Prophylaxis and treatment of infection in the bone marrow transplant recipient

Considerable progress has been made in the prophylaxis and treatment of infections in the bone marrow transplant recipient. Much of this progress is related to the availability of many new antimicrobial agents and biological products, as well as to an improved understanding of the pathogenesis of infections. Because of the expense associated with many of these agents and products, defensive strategies against infections must consider not only effectiveness but also cost (Table 16.9). It is now possible that a marrow transplant recipient could receive as many as five or six different prophylactic agents. While the use of an oral fluoroquinolone or oral fluconazole for prevention of serious bacterial and fungal infections is relatively inexpensive, the price of intravenous immune globulin and GM-CSF is considerably higher. Their routine use in all patients may not be economical. The results from ongoing trials comparing different dosing regimens of intravenous immune globulin and selectively using GM-CSF or G-CSF only in patients with suspected or documented infection will be important (80,173). On the other hand, the cost of providing CMV-seronegative blood products or prophylactic ganciclovir is justified by the high morbidity and mortality of CMV interstitial pneumonia in allotransplants. The low incidence of CMV disease in syngeneic transplants and autotransplants, however, makes CMV prophylaxis unnecessary. Similarly, in view of a recent controlled trial showing no benefit of intravenous immune globulin for prophylaxis of infections, intravenous immune globulin is also not needed in autotransplants. Trimethoprim-sulfamethoxazole is cheap prophylaxis for Pneumocystis carinii pneumonia, but the very low mortality from herpes simplex infection makes acyclovir a very expensive prophylaxis. Treatment options for the infected bone marrow transplant recipient have also become broader. The decline of Pseudomonas aeruginosa and other gram-negative bacillary infections and the availability of newer, more potent beta-lactam drugs makes monotherapy an appropriate and more cost-effective regimen for empiric therapy of many febrile patients. The introduction of fluconazole, itraconazole, and other newer antifungals offers promise for improving antifungal therapy, but these agents should not take the place of amphotericin B in a critically ill patient with suspected or documented fungal infection until results of ongoing controlled trials show equivalent efficacy. The role of biological response modifiers like macrophage colony-stimulating factor in the treatment of fungal infections also needs to be defined. Development of clinically applicable serologic tests for early detection of specific Candida or Aspergillus antigen is badly needed to help guide antifungal therapy.(ABSTRACT TRUNCATED AT 400 WORDS)