From the Guidelines

The appropriate steroid dose for P-ANCA vasculitis with pulmonary complications is oral prednisolone or prednisone starting at 1.0 mg/kg/d.

The dose of glucocorticoids may need to be adjusted based on the severity of the disease and the patient's response to treatment 1.
A more rapid reduction in glucocorticoid dose may be as effective as, but safer than, a standard glucocorticoid-tapering regimen, especially in patients with impaired kidney function 1.
Reduced-dose glucocorticoids (0.5 mg/kg/d) may be noninferior to high-dose glucocorticoids (1 mg/kg/d) in achieving remission, with fewer severe infections 1.

The KDIGO 2024 clinical practice guideline recommends glucocorticoids as a major contributor to treatment, but notes that the optimal dose and duration of treatment are uncertain 1.
Intravenous methylprednisolone (doses of 1-3 g) may be used for more severe presentations, but has not been tested in a randomized controlled trial 1.
Avacopan, an oral C5a receptor antagonist, may be an effective alternative to glucocorticoid treatment in AAV, with potential to improve kidney outcomes 1.

Glucocorticoids should be used in combination with other immunosuppressive agents, such as rituximab or cyclophosphamide, to induce remission in P-ANCA vasculitis with pulmonary complications 1.
The treatment approach should be individualized based on the patient's disease severity, kidney function, and other comorbidities 1.

From the Research

The appropriate steroid dose for P-ANCA vasculitis with pulmonary complications is not explicitly stated in the provided studies, but the treatment regimens mentioned can be used as a reference 2, 3, 4, 5, 6.
A study published in 2020 compared the use of standard-dose and reduced-dose regimens of oral glucocorticoids in patients with severe ANCA-associated vasculitis, and found that the reduced-dose regimen was noninferior to the standard-dose regimen with respect to death or end-stage kidney disease 3.
Another study published in 2013 mentioned that high-dose corticosteroid and cyclophosphamide were used to induce remission in patients with severe form of ANCA-associated vasculitis, while low-dose corticosteroid and cyclophosphamide or azathioprine were used in patients with mild form 4.
A case report published in 2008 described a patient with p-ANCA positive vasculitis who relapsed one year after starting hemodialysis treatment, and was successfully treated with steroids and cyclophosphamide 6.
The treatment regimens for ANCA-associated vasculitis often involve the use of glucocorticoids, cyclophosphamide, and other immunosuppressive agents, and the choice of treatment depends on the severity of the disease and the patient's response to therapy 2, 3, 4, 5, 6.

The treatment regimens for ANCA-associated vasculitis can be categorized into induction and maintenance phases, with the goal of inducing remission and preventing relapse 5.
Induction therapy often involves the use of cyclophosphamide or rituximab in combination with glucocorticoids, while maintenance therapy involves the use of rituximab, azathioprine, or methotrexate, with glucocorticoids being tapered 5.
The use of plasma exchange has also been studied in patients with severe ANCA-associated vasculitis, but its effectiveness is still debated 3.

The severity of ANCA-associated vasculitis can affect the treatment outcome, with more severe disease often requiring more aggressive treatment regimens 2, 3, 4, 5, 6.
The presence of pulmonary complications, such as diffuse alveolar hemorrhage and pulmonary fibrosis, can also impact the treatment outcome and require more intensive treatment regimens 4.