IgG4-Related disease with diffuse myopericardial involvement- value of CMR: a case report and literature review of cardiac involvement.

BACKGROUND: IgG4-related disease is a fibro-inflammatory disorder with an unknown etiology, which can affect multiple organ systems, including the cardiovascular system. While most reported cases of cardiovascular involvement are primarily associated with the aorta, there have been sporadic reports of isolated cardiac involvement. CASE PRESENTATION: This paper presents a documented case of IgG4-related systemic disease with symptoms indicative of restrictive cardiomyopathy. Subsequent Cardiac Magnetic Resonance imaging revealed diffuse myopericardial involvement, characterized by pericardial thickening and enhancement, accompanied by subepicardial and myocardial infiltration. Considering the rarity of cardiac involvement in our case, we conducted a thorough review of the existing literature pertaining to various patterns of cardiac involvement in IgG4-related disease, as well as the diagnostic modalities that can be employed for accurate identification and assessment. CONCLUSIONS: This case report sheds light on the importance of recognizing and evaluating cardiac manifestations in IgG4-related systemic disease to facilitate timely diagnosis and appropriate management.

Multimodality Imaging Features of Immunoglobulin G4-related Vessel Involvement.

Immunoglobulin 4 (IgG4)-related disease is a chronic immune-mediated fibroinflammatory disorder. Involvement of the vascular system, including large- and medium-sized vessels, is increasingly recognized. The varied appearances of vascular involvement reflect the sequela of chronic inflammation and fibrosis and can include aortitis and periaortitis with resultant complications such as aneurysm formation and dissection. A diagnosis of IgG4-related large vessel involvement should be considered when there is known or suspected IgG4-related disease elsewhere. Other organs that are typically affected in IgG4-related disease include the lacrimal and salivary glands, thyroid, pancreas, biliary tree, lungs, kidneys, and meninges. Diagnosis typically requires careful correlation with clinical, imaging, serum, and pathologic findings. Patients may be managed with corticosteroid therapy or the anti-CD20 monoclonal antibody, rituximab, if needed. The varied clinical presentations and imaging features of large vessel involvement are discussed herein. Keywords: Vascular, Inflammation, Aorta, IgG4-related Vessel Involvement © RSNA, 2024.

Semiquantitative 18F-FDG PET/CT in monitoring glucocorticoid response of immunoglobulin G4-related effusive constrictive pericarditis: a case report.

BACKGROUND: Immunoglobulin G4 (IgG4)-related effusive constrictive pericarditis (ECP) is a rare manifestation of IgG4-related disease (IgG4-RD). It can lead to persistent pericardial fibrosis, resulting in cardiac tamponade, diastolic dysfunction, and heart failure. Glucocorticoids are the primary treatment for effectively reducing inflammation and preventing fibrosis. However, guidelines for monitoring treatment response are lacking and tapering glucocorticoid therapy for specific target organs remains a challenge. Recent studies on IgG4-RD have demonstrated that semiquantitative measurements of fluorine-18 fluorodeoxyglucose (18F-FDG) uptake in the main involved organs in positron emission tomography/computed tomography (PET/CT) scanning are correlated to disease activity. We present a case of IgG4-related ECP to demonstrate the usefulness of 18F-FDG PET/CT for diagnosing and treatment follow-up of IgG4-related ECP. CASE PRESENTATION: Herein, a 66-year-old woman diagnosed with IgG4-related ECP presented with breathlessness, leg swelling, rales, and fever. Laboratory tests revealed markedly elevated levels of C-reactive protein, and transthoracic echocardiography revealed constrictive physiology with effusion. High IgG4 levels suggested an immune-related pathogenesis, while viral and malignant causes were excluded. Subsequent pericardial biopsy revealed lymphocyte and plasma cell infiltration in the pericardium, confirming the diagnosis of IgG4-related ECP. 18F-FDG PET/CT revealed increased uptake of 18F-FDG in the pericardium, indicating isolated cardiac involvement of IgG4-RD. Treatment with prednisolone and colchicine led to a rapid improvement in the patient's condition within a few weeks. Follow-up imaging with 18F-FDG PET/CT after 3 months revealed reduced inflammation and improved constrictive physiology on echocardiography, leading to successful tapering of the prednisolone dose and discontinuation of colchicine. CONCLUSION: The rarity of IgG4-related ECP and possibility of multiorgan involvement in IgG4-RD necessitates a comprehensive diagnostic approach and personalized management. This case report highlights the usefulness of 18F-FDG PET/CT in the diagnosis and treatment follow-up of isolated pericardial involvement in IgG4-RD.

Serial 68Ga-FAPI PET/CT After Treatment of Immunoglobulin G4-Related Pancreatitis and Retroperitoneal Fibrosis.

ABSTRACT: Immunoglobulin G4 (IgG4)-related disease is a fibroinflammatory condition involving diverse organs. We report a case of IgG4-related pancreatitis and retroperitoneal fibrosis with serial 68Ga-FAPI PET/CT scans after treatment. A 64-year-old man presented with left flank and epigastric pain. Laboratory, abdominal CT, and 68Ga-FAPI PET/CT findings were suggestive of IgG4-related pancreatitis and retroperitoneal fibrosis. Histology of the pancreas confirmed IgG4-related pancreatitis. The follow-up PET/CT scans after treatment with steroid therapy showed regression of 68Ga-FAPI uptake in the pancreas and periureteral soft tissue. The changes on 68Ga-FAPI PET/CT scans were much more prominent compared with the CT scans.

Pancreatic cancer detected with 18F-FDG PET/CT in a case of IgG4-related disease.

We present a case of a 67-year-old male presenting with severe abdominal pain, laboratory tests revealed IgG levels of 63.5 g/L, IgG4 levels of 63.7 g/L, and negative results for ANCA (Anti-Neutrophil Cytoplasmic Antibodies), Hematuria immunofixation electrophoresis, as well as Cold globulin qualitative test. 18F-FDG PET/CT revealed multiple lesions with increased metabolism in the submaxillary saliva gland, intrahepatic bile ducts, prostate, seminal vesicle glands, and the body of the pancreas. Additionally, a circular cystic-solid lesion with metabolic heterogeneity was observed in the head of the pancreas, accompanied by visible dilatation of the pancreatic duct. The diagnostic imaging suggested IgG4-related disease (IgG4-RD), while pancreatic malignancy could not be definitively ruled out. The patient underwent fine-needle aspiration (FNA) biopsies of lung nodules and the prostate gland, all of which were consistent with the diagnosis of IgG4-RD. Additionally, FNA biopsy of a pancreatic lesion is consistent with the diagnosis of pancreatic ductal adenocarcinoma.

Pretherapy 18F-FDG PET/CT in Predicting Disease Relapse in Patients With Immunoglobulin G4-Related Disease: A Prospective Study.

OBJECTIVE: To investigate whether the levels of inflammation detected by 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT) can predict disease relapse in immunoglobulin G4-related disease (IgG4-RD) patients receiving standard induction steroid therapy. MATERIALS AND METHODS: This prospective study analyzed pretherapy FDG PET/CT images from 48 patients (mean age, 63 ± 12.9 years; 45 males and 3 females) diagnosed with IgG4-RD between September 2008 and February 2018, who subsequently received standard induction steroid therapy as the first-line treatment. Multivariable Cox proportional hazards models were used to identify the potential prognostic factors associated with relapse-free survival (RFS). RESULTS: The median follow-up time for the entire cohort was 1913 days (interquartile range [IQR], 803-2929 days). Relapse occurred in 81.3% (39/48) patients during the follow-up period. The median time to relapse was 210 days (IQR, 140-308 days) after completion of standardized induction steroid therapy. Among the 17 parameters analyzed, Cox proportional hazard analysis identified whole-body total lesion glycolysis (WTLG) > 600 on FDG-PET as an independent risk factor for disease relapse (median RFS, 175 vs. 308 days; adjusted hazard ratio, 2.196 [95% confidence interval: 1.080-4.374]; P = 0.030). CONCLUSION: WTLG on pretherapy FDG PET/CT was the only significant factor associated with RFS in IgG-RD patients receiving standard steroid induction therapy.

Imaging manifestations of IgG4-related disease.

IgG4-related disease is a multisystem immune-mediated disorder associated with lesions manifesting an IgG4-rich plasma cell infiltrate and often raised serum IgG4 concentrations. The disease can mimic neoplastic, infective, and inflammatory processes due to features such as development of masses or organ enlargement. Prompt consideration of this diagnosis is essential to avoid unnecessary investigations and offer appropriate treatments, which can include steroids and other immunosuppressive agents. Although histology is typically diagnostic, imaging is critical to assess disease burden, determine biopsy targets, and evaluate response to treatment. Characteristic imaging features can also point towards the diagnosis in the absence of biopsy. This review highlights these features, as well as more atypical findings, grouped by organ or system. Differential diagnoses are emphasised. The full spectrum of imaging methods is discussed. Whole-body imaging with integrated 2-[18F]-fluoro-2-deoxy-d-glucose (FDG) positron-emission tomography (PET)/computed tomography (CT) has an evolving role in the detection of multi-organ involvement and subsequent follow-up.

Thoracoabdominal manifestations of immunoglobulin G4-related disease.

Immunoglobulin G4-related disease (IgG4-RD) comprises a group of immune-mediated diseases that, until recently, were considered separate entities. These entities have a similar clinical presentation, serological findings, and pathogenesis, so they are currently considered a single multisystemic disease. The common characteristic is the infiltration of involved tissues by plasma cells and lymphocytes that are positive for IgG4. Three major criteria have been proposed for the diagnosis of IgG4-RD: clinical, laboratory, and histological. The pancreas is the organ that is most affected by IgG4-RD, which can simulate a tumor. In this respect, a series of signs could help us suspect that the pancreatic findings do not reflect a tumor (halo sign, duct-penetrating sign, absence of vascular invasion, etc.). The differential diagnosis is important to avoid unnecessary surgical interventions.

Prominent 68 Ga-FAPI Uptake in Renal Parenchyma Caused by Immunoglobulin G4-Related Nephropathy.

ABSTRACT: A 57-year-old man presented with a dry cough and renal insufficiency. Serum immunoglobulin G4 (IgG4) level was markedly elevated, and IgG4-related disease was clinically considered. 18 F-FDG PET/CT revealed mild uptake in salivary glands and also moderately increased activity in renal parenchyma and prostate. 68 Ga-FAPI PET/CT detected prominent and evenly distributed 68 Ga-FAPI uptake in the kidney, and the pancreas, salivary gland, and prostate also showed intense activity, consistent with IgG4-related disease involving the kidney, pancreas, salivary gland, and prostate.

Una inusual causa de estrechez de la vía aérea laringotraqueal / An unusual cause of laryngotracheal airway narrowing

La enfermedad relacionada con inmunoglobulina (Ig) G4 es una enfermedad de reciente conocimiento que puede comprometer cualquier órgano teniendo preferencias por ciertas regiones del cuerpo, donde la región de cabeza y cuello es uno de sus principales puntos afectados, pudiendo comprometer tanto la órbita, glándulas salivales, glándulas lagrimales, glándula tiroides, cavidades paranasales, hueso temporal, faringe y laringe. Este último órgano es infrecuentemente comprometido, solo existiendo 12 casos registrados en la literatura antes de la publicación de este escrito. Presentamos un caso de una mujer de 49 años con historia de disnea frente a esfuerzo, diagnosticándose una estenosis subglótica la cual fue manejada quirúrgicamente con una reconstrucción laringotraqueal. En el estudio histopatológico se evidenció histología compatible con enfermedad relacionada con IgG4, por lo que se inició tratamiento médico con corticotera- pia oral por un lapso de 2 meses en conjunto con inmunología. Paciente luego de 4 años de seguimiento, no ha presentado recaídas, manteniendo un lumen subglótico adecuado.

Immunoglobulin (Ig) G4-related disease is a medical condition of recent knowledge that can compromise any organ, having preferences for certain regions of the body, where the head and neck region is one of the main affected points, being able to affect orbit, salivary glands, lacrimal glands, thyroid gland, paranasal cavities, temporal bone, pharynx and larynx. The latter is infrequently compromised, with only 12 cases registered in the literature before the publication of this writing. We present a case of a 49-year-old woman with a history of exertional dyspnea, diagnosed with a sub- glottic stenosis which was managed surgically with laryngotracheal reconstruction. The histopathological study revealed histology compatible with IgG4-related disease, so medical treatment with oral corticosteroid therapy was started for a period of 2 months in conjunction with immunology. After 4 years of follow-up, the patient has not presented relapses, maintaining an adequate subglottic lumen.