This is an Open Access article distributed
under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by-nc/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. |
Abstract Invasive
fungal infections (IFIs) mostly affect immunocompromised hosts and are
responsible for high rates of complications and mortality. Prevalence
of IFIs has been reported between 7 and 15% and is evolving due to the
introduction of new drugs in the prophylaxis of high-risk patients.
Invasive candidiasis has become less frequent, while cases of
aspergillosis are increasing. The most important risk factors for IFIs
can be divided into 3 categories: those related to the hematological
neoplasm, those related to the patient's lifestyle, and those dictated
by the transplant characteristics. In high-risk patients, prophylaxis
is driven by both local epidemiology and the timing of engraftment.
During the pre-engraftment period, a wide spectrum of drugs can be
chosen as antifungals, while in the post-engraftment period,
posaconazole is recommended for patients presenting with GvHD who are
undergoing immunosuppression. Regarding treatment, voriconazole is
still the recommended drug for invasive aspergillosis, although adverse
events, toxicity, and drug interactions are particularly relevant. In
the management of IFIs, international guidelines recommend the best
drugs for prophylaxis and treatment, but the future holds new molecules
that are already demonstrating excellent efficacy and tolerability. |
Introduction
Epidemiology
Over the last decade, the epidemiology of IFIs has undergone dramatic changes, largely due to the increasing number of immunosuppressive treatments, the use of invasive devices, and a higher volume of transplant procedures.[18]Risk factors for IFIs
Timely and correct identification of IFI risk factors is critical to improve patients' outcomes. Risk factors for IFIs in HCT candidates should be assessed over time, as they may differ from those initially identified at diagnosis. Transplant conditioning, post-engraftment complications, and prolonged follow-up may all modify the actual risk of IFI. Although risk factors may be already present at the time of the transplant, other less predictable variables may occur during the post-transplant clinical course. As shown in Table 2, three broad categories can be identified, deriving from patient comorbidities and lifestyle, as well as the primary hematologic disease.[11]Antifungal antifungal prophylaxis in allogeneic HCT recipients
Regarding IFI prophylaxis in patients undergoing allogeneic HCT, it is valuable to distinguish between two phases characterized by significantly different risk factors for IFI: the pre-engraftment and post-engraftment phases. During the pre-engraftment period, fluconazole is likely the most valuable choice for antifungal prophylaxis, given its low rate of pharmacological interactions and toxicities. Unfortunately, the moderate efficacy of fluconazole often limits its use.[13,14,75] It is therefore reasonable to prefer fluconazole only in low-risk patients and in hospitals where the epidemiological records show a low risk of mold infection. It is also important to combine the use of fluconazole with a mold-directed diagnostic workup (biomarkers and/or CT scan-based).[13,14,75] On the other hand, using fluconazole in association with other antifungal drugs has not shown any advantages.[13,14]IFI treatment
The choice of antifungal treatment should consider various factors, including prior use of mold-active azole prophylaxis, existing comorbidities, the likelihood of azole-resistant Aspergillus infection, and clinical conditions.Conclusions
In this review, we highlighted the main challenges of managing invasive fungal infections in HCT patients. In particular, we discussed the main risk factors for IFI and the most influential international guidelines for antifungal prophylaxis and treatment, according to the engraftment phase.References