Overview of IgG4-related aortitis and periaortitis. A decade since their first description.

Aortic involvement is relatively common in the context of IgG4-related disease (IgG4-RD). It includes IgG4-aortitis, and IgG4-(chronic) periaortitis (IgG4-CP). The latter overlaps with IgG4-retroperitoneal fibrosis (IgG4-RPF). Aortic wall thickening which characterizes these entities along with the presence of periaortic tissue in IgG4-CP, are often accompanied by aortic aneurysms, which belong to the group of the so-called inflammatory aneurysms. Both the thoracic and abdominal aorta can be affected. Aortitis appears to involve more often the former, while the opposite is the case for IgG4-CP. There is a lack of definitions and different classification criteria have been used to describe these entities. This report provides an overview on the current evidence of aortic involvement in IgG4-RD. It discusses the clinical, epidemiologic, serologic and histopathologic characteristics, as well as the imaging techniques used for their diagnosis and the therapeutic options and treatment outcomes. The differential diagnosis and underlying pathogenetic mechanisms are also discussed.