Diagnosis

Yes. Although ANCA is elevated in a majority of patients with granulomatosis with polyangiitis (GPA, formerly called Wegener’s), it is not detectable in all patients and is not necessary to make the diagnosis....

Granulomatosis with polyangiitis (GPA) is a new term introduced to replace the name Wegener’s granulomatosis. As the term is being adopted, the terminology “granulomatosis with polyangiitis (GPA) has been proposed....

Polyarteritis nodosa (PAN) is a vasculitis affecting medium-sized blood vessels. In patients with “cutaneous polyarteritis nodosa”, the findings of the disease are localized to the skin (purpura or subcutaneous nodules), but also sometimes the peripheral nerve(s) of the same limb (causing weakness and/or numbness). Patients with systemic polyarteritis nodosa have…...

The key difference between Takayasu arteritis (TAK) and giant cell arteritis (GCA) is the age of the patients affected by the disorders. Takayasu arteritis affects younger patients, generally less than 40 years of age, while giant cell arteritis affects older patients, generally over 50 years of age. Both Takayasu arteritis…...

PML is a brain infection that is caused by the JC virus. Exposure to this virus is common, but it generally causes problems only in patients who have been treated with aggressive immunosuppressive therapy, such as chemotherapy for cancer. PML has also been reported in patients receiving drugs to treat…...