Drug- and vaccine induced ANCA-associated vasculitis: An overview.

Many different drugs and/or vaccines may cause vasculitis which can be sometimes very severe. The clinical presentation varies from isolated skin vasculitis to multi-organ involvement with pulmonary-renal manifestations and/or cerebral vasculitis. Whereas causality is difficult to prove and rechallenges are considered unethical, pathophysiological mechanisms suggesting causality have been demonstrated for drugs such as hydralazine, propylthiouracil, levamisole, and immune checkpoint inhibitors. An important pathophysiological mechanism of drug-induced anti-neutrophil autoantibody (ANCA)-associated vasculitis is the fact that several drugs have been demonstrated to increase the formation of neutrophil extracellular traps which may result in the development of autoimmunity. The first step in medical management of drug-induced ANCA-associated vasculitis is discontinuation of the offending drug and a transparent discussion with the patient regarding the possibility that the drug or the vaccine may have caused vasculitis. Additional treatment with steroids and immunosuppressants is often needed in more severe cases of ANCA-associated vasculitis. In general, however, the long-term prognosis of drug-induced ANCA-associated vasculitis is more favorable compared to the prognosis of idiopathic ANCA-associated vasculitis. Physicians that are treating patients with vasculitis should be aware of the possible role of drugs and vaccines in the development ANCA-associated vasculitis.