Review

Seminars in Immunopathology

, Volume 36, Issue 4, pp 461-478

Open Access This content is freely available online to anyone, anywhere at any time.

The immunopathology of ANCA-associated vasculitis

  • Eoin F. McKinneyAffiliated withThe Cambridge Institute for Medical Research and the Department of Medicine, University of Cambridge School of Clinical MedicineThe Vasculitis and Lupus Service, Addenbrooke’s Hospital Email author 
  • , Lisa C. WillcocksAffiliated withThe Vasculitis and Lupus Service, Addenbrooke’s Hospital Email author 
  • , Verena BroeckerAffiliated withThe Department of Pathology, Addenbrooke’s Hospital
  • , Kenneth G. C. SmithAffiliated withThe Cambridge Institute for Medical Research and the Department of Medicine, University of Cambridge School of Clinical MedicineThe Vasculitis and Lupus Service, Addenbrooke’s Hospital

Abstract

The small-vessel vasculitides are a group of disorders characterised by variable patterns of small blood vessel inflammation producing a markedly heterogeneous clinical phenotype. While any vessel in any organ may be involved, distinct but often overlapping sets of clinical features have allowed the description of three subtypes associated with the presence of circulating anti-neutrophil cytoplasmic antibodies (ANCA), namely granulomatosis with polyangiitis (GPA, formerly known as Wegener’s Granulomatosis), microscopic polyangiitis (MPA) and eosinophilic granulomatosis with polyangiitis (eGPA, formerly known as Churg-Strauss syndrome). Together, these conditions are called the ANCA-associated vasculitidies (AAV). Both formal nomenclature and classification criteria for the syndromes have changed repeatedly since their description over 100 years ago and may conceivably do so again following recent reports showing distinct genetic associations of patients with detectable ANCA of distinct specificities. ANCA are not only useful in classifying the syndromes but substantial evidence implicates them in driving disease pathogenesis although the mechanism by which they develop and tolerance is broken remains controversial. Advances in our understanding of the pathogenesis of the syndromes have been accompanied by some progress in treatment, although much remains to be done to improve the chronic morbidity associated with the immunosuppression required for disease control.

Keywords

ANCA Vasculitis Anti-neutrophil cytoplasmic antibody PR3 MPO