The evolving landscape of vasculitis management: past, current and emerging.

Our understanding of ANCA vasculitis has advanced from discovery of putative auto-antibodies to a greater understanding of the myriad alterations of innate and adaptive immunity in this disease. The 21st International Vasculitis Workshop held in Barcelona served again as a forum for distributing and sharing advances in this field. B-cell and T-cell subsets are skewed in ANCA vasculitis patients, favoring a pro-inflammatory phenotype. Autoantigen expression of myeloperoxidase (MPO) and proteinase-3 (PR3) is influenced by alterations in chromatin modifications. Changes in DNA methylation may predict the likelihood of sustained remission in vasculitis patients. As our knowledge of disease pathogenesis and disease persistence have progressed, so too has our therapeutic armamentarium. Treatment options are emerging across a variety of immune targets, including the innate and adaptive immune system. Monoclonal antibodies targeting interleukins are available as are complement inhibitors that target the innate immune system. Addressing innate immune responses may be important to abate acute inflammatory responses at disease onset and limit subsequent damage, especially in patients with glomerulonephritis. With expanding therapeutic options, an important consideration remains as to when to stop therapy. A subset of patients discontinue therapy and remain off treatment without relapse, a state of long-term remission off therapy (LTROT). Future therapeutics could be derived from understanding the underlying immunological phenotype in LTROT and developing targeted therapies for durable remission without global immunosuppression. Management of ANCA vasculitis is moving rapidly towards more targeted, less toxic therapies that will optimistically lead to preservation, and perhaps restoration of health.