Noninfectious pneumonitis after blood and marrow transplant

Purpose of review Blood and marrow transplant recipients are predisposed to infectious and noninfectious pulmonary complications. Such complications can develop in 30-60% of blood and marrow transplant recipients and are the immediate cause of death in approximately 61%. This review will summarize recent developments in noninfectious complications that manifest as pulmonary infiltrates. Recent findings Recent data in blood and marrow transplant recipients suggest that noninfectious pulmonary diseases may be more common than infectious complications. The main noninfectious pulmonary complications that present as pulmonary infiltrates include idiopathic pneumonia syndrome, peri-engraftment respiratory distress syndrome and diffuse alveolar hemorrhage. Bronchoalveolar lavage fluid shows progressively bloodier return and/or over 20% hemosiderin-laden macrophages in diffuse alveolar hemorrhage. Peri-engraftment respiratory distress syndrome differs from idiopathic pneumonia syndrome by its occurrence during the neutrophil peri-engraftment period and favorable response to corticosteroid therapy. The treatment of noninfectious pulmonary complications is not based on randomized clinical trials. Summary Noninfectious pulmonary complications develop frequently in blood and marrow transplant recipients, The clinical presentations of idiopathic pneumonia syndrome, Peri-engraftment respiratory distress syndrome and diffuse alveolar hemorrhage may mimic pneumonia of infectious etiology. The therapeutic and prognostic implications mean that accurate diagnosis of these conditions is important.