Background Background. Because of the relatively small numbers of patients evaluated in the studies, primary central nervous system vasculitis (PCNSV) response to treatment is still uncertain.

Objectives To determine the response to therapy and long-term outcome of PCNSV we reviewed all cases of PCNSV seen at Mayo Clinic (Rochester, MN) from 1983 to 2011.

Methods The study consisted of a cohort of 163 consecutive patients with PCNSV who were seen at the Mayo Clinic over a 29-year period. The diagnosis of PCNSV was based on findings of brain or spinal cord biopsy, cerebral angiography, or both. Clinical, laboratory, radiological, pathological findings, therapy and outcomes of patients were collected.

Results GCs therapy was prescribed for 157 patients. In 75 patients, GCs initially were the only therapeutic agents used. The median initial oral prednisone dose was 60 mg/day. The median duration of prednisone therapy was 10 months. 74 patients received cyclophosphamide (CYC). 72/74 associated GCs. The median initial dose of oral CYC was 150 mg/day and the median duration of therapy was 7 months. 6 of the 157 patients initially received azathioprine (median initial dose 100 mg/day) and GCs, 3 mycophenolate mophetil and GCs, and one rituximab and GCs. Two patients associated plasma-exchange to CYC and GC therapy, and one infliximab. A favorable response to therapy was observed for 83% of patients treated with GCs alone and 76% treated with CYC. 44 patients had relapses that led to a change in therapy. The frequency of relapses were significantly lower in the patients treated with CYC compared to those treated with GCs alone (18% vs 39%, p=0.006). The median follow-up duration was 12 months (range: 0-13.7 years). Univariate logistic modeling was used to assess association of findings at diagnosis with the persistence of therapy at last follow-up, relapsing disease (at least 1 relapse), response to therapy, and Rankin score outcomes. Persistence of therapy at last follow-up was significantly associated y with MRI evidence of gadolinium enhanced cerebral lesions or meninges (OR: 2.3). Prednisone alone treatment was the only finding significantly associated with relapsing disease (OR: 2.9) MRI evidence of cerebral infarction (OR: 3.3) and large vessel involvement (OR: 6.1) were significantly associated with a poor response to therapy. Age- and sex-adjusted survival of the patients with PCNSV was significantly reduced compared to the estimated survival of the US white population (p<0.001). High disability scores at last follow-up (Rankin score of 4-6) were associated with older age (OR: 1.4) and MRI evidence of cerebral infarction (OR: 3.7), while patients with gadolinium enhanced cerebral lesions or meninges had lower disability at follow-up (OR: 0.35).

Conclusions Most patients with PCNSV showed a favorable response to GCs alone or in combination with CYC. Recognition of findings associated at diagnosis with therapy response and poor outcomes may aid decisions regarding therapy.

Disclosure of Interest None declared

DOI 10.1136/annrheumdis-2014-eular.2796