ANCA-Associated Vasculitis Treatment in Singapore

What is ANCA-Associated Vasculitis?

ANCA-associated vasculitis (AAV) is a group of rare autoimmune diseases that cause inflammation and damage to small blood vessels. The three main forms are granulomatosis with polyangiitis (GPA), microscopic polyangiitis (MPA), and eosinophilic granulomatosis with polyangiitis (EGPA).

The inflammation can affect multiple organs, particularly the kidneys, lungs, upper airways, skin and peripheral nerves. The eyes, gastrointestinal system and other organs may also be affected.

AAV is often associated with antineutrophil cytoplasmic antibodies (ANCA), which can contribute to abnormal immune activity. However, not every patient with AAV tests positive for ANCA, and a positive ANCA result alone does not establish the diagnosis.

What is the Importance of Timely Treatment?

Early diagnosis and treatment are important because active vasculitis can rapidly damage organs, particularly the kidneys and lungs. Severe disease can lead to rapidly progressive kidney failure, pulmonary haemorrhage or other life-threatening complications. Treatment aims to control inflammation, achieve remission and prevent permanent organ damage and relapses. Current guidelines recommend prompt induction therapy for organ- or life-threatening disease.

What are the Common Symptoms of ANCA-Associated Vasculitis?

• Persistent fatigue and weakness
• Fever or unexplained weight loss
• Joint and muscle pain
• Skin rashes or purpura, particularly on the legs
• Sinusitis, nasal congestion or recurrent nose problems
• Nosebleeds or nasal crusting
• Cough or shortness of breath
• Coughing up blood in severe lung involvement
• Blood or protein in the urine
• Swelling of the legs or feet
• Reduced kidney function
• Numbness, tingling or weakness due to nerve involvement
• Eye redness, pain or vision changes
• Gastrointestinal pain or other organ-specific symptoms

Causes and Risk Factors of ANCA-Associated Vasculitis

Causes

• The exact cause of ANCA-associated vasculitis is not fully understood. It is believed to result from an abnormal immune response in which activated immune cells and, in many patients, ANCA antibodies contribute to inflammation and injury of small blood vessels.
• Genetic susceptibility and environmental or infectious triggers may contribute to disease development.

Risk Factors

• Genetic susceptibility
• Family history of autoimmune or vasculitic disease
• Exposure to certain environmental or occupational factors
• Some infections or medications, particularly in selected forms of ANCA-positive vasculitis
• Increasing age for certain AVV subtypes

Latest Research and Technologies in the Treatment of ANCA-Associated Vasculitis in Singapore

Treatment research focuses on achieving remission, reducing glucocorticoid exposure, preventing relapses and limiting treatment-related complications.

• Reduced-dose glucocorticoid regimens may be used to reduce treatment toxicity while controlling inflammation.
• Rituximab and cyclophosphamide are important remission-induction treatments for selected patients with severe GPA or MPA. Maintenance therapy is often required after remission.
• Avacopan, a complement C5a receptor inhibitor, may help reduce glucocorticoid exposure in selected adults with GPA or MPA when used with appropriate standard treatment. Its suitability and local availability should be confirmed with the treating specialist.
• Plasma exchange may be considered for selected patients with severe kidney involvement or other specific high-risk presentations. It is not routinely required for every patient with AAV.
• Research is investigating biomarkers, complement pathways and immune mechanisms to improve prediction of disease activity and relapse.
• Kidney biopsy, advanced chest imaging and bronchoscopy when indicated can help assess organ involvement and guide treatment.