IgG4-related arteritis and periarteritis

IgG4-related arteritis and periarteritis is a form of IgG4-related cardiovascular disease, in which multi-vessel involvement is very common.

Epidemiology

IgG4-related arteritis and periarteritis predominantly affect men above 60 years of age .

Associations

Conditions associated with IgG4-related arteritis include :

  • inflammatory aneurysm
  • pericarditis
  • other organ involvement: pancreas, salivary glands, lymph nodes etc.

Clinical presentation

Clinical manifestations can be nonspecific and divers including fever, abdominal pain, backache and/or weight loss.  Biochemically IgG4-related cardiovascular disease is characterized by an elevated serum IgG4 concentration ≥ 1.35 mg/L .

Complications

IgG4-related arteritis of the non-coronary arteries to the following conditions :

Pathology

IgG4-related arteritis and periarteritis feature a fibrosclerotic inflammation of the adventitia characterized by a lymphoblastic infiltration. Involvement of the tunica media is less extensive .

Location

Many patients have involvement of multiple vascular territories. Arteries besides the aorta and coronary arteries that can be affected by IgG4-related disease include :

In addition, small and medium-sized arteries can be affected including:

Macroscopic appearance

Macroscopically IgG4-related arteritis features an inflammatory thickening of the adventitia with a red to brownish color .

Microscopic appearance

The microscopic appearance of IgG4-related cardiovascular disease includes the following histological features :

  • lymphoplasmacytic infiltration of IgG4-positive plasma cells
  • a storiform fibrotic pattern of radially arranged collagen fibers rough tissue
  • obliterative phlebitis
Immunohistochemistry

Immunohistochemistry stains should express IgG4 and CD138.

Radiographic features

General radiographic features of IgG4-related disease includes the following :

  • inflammatory vasculitis
  • aneurysmal change
  • pseudotumor formation
CT

CTA with multiplanar reconstructions is recommended for the evaluation of IgG4-related cardiovascular disease.  Delayed contrast enhancement might aid in the differentiation of inflammatory wall-thickening from mural thrombus formation .

CT imaging features include :

  • diffuse or partial arterial mural thickening (> 2 mm)
  • homogenous wall enhancement especially in a delayed phase
  • absence of calcifications
  • associated luminal stenosis
  • partial aneurysmal dilatation
MRI

MRI can help in the visualization of mural thickening and edema as well as in the evaluation of concomitant aortic disease. For the assessment, black-blood imaging might be beneficial.

Signal characteristics
  • T1 black-blood: hypointense
  • T2FS/STIR-black-blood: hyperintense
  • T1 C+ (Gd): perivascular delayed enhancement 
Nuclear medicine
PET-CT

PET-CT shows abnormally increased FDG uptake in the vessel wall and can provide important information in respect to disease activity .

Radiology report

The radiological report should include a description of the following features:

  • location and extent of the affected vessels
  • aneurysmal dilatations
  • thrombus formation
  • concomitant stenosis
  • pseudotumor formation
  • aortic involvement
  • involvement of other organs

Treatment and prognosis

IgG4-related disease responds to corticosteroid therapy. Another agent which has been used in the treatment is Rituximab .

History and etymology

A general concept of IgG4 related autoimmune disease was first described in 2003 by Terumi Kamisawa and colleagues .

Differential diagnosis

The differential diagnosis of IgG4 related coronary disease include the following :

See also

Siehe auch: