What is the primary treatment for Wegener's granulomatosis with polyangiitis?

Wegener's granulomatosis, now more commonly referred to as granulomatosis with polyangiitis (GPA), is a type of vasculitis that primarily affects small to medium-sized blood vessels. The condition is characterized by a triad of symptoms: necrotizing granulomatous inflammation, vasculitis, and involvement of the respiratory tract, kidneys, and often other organs.

The primary treatment for this condition focuses on suppressing the immune system to reduce inflammation and prevent damage to affected organs. The combination of cyclophosphamide and corticosteroids is effective because cyclophosphamide is a powerful immunosuppressive agent that targets rapidly dividing cells, including lymphocytes that drive the autoimmune process, while corticosteroids provide rapid anti-inflammatory effects that can help control symptoms and prevent relapses.

This treatment approach has been shown to be most effective in inducing remission, especially in severe cases involving organ systems such as the kidneys (indicated by rapidly progressive glomerulonephritis) or the lungs. The combination therapy not only aims to control acute disease manifestations but also helps reduce the risk of long-term complications associated with GPA.

Other treatment options like corticosteroids alone may not be sufficient for severe disease manifestations, and antibiotics like penicillin