What does the American College of Rheumatology (ACR) guideline recommend for induction and maintenance treatment of eosinophilic granulomatosis with polyangiitis (EGPA) based on disease severity and organ involvement?

ACR Guidelines for Eosinophilic Granulomatosis with Polyangiitis (EGPA)

Disease Severity Stratification

Treatment for EGPA must be stratified by disease severity using the Five-Factor Score (FFS) and presence of organ-threatening manifestations. 1

• Severe EGPA is defined by FFS ≥1 or presence of:

  • Renal insufficiency or proteinuria 1
  • Cardiomyopathy 1
  • Gastrointestinal tract involvement 1
  • Central nervous system involvement 1
  • Peripheral neuropathy 1
  • Alveolar hemorrhage 1

• Non-severe EGPA lacks these organ-threatening manifestations 1

Remission Induction Therapy

Severe EGPA (New-Onset, Active Disease)

For severe EGPA, initiate high-dose glucocorticoids combined with either cyclophosphamide or rituximab as first-line therapy. 1

• Glucocorticoids are mandatory as initial therapy in all patients 1
• Add cyclophosphamide as the primary immunosuppressant 1
• Rituximab is an acceptable alternative to cyclophosphamide 1, 2
• Rituximab is effective even in patients previously refractory to cyclophosphamide, with 36% achieving complete remission and all others achieving partial remission 2

Non-Severe EGPA (New-Onset, Active Disease)

For non-severe EGPA, glucocorticoids alone should be used as initial therapy. 1

• Glucocorticoid monotherapy is appropriate when organ-threatening features are absent 1
• Mepolizumab can be added to glucocorticoids in non-severe disease 1

Remission Maintenance Therapy

Severe EGPA

For maintenance in severe EGPA, use rituximab, mepolizumab, or traditional DMARDs in combination with glucocorticoids. 1

• Rituximab is recommended at 500 mg IV every 6 months 1
• Mepolizumab (IL-5 inhibitor) is an effective alternative 1
• Traditional DMARDs (methotrexate, azathioprine, mycophenolate mofetil) can be used 1
• Taper glucocorticoids to the minimum effective dose, with a target of ≤7.5 mg prednisone daily 1

Non-Severe EGPA

For non-severe EGPA maintenance, use glucocorticoids alone or combined with mepolizumab. 1

• Glucocorticoid monotherapy is acceptable 1
• Adding mepolizumab is particularly beneficial for patients requiring prednisone ≥7.5 mg daily for respiratory manifestations 1

Relapse Management

Defining Relapse

EGPA relapse is the recurrence of clinical signs or symptoms after remission, or the need to increase glucocorticoid dose or initiate/increase immunosuppressants. 1

• Critical distinction: Differentiate systemic relapse (vasculitis recurrence) from respiratory relapse (isolated asthma/ENT exacerbation) 1

Severe Systemic Relapses

For severe systemic relapses, use rituximab or cyclophosphamide with glucocorticoids. 1

• Rituximab is preferred over cyclophosphamide for relapses 1
• Treatment approach mirrors initial induction for severe disease 1

Non-Severe Systemic and Respiratory Relapses

For non-severe relapses, increase glucocorticoid dose and/or add mepolizumab. 1

• Escalate glucocorticoid dosing first 1
• Mepolizumab addition is particularly effective for respiratory relapses 1

Refractory Disease Management

Defining Refractory EGPA

Refractory EGPA is unchanged or increased disease activity after 4 weeks of appropriate remission-induction therapy. 1

• Distinguish systemic manifestation persistence from respiratory manifestation persistence 1

Treatment of Refractory Disease

For relapsing-refractory EGPA without organ- or life-threatening manifestations, use mepolizumab (IL-5 inhibitor) combined with glucocorticoids. 1

• Mepolizumab is specifically recommended for patients without severe organ involvement 1
• Mepolizumab is effective for remission maintenance, especially when prednisone ≥7.5 mg daily is needed for respiratory control 1
• Rituximab can be considered for ANCA-positive EGPA with severe vasculitis recurrence, though formal evidence is limited 3

Special Respiratory Management

In patients with active asthma or ENT involvement, optimize topical and/or inhaled therapy with specialist involvement. 1

• Pulmonologists should manage asthma components 1
• Otolaryngologists should manage ENT manifestations 1
• Systemic immunosuppression must accompany local therapies 1

Remission Definition

Remission is defined as absence of clinical signs or symptoms attributable to active disease, including asthma and ENT manifestations, with prednisone ≤7.5 mg daily. 1

• Both systemic and respiratory manifestations must be controlled 1
• Glucocorticoid dose is part of the remission definition 1

Monitoring Recommendations

Disease activity should be assessed using validated clinical tools only, not laboratory biomarkers alone. 1

• Eosinophil count and ANCA are commonly monitored but are unreliable for measuring disease activity 1
• Routine monitoring of lung function, cardiovascular events, and neurological complications is mandatory 1
• Long-term monitoring for comorbidities (cancer, infections, osteoporosis) is essential 1

Important Caveats

ANCA status (positive vs. negative) does not necessitate different treatment approaches. 1

• Approximately one-third of EGPA patients are ANCA-positive 1
• Treatment decisions are based on disease severity and organ involvement, not ANCA status 1

Treatment modifications are necessary for special populations (children, elderly, women of childbearing age, patients with comorbidities). 1

Relapse-free survival at 36 months is comparable between rituximab and cyclophosphamide, but rituximab-treated patients should be monitored for hypogammaglobulinemia. 2