of regulatory T cells aimed at suppressing autoimmune processes. High concentration level of IgG4 in IgG and cytokine TGFβ1 can determine the development of fibrotic changes in the orbital tissues. A decrease in the concentration of cytokine TGFβ1 can indicate an unfavorable course of the disease GO.

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.

[IGG4-related diseases in endocrinology]

Immunoglobulin-G4-related disease (IgG4-RD) is a chronic immunomediated pathology of different organs of local or systemic nature, which has been established as a separate clinical entity in the early 2000s and is characterized by storiform fibroid inflammation of the affected tissues, their increase, and elevated serum immunoglobulin-G4 (IgG4) levels. The most common manifestations of the disease are major salivary and lacrimal gland enlargement, lymphadenopathy and type 1 autoimmune pancreatitis (AIP1), however, other organs may be also involved (the thyroid, eyes, meninges, heart, lungs, kidneys, aorta, upper airways, mesentery, etc.). The effectiveness of treatment of IgG4-RD, as well as other pathological conditions, is also determined by the timely diagnosis. However, the latter is complicated due to the variety of clinical manifestations and rather variable diagnostic criteria. It is necessary to constantly update the evidence-based knowledge and diagnostic algorithms within this pathology in order to overcome the difficulties, and involve immunologists, endocrinologists, pathologists and specialists in other spheres. This review provides information about the etiology, pathogenesis, and current methods of diagnosis and treatment of IgG4-related diseases, as well as examples of some manifestations of IgG4-RD that an endocrinologist may face in practice.

An unusual presentation of propylthiouracil-induced anti-MPO and PR3 positive ANCA vasculitis with associated anti-GBM antibodies, IgA nephropathy and an IgG4 interstitial infiltrate: a case report

Background

A number of disease processes can culminate in rapidly progressive glomerulonephritis, including pauci-immune focal segmental necrotising glomerulonephritis, usually seen with positive serum antineutrophil cytoplasmic antibodies (ANCA). Propylthiouracil (PTU) has been associated with drug-induced ANCA-associated vasculitis (AAV), with antibodies against myeloperoxidase (MPO) and proteinase 3 (PR3) present individually and together having been recognised. ‘Double-positive’ vasculitis with ANCA and anti-glomerular basement membrane (GBM) antibodies has also been reported in association with PTU treatment. We present a case of PTU-induced anti-MPO and PR3 positive ANCA vasculitis with associated anti-GBM antibodies, IgA nephropathy and an IgG4 interstitial infiltrate.

Case presentation

A 51-year-old man presented 2 weeks after re-commencing propylthiouracil (PTU) treatment for Graves’ disease, with a severe acute kidney injury and haemato-proteinuria. He demonstrated positive titres for autoantibodies to PR3 (76.9 IU/mL), MPO (28.8 IU/mL) and GBM (94 IU/mL). Renal biopsy demonstrated numerous glomerular crescents, widespread IgG4-positive lymphoplasmacytic infiltrate and mesangial positivity for IgA. PTU was stopped and he was treated with steroids, plasma exchange and cyclophosphamide with sustained improvement in his renal function.

Conclusions

This case of drug-induced AAV presented a unique and intriguing collection of serological and histological features. We propose that the PTU-induced AAV resulted in epiphenomena of anti-GBM antibody production and an IgG4-cell-rich tubulointerstitial infiltrate. It is uncertain whether the mesangial IgA deposition preceded or resulted from the AAV.

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.

Orbital diseases mimicking graves' orbitopathy: a long-standing challenge in differential diagnosis

Graves' orbitopathy (GO) is the most common cause of orbital tissue inflammation, accounting for ~ 60% of all orbital inflammatory conditions in the population aged 21-60 years, and for ~ 40% in the population aged > 60 year. GO is observed in 25-30% of patients with Graves' hyperthyroidism and more rarely in association with hypothyroid autoimmune thyroiditis. In addition, a small proportion of GO patients (1-2%) do not have a clinically overt thyroid dysfunction. Clinically, GO is characterized by proptosis, inflammation involving the eyelids and the conjunctiva, extraocular muscle hypertrophy, with consequent reduction of ocular motility and diplopia, and in the most severe cases, compression of the optic nerves at the orbital apex, with reduction of visual acuity. At CT scan or MRI, a muscle increase involving the superior, medial and inferior rectus is quite typical. In the most severe forms, compression of the optic nerves at the orbital apex can be observed. Euthyroid GO is usually an early sign of a full-blown Graves' disease; however, in some cases, the orbital disease can remain isolated. Moreover, euthyroid GO can rarely be unilateral, which makes the picture even more confusing. Under those circumstances, the diagnostic process becomes obviously quite difficult, having other conditions mimicking GO been excluded. A number of inflammatory conditions affecting orbital tissue can mimic GO, thereby requiring an accurate evaluation for a proper differential diagnosis. The majority of these conditions are immune mediated. Most of them are benign, but they can be rather aggressive and some can cause visual loss. The most common inflammatory condition affecting orbital tissues and mimicking GO is idiopathic orbital inflammation. Other, more rare, orbital diseases that should be considered in the differential diagnosis are infections, orbital manifestations of systemic diseases, primitive and secondary orbital neoplasms, and orbital vascular alterations. In most instances, when an orbitopathy occurs in the absence of hyperthyroidism, the diagnosis of the disease underlying the ocular symptoms and signs is based on exclusion of the other conditions. Here we review the conditions that can mimic GO and how to distinguish them from this obnoxious eye disease.

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.