title: A clinicopathologic study of immunoglobulin G4-related sclerosing disease of the thoracic aorta.
abstract: OBJECTIVE
  Immunoglobulin G4-related sclerosing disease (IgG4-SD) has recently been reported to occur in the cardiovascular system and manifest as inflammatory abdominal aortic aneurysm. Thoracic aortic lesions are often associated with aortitis in several divergent etiologies. Thus, this study was performed to review thoracic aortic lesions from the aspect of IgG4-SD and to elucidate the clinicopathologic characteristics of this subgroup in the thoracic aorta.
  
  
  METHODS
  The study comprised 125 patients, including 71 with thoracic aortic aneurysm (TAA), 44 with aortic dissection, 7 with Takayasu aortitis, and 3 with infectious aortitis. IgG4-SD was identified by diffuse infiltration of numerous IgG4-positive plasmacytes by immunohistochemical examinations. Clinicopathologic features were compared between IgG4-related and IgG4-unrelated lesions.
  
  
  RESULTS
  Among the 125 patients, IgG4-SD was found in 5 patients with TAA but was not detected in the other subgroups of thoracic aortic lesion. IgG4-related TAA included one case of lymphoplasmacytic aortitis, 1 case of inflammatory aneurysm, and three cases of atherosclerotic aneurysms. Patients with IgG4-related TAA showed clinicopathologic features similar to patients with IgG4-SD: male gender, old age, history of bronchial asthma and allergies, elevation of white blood cell counts, C-reactive protein levels, and IgG4 and IgE concentrations (in one patient); eosinophilic infiltration, obliterative phlebitis, lymph follicle formation, and perineural inflammation. In addition, compared with IgG4-unrelated TAA, IgG4-related TAA was characterized by clinically more frequency of involvement of the aortic arch (P = .002), saccular formation (P = .003), and fibrous adhesion to surrounding tissue (P < .001), and histopathologically thicker entire aortic wall and adventitia (P < .001 each).
  
  
  CONCLUSIONS
  IgG4-SD is involved in 4% of all thoracic aortic lesions and uniformly presents in the form of an aneurysm with distinct histologic and clinicopathologic features. IgG4-SD represents one, albeit rare, etiology of TAA, especially those originating in the aortic arch.
authors.affiliation: Department of Pathology, National Hospital Organization, Kanazawa Medical Center, Kanazawa, Japan. sato-kasa@kinbyou.hosp.go.jp
authors.forename: Satomi
authors.initials: S
authors.lastname: Kasashima
authors.forename: Yoh
authors.initials: Y
authors.lastname: Zen
authors.forename: Atsuhiro
authors.initials: A
authors.lastname: Kawashima
authors.forename: Masamitsu
authors.initials: M
authors.lastname: Endo
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Matsumoto
authors.forename: Fuminori
authors.initials: F
authors.lastname: Kasashima
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Ohtake
authors.forename: Yasuni
authors.initials: Y
authors.lastname: Nakanuma
mesh_terms: D000368:Aged; D000784:Aortic Dissection / Q000150:complications / Q000276:immunology / Q000473:pathology; D000785:Aneurysm, Infected / Q000150:complications / Q000276:immunology / Q000473:pathology; D001013:Aorta, Thoracic / Q000473:pathology*; D017545:Aortic Aneurysm, Thoracic / Q000150:complications / Q000276:immunology / Q000473:pathology*; D001025:Aortitis / Q000150:complications / Q000276:immunology / Q000473:pathology*; D001327:Autoimmune Diseases / Q000150:complications; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood*; D007249:Inflammation; D008297:Male; D012598:Sclerosis; D013625:Takayasu Arteritis / Q000150:complications / Q000276:immunology / Q000473:pathology
chemical_list: D007074:Immunoglobulin G