IgG4-related cardiovascular disease. The emerging role of cardiovascular imaging

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 3.0 T 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 ± 6 v. 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.

Epicardial Space: Comprehensive Anatomy and Spectrum of Disease

The epicardial space (ES) is the anatomic region located between the myocardium and the pericardium. This space includes the visceral pericardium and the epicardial fat that contains the epicardial coronary arteries, cardiac veins, lymphatic channels, and nerves. The epicardial fat represents the main component of the ES. This fat deposit has been a focus of research in recent years owing to its properties and relationship with coronary gossypiboma plaque and atrial fibrillation. Although this region is sometimes forgotten, a broad spectrum of lesions can be found in the ES and can be divided into neoplastic and nonneoplastic categories. Epicardial neoplastic lesions include lipoma, paraganglioma, metastases, angiosarcoma, and lymphoma. Epicardial nonneoplastic lesions encompass inflammatory infiltrative disorders, such as immunoglobulin G4-related disease and Erdheim-Chester disease, along with hydatidosis, abscesses, coronary abnormalities, pseudoaneurysms, hematoma, lipomatosis, and gossypiboma. Initial imaging of epicardial lesions may be performed with echocardiography, but CT and cardiac MRI are the best imaging modalities to help characterize epicardial lesions. Due to the nonspecific onset of signs and symptoms, the clinical history of a patient can play a crucial role in the diagnosis. A history of malignancy, multisystem diseases, prior trauma, myocardial infarction, or cardiac surgery can help narrow the differential diagnosis. The diagnostic approach to epicardial lesions should be made on the basis of the specific location, characteristic imaging features, and clinical background. ©RSNA, 2024 Test Your Knowledge questions for this article are available in the supplemental material.

Semi-quantitative indices of 2-[18F]FDG PET/CT in assessing cardiovascular and non-cardiovascular manifestations of IgG4-related disease and treatment response

BACKGROUND

IgG4-related disease (IgG4-RD) is a heterogeneous autoimmune disorder characterised by inflammatory lesions. Diagnostic imaging, such as 2-[¹⁸F]FDG PET/CT, is critical in evaluation of the disease, especially for potentially lethal cardiovascular manifestations. This retrospective study examines the usefulness of semi-quantitative parameters of 2-[¹⁸F]FDG PET/CT in monitoring IgG4-RD in patients with and without cardiovascular manifestations.

METHODS

Patients diagnosed with IgG4-RD who underwent a 2-[¹⁸F]FDG PET/CT scan were identified and classified based on presence or absence of cardiovascular disease. Clinical and laboratory data were extracted and compared to three 2-[¹⁸F]FDG PET/CT semi-quantitative parameters: maximum standardised uptake value (SUVmax), metabolic tumour volume (MTV), and total lesion glycolysis (TLG). Tissue-to-background blood (TBR) values were also evaluated for cardiovascular manifestations. These data were also compared in patients before and after receiving immunosuppressive therapy.

RESULTS

Forty-six patients identified were divided into an eight member subgroup of patients with cardiovascular manifestations, and a thirty-eight member subgroup of patients without. Patients with cardiovascular lesions were most frequently identified incidentally on imaging evaluation for other diseases (37.5%), with none presenting with chest pain or other cardiovascular symptoms. Ten patients with pre-treatment and post-treatment 2-[¹⁸F]FDG PET/CT scans demonstrated significant decreases in all semi-quantitative parameters, with no significant decrease in total IgG or ESR. The decrease in SUVmax, MTV, TLG following therapy was replicated in patients with and without cardiovascular manifestations.

CONCLUSION

2-[¹⁸F]FDG PET/CT is an important investigation to determine all sites of involvement in this multisystemic disease and to rule out life-threatening cardiovascular manifestations even in the absence of symptoms. Semi-quantitative parameters such as SUVmax, MTV, TLG, and TBR are useful in assessing treatment response in patients. There are no serological substitutes that can quantify the extent of disease involvement like 2-[¹⁸F]FDG PET/CT.

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.

Vascular/perivascular inflammation in IgG4-related disease

BACKGROUND

Immunoglobulin G4-related disease (IgG4-RD) is characterized by the infiltration of IgG4-positive plasma cells and fibrosclerotic inflammation in multiple organs. Although vascular complications are present in some patients with IgG4-RD, vascular and/or perivascular inflammatory activity compared to control subjects remains unknown. This study sought to investigate vascular/perivascular inflammation in IgG4-RD patients compared to control subjects using 18F-fluorodeoxyglucose-positron emission tomography combined with computed tomography (FDG-PET/CT).

METHODS

We examined 37 consecutive patients diagnosed as IgG4-RD (29 males, mean age of 64.3 ± 8.3 years old), who underwent FDG-PET/CT. Thirty-seven age- and gender-matched subjects without IgG4-RD were employed as controls. Vascular/perivascular inflammation was quantified by blood-normalized standardized uptake value, known as a target-to-background ratio (TBR).

RESULTS

All IgG4-RD patients presented with multiple region involvements. Twelve (32.4%) of the IgG4-RD patients had vascular complications, all of which appeared in the abdominal aorta. IgG4-RD patients had significantly higher TBR values in the descending aorta, abdominal aorta, and common iliac artery than control subjects. Also, IgG4-RD patients with vascular complication exhibited higher TBR values in the infra-renal aorta and common iliac artery than those without vascular complication.

CONCLUSIONS

We found that vascular FDG activity is significantly elevated in IgG4-RD patients regardless of vascular complication than control subjects. FDG-PET/CT is a useful modality for assessing vascular/perivascular inflammation, which may contribute vascular complication in IgG4-RD patients.

Role of Cardiovascular Magnetic Resonance to Assess Cardiovascular Inflammation

Cardiovascular inflammatory diseases still represent a challenge for physicians. Inflammatory cardiomyopathy, pericarditis, and large vessels vasculitis can clinically mimic a wide spectrum of diseases. While the underlying etiologies are varied, the common physio-pathological process is characterized by vasodilation, exudation, leukocytes infiltration, cell damage, and fibrosis. Cardiovascular magnetic resonance (CMR) allows the visualization of some of these diagnostic targets. CMR provides not only morphological and functional assessment but also tissue catheterization revealing edema, hyperemia, tissue injury, and reparative fibrosis through T2 weighted images, early and late gadolinium enhancement, and parametric mapping techniques. Recent developments showed the role of CMR in the identification of ongoing inflammation also in other CV diseases like myocardial infarction, atherosclerosis, arrhythmogenic and hypertrophic cardiomyopathy. Future developments of CMR, aiming at the specific assessment of immune cell infiltration, will give deeper insight into cardiovascular inflammatory diseases.

Diagnostic Dilemma: Cardiorenal Syndrome As an Unusual Presentation of IgG4-Related Disease

IgG4-related kidney disease (IgG4 RKD) is a rare clinical entity characterized by lymphoplasmacytic infiltration rich in IgG4-positive plasma cells along with fibrosis affecting several organs. Tubulointerstitial nephritis is commonly the predominant finding on kidney biopsy. Our patient was admitted with a provisional diagnosis of cardiorenal syndrome of unknown etiology. The patient was dialysis dependent for around 45 days following which kidney biopsy revealed features of acute tubulointerstitial nephritis (ATIN) with IgG4-positive plasma cells and no glomerular involvement. Positron emission tomography-computed tomography was supportive of findings of sialadenitis along with myocarditis. Our patient responded to treatment with steroids with definitive improvement in both renal and cardiac functions. This case highlights the importance of IgG4 RKD as an important differential in patients with ATIN presenting as a clinical syndrome.

Left Ventricular Dysfunction Caused by IgG4-related Small Intramural Coronary Periarteritis

IgG4-related disease (IgG4-RD) is a systemic autoimmune disorder known to affect multiple organs. However, IgG4-RD rarely affects the myocardium. We herein report a case of left ventricular dysfunction due to cardiac involvement of IgG4-RD.

Kardiale Beteiligungen bei rheumatologischen Erkrankungen – eine Übersicht

Rheumatische Erkrankungen gehen mit einem erhöhten kardiovaskulären Risiko einher, können darüber hinaus jedoch im Bereich aller kardialen Strukturen zu spezifischen entzündlichen Veränderungen führen. Symptome wie Dyspnoe, Tachykardie und Leistungsminderung stehen patientenseitig im Vordergrund, wenngleich kardiale Beteiligungen nicht selten asymptomatisch verlaufen. Diagnostisch werden neben der klinischen Untersuchung und laborchemischen Verfahren apparative Diagnostiken wie Echokardiografie und Kardio-MRT aber auch invasive Verfahren wie die Herzkatheteruntersuchung und Myokardbiopsie angewendet. Die Therapie richtet sich nach der Grunderkrankung, den betroffenen kardialen Strukturen und reicht von einer medikamentösen Therapie bis zu interventionell-operativem Vorgehen.

Multisystem IgG4-related disease involving the abdomen and coronary arteries and causing chronic abdominal pain

IgG4-related disease was originally discovered in patients with autoimmune pancreatitis accompanied by elevated serum IgG4 levels and has subsequently been described in almost every organ system. IgG4-related disease presents with a variety of symptoms according to the organ affected and may be accompanied by serious complications such as organ dysfunction associated with IgG4-positive cell proliferation. We report a case of IgG4-related abdominal disease in a patient who also had involvement of the coronary artery.

[Immunoglobulin G4-Related Disease in the Thorax: Imaging Findings and Differential Diagnosis]

Immunoglobulin G4-related disease (IgG4-RD) is a chronic inflammatory condition involving multiple organs, including the salivary or lacrimal glands, orbit, pancreas, bile duct, liver, kidney, retroperitoneum, aorta, lung, and lymph nodes. It is histologically characterized by tissue infiltration with lymphocytes and IgG4-secreting plasma cells, storiform fibrosis, and obliterative phlebitis. In the thoracic involvement of IgG4-RD, mediastinal lymphadenopathy and perilymphangitic interstitial thickening of the lung are the most common findings. Peribronchovascular and septal thickening and paravertebral band-like soft tissue are characteristic findings of IgG4-RD. Other findings include pulmonary nodules or masses, ground-glass opacity, alveolar interstitial thickening, pleural effusion or thickening, mass in the chest wall or mediastinum, and arteritis involving the aorta and coronary artery. Radiologic differential diagnosis of various malignancies, infections, and inflammatory conditions is needed. In this review, we describe the imaging findings of IgG4-RD and the radiologic differential diagnoses in the thorax.

Coronary (peri)-arteritis in patients with IgG4-related disease: A case series from the Central Anatolia Region of Turkey

OBJECTIVE

Immunoglobulin G4-related disease (IgG4-RD) is a newly recognized fibro-inflammatory disease which affects many systems, as well as the cardiovascular system. Identifying the coronary involvement like periaortitis, coronary periarteritis and pericarditis is important, as they often cause unfavorable outcomes.

METHODS

Eighty-one patients with IgG4-RD were retrospectively evaluated for symptomatic coronary artery involvement from Hacettepe University Vasculitis Research Center (HUVAC) database. The demographic, laboratory, radiologic and clinical characteristics of the patients were assessed.

RESULTS

Among 81 patients with IgG4-RD, 6 patients (M/F:5/1) had coronary artery involvement. The patients' median age was 57 and serum IgG4 levels were above normal except for one case. All patients with coronary arteritis revealed an increased coronary vessel wall thickening and stenotic lesions. The coronary aneurysm and pericarditis were observed in half of the patients. Immunosuppressive treatments were given to all the patients and most of them followed in stable condition.

CONCLUSION

Coronary arteritis is a rare but notable manifestation of IgG4-RD. Although coronary periarteritis can cause significant morbidity and mortality, it seems better results can be achieved with early diagnosis and treatment.

Spinal Bony Involvement of IgG4-related Disease Treated by a Spondylectomy

Immunoglobulin G4-related sclerosing disease (IgG4RD) is an emerging immune-mediated fibro-inflammatory disorder which can involve any organ. We describe the first IgG4-RD spondylitis treated with total en-bloc spondylectomy (TES). A 55-year-old man presented with back pain. Magnetic resonance imaging (MRI) of the thoracic spine revealed a pathologic compression fracture on T11 vertebral body and both pedicles suggestive of primary bone tumor or bone metastasis. We conducted TES of T11, because we could not exclude the possibility of primary bone tumor including giant cell tumor. Immunohistochemical examination of the pathology specimens from pleura around the pedicle demonstrated diffuse infiltration of IgG4-bearing plasma cells. Six weeks later from the surgery, a delayed serologic test was done and his serum IgG4 concentration was 45 mg/dL. The final diagnosis was probable IgG4RD on the basis of serological, imaging, histopathological findings. After 6 weeks of oral prednisolone treatment, patient's back pain improved dramatically. IgG4RD is very rare systemic disease and its paraspinal soft tissue like pleura involvement with vertebra body invasion was absent until now. Our experience indicated that surrounding soft tissue biopsy would be helpful when a percutaneous vertebra bone biopsy mismatched with the image studies, even though vertebra body was main pathological lesion considering the possibility of IgG4RD.

The enigmatic immunoglobulin G4-related disease and its varied cardiovascular manifestations

Immunoglobulin G4-related disease (IgG4-RD) is a systemic fibroinflammatory disease characterised by multiorgan lymphoplasmacytic infiltration, obliterative phlebitis and storiform fibrosis. It can be associated with cardiovascular pathology. The objective of this narrative review is to summarise the published literature on cardiovascular manifestations of IgG4-RD and to provide a basis for diagnosis and management of the condition by the practising cardiologist.We propose the following categorisations of cardiovascular IgG4-RD: aortitis, medium-vessel arteritis, pulmonary vascular disease, phlebitis, valvulopathy, pericarditis, myocardial disease and antineutrophilic cytoplasmic antibody-associated vasculitis. We also review herein developments in radiological diagnosis and reported medical and surgical therapies. Cardiovascular lesions frequently require procedural and/or surgical interventions, such as aortic aneurysm repair and valve replacement. IgG4-RD of the cardiovascular system results in serious complications that can be missed if not evaluated aggressively. These are likely underdiagnosed, as clinical presentations frequently mimic cardiovascular disease due to more common aetiologies (myocardial infarction, abdominal aortic aneurysm and so on). While systemic corticosteroids are the mainstay of IgG4-RD treatment, biological and disease-modifying agents are becoming more widely used. Cardiologists should be aware of cardiovascular IgG4-RD as a differential diagnosis, and understand the roles of corticosteroids, disease-modifying agents and biologicals, as well as their integration with surgical approaches. There are several knowledge gaps, including diagnosis, risk factors, pathogenesis and appropriate management in Ig4-RD of the cardiovascular system. Areas lacking well-conducted randomized trials include safety of steroids in the setting of vascular aneurysms and the role of disease-modifying drugs and biological agents in patients with established cardiovascular complications of this multifaceted enigmatic disease.

Overview of IgG4-related aortitis and periaortitis. A decade since their first description

Aortic involvement is relatively common in the context of IgG4-related disease (IgG4-RD). It includes IgG4-aortitis, and IgG4-(chronic) periaortitis (IgG4-CP). The latter overlaps with IgG4-retroperitoneal fibrosis (IgG4-RPF). Aortic wall thickening which characterizes these entities along with the presence of periaortic tissue in IgG4-CP, are often accompanied by aortic aneurysms, which belong to the group of the so-called inflammatory aneurysms. Both the thoracic and abdominal aorta can be affected. Aortitis appears to involve more often the former, while the opposite is the case for IgG4-CP. There is a lack of definitions and different classification criteria have been used to describe these entities. This report provides an overview on the current evidence of aortic involvement in IgG4-RD. It discusses the clinical, epidemiologic, serologic and histopathologic characteristics, as well as the imaging techniques used for their diagnosis and the therapeutic options and treatment outcomes. The differential diagnosis and underlying pathogenetic mechanisms are also discussed.

New cardiac manifestation of IgG4-related disease: a case report

(IgG4-RD) is a systemic fibro-inflammatory immune-mediated disease, which has been defined in the past few years. IgG4-RD affects various organs and leads to a variety of clinical manifestations. As it is a relatively newly defined entity, new manifestations are now being recognised and reported. We describe a case involving the cardiovascular system.

Constrictive Pericarditis Caused by IgG4-Related Disease Requiring Pericardiectomy After Partial Response to Corticosteroids

Immunoglobulin G4-related disease is a systemic fibroinflammatory disease; pericardial involvement has occasionally been reported in publications. A 79-year-old man with biopsy-proven immunoglobulin G4-related disease with pleural involvement was admitted in acute heart failure, with imaging and hemodynamic studies consistent with constrictive pericarditis. He was treated with corticosteroids for 2 months with partial response manifest by decreases in pericardial thickening and immunoglobulin G4 levels. However, persistent constriction required pericardiectomy, leading to significant symptomatic improvement. (Level of Difficulty: Intermediate.).

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.

Clinical Utility of Diffusion-weighted Whole-body Magnetic Resonance Imaging with Background Body Signal Suppression for Assessing and Monitoring IgG4-related Disease

A 77-year-old man with symptoms of chest pain was diagnosed with immunoglobulin G4 (IgG4)-related disease. Fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) revealed an intense uptake in the submandibular gland, lymph nodes and abdominal aortic wall. Diffusion-weighted imaging with background body signal suppression (DWIBS) revealed signal enhancements at the same location as those of the FDG-PET/CT findings. The DWIBS signal intensity decreased after steroid treatment, so we decreased the steroid dosage. Relapse did not occur. DWIBS makes it possible to adjust the medicine dosage while confirming the therapeutic effects and will likely be a useful method for monitoring IgG4-related disease.

A comparison of the features of fluorine-18 fluorodeoxyglucose-positron emission tomography (FDG-PET) between IgG4-related disease with bilateral hilar lymphadenopathy and sarcoidosis

We aimed to show the differentiation of the degree and distribution on Fluorine-18 fluorodeoxyglucose-positron emission tomography (FDG-PET) between patients with immunoglobulin G4-related disease (IgG4-RD) and sarcoidosis, though both diseases frequently show bilateral hilar lymphadenopathy (BHL). The clinical records were retrospectively reviewed in 25 patients with IgG4-RD with BHL and 15 patients with sarcoidosis (stage I–II) diagnosed at Shinshu University Hospital. All patients underwent FDG-PET at Aizawa Hospital from January 2004 to December 2015. The FDG accumulation pattern and maximum standardized uptake value (SUVmax) of the hilar lymph nodes were compared between the two groups. The IgG4-RD group (21 men; median age 69 years) showed a significant male predominance and older age compared with the sarcoidosis group (3 men, median age 55.4 years). The IgG4-RD group showed a significantly higher incidence of FDG accumulation in the lachrymal gland, submandibular gland, pancreas, prostate and periurethral and periarterial regions compared with the sarcoidosis group. In contrast, the sarcoidosis group showed a significantly higher incidence of FDG accumulation in the supraclavicular and abdominal lymph nodes, muscle and soft tissues compared with the IgG4-RD group. Furthermore, the SUVmax of the hilar lymph nodes was significantly higher in the sarcoidosis group (median 7.20) than in the IgG4-RD group (median 4.20, p=0.002). In conclusion, significant differences were observed in the FDG accumulation patterns and SUVmax values of the hilar lymph nodes between IgG4-RD with BHL and sarcoidosis, although both diseases develop through the lymphatic routes of the lungs and are frequently associated with BHL.

IgG4-related disease: How to place it in the spectrum of immune-mediated and rheumatologic disorders?

IgG4-related disease (IgG4-RD) is an immune-mediated fibroinflammatory disorder that results from massive expansion of polyclonal IgG4-switched B and/or plasma cells. It can virtually affect all organs and its diagnosis relies on clinical, serological and histopathological criteria. The role of autoimmunity and adaptive immune system in IgG4-RD is reflected in plasmablast differentiation, germinal center formation and IgG4 production induced by CD4+ cells expressing CD40 ligand. IgG4-RD has been considered to be a Th2/Treg-driven disorder, but follicular helper T cells are important in driving the IgG subclass switch. Prompt clinical responses to rituximab, human leukocyte antigen (HLA) associations and the presence of autoantibodies also point to the importance of adaptive immune system. However, innate immunity may induce storiform fibrosis through T-cell independent responses as a consequence of toll-like receptors activation by microbe-and damage-associated molecular patterns, while macrophages and basophils also appear to have a significant role in IgG4-RD pathogenesis. Allergic mechanisms may drive IgG4-RD, but only a subgroup has elevated IgE serum levels and peripheral eosinophilia. Finally, the 2012 revised Chapel Hill Consensus Conference nomenclature pointed IgG4-RD as a cause of large-vessel vasculitis. This review aims to discuss how to place IgG4-RD in the spectrum of immune-mediated and rheumatologic disorders.

Cross-sectional pictorial review of IgG4-related disease

Immunoglobulin G4-related disease (IgG4-RD) is an autoimmune disorder characterized by the infiltration of one or more organs with IgG4-positive plasma cells resulting in inflammatory lesions and fibrosis. Although the pancreas is the most commonly affected organ, involvement of extrapancreatic organs is an increasingly recognized manifestation of the disease. Patients may be asymptomatic and serum IgG4 concentrations may be elevated or normal. Treatment consists of glucocorticosteroid treatment, with excellent response. A definitive diagnosis requires histopathology with imaging playing a key role in avoiding treatment delays. This pictorial review will focus on the most current knowledge regarding IgG4-RD including its common and less common manifestations and the roles of multidetector CT, MRI and ultrasound in the diagnosis and management of suspected IgG4-RD. Knowledge of the varied imaging findings of this multi systemic disease is essential for radiologists to avoid misdiagnosis and assist with timely and effective treatment.

Therapeutic response of immunoglobulin 4-related aortitis and pancreatitis demonstrated by diffusion-weighted MRI

Immunoglobulin (IgG) 4-related disease is a systemic inflammatory disease, and it affects vascular system as aortitis, periaortitis, or aneurysm. However, due to a lack of serum biomarker on aortic damage and the multiorgan involvement, it is difficult to assess aortic inflammatory activity of IgG4-related disease. We described a case of IgG4-related pancreatitis and aortitis, which was visualized with magnetic resonance merged image of diffusion weighted and T₁ weighted images. The aortic signal intensity or apparent diffusion coefficient value reduced or increased after oral prednisone administration, respectively. Magnetic resonance diffusion weighted image and apparent diffusion coefficient may be a useful imaging tool for assessment of vascular inflammation in IgG4-related aortitis.

Immunoglobulin G4-related disease complicated with vascular lesions: CT findings in 21 patients

PURPOSE

We aimed to analyze multislice computed tomography (MSCT) imaging features of vasculitis in immunoglobulin G4-related disease (IgG4-RD).

METHODS

In this retrospective study, we diagnosed 21 definite or possible IgG4-RD patients (71.4% male; mean age, 52.1±4.5 years) with vasculitis by MSCT and pathologic examination. The clinical background, laboratory analysis, pathologic results, CT images, and response to therapy were assessed and analyzed.

RESULTS

Under enhanced MSCT, 50 vasculitic lesions were identified and were divided into five types (types A-E) according to the CT findings on the basis of luminal changes. There were more vasculitic lesions observed below the diaphragm (n=30) than above it (n=20). Aneurysms and aneurysmal dilatation were more likely to be found in the aortaventralis (n=5), aortic arch (n=3) and iliac arteries (n=3). Most of the vascular lesions were characterized by wall thickening with a normal lumen (n=15) and slight stenosis (n=22). The affected vascular walls were all thickened between 4 and 18 mm. The walls of 19 patients (90.4%) were well circumscribed. The wall thickness of the aorta, including the aortaventralis and aortic arch, was more notable than that of the other vascular sites. Fourteen patients were followed up for 2-24 months. Wall thickness decreased in all cases. The average maximum thicknesses before and after therapy were 12.2±2.7 mm and 6.1±1.8 mm, which were significantly different (P < 0.001). The lumens of two patients were found to be slightly enlarged, while those of the other cases were unchanged after therapy.

CONCLUSION

IgG4-RD vascular lesions can be divided into five types, which are more likely to be present in the aorta and its main branches, and can rapidly diminish after steroid therapy. The lumen may be unchanged or slightly enlarged.

Prevalence of Elevated Serum IgG4 Level among Patients Diagnosed or Suspected with Cardiovascular Disorders

Immunoglobulin G4 (IgG4)-related disease, that is characterized by the elevation of circulating IgG4 level and the tissue-infiltration of IgG4-positive plasma cells, can target the cardiovascular tissue, although the diagnosis of IgG4-related cardiovascular lesion is not easy owing to the substantial risk for the tissue sampling. We herein examined the serum IgG4 levels among cardiac patients. In patients who were admitted to the cardiology department (n=477) and those who underwent computed tomography coronary artery angiography (n=401), elevated serum IgG4 level (≥135 mg/dL) was found 23 (4.8%) and 17 (4.2%), respectively. However, among those with elevated serum IgG4, only two patients could be clinicopathologically diagnosed with IgG4-related disease. Cardiovascular organ involvement may aggravate the prognosis of IgG4-related disease which in general not life-threatening. Considering that the non-negligible prevalence of high IgG4 level among cardiac patients who were not diagnosed with IgG4-related disease, however, physicians should not count too much on the serum IgG4 levels for the diagnosis of IgG4-related cardiovascular lesions, especially when histopathologic findings are not available, or when other-tissue involvement of IgG4-related disease is not apparent. (This is a translation of J Jpn Coll Angiol 2017; 57: 91–98.)

Immunoglobulin G4-related disease of the thickened aortic valve extending to the left ventricular outflow tract causing severe aortic regurgitation and complete atrioventricular block: a case report

Background

Immunoglobulin G4-related disease (IgG4-RD) is a systemic disease characterized by the tumefactive lesions and infiltration of IgG4-positive plasma cells. IgG4-RD has been described in various organs, but rarely the aortic valve. There are only a few reports of aortic stenosis, and none on significant aortic regurgitation. In addition, previous case reports relating to aortic valve lesions led to surgery as a first-line treatment. The effect of steroid treatment has not yet been determined.

Case Summary

A 62-year-old man, receiving steroid therapy, who presented with general malaise, shortness of breath, and bradycardia. He had suspected IgG4-RD because of pancreatitis, lacrimal gland enlargement, and retroperitoneal fibrosis. An examination revealed a thickened aortic valve extending to the left ventricular outflow tract with severe aortic regurgitation and complete atrioventricular block. He received intensive steroid therapy for a suspected IgG4-related aortic valve lesion. The complete atrioventricular block improved, but worsening aortic regurgitation caused congestive heart failure. He required replacement of the aortic valve. A histopathological examination of the excised aortic valve leaflets revealed IgG4-positive lymphoplasmacytic infiltration with fibrotic tissue. The prosthetic valve was functioning well without leakage around the valve at the 1-year follow-up.

Discussion

This case highlights the rare possibility that IgG4-RD of the aortic valve also causes significant aortic regurgitation. Conservative treatment with steroids may induce regression of the lesion and contribute to the stability of the prosthetic valve after surgery, but it may also exacerbate heart failure due to the progression of aortic regurgitation in patients with aortic valve lesions.

Noninvasive aortic imaging

Non-invasive imaging of the aorta has undergone considerable advancements in recent times; largely driven by the technological advances in computed tomography (CT) and magnetic resonance imaging (MRI). This review article highlights these recent advancements and discusses the current role of different imaging tools in the management of aortic diseases.

Clinical features of IgG4-related periaortitis/periarteritis based on the analysis of 179 patients with IgG4-related disease: a case-control study

BACKGROUND

Immunoglobulin G4-related disease (IgG4-RD) is a newly recognized systemic condition characterized by high serum immunoglobulin G4 (IgG4) concentration and IgG4-bearing plasma cell infiltration in affected organs. Although it has become evident that IgG4-RD also involves the systemic aortic/arterial system, the precise details of this condition remain unclear. The present study sought to clarify the clinical features of IgG4-related periaortitis/periarteritis.

METHODS

Among 223 patients with IgG4-RD, 179 (131 male, median onset age 67 years) were recruited for this study. Periaortitis/periarteritis was defined as vessel wall thickness with circumferential enhancement on contrast-enhanced computed tomography.

RESULTS

Periaortitis/periarteritis was identified in 65 (36.3%; 53 male) of 179 IgG-RD patients. The distribution of IgG4-related periaortitis/periarteritis could be broadly classified into five types, with the most prevalent Type 2 (44.6%) being localized at the infra-renal artery portion of the abdominal aorta and continuing to the iliac arteries. The infra-renal artery region of the abdominal aorta was most frequently involved (>80%) among IgG4-related periaortitis/periarteritis cases. Comparisons of clinical parameters between IgG4-RD patients with and without periaortitis/periarteritis revealed significantly higher propensities for older IgG4-RD onset age and highly active disease state featuring elevated serum IgG, IgG4, circulating immune complex, and soluble interleukin-2 receptor. All patients showed improvement of wall thickening after steroid therapy, although nine patients (20.9%) exhibited worsening of luminal dilatation. The main risk factor for this manifestation was prior luminal dilatation according to multivariate analysis.

CONCLUSION

IgG4-related periaortitis/periarteritis predominantly occurred at the infra-renal artery portion of the abdominal aorta, affected older IgG4-RD onset patients, and was prevalent in highly active disease states. As reported previously, the main risk factor for worsening luminal dilation after corticosteroid therapy was the existence of luminal dilation beforehand.

Neoplastic Pericardial Disease

Pericardial tumors are rare lesions that include a range of neoplastic conditions that may arise within the pericardium or metastasize to involve it secondarily. Understanding the spectrum of lesions that are included in the differential diagnosis of a pericardial mass-lesion is critical to making timely, accurate diagnoses and getting the appropriate therapy should one be necessary. This review summarizes the radiologic and pathologic findings of the most commonly encountered of these entities.