Although drugs from different pharmacological classes (polyenes, echinocandins and azoles) are available to treat post-transplant fungal infections, the best outcomes are achieved when preventive measures are successful.
Preventing fungal infections
Strategies to reduce the risk of IFIs include using HEPA filters, laminar flow isolation, reverse isolation, special diets and gut sterilization. [1-3] Other preventive strategies include:
- Tapering corticosteroids, which are risk factors for developing IFIs, as soon as possible
- Using non-myeloablative regimens, which reduce tissue injury/susceptibility to IFIs
- Use of post-transplant G-CSF to accelerate neutrophil recovery
- Prophylactic use of fluconazole to prevent Candida albicans invasion [4]
However, despite efforts to keep transplant patients from contacting common fungi, the overall incidence of post-transplant IFIs remains between 8% and 15%. [5]
Treating fungal infections
Aspergillus and Candida species are the two most common fungi to infect transplant patients. Outcomes are best for patients who are diagnosed quickly, treated as soon as possible and given the maximum tolerated doses. [4]
Combination anti-fungal therapies can also be administered, but to date there have been no randomized, comparative clinical trials to determine whether combination therapy is superior to single-agent therapy. [6]
Numerous drugs are available to treat post-transplant infections of Aspergillus, Candida and other fungal species. Table 1 lists the most common drugs used to treat fungal infections.
| Fungal species |
Drug(s) |
| Candida |
Fluconazole
Amphotericin B and
lipid formulations
Caspofungin
Voriconazole
Itraconazole
Anidulofungin
Posaconazole |
| Aspergillus |
Voriconazole
Amphotericin B
Itraconazole |
Table 1. Drugs available to treat fungal infections. [4,7]
Some more resistant fungi including Fusarium and Zygomycetes may develop and are often insensitive to the more commonly used anti-fungals, although a 2006 study of posaconazole found that it can be effective against Zygomycetes. [8]
References
- Hamza NS, Ghannoum MA, Lazarus HM. Choices aplenty: antifungal prophylaxis in hematopoietic stem cell transplant recipients. Bone Marrow Transplant. 2004; 34(5):377-389.
http://www.nature.com/bmt/journal/v34/n5/full/1704603a.html
- Guidelines for preventing opportunistic infections among hematopoietic stem cell transplant recipients: Recommendations of Centers for Disease Control, the Infectious Disease Society of America, and the American Society for Blood and Marrow Transplantation. Biol Blood Marrow Transplant. 2000; 6(6) Suppl:7-83.
http://download.journals.elsevierhealth.com/pdfs/journals/1083-8791/PIIS1083879100700024.pdf
- Alberti C, Bouakline A, Ribaud P, et al. Relationship between environmental fungal contamination and the incidence of invasive aspergillosis in haematology patients. J Hosp Infect. 2001; 48(3):198-206.
http://dx.doi.org/10.1053/jhin.2001.0998
- Wingard JR, Leather H. A new era of antifungal therapy. Biol Blood Marrow Transplant. 2004; 10(2):73-90.
http://dx.doi.org/10.1016/j.bbmt.2003.09.014
- Brown JMY. Fungal infections after hematopoietic cell transplantation. In: Blume KG, Forman SJ, Appelbaum FR, eds. Thomas' Hematopoietic Cell Transplantation, 3rd ed. Malden, Mass: Blackwell, 2004: 683-700.
- Johnson MD, Perfect JR. Combination antifungal therapy: what can and should we expect? Bone Marrow Transplant. 2007; 40(4):297-306.
http://www.nature.com/bmt/journal/v40/n4/abs/1705687a.html
- Chandrasekar P. Riches usher dilemmas: Antifungal therapy in invasive aspergillosis. Biol Blood Marrow Transplant. 2005; 11(2):77-84.
http://www.bbmt.org/article/PIIS108387910400624X/fulltext
- van Burik JA, Hare RS, Solomon HF, et al. Posaconazole is effective as salvage therapy in zygomycosis: a retrospective summary of 91 cases. Clin Infect Dis. 2006; 42(7):e61-65.
http://www.journals.uchicago.edu/doi/abs/10.1086/500212