Discontinuation of therapies in vasculitis.
For most patients with vasculitis, treatment will result in prevention of mortality and also lead to clinical remission. This increased survival is of course most welcome, but the burden of surviving an episode of acute vasculitis consists of the effects of the disease as well as the adverse events from treatment. Therefore, we have begun to explore the possibility of withdrawing treatment in order to avoid long-term medication toxicities. Whilst this will reduce short-term side effects, if withdrawal leads to subsequent uncontrolled flares of disease, the need for additional therapy may outweigh any benefit from a drug-free holiday. For very mild forms of vasculitis, such as isolated skin vasculitis, the best option may be to avoid treatment altogether. In those patients with vasculitis secondary to an identifiable agent such as drug toxicity or an infectious organism, discontinuing the offending drug or treating the infection will usually resolve or cure the vasculitis. In patients with localised vasculitis, surgical removal of the affected area can be curative. Other forms of vasculitis have a self-limited duration, after which there does not appear to be any clinical evidence of disease, such as is the case for the majority of patients with giant cell arteritis. By contrast, in many forms of vasculitis, especially those associated with the presence of anti-neutrophil cytoplasm antibody (ANCA), relapse occurs in at least half the patients. Where glucocorticoid therapy is used for any length of time, in doses of >5 mg/day, side effects are almost universal. Adding a concomitant agent in the attempt to shorten the course and/or reduce the dose of glucocorticoid treatment may be effective, but can also result in toxicity from the alternative agent, and leaves the patient on immunosuppressive therapy. More toxic therapy, such as cyclophosphamide, usually is administered only for a limited time or cumulative amount, in order to achieve induction of remission or flare in severe disease. The advent of targeted biologic therapy offers the opportunity to provide more effective, less toxic and perhaps more long-lasting control of disease. Rituximab in small-vessel vasculitis can result in long-lasting control of disease, for 18 months or more, from a single course of treatment. Suppression of the interleukin-6 pathway may be effective in large-vessel vasculitis. Unfortunately, none of these therapies is capable of 'cure' for the majority of patients. Therefore, discontinuation of therapy remains unachievable for most patients with vasculitis, at least in the first few years of disease. Short courses of intensive, aggressive therapy are followed by the use of maintenance treatment. Long-term follow-up studies are required to determine the potential benefit of early, more effective control of vasculitis.