Demographic and clinical characteristics
Fifty-nine patients with newly diagnosed or relapsing GPA (n=41) or MPA (n=18) were enrolled in this prospective study (Table 1). All patients presented with active vasculitis with a median BVAS of 16.5. Thirty-five patients had newly diagnosed AAV. Twenty-three of them were studied within 4-6 weeks after initiation of immunosuppressive therapy (up to 2-3 infusions of cyclophosphamide with high dose glucocorticoids) that was started before referral to our clinic, whereas 12 patients were not treated with any immunosuppressive agents at the time of testing. Twenty-four patients had relapsing AAV and continued maintenance immunosuppressive therapy at the time of testing. Six ANCA-negative patients had biopsy-proven localized GPA.
n 28 patients, testing was repeated in remission within 3 to 38 months (median 16 months) after the initiation of immunosuppressive treatment with rituximab (n=4), cyclophosphamide (n=20), methotrexate (n=3) or mycophenolate mofetil (n=1). Thirty-six healthy volunteers (9 males and 27 females, average age 55.7±12.4 years) comprised the control group.