Background: There is an unmet need for a less toxic, corticosteroid sparing therapy in ANCA vasculitis (AAV), as up to 50% of patients relapse by 5 years and 20% have sub-optimal disease control. Hydroxychloroquine (HCQ) has been effective and safe in autoimmune diseases such as systemic lupus erythematosus and rheumatoid arthritis. There is mechanistic rationale for the effectiveness of hydroxychloroquine in vasculitis, considering its effect on immune mediators involved in pathogenesis, including B cell activating factors, Toll-like receptors, autoreactive T cells and cytokines.

Objectives: To assess retrospectively the efficacy and safety of hydroxychloroquine (HCQ) in patients with systemic vasculitis

Methods: Patients were identified by searching our departmental vasculitis database including 248 patients in total and electronic clinical records. Twenty-six patients received hydroxychloroquine along with corticosteroids and immunosuppressants. We assessed the effect of hydroxychloroquine on clinical symptoms and the median dose of corticosteroids required.

Results: Twenty six patients with various vasculitides were treated with hydroxychloroquine (median dose 200 mg OD): 6 patients with Henoch Schonlein purpura (HSP), 6 urticarial vasculitis, 6 with ANCA+ vasculitis (AAV) (4 PR3-ANCA, 2 MPO-ANCA), 1 Eosinophilic Granulomatosis with Polyangiitis (EGPA), 2 Takayasu arteritis, 2 Behcet's disease, 1 adult Still's disease (AOSD), 1 relapsing polychondritis, 1 polyarteritis nodosa (PAN). The female: male ratio was 21:5. Median age was 53 years. The median duration of HCQ treatment was 3 years. Sixteen patients experienced a reduction in arthralgia, skin rashes improved in 8 patients and completely resolved in a further 4. Eight patients could reduce corticosteroid doses (from 9 mg to 6 mg) and 3 discontinued corticosteroids. Four patients developed fewer vasculitic relapses, 6 felt less fatigued, 2 patients no longer experienced abdominal pain and diarrhoea, 2 improved their mood and ability to think clearly. The 6 patients with AAV experienced improvement in arthralgia, reduced their prednisolone doses by a third, had fewer relapses and felt less tired. One patient developed asymptomatic QT prolongation and stopped the hydroxychloroquine, with no other adverse events reported.

Conclusions: All 26 patients reported symptomatic benefits associated with hydroxychloroquine treatment, especially improvement in joint pains, fatigue, rash. Vasculitic relapses were less frequent, with a reduction in corticosteroid doses. Hydroxychloroquine was generally well tolerated.

Disclosure of Interest: None declared

DOI: 10.1136/annrheumdis-2016-eular.5464