• Journal of Yeungnam Medical Science
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• v.37 no.2
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• pp.136-140
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• 2020

Immunoglobulin G4 (IgG4)-associated autoimmune hepatitis (AIH) is a very rare subtype of autoimmune hepatitis and characterized by marked elevated serum IgG and hepatic infiltration of IgG4-expressing plasma cells. Pathologic confirmation of hepatic IgG4-expressing plasma cells is usually required for the final diagnosis of IgG4-associated AIH. Herein, we report the case of a 47-year-old female diagnosed with autoantibody-negative IgG4-associated AIH mimicking lymphoproliferative disorders.

• Journal of the Korean Society of Radiology
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• v.83 no.4
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• pp.910-917
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• 2022

Immunoglobulin G4 (IgG4) related disease (IgG4-RD) is currently considered an immune-mediated condition and is recognized as a disorder group with common pathological, hematological, and clinical characteristics. This disease may involve diverse organs of the head and neck, and include mainly the lacrimal gland, orbit, thyroid gland, pituitary gland, and the meninges. Here, we report a case of IgG4-RD in a 65-year-old female showing head- and neck-limited but synchronously and mainly manifesting as otalgia and facial neuritis.

• Journal of the Korean Society of Radiology
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• v.82 no.2
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• pp.487-492
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• 2021

Immunoglobulin G4 (IgG4)-related disease is a systemic disease characterized by dense lymphoplasmacytic infiltrates with abundant IgG4-positive plasma cells and fibroblast proliferation. The retroperitoneal involvement of IgG4-related disease usually appears as a soft-tissue mass covering the abdominal aorta or entrapping the ureters, resulting in hydronephrosis. Here, we present a case of IgG4-related disease with retroperitoneal involvement in a 75-yearold woman with an unusual manifestation. A preoperative computed tomography (CT) scan revealed an irregular infiltrative retroperitoneal mass invading the normal anatomic barriers, raising the suspicion of malignancy or inflammation. Contrast-enhanced CT revealed a homogeneous progressive enhancement of the mass.

• Korean Journal of Veterinary Research
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• v.61 no.1
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• pp.5.1-5.7
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• 2021

The goal of this study was to measure immunoglobulin G4 (IgG4) concentrations and to evaluate the significance of these values in the management of canine pancreatitis. The medical records of 24 dogs that visited the Veterinary Medical Teaching Hospital between December 2016 and June 2018 were retrospectively reviewed to identify dogs that had been diagnosed with pancreatitis. The serum C-reactive protein and serum IgG4 concentration in the affected dogs were highly increased compared to the healthy group. Particularly, serum IgG4 measured significantly higher in dogs with pancreatitis and concurrent immune-mediated disease (p < 0.05). In conclusion, increased serum IgG4 concentrations are a characteristic finding in dogs with pancreatitis. The results of this research indicate that an elevation in IgG4 has the potential of being used as a tool for the diagnosis of pancreatitis and concurrent immune-mediated disease.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.46 no.1
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• pp.3-11
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• 2020

Immunoglobulin G4 (IgG4)-related dacryoadenitis and sialoadenitis (IgG4-DS) are part of a multiorgan fibroinflammatory condition of unknown etiology termed IgG4-related disease (IgG4-RD), which has been recognized as a single diagnostic entity for less than 15 years. Histopathologic examination is critical for diagnosis of IgG4-RD. CD4+ T and B cells, including IgG4-expressing plasma cells, constitute the major inflammatory cell populations in IgG4-RD and are thought to cause organ damage and tissue fibrosis. Patients with IgG4-RD who have active, untreated disease exhibit significant increase of IgG4-secreting plasmablasts in the blood. Considerable insight into the immunologic mechanisms of IgG4-RD has been achieved in the last decade using novel molecular biology approaches, including next-generation and single-cell RNA sequencing. Exploring the interactions between CD4+ T cells and B lineage cells is critical for understanding the pathophysiology of IgG4-RD. Establishment of pathogenic T cell clones and identification of antigens specific to these clones constitutes the first steps in determining the pathogenesis of the disease. Herein, the clinical features and mechanistic insights regarding pathogenesis of IgG4-RD were reviewed.

• Journal of the Korean Society of Radiology
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• v.79 no.5
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• pp.276-281
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• 2018

Immunoglobulin G4 (IgG4)-related lung disease has been actively studied over the past few years. Radiologic findings of IgG4-related lung disease vary among patients, but there are no long-term follow up studies regarding variations in imaging features over the course of disease progression. In two cases with relatively long-term follow up, diverse early and late computed tomography (CT) findings of IgG4-related lung disease are reviewed in this report. In contrast to nodular or diffuse ground-glass opacity, which was predominantly noted in CT scans at earlier stages of disease, honeycombing and traction bronchiectasis were regarded as late radiologic manifestations. Solid nodules might be visible in both early and late stages; however, development of new solid nodules and enlargement of preexisting nodules could occur during disease progression. Interlobular septal thickening and mediastinal/hilar lymphadenopathy were persistent, even in later stages of the disease. These findings might be useful in making an accurate and timely diagnosis of IgG4-related lung disease.

• Journal of the Korean Society of Radiology
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• v.82 no.3
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• pp.575-588
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• 2021

Immunoglobulin G4 (IgG4)-related disease is a systemic fibro-inflammatory disease characterized by pathologic findings in various organs. Imaging is critical for the diagnosis and treatment assessment of patients with IgG4-related disease. In this pictorial essay, we review the key features of multiple imaging modalities, typical pathologic findings, and differential diagnosis of IgG4-related disease. This systematic pictorial review can further our understanding of the broad-spectrum manifestations of this disease.

• Journal of the Korean Society of Radiology
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• v.84 no.3
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• pp.686-691
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• 2023

Immunoglobulin G4 (IgG4)-related disease (IgG4-RD) is a fibroinflammatory disorder that can involve any organ system; however, myocarditis is extremely rare. A 52-year-old male with dyspnea and chest discomfort underwent cardiac MRI that revealed edema and nodular, patchy, mesocardial and subendoardial delayed enhancement of left ventricle, suggesting myocarditis. Laboratory findings revealed elevated serum IgG4 and eosinophilia. Cardiac biopsy confirmed eosinophilic myocarditis with IgG4-positive cells. Here, we present an unusual case of IgG4-RD manifesting as eosinophilic myocarditis.

• Journal of Yeungnam Medical Science
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• v.39 no.2
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• pp.153-160
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• 2022

Multicentric Castleman disease (MCD) is an uncommon systemic lymphoproliferative disorder that may cause multiple organ damage. Castleman disease-associated diffuse parenchymal lung disease (DPLD) has not been well studied. A 32-year-old man was referred to our hospital for progressive generalized weakness, light-headedness, and dyspnea on exertion for more than one year. Laboratory evaluations showed profound anemia, an elevated erythrocyte sedimentation rate, and an increased C-reactive protein level with polyclonal hypergammaglobulinemia. Chest radiography, computed tomography (CT), and positron emission tomography-CT scan demonstrated diffuse lung infiltration with multiple cystic lesions and multiple lymphadenopathy. In addition to these clinical laboratory findings, bone marrow, lung, and lymph node biopsies confirmed the diagnosis of idiopathic MCD (iMCD). Siltuximab, an interleukin-6 inhibitor, and glucocorticoid therapy were initiated. The patient has been tolerating the treatment well and had no disease progression or any complications in 4 years. Herein, we report this case of human herpesvirus-8-negative iMCD-associated DPLD accompanied by multiple cystic lesions, multiple lymphadenopathy, and polyclonal hypergammaglobulinemia with elevated immunoglobulin G (IgG) and IgG4 levels. We recommend a close evaluation of MCD in cases of DPLD with hypergammaglobulinemia.

• Journal of the Korean Society of Radiology
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• v.84 no.6
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• pp.1373-1377
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• 2023

Immunoglobulin G4 (IgG4)-related lung disease can have various clinical courses. To our knowledge, reports of IgG4-related lung disease with waxing and waning pulmonary infiltrates only are very rare. A few lung nodules and ground glass opacities were incidentally found in a pre-operative evaluation in a 36-year-old female. The lung lesions showed waxing and waning in the follow-up chest CT. She underwent a surgical biopsy, and IgG4-related lung disease was confirmed.