Takayasu arteritis and primary sclerosing cholangitis: A casual association or different phenotypes of the same disease?

Takayasu arteritis and primary sclerosing cholangitis are two rare disorders. The pathogenesis of Takayasu arteritis involves immune-mediated mechanisms, and corticosteroids represent the mainstay for treatment. Conversely, the aetiology of primary sclerosing cholangitis remains elusive, even if dysimmunity seems to be one of the contributors to bile duct damage. Despite this, immunosuppressants do not alter disease course. In this paper we describe the association of these two rare disorders, with an unexpected normalization of cholestatic enzymes following steroid treatment. This might hint a novel subtype of sclerosing cholangitis with a prevalent immunebackground, or a local manifestation of Takayasu arteritis.