What is the initial treatment approach for patients with vasculitis?

Initial Treatment Approach for Vasculitis

High-dose glucocorticoid therapy should be initiated immediately for induction of remission in patients with vasculitis, with adjunctive immunosuppressive therapy added based on the specific type of vasculitis and disease severity. 1, 2

Classification and Initial Assessment

• Vasculitis should be classified according to vessel size (large, medium, or small) and disease severity to guide appropriate management 2
• Suspected diagnosis of large vessel vasculitis should be confirmed by imaging or histology before initiating treatment 1
• In ANCA-associated vasculitis with positive serology and rapidly deteriorating patients, treatment should not be delayed while waiting for biopsy results 2

Initial Treatment by Vasculitis Type

Large Vessel Vasculitis (Giant Cell Arteritis and Takayasu Arteritis)

• High-dose glucocorticoid therapy (40-60 mg/day prednisone-equivalent) should be initiated immediately for induction of remission 1, 2
• Maintain high-dose glucocorticoids for one month before gradual tapering 2
• For Giant Cell Arteritis (GCA):
  • Consider adjunctive therapy in selected patients (refractory/relapsing disease or increased risk for glucocorticoid-related adverse events) using tocilizumab 1
  • Methotrexate may be used as an alternative steroid-sparing agent 1, 2
• For Takayasu Arteritis (TAK):
  • All patients should receive non-biological glucocorticoid-sparing agents in combination with glucocorticoids 1, 2
  • Biological agents may be used in refractory or relapsing patients 1

ANCA-Associated Vasculitis (AAV)

• Combination therapy with glucocorticoids and either rituximab or cyclophosphamide is recommended as initial treatment 2, 3
• For patients with severe disease (markedly reduced or rapidly declining renal function, pulmonary hemorrhage):
  • Consider cyclophosphamide plus glucocorticoids, or a combination of rituximab and cyclophosphamide 2
  • More aggressive initial therapy may be required 2
• Factors favoring cyclophosphamide include severe renal disease 2
• Factors favoring rituximab include younger patients concerned about fertility and those with relapsing disease 2, 3

Dosing and Administration

• Glucocorticoids: Initial dose of 1 mg/kg/day (maximum 60 mg/day) for large vessel vasculitis 2
• Rituximab: For ANCA-associated vasculitis, 375 mg/m² once weekly for 4 weeks 3
• Cyclophosphamide: Oral dose of 2 mg/kg/day for 3-6 months in remission induction phase 2, 3

Common Pitfalls to Avoid

• Delaying treatment while waiting for biopsy results in rapidly deteriorating patients 2
• Using alternate-day glucocorticoid therapy, which increases risk of relapse 2
• Inadequate initial immunosuppression in severe disease 2
• Routine use of antiplatelet or anticoagulant therapy is no longer recommended for treatment of large vessel vasculitis unless indicated for other reasons 1

Monitoring and Follow-up

• Regular assessment of disease activity using validated tools such as Birmingham Vasculitis Activity Score (BVAS) 2
• ANCA persistence, increase in ANCA levels, or change from negative to positive may predict future relapse and should be considered when making treatment decisions 2
• Monitor for drug toxicity, including acute fall in white cell count, progressive leucopenia, and renal function 2
• Consider prophylaxis against Pneumocystis jiroveci and osteoporosis for patients on immunosuppressive therapy 2

Special Considerations

• Patients with AAV should be treated at centers with experience in AAV management 2
• Infusion-related reactions are common with rituximab (12% of patients), with the highest incidence during or after the first infusion 3
• Hypogammaglobulinemia may occur in patients treated with rituximab 3
• Infections are a common adverse event with both rituximab and cyclophosphamide treatment 3