Pneumocystis carinii pneumonitis following bone marrow transplantation

Pneumocystis carinii pneumonitis (PCP) can occur in immunocompromised hosts, especially AIDS and cancer patients. Although recent research has focused on PCP in AIDS patients, few studies have described the clinical presentation of PCP in recipients of bone marrow transplantation (BMT). Between 1976 and 1991, of 1454 BMT patients at the University of Minnesota, PCP was documented in only 19. Eighteen of these had not been receiving PCP prophylaxis. Patients presented with a brief period (2-10 days) of symptoms including dyspnea, cough, and fever in > 75% of patients, but had only scant abnormal physical findings. Chest X-rays showed bilateral infiltrates in 58% of all patients, though 15% had no or minimal X-ray findings. Bronchoscopic alveolar lavage confirmed the diagnosis most often, but 13% of lavages were negative and required biopsy for the diagnosis. High dose trimethoprim-sulfamethoxazole was the initial treatment for 84% of the patients though 25% of these patients were later switched to pentamidine due to poor response or hypersensitivity reactions. Despite prompt diagnosis and therapy, overall survival was poor, with only 37% of patients surviving pneumonitis. Patients developing PCP < 6 months post-BMT had greater mortality (89%) versus only 40% in later onset PCP (p < 0.0001). Despite this better survival in the late-onset PCP cohort, the development of pneumonitis in these patients underscores the necessity for continued PCP prophylaxis beyond 1 year in some patients. Ongoing immunocompromise and need for prophylaxis should be appreciated in patients with graft-versus-host disease. In addition, those with relapse of a chronic malignancy such as chronic myelogenous leukemia or low grade lymphoma should also be considered candidates for long-term prophylaxis.