Pulmonary interstitial changes following bone marrow transplantation. A complex, multifactor disorder

Observations of 20 consecutive bone marrow transplantation recipients disclosed two distinctive categories of pulmonary interstitial changes. Interstitial infiltrates occurring less than 14 days after transplantation were observed in 13 of 20 patients and are believed to represent pulmonary edema. A late pulmonary interstitial process, which appears more than 30 days following transplantation (median 57 days), was encountered in 10 of 14 patients with successful grafts; the late changes represent interstitial pneumonia, a common cause of morbidity and mortality following bone marrow transplantation. It is probably attributable to a combination of factors including the preparatory chemotherapy and radiotherapy, and delayed immunologic reconstitution following transplantation.