Bone marrow transplantation: current situation, complications and prevention.

The number of patients undergoing BMT is rising steadily. The increase is due to a broadening of the indications for transplantation and an increase in the donor pool. There has been a progressive improvement in outcome particularly due to a fall in transplant-related mortality. Methotrexate and cyclosporin are the mainstay of graft versus host disease (GVHD) prophylaxis, but acute GVHD remains a major problem in the unrelated donor recipient. Infections remain an important cause of death and emphasise the crucial role of antimicrobial prophylaxis; death from Gram-negative sepsis has been significantly reduced by the use of prophylactic antibiotics. Fungal infections carry a high mortality, especially in allogenic transplant recipients. Fluconazole is used to protect patients in the neutropenic period and beyond in higher risk individuals. Viral infections, which may occur late, are emerging as a significant cause of morbidity and mortality in the allogeneic, particularly unrelated transplantation setting. A long term susceptibility to encapsulated bacteria suggests delayed immune reconstitution; revaccination policies are standard in most units. The longer term effects of transplantation are increasingly important with improving survival and include chronic GVHD, endocrine, cardiorespiratory and other systemic abnormalities. The increased risk of secondary malignancies is also of concern.