IgG4-related aortitis/periaortitis and periarteritis: a distinct spectrum of IgG4-related disease

Fibrotic phenotype of IgG4-related disease

A prompt response to glucocorticoids is a clinical hallmark of IgG4-related disease. However, manifestations characterised by prominent tissue fibrosis on histological examination can be less responsive to glucocorticoid therapy than other types of IgG4-related disease. These manifestations include retroperitoneal fibrosis, fibrosing mediastinitis, Riedel thyroiditis, orbital pseudotumor, and hypertrophic pachymeningitis, among others. To explain this discrepancy, a preliminary distinction into proliferative and fibrotic phenotypes of IgG4-related disease has been proposed on the basis of clinical presentation, pathological features, and response to immunosuppressive therapy. Implications of this classification for patient management remain an important area of investigation. In this Series paper, we aim to dissect the pathophysiology of tissue fibrosis in IgG4-related disease and discuss how clinicians should approach the management of fibrotic manifestations of IgG4-related disease based on the most recent diagnostic and therapeutic developments.

Coronary Artery Wall Contrast Enhancement Imaging Impact on Disease Activity Assessment in IgG4-RD a direct marker of coronary involvement

BACKGROUND

Coronary artery wall contrast enhancement (CE) has been applied to non-invasive visualization of changes to the coronary artery wall in systemic lupus erythematosus (SLE). This study investigated the feasibility of quantifying CE to detect coronary involvement in IgG4-related disease (IgG4-RD), as well as the influence on disease activity assessment.

METHODS

A total of 93 subjects (31 IgG4-RD; 29 SLE; 33 controls) were recruited in the study. Coronary artery wall imaging was performed in a 3.0T MRI scanner. Serological markers and IgG4-RD Responder Index (IgG4-RD-RI) scores were collected for correlation analysis.

RESULTS

Coronary wall CE was observed in 29 (94%) IgG4-RD patients and 22 (76%) SLE patients. Contrast-to-noise ratio (CNR) and total CE area were significantly higher in patient groups compared to controls (CNR: 6.1 ± 2.7 [IgG4-RD] v. 4.2 ± 2.3 [SLE] v. 1.9 ± 1.5 [control], P < 0.001; Total CE area: 3.0 [3.0-6.6] v. 1.7 [1.5-2.6] v. 0.3 [0.3-0.9], P < 0.001). In the IgG4-RD group, CNR and total CE area were correlated with the RI (CNR: r =0.55, P =0.002; total CE area: r = 0.39, P = 0.031). RI´ scored considering coronary involvement by CE, differed significantly from RI scored without consideration of CE (RI v. RI´: 15 ± 6v. 16 ± 6, P < 0.001).

CONCLUSIONS

Visualization and quantification of CMR coronary CE by CNR and total CE area could be utilized to detect subclinical and clinical coronary wall involvement, which is prevalent in IgG4-RD. The potential inclusion of small and medium-sized vessel involvements in the assessment of disease activity in IgG4-RD is worthy of further investigation.

The cardiovascular pathologist in the aortic team

Aortic diseases require a multidisciplinary management for diagnosis, treatment and follow-up with better outcomes in referral centers using a team-based approach. The setting up of a multi-disciplinary aortic team for the discussion of complex cases has been already proposed; it is also supported by the ACC/AHA. Surgeons and radiologists, more or less other physicians such as cardiologists, geneticists, rheumatologists/internal medicine specialists and pathologists are involved into such a team. The role of the cardiovascular pathologist is to examine the aortic specimens, to diagnose and classify the aortic lesions. Herein, the role of the pathologist in the aortic team is discussed and the pathobiology of aortic diseases is reviewed for reference by pathologists. The aortic specimens are mainly obtained from emergency or elective surgical procedures on the thoracic aorta, less frequently from organ/tissue (including cardiac or heart valve) donors, post-mortem procedures or abdominal aortic surgery. In the last decade, together with the progress of medical sciences, the histological definitions and classifications of the aortic pathology are undergoing thorough revisions that are addressed to an etiopathogenetic approach because of possible clinico-pathological correlations, therapeutic and prognostic impact. Pathologists may also have an important role in research and teaching. Therefore, histological analyses of the aortic specimens require adequate sample processing and pathologist expertise because histology contributes to definite diagnosis, correct management of patients and even (in genetic diseases) families, but also to research in the challenging field of aortopathies.

Current and future advances in practice: IgG4-related disease

IgG4-related disease (IgG4-RD) is an increasingly recognized cause of fibroinflammatory lesions in patients of diverse racial and ethnic backgrounds and is associated with an increased risk of death. The aetiology of IgG4-RD is incompletely understood, but evidence to date suggests that B and T cells are important players in pathogenesis, both of which are key targets of ongoing drug development programmes. The diagnosis of IgG4-RD requires clinicopathological correlation because there is no highly specific or sensitive test. Glucocorticoids are highly effective, but their use is limited by toxicity, highlighting the need for studies investigating the efficacy of glucocorticoid-sparing agents. B cell-targeted therapies, particularly rituximab, have demonstrated benefit, but no randomized clinical trials have evaluated their efficacy. If untreated or under-treated, IgG4-RD can cause irreversible organ damage, hence close monitoring and consideration for long-term immunosuppression is warranted in certain cases.

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.

Comparison of clinical features and outcomes of proliferative, fibrotic, and mixed subtypes of IgG4-related disease: A retrospective cohort study

BACKGROUND

Immunoglobulin G4-related disease (IgG4-RD) is a recently recognized immune-mediated disorder that can affect almost any organ in the human body. IgG4-RD can be categorized into proliferative and fibrotic subtypes based on patients' clinicopathological characteristics. This study aimed to compare the clinical manifestations, laboratory findings, and treatment outcomes of IgG4-RD among different subtypes.

METHODS

We prospectively enrolled 622 patients with newly diagnosed IgG4-RD at Peking Union Medical College Hospital from March 2011 to August 2021. The patients were divided into three groups according to their clinicopathological characteristics: proliferative, fibrotic, and mixed subtypes. We compared demographic features, clinical manifestations, organ involvement, laboratory tests, and treatment agents across three subtypes. We then assessed the differences in treatment outcomes among 448 patients receiving glucocorticoids alone or in combination with immunosuppressants. Moreover, risk factors of relapse were revealed by applying the univariate and multivariate Cox regression analysis.

RESULTS

We classified the 622 patients into three groups consisting of 470 proliferative patients, 55 fibrotic patients, and 97 mixed patients, respectively. We found that gender distribution, age, disease duration, and frequency of allergy history were significantly different among subgroups. In terms of organ involvement, submandibular and lacrimal glands were frequently involved in the proliferative subtype, while retroperitoneum was the most commonly involved site in both fibrotic subtype and mixed subtype. The comparison of laboratory tests revealed that eosinophils ( P = 0.010), total IgE ( P = 0.006), high-sensitivity C-reactive protein ( P <0.001), erythrocyte sedimentation rate ( P <0.001), complement C4 ( P <0.001), IgG ( P = 0.001), IgG1 (P <0.001), IgG4 (P <0.001), and IgA ( P <0.001), at baseline were significantly different among three subtypes. Compared with proliferative and mixed subtypes, the fibrotic subtype showed the lowest rate of relapse (log-rank P = 0.014).

CONCLUSIONS

Our study revealed the differences in demographic characteristics, clinical manifestations, organ involvement, laboratory tests, treatment agents, and outcomes across proliferative, fibrotic, and mixed subtypes in the retrospective cohort study. Given significant differences in relapse-free survival among the three subtypes, treatment regimens, and follow-up frequency should be considered separately according to different subtypes.

IgG4-related disease involving coronary and pulmonary arteries: a case report and literature review

Background

IgG4-related disease (IgG4-RD) is an inflammation-mediated autoimmune disease characterized by infiltration of IgG4 plasma cells in target organs, storiform fibrosis and obliterative phlebitis, accompanied by or without elevated serum IgG4 concentrations. Multiple sites can be involved, including large vessels. Coronary and pulmonary arteries are less involved, while simultaneous involvement of coronary and pulmonary arteries is less reported. This case is unique in terms of simultaneous involvement of coronary and pulmonary arteries in a female patient with possible IgG4-RD and the first review of relevant domestic literature.

Case Description

This case is a middle-aged female patient with both coronary artery and pulmonary artery involvement, with cardiac insufficiency as the main manifestation. Cardiac ultrasound revealed the cardiac insufficiency and abnormal wrapping of multiple arteries. Imaging examinations including coronary artery computed tomography angiography (CTA), pulmonary artery CTA and cardiac magnetic resonance imaging (MRI) further confirmed the lesions of the left main coronary artery, anterior descending branch, circumflex branch and pulmonary artery. Then the patient was diagnosed with possible IgG4-RD. After glucocorticoid treatment, the patient's clinical symptoms and cardiac function improved, and her serum IgG4 levels decreased.

Conclusions

When the arterial system is involved in IgG4 disease, it is known as IgG4-related artery disease. Combined with the case of this patient, this paper reviewed the literature on IgG4-related artery disease, and searched and summarized the related domestic literature on coronary/pulmonary artery disease to improve people's understanding of IgG4-related artery disease.

Comparison of 18 F-FDG PET Findings of Pegfilgrastim-Induced Aortitis With Other Types of Large-Vessel Vasculitis : A Retrospective Observational Study

PURPOSE OF THE REPORT

To elucidate the PET/CT findings of pegfilgrastim-induced aortitis (PFIA) and compare them with those of other large-vessel vasculitis.

METHODS

We enrolled 45 patients diagnosed with the following: PFIA, n = 8; Takayasu arteritis (TA), n = 12; giant cell arteritis (GCA), n = 6; and immunoglobulin G4-related aortitis (IgG4-A), n = 19. Records of PET/CT performed before treatment initiation were collected. The aorta and its branches were divided into 16 anatomic regions. Presence of abnormal 18 F-FDG uptake in each region was determined and measured.

RESULTS

The 18 F-FDG-positive areas of PFIA were distributed in the regions of the ascending aorta to the suprarenal abdominal aorta, cervical branches of the aorta, and external iliac arteries, similar to those of TA. However, TA had a higher proportion of 18 F-FDG-positive areas than PFIA in almost all anatomic regions. These areas of GCA were widespread throughout the entire aorta and the upper and lower limbs, whereas those of IgG4-A were observed from the abdominal aorta to iliac arteries. SUV max , SUV peak , metabolic volume, and total lesion glycolysis were higher in GCA than in PFIA, TA, and IgG4-A.

CONCLUSIONS

Pegfilgrastim-induced aortitis distribution on PET/CT was frequently observed in the aorta, cervical branches, and extra iliac arteries. The low proportion of 18 F-FDG-positive areas in PFIA was different from that of TA, GCA, and IgG4-A. These findings may help identify and differentiate various aortitis types in clinical practice.

Vascular Involvement of Immunoglobulin G4-Related Disease: A Case Report

Immunoglobulin-G4-related disease (IgG4-RD) is a fibro-inflammatory condition that can impact any organs/tissues, including the vascular systems, resulting in aortitis/periaortitis/periarteritis (PAO/PA). The complex nature of this disease and limited understanding have led to potential delays in identifying and managing irreversible organ damage. Herein, we report a 17-year-old female with hyper IgG4 disease, sclerosing mesenteritis, short stature, and insulin resistance who presented with symptoms of fever, epigastric pain, left flank pain, vomiting, dizziness, decreased urine output, and diarrhea. Imaging studies revealed an arterial wall thickening of the ascending aorta and aortic arch, splenic abscesses, and enlarged lymph nodes, consistent with IgG4-related aortitis. Treatment with steroids and antifungal agents was initiated. However, the patient developed septic shock and multi-organ failure requiring inotropes and mechanical ventilation. Ascending aortic aneurysm rupture, in this case, probably led to the patient's demise, but unfortunately, no autopsy was done to confirm it. This case highlights the importance of identifying and addressing vascular involvement in IgG4-RD to prevent irreversible organ damage and mortality.

Memory CD4+T cell profile is associated with unfavorable prognosis in IgG4-related disease: Risk stratification by machine-learning

IgG4-related disease (IgG4-RD) is a chronic immune-mediated disease with heterogeneity. In this study, we used machine-learning approaches to characterize the immune cell profiles and to identify the heterogeneity of IgG4-RD. The XGBoost model discriminated IgG4-RD from HCs with an area under the receiver operating characteristic curve of 0.963 in the testing set. There were two clusters of IgG4-RD by k-means clustering of immunological profiles. Cluster 1 featured higher proportions of memory CD4⁺T cell and were at higher risk of unfavorable prognosis in the follow-up, while cluster 2 featured higher proportions of naïve CD4⁺T cell. In the multivariate logistic regression, cluster 2 was shown to be a protective factor (OR 0.30, 95% CI 0.10-0.91, P = 0.011). Therefore, peripheral immunophenotyping might potentially stratify patients with IgG4-RD and predict those patients with a higher risk of relapse at early time.

IgG4 related disease and aortitis: an up-to-date review

Aortic involvement in immunoglobulin G4-related disease (IgG4-RD) is extremely rare and is often overlooked during the aortitis work-up. IgG4-related aortitis differs from non-IgG4-related aortitis in its histopathological features, site of involvement, laboratory markers, and treatment options. The histopathological examination of the vessel walls characteristically reveals adventitial thickening with intimal sparing, typically affecting the infrarenal abdominal aorta. In addition, inadequate knowledge about the disease often leads to delayed or missed diagnosis and undermanagement of a potentially treatable condition. Hence, in this paper, we review the unique clinical manifestations, laboratory markers, diagnostic features, current treatment strategies, and novel experimental therapeutic options in the management of IgG4-related aortitis.

Thoracic manifestations of IgG4-related disease

Immunoglobulin G4-related disease (IgG4-RD) is a recently described rare systemic fibroinflammatory disease with an estimated incidence of less than 1 in 100,000 persons per year. The disease can affect virtually any organ and is characterized by unifying histopathological findings. Recently, four subgroups of patients have been characterized: hepatobiliary, head and neck, Mikulicz syndrome and retroperitoneal fibrosis, who illustrate the mainly abdominal and ENT tropism of the disease. Yet, thoracic involvement is not uncommon. It can be detected in up to 30% of patients with systemic IgG4-RD and is the exclusive manifestation of the disease in about 10% of cases. Clinical symptoms are nonspecific and may include dyspnoea, cough or chest pain. Chest CT findings are heterogeneous and primarily include peribronchovascular thickening, nodules, ground-glass opacities and lymphadenopathy. There is no specific diagnostic test for IgG4-RD thoracic involvement, which may mimic malignancy or vasculitis. Therefore, a cautious approach is needed to make an accurate diagnosis: a search for extra-thoracic manifestations, elevated serum IgG4 levels, circulating levels of plasmablasts and pathologic evidence of disease is warranted. Although very suggestive, neither the presence of a polyclonal IgG4 lymphoplasmacytic infiltrate, storiform fibrosis or obliterative phlebitis are sufficient to confirm the histological diagnosis. Steroids are recommended as first-line therapy. Rituximab or disease-modifying antirheumatic drugs may be used in relapsed or rare cases of steroid-refractory disease. In this review, we summarize current knowledge regarding the pathophysiology, epidemiology, diagnostic modalities (clinical-biological-imaging-histopathology) and treatment of IgG4-RD thoracic involvement.

Multidisciplinary diagnosis and management of inflammatory aortic aneurysms

BACKGROUND

Inflammatory abdominal aortic aneurysms (IAAAs) are a variant involving a distinct immunoinflammatory process, with nearly one half believed to be associated with IgG4-related disease (IgG4-RD).

METHODS

MEDLINE and Google Scholar searches were conducted for English-language publications relevant to inflammatory aortic aneurysms from January 1970 onward. The search terms included inflammatory aortic aneurysms, aortitis, periaortitis, IgG4-related disease, and retroperitoneal fibrosis. Relevant studies were selected for review based on their relevance.

RESULTS

Morphologically, IAAAs are characterized by a thickened aneurysm wall often displaying contrast enhancement and elevated metabolic activity on fluorine-18 fluorodeoxyglucose-positron emission tomography imaging. A strong association exists with perianeurysmal and retroperitoneal fibrosis. Although the rupture risk appears lower with IAAAs than with noninflammatory abdominal aortic aneurysms (AAAs), the currently recommended diameter threshold for operative management is the same. Open repair has been associated with increased morbidity compared with noninflammatory AAAs, and a retroperitoneal approach or minimal dissection transperitoneal approach has been recommended to avoid duodenal and retroperitoneal structural injuries. Endovascular aneurysm repair has been increasingly used, especially for patients unfit for open surgery. It is important to exclude an infectious etiology before the initiation of immunosuppressive therapy or operative repair. Multimodality imaging follow-up is critical to monitor disease activity and secondary involvement of retroperitoneal structures by the associated fibrotic process. Maintenance of immunosuppressive therapy will be needed postoperatively for most patients with active systemic disease, especially those with IgG4-RD and those with persistent symptoms. Additional interventions aimed at ureteral decompression could also be required, and lifelong follow-up is mandatory.

CONCLUSIONS

Preoperative multimodality imaging is a diagnostic cornerstone for assessment of the disease extent and activity. IgG4-RD is an increasingly recognized category of IAAAs, with implications for tailoring adjunctive medical therapy. Open surgical repair remains the procedure of choice, although endovascular aneurysm repair is increasingly being offered. Maintenance immunosuppressive therapy can be offered according to the disease activity as assessed by follow-up imaging studies.

Clinical and Serological Features in Latin American IgG4-Related Disease Patients Differ According to Sex, Ethnicity, and Clinical Phenotype

BACKGROUND/OBJECTIVE

Data on IgG4-related disease (IgG4-RD) come almost exclusively from cohorts from Asia, Europe, and North America. We conducted this study to describe the clinical presentation, phenotype distribution, and association with sex, ethnicity, and serological markers in a large cohort of Latin American patients with IgG4-RD.

METHODS

We performed a multicenter medical records review study including 184 Latin American IgG4-RD patients. We assigned patients to clinical phenotypes: group 1 (pancreato-hepato-biliary), group 2 (retroperitoneal/aortic), group 3 (head and neck-limited), group 4 (Mikulicz/systemic), and group 5 (undefined). We focused the analysis on how sex, ethnicity, and clinical phenotype may influence the clinical and serological presentation.

RESULTS

The mean age was 50.8 ± 15 years. Men and women were equally affected (52.2% vs 48.8%). Fifty-four patients (29.3%) were assigned to group 1, 21 (11.4%) to group 2, 57 (30.9%) to group 3, 32 (17.4%) to group 4, and 20 (10.8%) to group 5. Male sex was associated with biliary tract (odds ratio [OR], 3.4; 95% confidence interval [CI], 1.36-8.26), kidney (OR, 3.4; 95% CI, 1.28-9.25), and retroperitoneal involvement (OR, 5.3; 95% CI, 1.45-20). Amerindian patients presented more frequently with atopy history and gallbladder involvement. Group 3 had a female predominance.

CONCLUSIONS

Latin American patients with IgG4-RD were younger, and men and women were equally affected compared with White and Asian cohorts. They belonged more commonly to group 1 and group 3. Retroperitoneal and aortic involvement was infrequent. Clinical and serological features differed according to sex, ethnicity, and clinical phenotype.

The role of PET/CT in large vessel vasculitis and related disorders: diagnosis, extent evaluation and assessment of therapy response

Large vessel vasculitides (LVV) are defined as chronic inflammatory disorders that affect the arteries with two major variants being distinguished: giant cell arteritis (GCA) and Takayasu's arteritis (TAK). These often present with nonspecific constitutional symptoms which makes an accurate diagnosis often challenging. Nevertheless, timely diagnosis is of utmost importance to initiate treatment and to avoid potential life-threatening complications. [¹⁸F]FDG-PET/CT is nowadays widely accepted as useful tool to aid in the diagnosis of large vessel vasculitis. However, its role to monitor disease activity and to predict disease relapse during follow-up is less obvious since vascular [¹⁸F]FDG uptake can be detected in the absence of clinical or biochemical signs of disease activity. In addition to the two major variants, [¹⁸F]FDG-PET/CT has shown promise in (peri-)aortitis and related disorders. This article aims to provide an update on the current knowledge and limitations of [¹⁸F]FDG-PET/CT for the diagnosis and assessment of treatment response in LVV. Furthermore, other radiopharmaceuticals targeting key components of the vascular immune system are being discussed which could provide an interesting alternative to image vascular inflammation in LVV.

Inflammatory Diseases of the Aorta: JACC Focus Seminar, Part 2

Inflammatory aortitis is most often caused by large vessel vasculitis (LVV), including giant cell arteritis, Takayasu's arteritis, immunoglobulin G4-related aortitis, and isolated aortitis. There are distinct differences in the clinical presentation, imaging findings, and natural history of LVV that are important for the cardiovascular provider to know. If possible, histopathologic specimens should be obtained to aide in accurate diagnosis and management of LVV. In most cases, corticosteroids are utilized in the acute phase, with the addition of steroid-sparing agents to achieve disease remission while sparing corticosteroid toxic effects. Endovascular and surgical procedures have been described with success but should be delayed until disease control is achieved whenever possible. Long-term management should include regular follow-up with rheumatology and surveillance imaging for sequelae of LVV.

The levels of IL-1β and soluble IL-1 receptors in patients with IgG4-related periaortitis/periarteritis

PURPOSE

IgG4-related disease (IgG4-RD) is a chronic fibrotic inflammatory and an immune-mediated disease characterized by high serum IgG4 concentration and IgG4-bearing plasma cell infiltration in affected organs. IgG4-related periaortitis/periarteritis is a recently identified disease entity in IgG4-RD that affects the cardiovascular system, and its pathogenesis and characteristics remain unclear. The inflammatory cytokine IL-1β is involved in a variety of cellular activities including inflammation, fibrosis, and angiogenesis. The present study compared the levels of the inflammatory cytokine IL-1β and two soluble IL-1 receptors, IL-1R1 and IL-1R2, between IgG4-RD patients with and without IgG4-related periaortitis/periarteritis.

METHODS

The patients with IgG4-related periaortitis/periarteritis (n ​= ​38), those without (n ​= ​66) and healthy (n ​= ​33) were recruited to measure cytokines of IL-1β and soluble receptors (sIL-1R1 and sIL-1R2) in sera by ELISA assay.

RESULTS

Serum IgG4 was significantly higher in patients with periaortitis/periarteritis compared to non-periaortitis/periarteritis (p ​= ​0.0074), while serum IL-1β was significantly lower in patients with periaortitis/periarteritis (p ​= ​0.00037). The three groups did not show significant difference in sIL1-R1, while sIL-1R2 in the periaortitis/periarteritis and healthy group was higher than in the group without periaortitis/periarteritis (p ​= ​0.00001).

CONCLUSIONS

The characteristic changes in IL-1β, sIL-1R1, and sIL-1R2 levels in IgG4-RD patients with and without IgG4-related periaortitis/periarteritis may indicate an active phase of the inflammatory process in these diseases.

Occult myocardial infarction due to an unusual cause: a case report of periarteritis involving the left coronary artery

Background

Immunoglobulin G4-related disease (IgG4-RD) is an immune-mediated condition that affects multiple organs and systems.

Case summary

A 51-year-old man with a history of occult left apex myocardial infarction diagnosed based on electrocardiographic and echocardiographic findings underwent coronary computed tomography (CT) angiography for the evaluation of coronary artery disease; the findings revealed a soft-tissue mass that surrounded the aortic root and the distal portion of the left coronary artery. The mass was considered an inflammatory lesion; high glucose uptake on positron emission tomography/CT supported this assumption. Coronary angiography revealed 80% stenosis of the distal portion of the left anterior descending artery, which corresponded with the infarction. Intravascular ultrasound revealed hypoechoic regions outside the lumina of the stenotic segment. Based on these findings, IgG4-related periaortitis/periarteritis was suspected; the patient was accordingly treated with oral prednisone and methotrexate. At the 3-month follow-up, the periaortic mass had slightly reduced in size.

Discussion

Identification and diagnosis of IgG4-related cardiovascular disease are challenging; cases with localized coronary artery involvement may be misdiagnosed as atherosclerotic coronary artery disease. Although imaging techniques, including intracoronary imaging, may aid in differential diagnosis, their sensitivity and specificity still warrant further studies. Practical criteria that facilitate diagnosis and a better understanding of the disease are required.

IL1R1 gene variants associate with disease susceptibility to IgG4-related periaortitis/periarteritis in IgG4-related disease

BACKGROUND

IgG4-related disease (IgG4-RD) is an immune-mediated disorder characterized by high serum IgG4 concentration and IgG4-bearing plasma cell infiltration in affected organs. IgG4-related periaortitis/periarteritis is a recently identified disease entity in IgG4-RD that affects the cardiovascular system. Since the genetic factors related to disease onset are unclear, we examined the genetic associations with IgG4-related periaortitis/periarteritis susceptibility.

METHODS

A small scale of genome-wide association analysis identified that interleukin 1 receptor type 1 (IL1R1) gene variants were correlated with the development of IgG4-related periaortitis/periarteritis in 75 patients with IgG4-RD. Accordingly, 8 single nucleotide polymorphisms (SNPs) in the IL1R1 gene were selected and genotyped in 124 patients with IgG4-RD (43 with periaortitis/periarteritis and 81 without periaortitis/periarteritis) and 344 healthy subjects.

RESULTS

The minor allele frequencies of 6 SNPs (rs2287049, rs3917273, rs2160227, rs951192, rs3917318, rs7582198) were significantly increased in IgG4-related periaortitis/periarteritis patients compared with those without periaortitis/periarteritis (corrected P < 0.05). In addition, the frequency of the AGAAA haplotype, comprised of 5 SNPs (rs3917273, rs2160227, rs951192, rs3917318, rs7582198), was significantly higher in patients with periaortitis/periarteritis (OR = 2.41, 95% CI:1.42-4.10).

CONCLUSION

Our findings indicated that IL1R1 genetic polymorphisms contributed to IgG4-related periaortitis/periarteritis and the possibility of certain genetic factors influencing the risk of specific IgG4-RD manifestations.

Retroperitoneal fibrosis, a rare entity with urorenal and vascular subtypes - preliminary data

Introduction

Retroperitoneal fibrosis (RPF) is a rare disease associated with the formation of hard inflammatory and fibrous tissue in the retroperitoneum. Taking into consideration the fact that RPF is a rare disease with different subtypes, we compared the basal clinical and biochemical characteristics of the vascular and urorenal subtypes.

Patients and methods

From January 2005 until December 2021, 27 patients were identified as vascular subtype (18 males) and 11 as urorenal subtype (9 males).

Results

Patients with a primary urorenal origin had significantly worse kidney function as reflected by serum creatinine and eGFR (both p < 0.001); they also had higher serum cholesterol (p < 0.01). Hypertension, diabetes, hyperlipidemia and nicotinism were significantly more prevalent in vascular subtype (all p < 0.001).

Conclusion

Vascular subtype is more prevalent in our study with more cardiovascular risk factor present. Due to the diversity of symptoms, diagnosis of RPF becomes a challenge for specialists as well as therapy.

A case report of recurrent acute myocardial infarction and cardiac arrest due to aortic dissection secondary to IgG4-related aortitis

Occlusion of the right coronary artery is a relatively rare complication of type A aortic dissection and an example of type 2 myocardial infarction (MI) as well but when it occurs, it may have a fatal result for the patient. Aortic pseudoaneurysms are local type A dissections with a restricted extent in which the majority of the aortic wall has been breached and luminal blood is held in only by a thin rim of the remaining wall, mainly purely the adventitia. They typically occur from iatrogenic trauma by interventional procedures or previous cardiac surgery. We present a case of a 56-years-old patient who suffered an acute functional MI due to such pseudoaneurysm formed in the context of an undiagnosed aortitis. The etiology remained unclear until the surgical aortic prosthesis was deemed necessary, finding chronic IgG4 infiltrates in the aortic tissue. To our knowledge, this is the first case of IgG4-related aortitis causing functional MI and cardiogenic shock.

Mimickers of Large Vessel Giant Cell Arteritis

Giant cell arteritis (GCA) is a large-vessel granulomatous vasculitis occurring in patients over 50-year-old. Diagnosis can be challenging because there is no specific biological test or other diagnoses to consider. Two main phenotypes of GCA are distinguished and can be associated. First, cranial GCA, whose diagnosis is usually confirmed by the evidence of a non-necrotizing granulomatous panarteritis on temporal artery biopsy. Second, large-vessel GCA, whose related symptoms are less specific (fever, asthenia, and weight loss) and for which other diagnoses must be implemented if there is neither cephalic GCA nor associated polymyalgia rheumatica (PMR) features chronic infection (tuberculosis, Coxiella burnetti), IgG4-related disease, Erdheim Chester disease, and other primary vasculitis (Behçet disease, relapsing polychondritis, or VEXAS syndrome). Herein, we propose a review of the main differential diagnoses to be considered regarding large vessel vasculitis.

How to mimic a type A intramural hematoma: A case of IgG4-related aortitis associated with cerebral hemorrhage

IgG4-related aortitis is an inflammatory condition of the aorta, characterized by aortic wall thickening and periaortic soft-tissue involvement. Therefore, this condition can mimic an aortic intramural hematoma (IMH), due to similar radiological findings. We hereby report the case of an IgG4-related aortitis misdiagnosed as an IMH, associated with cerebral hemorrhage, possibly due to cerebral vascular system involvement.

A rare case of sudden death due to IgG4-related giant coronary artery aneurysms

Immunoglobulin G4-related disease (IgG4-RD) is a fibro-inflammatory condition that can affect many organs, either simultaneously or metachronously. In recent years, IgG4-related vascular complications of larger arteries such as the aorta and iliac arteries have been increasingly identified. Among vascular complications, coronary artery involvement in the forms of either periarteritis or coronary artery aneurysms (CAAs) has also been reported; however, are very rare in comparison. This case report presents a rare case of a sudden death due to occlusive thrombosis of IgG4-related giant CAAs measuring up to 10 cm in diameter, demonstrates their possible clinical progression, and shows how they can distort normal anatomy which may then pose challenges in the interpretation of postmortem-computed tomography scans. It also briefly discusses the diagnosis of IgG4-RD in arteries, both clinically and in the postmortem setting.

Aortitis: an update

PURPOSE OF REVIEW

Aortitis is the inflammation of the aorta due to various causes. Clinical presentations vary as well as the imaging findings. Exact pathogenetic mechanisms or triggering factors, as well as the best diagnostic and monitoring modalities and treatment strategies, are yet to be elucidated. We reviewed recent studies in aortitis and associated diseases.

RECENT FINDINGS

Multiple cohort studies reporting long-term outcomes in patients with noninfectious aortitis were recently published. Comparative features of isolated aortitis were described. Six angiographic clusters for giant cell arteritis and Takayasu have been identified. New classification criteria have been proposed for IgG4-related disease by a data-driven method. The ultrasonographic slope sign and a halo score were described as specific imaging parameters in giant cell arteritis. The promising role of PET-computed tomography, not only in the diagnosis of aortitis but also in monitoring disease activity, has been noted. Results of in-vitro studies on Janus kinase (JAK)/signal transducers and activators of transcription and mammalian target of rapamycin (mTOR) pathways, comparative studies with leflunomide as an induction therapy, and a long-term follow-up study with tocilizumab may contribute to the management of Takayasu arteritis.

SUMMARY

An impressive number of studies have addressed aortitis in recent years. However, there still is a lack of robust data on causes, monitoring disease activity by imaging and biomarkers, and drugs providing steroid-free remission in noninfectious aortitis.

Differences in clinical characteristics of IgG4-related disease across age groups: a prospective study of 737 patients

OBJECTIVE

The aim of this study was to compare the clinical characteristics of IgG4-related disease (IgG4-RD) among different age groups.

METHODS

We conducted a prospective study of 737 patients who were newly diagnosed with IgG4-RD and compared detailed demographic features, organ involvements, laboratory tests, treatments and outcomes across age groups. The patients were divided into five groups according to their age at diagnosis: ≤39, 40-49, 50-59, 60-69 and ≥70 years. The clinical characteristics of paediatric patients were also described.

RESULTS

Sex ratio, disease duration, allergy history and clinical symptoms were significantly different across age groups. Besides, the proportions of superficial organ involvement (lacrimal gland and sinus) decreased with age, while the proportions of internal organ involvement (pancreas, biliary tract, retroperitoneal tissue, lung and prostate) increased with age, which was more prominent in male patients. Mikulicz's disease was the most common manifestation (70%) in paediatric IgG4-RD patients. Multiple Cox analysis identified that age ≤56 years at diagnosis was an independent risk factor of relapse.

CONCLUSION

We revealed the impact of age on clinical characteristics of IgG4-RD, which indicated that different management might be required among different age groups.

Multifocal IgG4-related aortitis and periaortitis simulating aortic dissection

Immunoglobulin G4-related aortitis (IgG4-RA) is histologically characterized by the infiltration of IgG4 positive plasma cells and fibrosis in systemic organs and the elevation of serum IgG4 levels. The cardiovascular system is commonly involved with various possible presentations such as aortitis, arteritis, periaortitis, periarteritis, and inflammatory aneurysm. We present a case of a 48-year-old male without known previous medical history, admitted for further workup of long-standing chest pain and shortness of breath with suspected aortic dissection on initial assessment. Investigation with computed tomography angiography (CTA) and magnetic resonance angiography (MRA) indicated severe thoracic and abdominal aortoarteritis associated with an ascending thoracic aortic aneurysm, which was confirmed to be IgG4-RA on histopathologic analysis. Thoracic and abdominal IgG4-RA clinical and radiological presentation may simulate other causes of acute aortic syndrome such as aortic dissection, atherosclerotic aneurysm and inflammatory conditions. Accurate recognition of IgG4-RA diagnostic imaging features are essential for early diagnosis and treatment surveillance.

Marfan syndrome resulting from a rare pathogenic FBN1 variant, ascertained through a proband with IgG4-related arteriopathy

A 57-year-old man with a family history of aortic aneurysm was found, during assessment of unexplained fever, to have an infrarenal aortic aneurysm requiring immediate repair. Dilatation of popliteal and iliac arteries was also present. Progressive aortic root dilatation with aortic regurgitation was documented from 70 years leading to valve-sparing aortic root replacement at 77 years, at which time genetic studies identified a likely pathogenic FBN1 missense variant c.6916C > T (p.Arg2306Cys) in exon 56. The proband's lenses were normally positioned and the Marfan syndrome (MFS) systemic score was 0/20. Cascade genetic testing identified 15 other family members with the FBN1 variant, several of whom had unsuspected aortic root dilatation; none had ectopia lentis or MFS systemic score ≥ 7. Segregation analysis resulted in reclassification of the FBN1 variant as pathogenic. The combination of thoracic aortic aneurysm and dissection (TAAD) and a pathogenic FBN1 variant in multiple family members allowed a diagnosis of MFS using the revised Ghent criteria. At 82 years, the proband's presenting abdominal aortic aneurysm was diagnosed retrospectively to have resulted from IgG4-related inflammatory aortopathy.

IgG4-related disease: a contemporary review

Background/aim

Immunoglobulin G4-related disease (IgG4-RD), is an immune-mediated fibroinflammatory condition, which may involve multiple organs and mostly presents with high serum IgG4 levels and specific histopathological characteristics. As IgG4-RD is a relatively new entity the etiology, prevalence and epidemiologic knowledge is quite limited. Although involvement of almost all anatomical regions has been reported, the most commonly affected regions are pancreas, lacrimal glands, salivary glands, retroperitoneum, orbita, lymph nodes, kidney and lungs. Diagnosis is made with combined evaluation of clinical, radiological and histopathological findings. Typical histopathological features include storiform fibrosis, dense lymphoplasmacytic infiltrates and obliterative phlebitis. Its course is typically marked by remission and relapsing attacks and it may lead to fibrosis, destructive lesions in tissues and organ failure unless promptly treated. In the treatment of IgG4-RD, many approaches including surgical resection of tissues, systemic glucocorticoids, steroid-sparing immunosuppressive drugs, and biological agents are employed. Although association is not clear, malignancies are frequently reported in IgG4-RD patients. Therefore, it is prudent to monitor patients for the symptoms of malignant diseases.

Conclusion

In this review, recent advances in clinico-pathological characteristics, diagnosis, and treatment of IgG4–RD are discussed.

Vasculitis beyond aortitis in IgG4-related disease (IgG4-RD): case report and review of the literature

IgG4-related disease (IgG4-RD) can affect almost every tissue/organ. Vascular involvement in the setting of IgG4-RD is increasingly being recognized with most of the cases pertaining patients with aortitis and/or periaortitis with or without aneurysm formation. However, it is now evident that other vessels like iliac arteries, coronary arteries, carotids, and others can also be affected being often underdiagnosed. Vascular involvement is expressed as vessel wall thickening, while aneurysm formation is also occasionally seen. Although histopathological findings are the cornerstone in the diagnosis of IgG4-RD, imaging modalities like magnetic resonance imaging (MRI) and positron emission tomography (PET) are similarly important when vascular involvement occurs, helping in the mapping of the disease and in identifying other, more accessible to biopsy, affected organs. Inflammation markers like erythrocyte sedimentation rate and C-reactive protein have also been described in IgG4-RD patients with vascular involvement. Herein, we present a case of a middle-aged man with long-term high inflammation markers who eventually diagnosed with IgG4-RD after an ascending aorta aneurysm operation, while a subsequent comprehensive magnetic resonance angiography revealed also involvement of the abdominal aorta and the left subclavian and left common carotid. Moreover, we sought to review the current literature about medium- and large-vessel involvement, beyond the aorta, in patients with IgG4-RD.