Noninfectious Pulmonary Involvement in Hematopoietic Stem Cell or Bone Marrow Transplant Recipients

Abstract

About 50% of blood and marrow stem cell transplant (BMT) recipients develop pulmonary complications following transplant. Bronchiolitis obliterans (BO), diffuse alveolar hemorrhage (DAH), peri-engraftment respiratory distress syndrome (PERDS), bronchiolitis obliterans organizing pneumonia (BOOP), idiopathic pneumonia syndrome (IPS), delayed pulmonary toxic syndrome (DPTS), pulmonary veno-occlusive disease (PVOD), and pulmonary cytolytic thrombi (PCT) are among the non-infectious pulmonary complications that have been documented with varying frequency. The pathogenesis of these complications has not been clearly defined, and treatment is derived from anecdotal reports rather than from randomized clinical trials. BO affects exclusively allogeneic transplant recipients, is thought possibly to be a manifestation of chronic graft-versus-host disease (GVHD), and is associated with a high case fatality rate due to the absence of effective therapy. BOOP is less common than BO and affects both autologous and allogeneic transplant recipients. BOOP responds favorably to steroid therapy. DPTS develops in the majority of autologous BMT recipients who have received high-dose chemotherapy for breast cancer prior to transplant. It usually responds to corticosteroid treatment and has not been reported to cause death. All 16 reported cases of BMT recipients with PCT had allogeneic grafts, and most had active GVHD at the time of presentation. BMT recipients with PCT present with fever and pulmonary nodules. Despite the absence of specific therapy, BMT recipients with PCT usually improve. In the majority of the reported cases of BMT recipients with PVOD, the patients have received allogeneic transplants. Since most cases of PVOD in BMT recipients are diagnosed post-mortem, the natural course is not known. Despite anecdotal reports of favorable response to steroid therapy, the prognosis of PVOD is poor.