What is the initial treatment for vasculitis?

Initial Treatment for Vasculitis

The initial treatment for vasculitis should be high-dose glucocorticoids combined with either cyclophosphamide or rituximab, with the specific regimen determined by the type of vasculitis, disease severity, and organ involvement. 1, 2

Classification and Treatment Approach

• Treatment decisions must be based on vasculitis classification by vessel size, disease severity, and organ involvement to ensure appropriate management 1
• Vasculitis should be categorized as large vessel (Giant Cell Arteritis, Takayasu Arteritis), medium vessel, or small vessel (ANCA-associated) to guide therapy 2
• For ANCA-associated vasculitis (AAV), patients should be further classified as having localized, early systemic, generalized, severe, or refractory disease 2

Initial Treatment Regimens by Vasculitis Type

ANCA-Associated Vasculitis (AAV)

• First-line induction therapy: High-dose glucocorticoids (prednisolone 1 mg/kg/day, maximum 60 mg/day) combined with either:
  • Cyclophosphamide (oral 2 mg/kg/day or IV pulsed at 15 mg/kg every 2-3 weeks) OR
  • Rituximab (375 mg/m² weekly for 4 weeks) 1, 2
• Factors favoring cyclophosphamide include severe renal disease 2
• Factors favoring rituximab include younger patients concerned about fertility and those with relapsing disease 1, 2
• For severe disease with pulmonary hemorrhage or rapidly progressive renal disease, consider combination of rituximab and cyclophosphamide 2
• Add plasmapheresis for patients with rapidly increasing serum creatinine, dialysis requirement, diffuse pulmonary hemorrhage, or anti-GBM overlap syndrome 1

Large Vessel Vasculitis

• Giant Cell Arteritis: Immediate high-dose glucocorticoids with consideration of adjunctive immunosuppressive therapy (methotrexate or tocilizumab) as steroid-sparing agents 1, 2
• Takayasu Arteritis: Non-biological glucocorticoid-sparing agents in combination with glucocorticoids 2

Dosing and Administration

• Glucocorticoids: Initial dose of 1 mg/kg/day (maximum 60 mg/day) 1, 2
• Cyclophosphamide dosing:
  • Oral: 2 mg/kg/day (maximum 200 mg/day)
  • IV pulse: 15 mg/kg every 2-3 weeks
  • Adjust dose for renal function and age 1
• Rituximab: 375 mg/m² weekly for 4 weeks 1, 3

Duration of Initial Treatment

• Maintain high-dose glucocorticoids for 1 month, then taper gradually 1, 2
• Discontinue cyclophosphamide after 3 months in patients who remain dialysis-dependent without extrarenal manifestations 1
• For most patients, transition to maintenance therapy after 3-6 months of induction therapy 1

Supportive Care and Prophylaxis

• Provide Pneumocystis jiroveci prophylaxis with trimethoprim-sulfamethoxazole for all patients on cyclophosphamide 1
• Administer mesna to patients receiving cyclophosphamide to prevent hemorrhagic cystitis 1
• Initiate bone protection therapy for patients on long-term glucocorticoids 1
• Regularly monitor blood counts, renal function, and urinalysis 1

Common Pitfalls to Avoid

• Do not delay treatment while waiting for biopsy results in rapidly deteriorating patients 1, 2
• Avoid alternate-day glucocorticoid therapy, which increases risk of relapse 2
• Do not provide inadequate initial immunosuppression in severe disease 1, 2
• Avoid changing immunosuppression based solely on changes in ANCA titer 1
• Be aware that glucocorticoid side effects significantly impact patients' quality of life, with moon face/buffalo hump, weight gain, insomnia, and decreased quality of life reported as most troublesome 4

Special Considerations

• Patients with AAV should be treated at centers with experience in AAV management when possible 2
• Drug-induced vasculitis may resolve with withdrawal of the offending agent alone, without requiring immunosuppressive therapy 5
• Be aware that biological agents themselves can rarely induce vasculitis as an adverse effect, particularly anti-TNF-α medications 6