What is the first-line treatment for severe Wegener's granulomatosis?

Severe Wegener's granulomatosis, also known as Granulomatosis with Polyangiitis (GPA), typically requires strong immunosuppressive therapy due to the life-threatening nature of the disease and its potential to involve vital organs such as the kidneys and lungs. Cyclophosphamide is considered first-line treatment for patients with severe manifestations of the disease, as it is effective in rapidly inducing remission.

Cyclophosphamide works as an alkylating agent that inhibits DNA synthesis and consequently acts on rapidly dividing cells, including those of the immune system. This results in the suppression of the aggressive immune response seen in Wegener's granulomatosis, thereby reducing inflammation and damage to affected tissues.

Corticosteroids are often used in conjunction with cyclophosphamide to help control inflammation more rapidly, but they are not used as monotherapy for severe cases due to insufficient effectiveness in controlling the disease on their own. Other agents like azathioprine may be used for maintenance therapy after remission has been achieved, but they are not suitable for initial treatment in severe cases.

Therefore, the strong immunosuppressive action of cyclophosphamide makes it the most appropriate choice for promptly addressing severe Wegener's granulomatosis and