Fatal cerebral zygomycosis breakthrough in a patient with acute lymphoblastic leukemia on voriconazole prophylaxis after cord blood SCT

Voriconazole associated mucormycosis in a patient with relapsed acute lymphoblastic leukemia and hematopoietic stem cell transplant failure: A case report

The patients with hematologic malignancies and hematopoietic stem cell transplantation (HSCT) recipients are at high risk for invasive fungal diseases (IFDs) mainly due to the severe and prolonged neutropenia related to high-dose chemotherapy. Voriconazole prophylaxis is recommended for possible IFDs. Mucormycosis is a fulminant infection, which may occur after voriconazole prophylaxis for invasive aspergillosis in immunocompromised hosts. Here, we report mucormycosis after 4 months of voriconazole prophylaxis in a young patient with relapsed acute lymphoblastic leukemia and hematopoietic stem cell transplant failure and discuss the clinical manifestation, imaging, laboratory findings and therapeutic regimens. Clinician's awareness of this entity and timely diagnosis using conventional and molecular methods are the promising approach for the management of this devastating infection.

Breakthrough invasive fungal diseases during voriconazole treatment for aspergillosis: A 5-year retrospective cohort study

Breakthrough invasive fungal diseases (bIFDs) during voriconazole treatment are concerning, as they are associated with high rates of mortality and pathogen distribution. To evaluate the prevalence, incidence, patient characteristics, including IFD events, and overall mortality of bIFDs during voriconazole treatment for invasive aspergillosis (IA). We retrospectively analyzed the medical records of consecutive patients who had undergone voriconazole treatment for IA and who had bIFD events between January 2011 and December 2015. Eleven bIFD events occurred in 9 patients. The prevalence and incidence of bIFDs were 2.25% (9/368) and 0.22 cases per year, respectively. Overall mortality was 44.4% (4/9). The severity of the illness and persistence of immunodeficiency, mixed infection, and low concentration of the treatment drug at the site of infection were identified as possible causes of bIFDs. Seven of 11 events (63.6%) required continued voriconazole treatment with drug level monitoring. In 4 (36.3%) cases, the treatment was changed to liposomal amphotericin B. Two cases resulted in surgical resection (18.2%). Clinicians should be aware that bIFDs during voriconazole treatment for IA can occur, and active therapeutic approaches are required in these cases.

Use of Fungal Diagnostics and Therapy in Pediatric Cancer Patients in Resource-Limited Settings

Fungal diseases are an important cause of mortality in immunocompromised hosts, and their incidence in pediatric cancer patients in low- to middle-income countries is underestimated. In this review, we present relevant, up-to-date information about the most common opportunistic and endemic fungal diseases among children with cancer, their geographic distribution, and recommended diagnostics and treatment. Efforts to improve the care of children with cancer and fungal disease must address the urgent need for sustainable and cost-effective solutions that improve training, fungal disease testing capability, and the use of available resources. We hope that the collective information presented here will be used to advise healthcare providers, regional and country health leaders, and policymakers of the current challenges in diagnosing and treating fungal infections in children with cancer in low- to middle-income countries.

Breakthrough filamentous fungal infections in pediatric hematopoetic stem cell transplant and oncology patients receiving caspofungin

BACKGROUND

Caspofungin is an echinocandin class antifungal medication that is commonly used empirically in immunocompromised patients at high risk for invasive fungal disease.

OBJECTIVE

To describe the clinical characteristics of breakthrough fungal infections in pediatric hematopoetic stem cell transplant recipients, and oncology and hematology patients receiving caspofungin.

METHODS

A five-year retrospective review, from 2004 through 2008, of all cases of proven invasive filamentous fungal infection of children admitted to The Hospital for Sick Children (Toronto, Ontario) was conducted. A breakthrough infection was defined as new onset of symptoms that were later proven to be due to an invasive mold infection on day 3 or later after initiation of caspofungin therapy.

RESULTS

Six confirmed positive cultures (Aspergillus fumigatus [two cases], Aspergillus niger, Fusarium oxysporum, Alternaria infectoria and Rhizomucor pusillus) met the criteria for breakthrough filamentous mold infection while on caspofungin therapy. Underlying immunocompromising conditions included acute lymphoblastic leukemia (two cases), acute myeloid leukemia (two cases), Burkitt's lymphoma and aplastic anemia. Four of the patients underwent a hematopoetic stem cell transplant. All patients received a lipid amphotericin B product as part of their treatment for breakthrough infection. Five patients also received voriconazole and one received posaconazole. Four of the six patients died and two responded with a clinical and microbiological cure.

DISCUSSION

There are few descriptions of breakthrough fungal infections in pediatric patients receiving caspofungin. The six cases presented here, all microbiologically proven, are likely only a fraction of the total number of possible breakthrough invasive fungal infections that occured over the study period.

CONCLUSION

Clinicians must remain aware that breakthrough fungal infections by species not covered by particular antifungals, including caspofungin, do occur and may have poor outcomes.

Voriconazole and its clinical potential in the prophylaxis of systemic fungal infection in patients with hematologic malignancies: a perspective review

Invasive fungal infections (IFIs) have become high prevalence in patients with hematologic malignancies. Drug-based strategies for IFIs include various approaches such as prophylactic, empiric, preemptive, and directed treatment. Prophylaxis is an attractive strategy in high-risk patients, given the lack of reliable diagnostics and the high mortality rate associated with IFIs. Prophylaxis includes the use of antifungal drugs in all patients at risk. An ideal antifungal compound for prophylaxis should have a potent and broad activity, be available both orally and intravenously, and have a low toxicity profile. Voriconazole fulfills all these criteria. The clinical efficacy of voriconazole against the majority of fungal pathogens makes it potentially very useful for the prevention of IFIs in patients with hematologic malignancies. Voriconazole appears to be very effective for the primary and secondary prevention of IFIs in these patients and recipients of allogeneic hematopoietic stem-cell transplantation. Randomized controlled trials evaluating voriconazole as primary antifungal prophylaxis in patients with neutropenia treated for a variety of hematologic malignancies have been performed, confirming its value as a prophylactic agent. Voriconazole is generally safe and well tolerated; however, its use is also associated with a number of concerns. In most patients with hematologic malignancies there is the potential for pharmacokinetic drug-drug interactions given that voriconazole is metabolized through the P450 cytochrome system.

Mucormycosis treated with posaconazole: review of 96 case reports

Mucormycosis is an emerging invasive fungal infection, primarily affecting immunocompromised patients. The disease is difficult to diagnose and mortality reaches 40% even if treated adequately. Depending on site of infection and risk factors, surgical debridement in combination with systemically active antifungal drugs are the mainstay treatment strategies. Lipid-based amphotericin B is the treatment of choice for first-line therapy while posaconazole may be a promising alternative. We performed a PubMed search on reports of patients with mucormycosis treated with posaconazole. From 2003 to 2011, 96 cases have been published. Diagnosis was based on histology alone in 2 (2.1%) and microbiological evidence in 67 (69.8%), while no data on the diagnostic approach was reported in 27 (28.1%) patients. The most frequent pathogens were Rhizopus spp. (31.2%), followed by Mucor spp. (14.6%). The site of infection was predominantly rhino-orbital (38.5%, of which 43% also had central nervous system [CNS] involvement), followed by disseminated disease (22.1%). A complete response was achieved in 62 (64.6%), partial response in 7 (7.3%) patients, and stable disease in 1 (1%). Overall mortality was 24% (lacking data for three patients). In published case reports on posaconazole treatment for mucormycosis, the drug was frequently and successfully used in combination or as second line therapy.

The impact of the host on fungal infections

Outcomes of fungal infections in immunocompromised individuals depend on a complex interplay between host and pathogen factors, as well as treatment modalities. Problems occur when host responses to an infection are either too weak to effectively help eradicate the pathogen, or when they become too strong and are associated with host damage rather than protection. Immune reconstitution syndrome (IRS) can be generally defined as a restoration of host immunity in a previously immunosuppressed patient that becomes dysregulated and overly robust, resulting in host damage and sometimes death. IRS associated with opportunistic mycoses presents as new or worsening clinical symptoms or radiographic signs consistent with an inflammatory process that occur during receipt of an appropriate antifungal, and that cannot be explained by a newly acquired infection. Because there are currently no established tests or biomarkers for IRS, it can be difficult to distinguish from progression of the original infection, although culture and biomarkers for the fungal pathogen or infection are typically negative during diagnostic workup. IRS was originally characterized in human immunodeficiency virus-infected patients receiving antiretroviral therapy, but has subsequently been described in solid-organ transplant recipients, neutropenic patients, women in the postpartum period, and recipients of tumor necrosis factor-α inhibitor therapy. In each of these cases, recovery of the host's immunity during treatment of an initial infection results in a powerful proinflammatory environment that overshoots and leads to host damage. Optimal management of IRS has not been established at present, but often involves treatment with a corticosteroid or other anti-inflammatory compounds. This article uses a number of patient cases to explore the intricacies of diagnosing and managing a patient with IRS, as well as the other extreme, namely patients who are so immunocompromised without immune recovery that they essentially become breeding grounds for a wide range of opportunistic pathogens, often simultaneously.

Invasive mycoses: strategies for effective management

Effective management of invasive fungal infections (IFIs) depends on early individualized therapy that optimizes efficacy and safety. Considering the negative consequences of IFI, for some high-risk patients the potential benefits of prophylactic therapy may outweigh the risks. When using a prophylactic, empiric, or preemptive therapeutic approach, clinicians must take into account the local epidemiology, spectrum of activity, pharmacokinetic and pharmacodynamic parameters, and safety profile of different antifungal agents, together with unique host-related factors that may affect antifungal efficacy or safety. Therapeutic drug monitoring is increasingly recognized as important or necessary when employing lipophilic triazoles (itraconazole, voriconazole, posaconazole) or flucytosine. Because early diagnostics remain limited for uncommon, yet emerging opportunistic molds (e.g., Mucorales), and treatment delay is associated with increased mortality, early effective management often depends on a high index of suspicion, taking into account predisposing factors, host cues favoring mucormycosis, and local epidemiology. Antifungal options for mucormycosis are limited, and optimal management depends on a multimodal approach that includes early diagnosis/clinical suspicion, correction of underlying predisposing factors, radical debridement of affected tissues, and extended antifungal therapy. This article discusses strategies for the effective management of invasive mycoses, with a particular focus on antifungal hepatotoxicity.