IgG4-related inflammatory abdominal aortic aneurysm

Purpose of review IgG4-related systemic disease is a recently proposed entity characterized by high serum IgG4 concentrations, sclerosing inflammation containing numerous IgG4-positive plasmacytes, dramatic responsiveness to steroid therapy, and occurrence of multiple organs. This review described that some cases of inflammatory abdominal aortic aneurysm (IAAA) have similar clinicopathological features that are now considered to represent aortic lesions of IgG4-related systemic disease under the concept of IgG4-related IAAA. Recent findings IgG4-related IAAA is characterized by high serum IgG4 and immunoglobulin E levels, high titers of antinuclear antibodies, and high prevalence of allergic disorders such as bronchial asthma. The patients show a risk of developing IgG4-related systemic diseases in other organs during their life. Histologically, sclerosing inflammation containing numerous IgG4-positive plasmacytes is observed predominantly in the adventitia. Similar lesions have also been reported in the thoracic aorta and large arteries. Summary Recognition of the fact that IgG4-related systemic disease could involve the vascular lesions offers potential new management of those. However, only 3 years have passed since the first report of IgG4-related IAAA. Further studies are necessary to elucidate other vascular lesions associated with IgG4-related systemic disease, the usefulness of steroid therapy for the management of IgG4-IAAA, and underlying pathological and immunological characteristics.