Hydroxychloroquine as a potential therapy for ANCA-associated vasculitis

Antimalarial agents have been used to treat various autoimmune rheumatic diseases for over a century. Hydroxychloroquine is a safe, effective and inexpensive antimalarial drug with additional antithrombotic, cardioprotective, antimicrobial, and anti-neoplastic benefits. It has been used extensively in various diseases, especially systemic lupus erythematosus and rheumatoid arthritis; however, it has not been used in anti-neutrophil cytoplasmic antibody associated vasculitides (AAVs). There exists a significant unmet need for safe and inexpensive treatments for non-severe AAV or those with low-grade “grumbling” disease activity who do not warrant significant escalation of therapy but who remain at risk of disease flares and damage accumulation. Hydroxychloroquine may be an option to help fill this void. Although the mechanisms of action of Hydroxychloroquine are not fully understood, it interacts with various inflammatory mediators involved in the pathogenesis of AAV. Based on these benefits, along with the unmet need in AAV, we present evidence to support the use of Hydroxychloroquine as a potential therapy for AAV.