Special considerations for the patient undergoing allogeneic or autologous bone marrow transplantation

Improvements in the diagnosis, treatment, and prevention of infectious complications of bone marrow transplantation over the past two decades have markedly reduced the morbidity and mortality of this procedure. We are now able to begin early empiric antibiotic coverage with less toxic, but equally effective, antibacterial agents. Once believed to be uniformly fatal, complications such as CMV pneumonia are now considered treatable in at least half the cases with a combination of intravenous immunoglobulin and ganciclovir. Although probably the most controversial, prophylactic therapy has improved the outcome of patients undergoing bone marrow transplantation. The appropriate setting, agents to use, dose, and dose intervals will require further study in coming years. In the introduction to this article, we attempted to outline what is known about the immunobiology of bone marrow transplantation. A clear understanding of this process helps us recognize and anticipate the infectious complications encountered in this population of patients. It may also allow clinicians to focus more on immune augmentation as a means of prevention, as has been attempted with the newly available cytokines and the use of intravenous immunoglobulin infusions. Despite improvements in diagnosis, treatment, and prevention, infectious complications remain the leading cause of morbidity and mortality in the patient undergoing bone marrow transplantation. Future studies are required in this area to build on the successes of the last two decades.