A Case of IgG4-Related Aortitis and Pericarditis: Diagnostic Challenges and Natural History

Clinicopathological features of immunoglobulin G4-related constrictive pericarditis

AIM

Constrictive pericarditis (CP) is characterised by scarring fibrosis and a loss of pericardial elasticity, which causes heart failure. IgG4 (immunoglobulin G4)-related disease (IgG4-RD) is a systemic fibro-inflammatory disease characterised by the infiltration of IgG4-immunopositive plasmacytes and high serum IgG4 levels that frequently shape tumorous lesions. Although pericardial involvement of IgG4-RD is rare, with indications of CP, pericardial effusion and irregular masses, the clinical and pathological features remain unclear. In this study, we examined the relationship between CP and IgG4-RD.

METHODS

Among 35 thick-walled CP cases (histologically pericardial thickening ≥2 mm), eight cases were aetiology identified. Using the diagnostic criteria for IgG4-RD, 11 cases were classified as IgG4-CP, whereas the remainder were considered true idiopathic CP (16 cases) and the clinical pathological features were evaluated.

RESULTS

Compared with the other groups, the IgG4-CP group was more common in men and associated with low-grade fever and massive pericardial effusion with frequent recurrence. Deaths resulting from heart failure occurred in a few cases of the IgG4-CP group, but not in other groups. An increase in C-reactive protein and a high positivity rate of anti-nuclear antibodies frequently occurred in the IgG4-CP group. Histologically, the IgG4-CP group included lymphoid follicle, eosinophil infiltration and few calcifications.

CONCLUSIONS

Pericardial IgG4-RD occurs not only as nodular lesions, but also as thick-walled CP, and accounts for approximately 40% of thick-walled CP cases of unknown cause. The predominant clinical characteristic was refractory and recurrent pericardial effusion. Recognising IgG4-RD as a cause of CP is important to initiate appropriate therapy.

Elevated Serum Levels of IgG4 in Patients with Heart Failure with Reduced Ejection Fraction: A Prospective Controlled Study

(1) Background: Immunoglobulin gamma subclass 4 (IgG4) is a serum protein belonging to the immunoglobulin superfamily. It has a central role in certain immune-mediated conditions defined as IgG4-related disease. There is a paucity of data regarding the potential association of IgG4 and cardiovascular diseases. Our aim is to study the serum levels of IgG4 in patients with ischemic and non-ischemic dilated cardiomyopathy (DCM). (2) Methods: patients with ischemic and non-ischemic DCM were included in this study. Non-ischemic DCM was defined as a left ventricular ejection fraction (LVEF) < 40% without coronary artery disease (CAD). Ischemic DCM was defined as a LVEF < 40% and proven CAD. The serum concentrations of IgG4 were measured by turbidimetry. (3) Results: Overall 98 patients with cardiomyopathy had significantly higher levels of IgG4 compared with the control group (77.4 ± 64.0 vs. 50.3 ± 28.8 mg/dL, p < 0.01). Although there was no difference in the total IgG levels in patients with ischemic DCM, the serum concentrations of IgG4 were significantly higher than the corresponding values in the control group (89.8 ± 67.3 vs. 50.3 ± 28.8 mg/dL; interquartile ranges: 40.4−126.5 vs. 31.8−66.8 mg/dL, p < 0.01). This was altered by gender and smoking. (4) Conclusions: The patients with ischemic DCM had increased serum concentrations of IgG4. Future studies are warranted to explore the potential role of an IgG4-mediated process in patients with heart failure with reduced LVEF.

FDG PET/CT in Sacroiliac IgG4 Disease

ABSTRACT

A 68-year-old woman with abdominal pain and a raised C-reactive protein was investigated with a CT of the abdomen. CT showed an irregular soft tissue mass anterior to the aorta, which was thought to be neoplastic. The patient underwent 18F-FDG PET/CT, which demonstrated hypermetabolic activity in this mass, as well as further foci of hypermetabolic activity in head and neck, sacroiliac joints, and pelvic floor muscles. A CT-guided biopsy of the sacroiliac joint was performed and revealed IgG4-related disease.

Pericarditis as a manifestation of IgG4-related disease

IgG4-related disease (IgG4-RD) is a systemic, immune-mediated fibro-inflammatory disease that can affect virtually every organ system. It is usually insidious in onset and often mimics malignant or other inflammatory disorders. Diagnosis frequently requires a combination of clinical, serological, radiographic, and histopathological features, including increased serum-IgG4 levels and tissue infiltration of IgG4-positive plasma cells with associated fibrosis. Unlike more frequently affected sites, including the hepatobiliary system, salivary glands and retroperitoneum, pericardial involvement of IgG4-RD has only rarely been described. We report the case of a 76-year-old woman presenting with refractory pericarditis and imminent cardiac tamponade, successfully treated with therapeutic pericardiectomy. A diagnosis of IgG4-RD was made based on elevated serum-IgG4 levels and the presence of typical pericardial histopathological findings, meeting all 3 of the 2011 comprehensive diagnostic criteria for IgG4-RD. Following pericardiectomy, the patient remained in remission without a need for glucocorticoids or additional immunosuppressive therapy. Adding to this case, we reviewed the literature for previously described cases of IgG4-RD presenting with pericarditis and described their characteristics and the available treatment options. Our case-based literature review provides a clear overview of the diagnostic process for IgG4-RD and the need to apply classification criteria with the necessary caution, particularly in the case of rare disease manifestations, including pericarditis.

A case report of IgG4-related disease: an insidious path to the diagnosis through kidney, heart and brain

Background

IgG4-related disease, described around the years 2000 as a form of autoimmune pancreatitis, is now increasingly accepted as a systemic syndrome. The diagnosis is based on both comprehensive and organ-specific criteria. For the kidney, Mayo clinic classification and the guidelines of the Japanese Nephrology Society are used. Ultimately, together with parameters that characterize every organ or apparatus involved, the key element is the confirmation of growing levels of IgG4 in blood or in tissues.

Case presentation

We describe a male patient with chronic renal failure associated to hypertension without proteinuria. IgG4-related disease was diagnosed through renal biopsy. After an initial positive response to steroids, he presented tinnitus, and histological assessment showed cerebral and subsequently cardiac damage, both IgG4-related. This case appears unique for the type of histologically documented cardiac and neurological parenchymal involvement, and at the same time, exemplifies the subtle and pernicious course of the disease. Frequently, blurred and non-specific signs prevail. Here, kidney damage was associated with minimal urinary findings, slowly progressive renal dysfunction and other factors that can be equivocated in the differential diagnosis. Neurological involvement was represented by tinnitus alone, while cardiac alterations were completely asymptomatic.

Conclusions

This report is representative of the neurological and cardiac changes described in the literature for IgG4-related disease, which may be correlated or not with the renal form and highlights the need, in some cases, of targeted therapeutic approaches. In addition to glucocorticoids, as in this case, rituximab may be necessary.