ANCA-Associated Vasculitis Pathogenesis and Management

Anti-neutrophil cytoplasmic antibody-associated vasculitis (AAV) comprises a group of small vessel disorders in which autoantibodies against neutrophil enzymes drive inflammation and vascular injury. Two principal antigenic targets, myeloperoxidase (MPO) and proteinase 3 (PR3), promote neutrophil activation, endothelial adhesion and release of reactive oxygen species. Genetic predisposition, environmental triggers and complement activation—particularly through the C5a–C5a receptor axis—amplify neutrophil priming and monocyte recruitment. Distinct clinical subsets are recognised: granulomatosis with polyangiitis (GPA) with granulomatous inflammation, microscopic polyangiitis (MPA) with predominantly necrotising vasculitis, and eosinophilic GPA (EGPA) with eosinophil-rich infiltrates. Organ systems commonly affected include the kidneys, lungs, skin and peripheral nerves. Standard induction regimens combine glucocorticoids with cyclophosphamide or rituximab, followed by maintenance therapy with azathioprine, methotrexate or periodic B-cell depletion. Emerging strategies target complement C5a receptor blockade, personalised immunophenotyping and minimisation of cumulative toxicity. Early diagnosis, careful monitoring of disease activity and tailored immunosuppression have improved long-term survival, reduced relapse rates and preserved organ function worldwide.

Research from Nature Portfolio

Recent single-cell multi-omics analysis of newly diagnosed MPA has delineated two immunological phenotypes: one dominated by CD14+ monocytes exhibiting interferon-stimulated signatures and another marked by activated monocytes persisting despite therapy. These phenotypes predict relapse risk and therapeutic response, paving the way for precision immunomodulation. A genome-wide association study of EGPA stratified by ANCA status uncovered distinct genetic loci for MPO+ ANCA EGPA—sharing HLA associations with other autoimmune vasculitides—and loci for ANCA-negative EGPA linked to mucosal barrier dysfunction. This genetic stratification suggests divergent pathogenic mechanisms and novel targets. A consensus expert statement has also endorsed high-precision immunoassays over indirect immunofluorescence for ANCA detection, standardising diagnostic workflows and reducing assay variability across laboratories.

ANCA-Associated Vasculitis Pathogenesis and Management publication trend

The graph below shows the total number of articles in anca-associated vasculitis pathogenesis and management across all publications each year (not limited to Nature Index journals).

Technical terms

ANCA: autoantibodies directed against neutrophil cytoplasmic antigens, central to small vessel vasculitis.

Myeloperoxidase (MPO): neutrophil granule enzyme targeted by one ANCA subtype, often linked to renal involvement.

Proteinase 3 (PR3): serine protease in neutrophils recognised by another ANCA subtype, associated with granulomatous inflammation.

Complement C5a receptor: cell-surface receptor mediating neutrophil recruitment and activation following complement cleavage.

CD14+ monocyte: circulating myeloid cell subset implicated in antigen presentation and cytokine production in vasculitis.

Interferon-stimulated genes: transcripts induced by type I interferons, marking an inflammatory monocyte phenotype.

Genome-wide association study (GWAS): analysis identifying genetic loci associated with disease susceptibility across the genome.

References

1. Single-cell multi-omics analysis identifies two distinct phenotypes of newly-onset microscopic polyangiitis. Nature Communications (2023).
2. Genome-wide association study of eosinophilic granulomatosis with polyangiitis reveals genomic loci stratified by ANCA status. Nature Communications (2019).
3. Revised 2017 international consensus on testing of ANCAs in granulomatosis with polyangiitis and microscopic polyangiitis. Nature Reviews Rheumatology (2017).
4. Rituximab as therapy to induce remission after relapse in ANCA-associated vasculitis. Annals of the Rheumatic Diseases (2020).
5. Long-term follow-up of a combined rituximab and cyclophosphamide regimen in renal anti-neutrophil cytoplasm antibody-associated vasculitis. Nephrology Dialysis Transplantation (2018).
6. ANCA-Associated Vasculitis: An Update. Journal of Clinical Medicine (2021).