Treatment of Diffuse Alveolar Hemorrhage

Immediate Immunosuppressive Therapy

The American Society of Nephrology recommends immediate initiation of high-dose intravenous glucocorticoids combined with either rituximab or cyclophosphamide for diffuse alveolar hemorrhage with hypoxemia, and strongly consider adding plasma exchange 1, 2
Administer IV methylprednisolone 500-1000 mg/day for 3 consecutive days, with a maximum cumulative dose of 3 grams, as recommended by the Kidney International guidelines 3, 4
Transition to weight-based oral prednisone, with dosing as follows: <50 kg: 50 mg/day, 50-75 kg: 60 mg/day, >75 kg: 75 mg/day, according to the Kidney International guidelines 5
Taper gradually to reach 5 mg/day by weeks 19-52, as recommended by the Kidney International guidelines 5, 4

Rituximab is preferred over cyclophosphamide when combined with glucocorticoids for remission induction, with a dosing regimen of 375 mg/m²/week × 4 weeks, as recommended by the Kidney International guidelines 3, 5
Alternative cyclophosphamide dosing if rituximab is unavailable: IV: 15 mg/kg at weeks 0, 2, 4, 7, 10, 13, with a reduction of 2.5 mg/kg for age >60 years or GFR <30 ml/min/1.73 m², according to the Kidney International guidelines 5, 6

The American Society of Apheresis recommends considering plasma exchange in DAH with hypoxemia, particularly when serum creatinine >3.4 mg/dL, patient requires dialysis, or concomitant anti-glomerular basement membrane disease is present 1, 2, 7
The PEXIVAS trial did not demonstrate definitive mortality benefit for plasma exchange in DAH, but recent guidelines note increased infection risk without clear mortality benefit in DAH without kidney involvement, as reported in the American Journal of Kidney Diseases 8, 7

Use lung-protective ventilation with tidal volumes 6-8 mL/kg predicted body weight, and maintain plateau pressure ≤30 cmH₂O, as recommended by the Praxis Medical Insights guidelines 3
Apply moderate PEEP (6-8 cmH₂O), according to the Praxis Medical Insights guidelines 9

Continue maintenance immunosuppression for 18 months to 4 years to prevent relapse, with preferred maintenance agents including rituximab, azathioprine, and mycophenolate mofetil, as recommended by the Kidney International guidelines 4, 2, 5

Avacopan (30 mg twice daily) may be used as an alternative to glucocorticoids in patients at high risk for steroid toxicity, particularly those with GFR <30 ml/min/1.73 m², as reported in the Kidney International guidelines 5, 6, 3
High-dose intravenous immunoglobulin can be considered in ICU patients with particularly high infection risk, according to the Kidney International guidelines 1, 2

DAH occurs in 25% of ANCA-associated vasculitis patients and carries high early mortality when associated with older age, severe kidney failure, degree of hypoxemia, and involvement of >50% of lung area at presentation, as reported in the American Journal of Kidney Diseases 8, 7, 3
Track PaO₂/FiO₂ ratio improvement, serial chest imaging, and serial hemoglobin levels to assess treatment response, as recommended by the Praxis Medical Insights guidelines 9, 7

In the absence of hypoxemia, DAH has a benign prognosis and responds as extrapulmonary disease is controlled with standard immunosuppression; plasma exchange is not required, according to the Kidney International guidelines 1, 2
For patients not responding to initial therapy, increase glucocorticoids, switch to rituximab or cyclophosphamide, and re-evaluate diagnosis to exclude medication nonadherence, infection, malignancy, or drug-induced vasculitis, as recommended by the American Journal of Kidney Diseases 10, 11, 4