Antifungal prophylaxis in hematopoietic stem cell transplant recipients: the unfinished tale of imperfect success

A case report of the metagenomics next-generation sequencing for early detection of central nervous system mucormycosis with successful rescue in patient with recurrent chronic lymphocytic leukemia

Background

Central nervous system (CNS) mucormycosis is insidious and difficult to diagnose. It progresses rapidly and causes high mortality. Rare cases have been reported during ibrutinib use, which have poor prognosis. Through this case, we share the experience of successful diagnosis and treatment. We also emphasize the importance of focusing on high-risk groups, early diagnosis and prompt management.

Case Description

In this case, a 52-year-old patient was diagnosed with chronic lymphocytic leukemia (CLL) for more than 5 years. He was in remission after rituximab plus fludarabine and cyclophosphamide (RFC) regimen, and relapsed in the fourth year. During the ibrutinib monotherapy, the patient presented with sudden headache. Cranial imaging examination revealed a definite right occipitoparietal lobe mass with extensive edema. A rapid diagnosis of mucormycosis infection was made using metagenomic next-generation sequencing (mNGS). The patient at that time didn't have neutropenia, but he had hypogammaglobulinemia. The infection was treated with amphotericin B cholesteryl sulfate complex, posaconazole, and interventional surgery, and the treatment was successful. At the same time, we considered the control of disease progression in this relapsed patient with, as well as to the drug interaction with posaconazole. We chose the next generation Bruton's tyrosine kinase (BTK) inhibitor zanubrutinib as the treatment, whose safety has been identified. As of the submission date, the patient has been followed up for nearly 1 year, and his disease is stable.

Conclusions

When new clinical problems arise in recurrent CLL patients, it is important to identify multiple factors, especially the insidious fungal infections. In particular, the immunocompromised patients should be concerned. CNS mucormycosis is extremely deadly, the early diagnosis will improve the prognosis. In clinical practice, the gold standard diagnosis of mucormycosis is difficult to obtain through pathology. In this case, mNGS was applied to quickly diagnose mucormycosis, enabling earlier treatment and ameliorating the prognosis. Thus, it will help us to early detect this group of people who may be potentially infected. Current guidelines do not recommend the prophylactic use of antifungal agents in treated CLL patients. However, in patients with prior severe infection or hypogammaglobulinemia, intravenous immunoglobulin is recommended to reduce the associated infection rate.

Systemic antifungal strategies in allogeneic hematopoietic stem cell recipients hospitalized in french hematology units: a post-hoc analysis of the cross-sectional observational AFHEM study

Background

Invasive fungal diseases (IFD) remain a major complication of allogeneic hematopoietic stem cell transplantation (alloHSCT) and are associated with high mortality rates in patients receiving alloHSCT. Antifungal prophylaxis is increasingly being used in the management of IFDs in patients receiving alloHSCT.

Methods

A post-hoc analysis of the cross-sectional observational AFHEM study was carried out to describe the use of antifungal drugs in real-life clinical practice in alloHSCT recipients hospitalized in French hematological units.

Results

A total of 147 alloHSCT recipients were enrolled; most were adults (n = 135; 92%) and had received alloHSCT < 6 months prior to enrollment (n = 123; 84%). Overall, 119 (81%) patients received a systemic antifungal therapy; of these, 95 (80%) patients received antifungal prophylaxis. Rates of patients receiving systemic antifungal treatment were similar irrespective of transplant time, neutropenic, and graft-versus-host disease status. Among patients on systemic antifungal treatment, 83 (70%) received an azole, 22 (18%) received an echinocandin, and 16 (13%) received a polyene.

Conclusions

This work provides evidence of the antifungal strategies used in alloHSCT recipients hospitalized in French hematological units. Unlike earlier studies, the AFHEM study showed that prophylaxis appears to be the leading antifungal strategy used in alloHSCT recipients in France.

Comparative effects of fluconazole, posaconazole, and isavuconazole upon tacrolimus and cyclosporine serum concentrations

INTRODUCTION

Calcineurin inhibitors are commonly used in hematopoietic stem cell transplant (HSCT) patients to prevent graft versus host disease, but as CYP3A4 substrates they are frequently involved in drug-drug interactions. The purpose of this study is to characterize the effects of isavuconazole, fluconazole, and posaconazole on tacrolimus and cyclosporine serum concentrations and dose adjustments in allogeneic HSCT patients.

METHODS

This retrospective study included patients admitted to Oregon Health and Science University between April 2008 and December 2018 who underwent hematopoietic stem cell transplantation and received concomitant tacrolimus or cyclosporine and fluconazole, isavuconazole or posaconazole therapy. Data on patient characteristics, drug dosing, and serum drug concentrations were collected through chart review, and descriptive statistics were used to summarize the results.

RESULTS

A total of 139 patients were included in this study. We found fluconazole initiation leads to a 25% reduction in both tacrolimus and cyclosporine doses in order to maintain goal serum concentrations. Posaconazole and isavuconazole initiation requires tacrolimus dose reductions by 53% and 21%, respectively.

CONCLUSIONS

Based on our experience, FLC, POS, and ISA initiation may require CNI dose reductions and close monitoring of CNI levels to ensure levels remain within goal serum concentrations. Larger studies are needed to fully quantify the percentage in CNI dose reductions and characterize differences among these antifungals.

Low-dose liposomal amphotericin B for antifungal prophylaxis in paediatric allogeneic haematopoietic stem cell transplantation

BACKGROUND

Primary antifungal prophylaxis in paediatric allogeneic HSCT recipients is mainly based on azoles, which can have related toxicity and drug interactions. Low-dose liposomal amphotericin B (L-AmB) is an attractive intravenous alternative because of its low toxicity and lower risk of interactions.

OBJECTIVES

To evaluate the effectiveness and safety of L-AmB (1 mg/kg/day) for primary antifungal prophylaxis in pre-engraftment paediatric HSCT patients.

PATIENTS AND METHODS

Retrospective, observational study including all consecutive patients aged ≤18 years who underwent HSCT and received antifungal prophylaxis with intravenous L-AmB (1 mg/kg/day, from day -1 to 48 h before discharge) between January 2012 and December 2016.

RESULTS

In total, 125 HSCT procedures in 118 patients were included, median age 7.2 years (IQR 4.2-11.5). Haematological malignancies were the main underlying condition (63.6%), and 109 (87.2%) were considered at high risk for invasive fungal infection (IFI). Ten patients (7.7%), all high risk, developed breakthrough IFI (three Candida spp., seven invasive mould infections) and tended to have higher overall mortality. The only statistically significant risk factor for IFI was cytomegalovirus co-infection. Adverse events, all grade I, occurred in 25 (20%), requiring L-AmB withdrawal in one case. Overall survival at 30 days was 99.2%. At study completion, one patient had died of IFI.

CONCLUSIONS

The incidence of breakthrough IFI was comparable to that of previous reports, with a very low rate of significant toxicity. Thus, prophylactic L-AmB may be a safe, effective option for antifungal prophylaxis in the pre-engraftment phase for children undergoing HSCT, even those at high risk.

Immune Cell Degranulation in Fungal Host Defence

Humans have developed complex immune systems that defend against invading microbes, including fungal pathogens. Many highly specialized cells of the immune system share the ability to store antimicrobial compounds in membrane bound organelles that can be immediately deployed to eradicate or inhibit growth of invading pathogens. These membrane-bound organelles consist of secretory vesicles or granules, which move to the surface of the cell, where they fuse with the plasma membrane to release their contents in the process of degranulation. Lymphocytes, macrophages, neutrophils, mast cells, eosinophils, and basophils all degranulate in fungal host defence. While anti-microbial secretory vesicles are shared among different immune cell types, information about each cell type has emerged independently leading to an uncoordinated and confusing classification of granules and incomplete description of the mechanism by which they are deployed. While there are important differences, there are many similarities in granule morphology, granule content, stimulus for degranulation, granule trafficking, and release of granules against fungal pathogens. In this review, we describe the similarities and differences in an attempt to translate knowledge from one immune cell to another that may facilitate further studies in the context of fungal host defence.

Effectiveness and Cost-Effectiveness of Prophylactic Voriconazole and Fluconazole Regarding Prevention of Post-hematopoietic Stem Cell Transplantation Invasive Fungal Infection and Its Related Death: A Single Center Experience

Purpose

Analyzing effectiveness and cost-effectiveness of voriconazole versus fluconazole prophylaxis in hematopoietic stem cell transplantation (HSCT).

Methods

The research included 70 patients; 34 undergoing allogeneic HSCT and 36 undergoing autologous stem cell transplantation (ASCT), alternated to receive either voriconazole or fluconazole prophylaxis for 180 days on a 1:1 basis. Patients were monitored for occurrence of invasive fungal infections (IFI), IFI-related death (IRD) and total death events. Cost-effectiveness of both agents in both groups was also assessed.

Results

Antifungal prophylactic drug had no impact on incidence of IFI and IRD in both allogeneic HSCT and ASCT (P = .452 and P = 1.000; P = .457 and P = .146 respectively). An insignificant difference occurred among patients receiving voriconazole or fluconazole regarding overall survival (OS) and fungal infection-free survival (FFS) in both groups (P = .705 and P = .879; P = .713 and P = .681 respectively). Regarding cost-effectiveness, voriconazole dominated fluconazole regarding prevention of IFI and IRD but was less costly/less effective regarding prevention of total death events and gaining life years in the allogeneic HSCT setting. In the ASCT setting, voriconazole was not cost-effective regarding avoidance of IFI and IRD and was dominated by fluconazole regarding avoidance of total death events and gaining life years.

Conclusions

Voriconazole does not differ from fluconazole regarding its efficacy in prevention of IFI and IRD and does not improve OS and FFS in both allogeneic HSCT and ASCT settings. Voriconazole is cost-effective regarding protection from IFI and IRD in allogeneic HSCT but not cost-effective in ASCT.

Invasive fungal disease is associated with chronic graft-versus-host disease after allogeneic hematopoietic stem cell transplant: a single center, retrospective study

BACKGROUND

Invasive fungal disease (IFD) and graft-versus-host disease (GVHD) are major causes of morbidity and mortality after allogeneic hematopoietic stem cell transplantation (allo-HSCT). However, the impacts of IFD on chronic GVHD remain unknown.

METHODS

We conducted a retrospective study of 510 patients with hematologic malignancy undergoing allo-HSCT to explore the effects of IFD on chronic GVHD.

RESULTS

The 2-year cumulative incidences of overall (limited and extensive) and extensive chronic GVHD post-transplantation were higher in patients with IFD compared with those without IFD (69.5% ± 4.2% versus 32.9% ± 2.4%, P < .001; 43.0% ± 5.2% versus 6.6% ± 1.4%, P < .001, respectively). Moreover, the patients with IFD had higher 5-year transplant-related mortality, lower 5-year overall survival and lower 5-year disease-free survival (29.8% ± 4.3% versus 9.8% ± 1.6%, P < .001; 50.5% ± 4.9% versus 71.3% ± 2.4%, P < .001 and 48.8% ± 4.7% versus 71.8% ± 2.3%, P < .001, respectively). Multivariable analyses demonstrated that IFD increased the risk of chronic GVHD.

CONCLUSION

Our results suggest that IFD significantly contributes to the development of chronic GVHD after allo-HSCT.

[Pulmonary infiltrates in haematological patients]

BACKGROUND

Pulmonary complications are frequent in haematologic patients.

METHOD

This review article summarizes the outcome of a discussion that took place during an expert meeting on the subject of pulmonary infiltrates.

RESULTS AND CONCLUSIONS

The most common causes of pulmonary infiltrates in haematologic patients are bacterial infections. Viral infections are subject to relevant seasonal variations, but they may also cause an important proportion of pulmonary infiltrates. Microbiological examination of respiratory tract material (if possible, bronchoalveolar lavage, BAL) is the most important diagnostic procedure. Particularly in the case of prolonged (> 7 days) neutropenia, the likelihood of infiltrates being caused by fungal infections increases. For a differential diagnosis, however, also non-infectious causes, e.g. drug-induced infiltrates, have to be taken into consideration. The diagnostic workup, however, should not delay a timely start of an adequate antimicrobial therapy.

How to prophylax against invasive fungal infections in adult ALL? An unmet need

Although the benefit for any type of antifungal prophylaxis in patients with acute myelogenous leukaemia is well accepted, less is known about the risk for invasive fungal infections (IFIs) and the optimal prophylaxis strategies in patients with acute lymphocytic leukaemia (ALL). Based on recent studies, ALL is a disease that appears to be associated with significant risk for IFIs. The pharmacokinetic interactions between azoles and vincristine, an antineoplastic agent that is part of modern combination chemotherapies in ALL, results in clinically significant neurotoxicity that makes the use of azoles problematic. However, a number of questions regarding azole-vincristine interactions remain unanswered. In this viewpoint, we call for a renewed interest in antifungal prophylaxis studies in ALL in view of the availability of several non-azole novel antifungal agents that are under preclinical and/or clinical development. This is clearly a major unmet need in modern clinical mycology.

Methods of Controlling Invasive Fungal Infections Using CD8+ T Cells

Invasive fungal infections (IFIs) cause high rates of morbidity and mortality in immunocompromised patients. Pattern-recognition receptors present on the surfaces of innate immune cells recognize fungal pathogens and activate the first line of defense against fungal infection. The second line of defense is the adaptive immune system which involves mainly CD4+ T cells, while CD8+ T cells also play a role. CD8+ T cell-based vaccines designed to prevent IFIs are currently being investigated in clinical trials, their use could play an especially important role in acquired immune deficiency syndrome patients. So far, none of the vaccines used to treat IFI have been approved by the FDA. Here, we review current and future antifungal immunotherapy strategies involving CD8+ T cells. We highlight recent advances in the use of T cells engineered using a Sleeping Beauty vector to treat IFIs. Recent clinical trials using chimeric antigen receptor (CAR) T-cell therapy to treat patients with leukemia have shown very promising results. We hypothesized that CAR T cells could also be used to control IFI. Therefore, we designed a CAR that targets β-glucan, a sugar molecule found in most of the fungal cell walls, using the extracellular domain of Dectin-1, which binds to β-glucan. Mice treated with D-CAR+ T cells displayed reductions in hyphal growth of Aspergillus compared to the untreated group. Patients suffering from IFIs due to primary immunodeficiency, secondary immunodeficiency (e.g., HIV), or hematopoietic transplant patients may benefit from bioengineered CAR T cell therapy.

Echinocandin prophylaxis in patients undergoing haematopoietic cell transplantation and other treatments for haematological malignancies

Antifungal prophylaxis is the standard of care for patients undergoing intensive chemotherapy for haematological malignancy or haematopoietic cell transplantation (HCT). Prophylaxis with azoles reduces invasive fungal infections and may reduce mortality. However, breakthrough infections still occur, and the use of azoles is sometimes complicated by pharmacokinetic variability, drug interactions, adverse events and other issues. Echinocandins are highly active against Candida species, including some organisms resistant to azoles, and have some clinical activity against Aspergillus species as well. Although currently approved echinocandins require daily intravenous administration, the drugs have a favourable safety profile and more predictable pharmacokinetics than mould-active azoles. Clinical data support the efficacy and safety of echinocandins for antifungal prophylaxis in haematology and HCT patients, though data are less robust than for azoles. Notably, sparse evidence exists supporting the use of echinocandins as antifungal prophylaxis for patients with significant graft-versus-host disease (GvHD) after HCT. Two drugs that target (1,3)-β-d-glucan are in development, including an oral glucan synthase inhibitor and an echinocandin with unique pharmacokinetics permitting subcutaneous and weekly administration. Echinocandins are a reasonable alternative to azoles and other agents for antifungal prophylaxis in patients undergoing intensive chemotherapy for haematological malignancy or those receiving HCT, excluding those with significant GvHD.

Invasive Aspergillosis in Hematological Patients

Invasive aspergillosis (IA) is still one of the leading causes of morbidity and mortality in hematological patients, although its outcome has been improving. Prolonged and profound neutropenia in patients receiving intensive chemotherapy for acute leukemia and stem cell transplantation is a major risk factor for IA. Allogeneic stem cell transplant recipients with graft-versus-host disease and corticosteroid use are also at high risk. Management in a protective environment with high efficiency particular air (HEPA) filter is generally recommended to prevent aspergillosis in patients with prolonged and profound neutropenia. Antifungal prophylaxis against Aspergillus species should be considered in patients with past history of aspergillosis or colonization of Aspergillus species, at facilities with high incidence of IA and those without a protective environment. Early diagnosis and prompt antifungal treatment is important to improve outcome. Imaging studies such as computed tomography and biomarkers such as galactomannan antigen and β-D-glucan are useful for early diagnosis. Empirical antifungal treatment based on persistent or recurrent fever during neutropenia despite broad-spectrum antibiotic therapy is generally recommended in high-risk patients. Alternatively, a preemptive treatment strategy has recently been proposed in the context of progress in the early diagnosis of IA based on the results of imaging studies and biomarkers. Voriconazole is recommended for initial therapy for IA. Liposomal amphotericin B is considered as alternative initial therapy. Combination antifungal therapy of echinocandin with voriconazole or liposomal amphotericin B could be a choice for refractory cases.

Fungal Pneumonia in Patients with Hematologic Malignancy and Hematopoietic Stem Cell Transplantation

Fungal pneumonias cause unacceptable morbidity among patients with hematologic malignancies (HM) and recipients of hematopoietic stem cell transplantation (HSCT). The high incidence of fungal pneumonias in HM/HSCT populations arises from their frequently severe, complex, and persistent immune dysfunction caused by the underlying disease and its treatment. The cytopenias, treatment toxicities, and other immune derangements that make patients susceptible to fungal pneumonia frequently complicate its diagnosis and increase the intensity and duration of antifungal therapy. This article addresses the host factors that contribute to susceptibility, summarizes diagnostic recommendations, and reviews current guidelines for management of fungal pneumonia in patients with HM/HSCT.

Posaconazole for primary antifungal prophylaxis in patients with acute myeloid leukaemia or myelodysplastic syndrome during remission induction chemotherapy: a single-centre retrospective study in Korea and clinical considerations

Posaconazole was introduced as the primary antifungal prophylaxis (PAP) in acute myeloid leukaemia (AML) or myelodysplastic syndrome (MDS) patients during remission induction chemotherapy. Data on breakthrough invasive fungal infections (IFIs) from various centres are essential, as there are several considerations in treating IFIs in the posaconazole era. The aim of this study was to evaluate the effectiveness of posaconazole PAP and identify characteristics of IFIs at a single centre in Korea. We retrospectively reviewed consecutive patients with AML/MDS undergoing remission induction chemotherapy between December 2010 and November 2013. Of the 424 patients, 140 received posaconazole and 284 received fluconazole prophylaxis. The incidence of breakthrough proven/probable IFIs (15.5% vs. 2.9%, P < 0.001) and empirical antifungal treatment (EAFT) (45.8% vs. 12.9%, P < 0.001) decreased in the posaconazole group compared to the fluconazole group. In the posaconazole PAP group, two cases of breakthrough mucormycosis were noted among 13 proven/probable/possible IFI cases (15.4%). Overall and IFI-related mortality was 12.1% and 1.9% respectively. Fungus-free survival was significantly higher in the posaconazole group (74.7% vs. 87.1%, P = 0.028). Breakthrough IFIs and EAFT decreased significantly after posaconazole PAP. The benefit in fungus-free survival was noted with posaconazole PAP. Clinicians should be vigilant to identify non-Aspergillus IFIs with active diagnostic effort.

α-Mannan induces Th17-mediated pulmonary graft-versus-host disease in mice

Allogeneic hematopoietic stem cell transplantation (HSCT) is a curative therapy for various hematopoietic disorders. Graft-versus-host disease (GVHD) and infections are the major obstacles of HSCT, and their close relationship has been suggested. Although roles of bacterial and viral infections in the pathophysiology of GVHD are well described, impacts of fungal infection on GVHD remain to be elucidated. In mouse models of GVHD, injection of α-mannan (Mn), a major component of fungal cell wall, or heat-killed Candida albicans exacerbated GVHD, particularly in the lung. Mn-induced donor T-cell polarization toward Th17 and lung-specific chemokine environment in GVHD led to accumulation of Th17 cells in the lung. The detrimental effects of Mn on GVHD depended on donor IL-17A production and host C-type lectin receptor Dectin-2. These results suggest a previously unrecognized link between pulmonary GVHD and fungal infection after allogeneic HSCT.

Pneumonia in the immunocompromised host

PURPOSE OF REVIEW

Novel treatment modalities for previously fatal diseases, including newer chemotherapeutic and biologic agents and the expansion of the indications for solid organ and stem cell transplantation, have resulted in prolonged patient survival and a significant increase in the population of immunocompromised hosts (ICHs).

RECENT FINDINGS

This review discusses the increasing spectrum of opportunistic infections in the ICH, the general approach for early diagnosis and treatment of pulmonary infections in this population, and the current and novel diagnostic modalities available to establish a rapid and specific microbiologic diagnosis, focusing on recent controversies and advances.

SUMMARY

Early diagnosis and prompt initiation of effective therapy for infection help reduce morbidity in ICHs. Advances in diagnostic assays using nonculture-based methods, such as nucleic acid amplification, may allow for earlier targeted therapy. Invasive procedures including bronchoscopy and biopsy remain essential and should be vigorously pursued in ICHs given the broad differential diagnosis of possible pulmonary pathogens in this population, and the need to establish a specific diagnosis to allow accurate targeted therapy.

Evaluation of invasive aspergillosis risk of immunocompromised patients alternatively hospitalized in hematology intensive care unit and at home

Contrary to hospital exposure, little is known about the indoor fungal exposure of hematology patients at home. The aim of our study was to investigate the mold exposure of hematology patients both at home and at hospital to assess their invasive aspergillosis (IA) risk. Fungal exposure was assessed by quantifying opportunistic molds at hospital during hospitalization and in homes of 53 hematology patients. IA was diagnosed in 13 of 53 patients and invasive fungal infection (IFI) in one patient. In hospital, no opportunistic species, or low levels of opportunistic species, were found in 98% of weekly controls. Only 2% of hematology intensive care unit (ICU) controls showed a high level of Aspergillus fumigatus spores in corridor air. Five patients IA were hospitalized during these periods. Seven dwellings of 53 (5/14 dwellings of patients with IA/IFI and 2/39 dwellings of non-IA patients) had a percentage of A. fumigatus and Aspergillus flavus to total mold (significant predictor variable of IA/IFI in our study, general linear model, P-value = 0.02) as high as 15%. Maintaining a 'zero Aspergillus' goal at hospital is essential, and establishing specific and individually opportunistic mold monitoring at home could help to further reduce the IA risk through continuous surveillance.

PRACTICAL IMPLICATIONS

This study emphasizes the fact that preventive measures should not be aimed only at the hospital setting: among patients diagnosed with invasive aspergillosis/invasive fungal infection (IA/IFI), 5 of 14 (36%) were exposed to opportunistic fungal species at home exclusively. Moreover, four of these five patients were living in homes having the highest percentage of Aspergillus fumigatus and Aspergillus flavus (>15%), one of which had 48% of A. fumigatus. Therefore, our work supports the need for a counselor to carry out an environmental survey in patients’ homes.

Clinical efficacy and safety of primary antifungal prophylaxis with posaconazole versus fluconazole in allogeneic blood hematopoietic stem cell transplantation recipients-A retrospective analysis of a single medical center in Taiwan

BACKGROUND/PURPOSE

The efficacy and safety of posaconazole compared to fluconazole as antifungal prophylaxis in patients receiving allogeneic blood hematopoietic stem cell transplantation (allo-HSCT) during the early neutropenic phase without graft-versus-host disease (GVHD) was uncertain.

METHODS

The medical records of allo-HSCT recipients from a single institution, who received oral fluconazole (from January 2005 to June 2011) or oral posaconazole (from June 2011 to December 2013) during the early neutropenic phase (until engraftment), were retrospectively reviewed.

RESULTS

There were 52 allo-HSCT recipients, two of whom were younger than 18 years of age. Twelve cases received posaconazole and 40 cases received fluconazole as primary antifungal prophylaxis. The two groups had similar transplant characteristics, conditioning, and GVHD prophylaxis regimens. The fluconazole group had a higher risk for development of invasive fungal infections within 90 days after allo-HSCT (43% vs. 8.3%, p = 0.039). Kaplan-Meier analysis indicated that the cumulative incidence of invasive fungal infection for 90 days after allo-HSCT was higher in the fluconazole group (log rank test, p = 0.047). Early discontinuation of antifungal prophylaxis for intolerance was significantly lower in the posaconazole group (8.3% vs. 50%, p = 0.017). Both groups had similar rates of impaired liver function.

CONCLUSION

Analysis of primary fungal prophylaxis during the early neutropenic phase following allo-HSCT indicated that posaconazole was more effective and was better tolerated than fluconazole. Both drugs had similar safety profiles.

Bioengineering T cells to target carbohydrate to treat opportunistic fungal infection

Clinical-grade T cells are genetically modified ex vivo to express chimeric antigen receptors (CARs) to redirect their specificity to target tumor-associated antigens in vivo. We now have developed this molecular strategy to render cytotoxic T cells specific for fungi. We adapted the pattern-recognition receptor Dectin-1 to activate T cells via chimeric CD28 and CD3-ζ (designated "D-CAR") upon binding with carbohydrate in the cell wall of Aspergillus germlings. T cells genetically modified with the Sleeping Beauty system to express D-CAR stably were propagated selectively on artificial activating and propagating cells using an approach similar to that approved by the Food and Drug Administration for manufacturing CD19-specific CAR(+) T cells for clinical trials. The D-CAR(+) T cells exhibited specificity for β-glucan which led to damage and inhibition of hyphal growth of Aspergillus in vitro and in vivo. Treatment of D-CAR(+) T cells with steroids did not compromise antifungal activity significantly. These data support the targeting of carbohydrate antigens by CAR(+) T cells and provide a clinically appealing strategy to enhance immunity for opportunistic fungal infections using T-cell gene therapy.

Feasibility and effectiveness of posaconazole prophylaxis in combination with micafungin bridging for patients undergoing allogeneic stem cell transplantation: a 6-yr analysis from the cologne cohort for neutropenic patients

INTRODUCTION

Invasive fungal diseases (IFDs) are an important cause of morbidity and mortality in patients undergoing allogeneic stem cell transplantation (SCT).

METHODS

To compare the effectiveness of two prophylactic antifungal regimens used as standard of care (SOC) in the setting of SCT during the periods of May 2006 - September 2009 (oral posaconazole, POS) and October 2009 - July 2011 (oral posaconazole with intravenous micafungin bridging, POS-MIC), data from the Cologne Cohort of Neutropenic Patients (CoCoNut) study were analyzed after nearest-neighbor matching. Endpoints were occurrence of breakthrough probable/proven IFD under prophylaxis, incidence and duration of persistent febrile neutropenia, incidence of unspecific pneumonic infiltrates, possible IFD, positive galactomannan tests, as well as fungal-free and overall survival.

RESULTS

Of 291 patients with 307 SCTs observed during the study period, 212 fulfilled the inclusion criteria and were included into the analysis. Patients receiving POS-MIC were less likely to develop a pneumonic infiltrate (RR 0.71, 95% CI 0.51-1.00) or possible IFD (RR 0.36, 95% 0.15-0.87). They also demonstrated improved fungal-free survival at day 100 (P = 0.009). No significant differences were observed for the incidence of probable or proven IFD, positive galactomannan tests, persistent febrile neutropenia, duration of hospitalization and overall mortality. There was no grade III or IV CTCAE (Common Terminology Criteria for Adverse Events) toxicity related to antifungal prophylaxis.

CONCLUSION

Our results suggest that both prophylactic regimens, POS and POS-MIC are feasible, safe and effective. Our data suggest that bridging with intravenous micafungin could indeed improve exposure to antifungal prophylaxis, which may explain the reduced incidence of pneumonia and IFD in the bridging group.

Incidence density of invasive fungal infections during primary antifungal prophylaxis in newly diagnosed acute myeloid leukemia patients in a tertiary cancer center, 2009 to 2011

Although primary antifungal prophylaxis (PAP) is routinely administered in patients with acute myeloid leukemia (AML) during remission-induction and consolidation chemotherapy, the impact of PAP on the incidence of invasive fungal infections (IFIs) is not well described. We retrospectively analyzed the incidence of IFIs in 152 patients with AML who had been admitted to a tertiary cancer center between August 2009 and March 2011 and received PAP within 120 days after first remission-induction chemotherapy. We excluded patients who had undergone stem cell transplantation. Patients received a PAP drug with anti-Aspergillus activity during 72% (7,660/10,572) of prophylaxis-days. The incidence of documented IFIs (definite or probable according to revised European Organization for Research and Treatment of Cancer [EORTC] criteria) was 2.0/1,000 prophylaxis-days (95% confidence interval [CI], 1.23 to 3.04). IFIs due to molds were more common than IFIs due to yeasts (1.5/1,000 prophylaxis-days versus 0.4/1,000 prophylaxis-days; P = 0.01). Echinocandin-based PAP (8.6 and 7.1/1,000 prophylaxis-days, respectively) was associated with higher rates of documented IFIs than anti-Aspergillus azoles (voriconazole or posaconazole) (2.4 and 1.1/1,000 prophylaxis-days, respectively) at both 42 days (P = 0.03) and 120 days (P < 0.0001) after first remission-induction chemotherapy. The incidence of overall (documented and presumed) IFIs (P < 0.001), documented IFIs (P < 0.01), and empirical antifungal therapies (P < 0.0001) was higher during the first 42 days than after day 42. Despite the broad use of PAP with anti-Aspergillus activity, IFIs, especially molds, remain a significant cause of morbidity and mortality in AML patients, predominantly during the remission-induction phase. Patients receiving echinocandin-based PAP experienced higher rates of IFIs than did those receiving anti-Aspergillus azoles.

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.

How I treat mucormycosis

Unlike invasive aspergillosis, the prognosis and outcome of hematologic malignancy patients who develop invasive mucormycosis have not significantly improved over the past decade as a majority of patients who develop the infection still die 12 weeks after diagnosis. However, early recognition and treatment of invasive mucormycosis syndromes, as well as individualized approaches to treatment and secondary prophylaxis, could improve the odds of survival, even in the most persistently immunosuppressed patient receiving chemotherapy and/or of stem cell transplantation. Herein, we describe the subtle clinical and radiographic clues that should alert the hematologist to the possibility of mucormycosis, and aggressive and timely treatment approaches that may limit the spread of infection before it becomes fatal. Hematology patients with this opportunistic infection require integrated care across several disciplines and frequently highly individualized and complex sequence of decision-making. We also offer perspectives for the use of 2 antifungals, amphotericin B products and posaconazole, with activity against Mucorales. The availability of posaconazole in an oral formulation that can be administered safely for prolonged periods makes it an attractive agent for long-term primary and secondary prophylaxis. However, serum drug concentration monitoring may be required to minimize breakthrough infection or relapsing mucormycosis associated with inadequate blood concentrations.

Antifungal prophylaxis during treatment for haematological malignancies: are we there yet?

Antifungal prophylaxis during treatment for haematological malignancies has been studied for 50 years, yet it has not been wholly effective even when using antifungal drugs that exhibit potent activity in vitro against a broad range of fungal pathogens. Trials have demonstrated that it can reduce the incidence of invasive fungal diseases (IFD) and fungal deaths, but only two studies have had an impact on overall mortality. Furthermore, it has not significantly reduced the need for empirical antifungal therapy. Posaconazole was effective in preventing invasive aspergillosis in two studies of high-risk patients, and consensus guidelines grade it as a suitable choice for antifungal prophylaxis of invasive mould disease; however, its bioavailability was compromised by vomiting or diarrhoea so that an alternative parenteral antifungal drug was required. A recent trial of voriconazole prophylaxis after allogeneic stem cell transplantation failed to show superiority over fluconazole. With more accurate definitions of IFD, that utilize fungal biomarkers, such as galactomannan, together with computerized tomographic imaging, there is growing interest in a diagnostic-driven strategy, which could prove to be a more efficacious approach.