IgG4-related disease: a contemporary review

Abstract

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.

Keywords: IgG4-related disease; clinico-pathological characteristics; diagnosis; treatment.

Figure 1

Characteristic histopathologic features of IgG4-RD. (A–D) IgG4-RD of the lung. (A) Lung parenchyma showing dense lymphoplasmocytic infiltration with lymphoidfollicles. (B) CD138 positive plasma cells. (C, D) IgG+ positive plasma cells. (Image courtesy of Nalan AKYÜREK).

Figure 2

Characteristic histopathologic features of IgG4-RD. (A–C) IgG4-RD of the omentum. (A) Omental biopsy showing fat necrosis areas and peripherally located dense lymphoplasmocytic infiltrate. (B) Higher power view of dense lymphoplasmocytic infiltrate. (C) IgG4 positive plasma cells in one high power field. (Image courtesy of Nalan AKYÜREK).

Figure 3

PET findings in RPF. 18F-FDG PET scans in a patient with idiopathic RPF show intense accumulation of ¹⁸F-FDG arround the abdominal aorta [A, axial CT, B, axial PET, C, axial fusion images, D, coronal fusion images, E, coronal maximum intensity projection (MİP) PET images)]. (Image courtesy of Özlem ATAY).

Figure 4

A and B, retroperitoneal fibrosis. Contrast-enhanced axial images (A) and coronal image (B) of computed tomography of the abdomen show heterogenous soft tissue densities surrounding aorta in the retroperitoneum at the infrarenal level. Soft tissue densities severely surround aorta, aortic bifurcation and main iliac arteries bilaterally (black arrow). (Image courtesy of Emetullah CİNDİL).