What is Granulomatosis with Polyangiitis (GPA), formerly known as Wegener's granulomatosis?

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From the Guidelines

Wegener's granulomatosis, now known as granulomatosis with polyangiitis (GPA), should be treated with a combination of corticosteroids and immunosuppressants, with rituximab (375 mg/m² weekly for 4 weeks) being the preferred option over cyclophosphamide for remission induction, as recommended by the 2021 American College of Rheumatology/Vasculitis Foundation guideline 1.

Treatment Approach

The treatment approach for GPA typically involves a combination of high-dose prednisone (1 mg/kg/day, maximum 80 mg daily) and an immunosuppressant, such as rituximab or cyclophosphamide.

  • Induction therapy usually lasts 3-6 months until remission is achieved.
  • Maintenance therapy follows with less toxic medications like azathioprine (2 mg/kg/day), methotrexate (20-25 mg weekly), or mycophenolate mofetil (2 g/day) for at least 18-24 months.

Disease Characteristics

GPA is characterized by the presence of anti-neutrophil cytoplasmic antibodies (ANCA), particularly those targeting proteinase 3, which contribute to the inflammatory process by activating neutrophils that damage blood vessel walls 1.

Treatment Recommendations

The 2021 American College of Rheumatology/Vasculitis Foundation guideline recommends the following treatment approach for GPA:

  • Remission induction therapy: rituximab (375 mg/m² weekly for 4 weeks) or cyclophosphamide (either oral at 2 mg/kg/day or intravenous pulses) 1.
  • Remission maintenance therapy: azathioprine (2 mg/kg/day), methotrexate (20-25 mg weekly), or mycophenolate mofetil (2 g/day) for at least 18-24 months 1.

Important Considerations

Trimethoprim-sulfamethoxazole may be added to prevent Pneumocystis pneumonia and potentially reduce relapse risk 1. The disease can be life-threatening if left untreated, with potential complications including kidney failure, lung damage, and cardiovascular problems 1.

From the Research

Definition and Treatment of Wegener's Granulomatosis

  • Wegener's granulomatosis (WG) is a form of systemic vasculitis that typically involves the kidneys and upper and lower respiratory tract 2.
  • The treatment of WG aims to limit the extent and severity of permanent organ damage by controlling the disease promptly and to minimize the short- and long-term morbidity that often results from therapy 3.
  • The mainstay of therapy for generalized, multisystemic WG is cyclophosphamide (CYC) plus corticosteroids (CS), but concern about late toxicities associated with CYC has led to novel treatment approaches 2.

Treatment Strategies

  • Current treatment strategies involve a short-course (3-6 months) induction treatment with CYC plus CS, followed by maintenance therapy with less toxic agents (e.g., methotrexate, azathioprine) 2.
  • Rituximab, a chimeric anti-CD20 antibody, has been shown to be effective in inducing remission in patients with refractory WG 4, 5, 6.
  • Leflunomide maintenance may increase the efficacy of rituximab and prolong the disease-free period 4.

Clinical Manifestations and Pathogenesis

  • Clinical manifestations of WG are protean, and virtually any organ can be involved 2.
  • The pathogenesis of WG has not been elucidated, but both cellular and humoral components are involved, and circulating antineutrophil cytoplasmic antibodies (cANCA) likely play a role in the pathogenesis and often correlate with activity of the disease 2.

Efficacy and Safety of Rituximab

  • Rituximab has been shown to be well-tolerated and effective in inducing remission in patients with refractory WG 4, 5, 6.
  • Rituximab can cause swift B-lymphocyte depletion and complete clinical remission, and can be retreated for recurring/rising ANCA titers 6.

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Research

Wegener's granulomatosis: evolving concepts in treatment.

Seminars in respiratory and critical care medicine, 2004

Research

Treatment of Wegener's granulomatosis.

Rheumatic diseases clinics of North America, 2001

Research

Rituximab for refractory Wegener's granulomatosis: report of a prospective, open-label pilot trial.

American journal of respiratory and critical care medicine, 2006

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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