Retroperitoneal and aortic manifestations of immunoglobulin G4-related disease.
Retroperitoneal fibrosis is one of the prototypic manifestations of immunoglobulin G4 (IgG4)-related disease (IgG4-RD), but there is growing evidence that the aorta is also involved. These 2 conditions are closely linked, and based on the epicenter of the disease, the clinical manifestations can be classified as retroperitoneal fibrosis, inflammatory abdominal aortic aneurysm (including a combination of the 2), and thoracic aortitis. IgG4-RD is responsible for only a subset (∼50%) of cases of retroperitoneal fibrosis and inflammatory aortic aneurysms. Histological features include an extensive lymphoplasmacytic infiltrate rich in IgG4-positive plasma cells, fibrosis arranged in a storiform pattern, moderate tissue eosinophilia, and partially or completely obliterated veins. Among the 3 layers comprising the aorta, the adventitia is most susceptible to IgG4-related inflammation. The inflammatory process can also disrupt the lamellar elastic fibers in the media, which is seemingly a critical event leading to aneurysmal transformation. Steroid therapy is effective for both retroperitoneal and aortic lesions, as it is for the other manifestations of IgG4-RD. The risk of rupture appears to be low in patients with IgG4-related aortic aneurysms, but immunosuppressive therapy may trigger this critical complication by reducing the wall thickness.
Histopathology Section, Institute of Liver Studies, King's College Hospital, Denmark Hill, London, UK. yoh.zen@kcl.ac.uk
Yoh
Y
Zen
Satomi
S
Kasashima
Dai
D
Inoue
D001011:Aorta / Q000187:drug effects / Q000473:pathology; D001014:Aortic Aneurysm; D001327:Autoimmune Diseases / Q000188:drug therapy / Q000276:immunology / Q000378:metabolism / Q000473:pathology*; D004804:Eosinophils / Q000473:pathology; D005355:Fibrosis; D005938:Glucocorticoids / Q000627:therapeutic use; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood*; D007166:Immunosuppressive Agents / Q000009:adverse effects; D010950:Plasma Cells / Q000378:metabolism / Q000473:pathology; D012185:Retroperitoneal Fibrosis / Q000188:drug therapy / Q000276:immunology / Q000378:metabolism / Q000473:pathology*; D012421:Rupture / Q000139:chemically induced
D005938:Glucocorticoids; D007074:Immunoglobulin G; D007166:Immunosuppressive Agents