Nonbacterial pneumonia after allogeneic marrow transplantation: a review of ten years' experience.

Pneumonia due to causes other than bacterial or fungal infection has been a frequent complication of allogeneic marrow transplantation. Data on 525 patients who received allogeneic marrow transplants during a 10-year period were reviewed. Of these patients, 41% developed pneumonia; this incidence was significantly higher than that among recipients of syngeneic (twin) transplants. Cytomegaloviral pneumonia (85 cases) and idiopathic pneumonia (63 cases) occurred most commonly. The incidence of pneumonia was higher among older patients, among patients who received transplants because of hematologic malignancy, and among patients with aplastic anemia who received total-body irradiation or procarbazine plus antithymocyte globulin for conditioning before transplantation. The development of cytomegaloviral pneumonia was unrelated to the serologic characteristics of either the patient or the donor before transplantation, and an increase in the titer of antibody to cytomegalovirus did not significantly improve the chances for survival. Mortality from all forms of pneumonia was high. Until effective means for prevention or treatment of cytomegaloviral and idiopathic pneumonia become available, the occurrence of these infections will continue to limit the success of allogeneic marrow transplantation.