Anti-neutrophil cytoplasmic antibody-associated vasculitis

= Anti-neutrophil Cytoplasmic Antibody-associated Vasculitis = Anti-neutrophil cytoplasmic antibody-associated vasculitis (ANCA-associated vasculitis) is a group of rare autoimmune diseases characterized by inflammation of small to medium-sized blood vessels. This inflammation can lead to damage in various organs, most commonly the kidneys and lungs.

Classification

ANCA-associated vasculitis is classified into three main types:

• Granulomatosis with polyangiitis (GPA), formerly known as Wegener's granulomatosis.
• Microscopic polyangiitis (MPA).
• Eosinophilic granulomatosis with polyangiitis (EGPA), formerly known as Churg-Strauss syndrome.

Pathophysiology

The pathophysiology of ANCA-associated vasculitis involves the production of autoantibodies against neutrophil cytoplasmic antigens. These antibodies, known as ANCAs, primarily target two proteins:

• Proteinase 3 (PR3), associated with GPA.
• Myeloperoxidase (MPO), associated with MPA and EGPA.

The binding of ANCAs to these antigens on neutrophils leads to neutrophil activation, degranulation, and the release of reactive oxygen species, causing damage to the endothelium of blood vessels.

Clinical Features

The clinical presentation of ANCA-associated vasculitis can vary widely depending on the organs involved. Common symptoms include:

• Renal involvement: Hematuria, proteinuria, and renal failure.
• Pulmonary involvement: Cough, hemoptysis, and pulmonary infiltrates.
• ENT involvement: Sinusitis, nasal crusting, and otitis media.
• Skin involvement: Purpura and skin ulcers.

Diagnosis

Diagnosis of ANCA-associated vasculitis involves a combination of clinical evaluation, laboratory tests, and imaging studies. Key diagnostic tests include:

• ANCA testing: Detection of PR3-ANCA or MPO-ANCA in the blood.
• Biopsy: Histological examination of affected tissues, such as kidney or lung, to confirm vasculitis.
• Imaging studies: CT or MRI to assess organ involvement.

Treatment

The treatment of ANCA-associated vasculitis typically involves immunosuppressive therapy to control inflammation and prevent organ damage. Common treatment regimens include:

• Corticosteroids: High-dose prednisone to rapidly reduce inflammation.
• Cyclophosphamide or Rituximab: To induce remission.
• Azathioprine or Methotrexate: For maintenance therapy.

Prognosis

The prognosis of ANCA-associated vasculitis has improved significantly with modern treatment strategies. However, the disease can be life-threatening if not treated promptly. Long-term management focuses on preventing relapses and monitoring for treatment-related side effects.

See Also

• Autoimmune diseases
• Vasculitis
• Nephrology

External Links

• [Vasculitis Foundation](https://www.vasculitisfoundation.org/)
• National Organization for Rare Disorders

NIH genetic and rare disease info

• NIH info on Anti-neutrophil cytoplasmic antibody-associated vasculitis

Anti-neutrophil cytoplasmic antibody-associated vasculitis is a rare disease.