Recombinant interferon γ1b immune enhancement in 20 patients with hematologic malignancies and systemic opportunistic infections treated with donor granulocyte transfusions

How are granulocytes for transfusion best used? The past, the present and the future

Granulocyte transfusions continue to be used in clinical practice, predominantly for treatment of refractory infection in the setting of severe neutropenia. There is biological plausibility for effectiveness in these patients with deficiencies of neutrophils, either as a consequence of disease or treatment. However, there is a chequered history of conducting and completing interventional trials to define optimal use, and many uncertainties remain regarding schedule and dose. Practice and clinical studies are severely limited by the short shelf life and viability of current products, which often restricts the timely access to granulocyte transfusions. In the future, methods are needed to optimise donor-derived granulocyte products. Options include use of manufactured neutrophils, expanded and engineered from stem cells. Further possibilities include manipulation of neutrophils to enhance their function and/or longevity. Granulocyte transfusions contain a heterogeneous mix of cells, and there is additional interest in how these transfusions may have immunomodulatory effects, including for potential uses as adjuncts for anti-cancer effects.

CcpA- and Shm2-Pulsed Myeloid Dendritic Cells Induce T-Cell Activation and Enhance the Neutrophilic Oxidative Burst Response to Aspergillus fumigatus

Aspergillus fumigatus causes life-threatening opportunistic infections in immunocompromised patients. As therapeutic outcomes of invasive aspergillosis (IA) are often unsatisfactory, the development of targeted immunotherapy remains an important goal. Linking the innate and adaptive immune system, dendritic cells are pivotal in anti-Aspergillus defense and have generated interest as a potential immunotherapeutic approach in IA. While monocyte-derived dendritic cells (moDCs) require ex vivo differentiation, antigen-pulsed primary myeloid dendritic cells (mDCs) may present a more immediate platform for immunotherapy. To that end, we compared the response patterns and cellular interactions of human primary mDCs and moDCs pulsed with an A. fumigatus lysate and two A. fumigatus proteins (CcpA and Shm2) in a serum-free, GMP-compliant medium. CcpA and Shm2 triggered significant upregulation of maturation markers in mDCs and, to a lesser extent, moDCs. Furthermore, both A. fumigatus proteins elicited the release of an array of key pro-inflammatory cytokines including TNF-α, IL-1β, IL-6, IL-8, and CCL3 from both DC populations. Compared to moDCs, CcpA- and Shm2-pulsed mDCs exhibited greater expression of MHC class II antigens and stimulated stronger proliferation and IFN-γ secretion from autologous CD4⁺ and CD8⁺ T-cells. Moreover, supernatants of CcpA- and Shm2-pulsed mDCs significantly enhanced the oxidative burst in allogeneic neutrophils co-cultured with A. fumigatus germ tubes. Taken together, our in vitro data suggest that ex vivo CcpA- and Shm2-pulsed primary mDCs have the potential to be developed into an immunotherapeutic approach to tackle IA.

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection: let the virus be its own demise

There has been a collaborative global effort to construct novel therapeutic and prophylactic approaches to SARS-CoV-2 management. Although vaccine development is crucial, acute management of newly infected patients, especially those with severe acute respiratory distress syndrome, is a priority. Herein we describe the rationale and potential of repurposing a dual plasmid, Vigil (pbi-shRNA^furin-GM-CSF), now in Phase III cancer trials, for the treatment of and, in certain circumstances, enhancement of the immune response to SARS-CoV-2.

Therapeutic Challenges of Non-Aspergillus Invasive Mold Infections in Immunosuppressed Patients

While Aspergillus spp. remain the major cause of invasive mold infections in hematologic cancer patients and transplant recipients, other opportunistic molds, such as Mucorales, Fusarium, and Scedosporium spp. are increasingly encountered in an expanding population of patients with severe and prolonged immunosuppression. High potential for tissue invasion and dissemination, resistance to multiple antifungals and high mortality rates are hallmarks of these non-Aspergillus invasive mold infections (NAIMIs). Assessment of drug efficacy is particularly difficult in the complex treatment scenarios of NAIMIs. Specifically, correlation between in vitro susceptibility and in vivo responses to antifungals is hard to assess, in view of the multiple, frequently interrelated factors influencing outcomes, such as pharmacokinetic/pharmacodynamic parameters determining drug availability at the site of infection, the net state of immune suppression, delay in diagnosis, or surgical debulking of infectious foci. Our current therapeutic approach of NAIMIs should evolve toward a better integration of the dynamic interactions between the pathogen, the drug and the host. Innovative concepts of experimental research may consist in manipulating the host immune system to induce a specific antifungal response or targeted drug delivery. In this review, we discuss the challenges in the management of NAIMIs and provide an update about the latest advances in diagnostic and therapeutic approaches.

Diagnosis and management of Aspergillus diseases: executive summary of the 2017 ESCMID-ECMM-ERS guideline

The European Society for Clinical Microbiology and Infectious Diseases, the European Confederation of Medical Mycology and the European Respiratory Society Joint Clinical Guidelines focus on diagnosis and management of aspergillosis. Of the numerous recommendations, a few are summarized here. Chest computed tomography as well as bronchoscopy with bronchoalveolar lavage (BAL) in patients with suspicion of pulmonary invasive aspergillosis (IA) are strongly recommended. For diagnosis, direct microscopy, preferably using optical brighteners, histopathology and culture are strongly recommended. Serum and BAL galactomannan measures are recommended as markers for the diagnosis of IA. PCR should be considered in conjunction with other diagnostic tests. Pathogen identification to species complex level is strongly recommended for all clinically relevant Aspergillus isolates; antifungal susceptibility testing should be performed in patients with invasive disease in regions with resistance found in contemporary surveillance programmes. Isavuconazole and voriconazole are the preferred agents for first-line treatment of pulmonary IA, whereas liposomal amphotericin B is moderately supported. Combinations of antifungals as primary treatment options are not recommended. Therapeutic drug monitoring is strongly recommended for patients receiving posaconazole suspension or any form of voriconazole for IA treatment, and in refractory disease, where a personalized approach considering reversal of predisposing factors, switching drug class and surgical intervention is also strongly recommended. Primary prophylaxis with posaconazole is strongly recommended in patients with acute myelogenous leukaemia or myelodysplastic syndrome receiving induction chemotherapy. Secondary prophylaxis is strongly recommended in high-risk patients. We strongly recommend treatment duration based on clinical improvement, degree of immunosuppression and response on imaging.

Natural killer cells as a therapeutic tool for infectious diseases - current status and future perspectives

Natural Killer (NK) cells are involved in the host immune response against infections due to viral, bacterial and fungal pathogens, all of which are a significant cause of morbidity and mortality in immunocompromised patients. Since the recovery of the immune system has a major impact on the outcome of an infectious complication, there is major interest in strengthening the host response in immunocompromised patients, either by using cytokines or growth factors or by adoptive cellular therapies transfusing immune cells such as granulocytes or pathogen-specific T-cells. To date, relatively little is known about the potential of adoptively transferring NK cells in immunocompromised patients with infectious complications, although the anti-cancer property of NK cells is already being investigated in the clinical setting. This review will focus on the antimicrobial properties of NK cells and the current standing and future perspectives of generating and using NK cells as immunotherapy in patients with infectious complications, an approach which is promising and might have an important clinical impact in the future.

Recent Advances in the Pathogenesis of Mucormycoses

PURPOSE

The purposes of this review are to describe the pathogenesis of mucormycosis and to address recent research advances in understanding the mechanisms of fungal invasion and dissemination.

METHODS

Studies and reviews published in the PubMed and ClinicalTrials.gov databases until December 2017 that explored or reported recent advances in the understanding of the pathogenesis of mucormycosis were reviewed.

FINDINGS

To cause disease, fungal spores need to evade the innate immune system and germinate, leading to angioinvasion and tissue destruction. Recent studies have found that Mucorales are able to downregulate several host defense mechanisms and have identified the specific receptors through which Mucorales attach to the endothelium, facilitating their endocytosis and subsequent angioinvasion. In addition, certain conditions found to act through various mechanisms and pathways in experimental and animal studies, such as hyperglycemia, elevated iron concentrations, and acidosis (particularly diabetic ketoacidosis), increase the virulence of the fungi and enhance their attachment to the endothelium, rendering patients with uncontrolled diabetes and patients with iron overload susceptible to mucormycosis. The role and various antifungal functions of platelets and natural killer cells are highlighted, and the potential contribution of alternative therapies, such as manipulating the innate immune host defenses with granulocyte transfusions or administration of growth factors and using the antifungal effects of calcineurin inhibitors, are presented. Finally, directions and possible implications for future research are provided.

IMPLICATIONS

This article provides a comprehensive overview of research advances in the pathogenesis of infections caused by Mucorales and helps future studies develop effective treatment strategies and improve patient outcomes.

The in vitro effects of interferon-gamma, alone or in combination with amphotericin B, tested against the pathogenic fungi Candida albicans and Aspergillus fumigatus

Objective

Recent studies into the antifungal activity of NK-cells against the Aspergillus fumigatus have presented differing accounts on their mode of antifungal activity. One of these mechanisms proposed that NK-cells may kill the fungus via the direct effects of exposure to Interferon gamma (IFN-γ).

Results

In this study we investigated the direct antifungal effects of recombinant human IFN-γ against a range of pathogenic fungi by measuring cellular damage using an XTT-based assay and cell viability through plate counts. It was found that 32 pg/ml of IFN-γ exhibited a significant but small antifungal effect on A. fumigatus (p = 0.02), Aspergillus flavus (p = 0.04) and Saccharomyces cerevisiae (p = 0.03), inhibiting growth by 6, 11 and 17% respectively. No significant inhibitory effects were observed in Candida species (p > 0.05 for all species tested) or Cryptococus neoformans (p = 0.98). Short term exposure (3 h) to a combination of amphotericin B (1 µg/ml) and IFN-γ (32 pg/ml) increased the effectiveness of amphotericin B against A. fumigatus and S. cerevisiae but not Candida albicans. These data suggest that IFN-γ does not possess strong antifungal activity but can enhance the effect of amphotericin B under some testing conditions against Aspergillus species.

Bacterial Pneumonia in Patients with Cancer: Novel Risk Factors and Management

Bacterial pneumonias exact unacceptable morbidity on patients with cancer. Although the risk is often most pronounced among patients with treatment-induced cytopenias, the numerous contributors to life-threatening pneumonias in cancer populations range from derangements of lung architecture and swallow function to complex immune defects associated with cytotoxic therapies and graft-versus-host disease. These structural and immunologic abnormalities often make the diagnosis of pneumonia challenging in patients with cancer and impact the composition and duration of therapy. This article addresses host factors that contribute to pneumonia susceptibility, summarizes diagnostic recommendations, and reviews current guidelines for management of bacterial pneumonia in patients with cancer.

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.

Granulocyte transfusions in the management of invasive fungal infections

Granulocyte transfusions have a long history of being used in patients with neutropenia or neutrophil dysfunction to prevent and treat invasive fungal infections. However, there are limited and conflicting data concerning its clinical effectiveness, considerable variations in current granulocyte transfusion practices, and uncertainties about its benefit as an adjunct to modern antifungal therapy. In this review, we provide an overview on granulocyte transfusions and summarize the evidence on their role in the prevention and treatment of invasive fungal infections.

Immunotherapy of Fungal Infections

Fungal organisms are ubiquitous in the environment. Pathogenic fungi, although relatively few in the whole gamut of microbial pathogens, are able to cause disease with varying degrees of severity in individuals with normal or impaired immunity. The disease state is an outcome of the fungal pathogen's interactions with the host immunity, and therefore, it stands to reason that deep/invasive fungal diseases be amenable to immunotherapy. Therefore, antifungal immunotherapy continues to be attractive as an adjunct to the currently available antifungal chemotherapy options for a number of reasons, including the fact that existing antifungal drugs, albeit largely effective, are not without limitations, and that morbidity and mortality associated with invasive mycoses are still unacceptably high. For several decades, intense basic research efforts have been directed at development of fungal immunotherapies. Nevertheless, this approach suffers from a severe bench-bedside disconnect owing to several reasons: the chemical and biological peculiarities of the fungal antigens, the complexities of host-pathogen interactions, an under-appreciation of the fungal disease landscape, the requirement of considerable financial investment to bring these therapies to clinical use, as well as practical problems associated with immunizations. In this general, non-exhaustive review, we summarize the features of ongoing research efforts directed towards devising safe and effective immunotherapeutic options for mycotic diseases, encompassing work on antifungal vaccines, adoptive cell transfers, cytokines, antimicrobial peptides (AMPs), monoclonal antibodies (mAbs), and other agents.

Optimizing Outcomes in Immunocompromised Hosts: Understanding the Role of Immunotherapy in Invasive Fungal Diseases

A major global concern is the emergence and spread of systemic life-threatening fungal infections in critically ill patients. The increase in invasive fungal infections, caused most commonly by Candida and Aspergillus species, occurs in patients with impaired defenses due to a number of reasons such as underlying disease, the use of chemotherapeutic and immunosuppressive agents, broad-spectrum antibiotics, prosthetic devices and grafts, burns, neutropenia and HIV infection. The high morbidity and mortality associated with these infections is compounded by the limited therapeutic options and the emergence of drug resistant fungi. Hence, creative approaches to bridge the significant gap in antifungal drug development needs to be explored. Here, we review the potential anti-fungal targets for patient-centered therapies and immune-enhancing strategies for the prevention and treatment of invasive fungal diseases.

Granulocyte transfusions in children and adults with hematological malignancies: benefits and controversies

Bacterial and fungal infections continue to pose a major clinical challenge in patients with prolonged severe neutropenia after chemotherapy or hematopoietic stem cell transplantation (HSCT). With the advent of granulocyte colony-stimulating factor (G-CSF) to mobilize neutrophils in healthy donors, granulocyte transfusions have been broadly used to prevent and/or treat life-threatening infections in patients with severe febrile neutropenia and/or neutrophil dysfunction. Although the results of randomized controlled trials are inconclusive, there are suggestions from pilot and retrospective studies that granulocyte transfusions may benefit selected categories of patients. We will critically appraise the evidence related to the use of therapeutic granulocyte transfusions in children and adults, highlighting current controversies in the field and discussing complementary approaches to modulate phagocyte function in the host.

Pneumonia in the neutropenic cancer patient

PURPOSE OF REVIEW

Pneumonia is the leading cause of death among neutropenic cancer patients, particularly those with acute leukaemia. Even with empiric therapy, case fatality rates of neutropenic pneumonias remain unacceptably high. However, recent advances in the management of neutropenic pneumonia offer hope for improved outcomes in the cancer setting. This review summarizes recent literature regarding the clinical presentation, microbiologic trends, diagnostic advances and therapeutic recommendations for cancer-related neutropenic pneumonia.

RECENT FINDINGS

Although neutropenic patients acquire pathogens both in community and nosocomial settings, patients' obligate healthcare exposures result in the frequent identification of multidrug-resistant bacterial organisms on conventional culture-based assessment of respiratory secretions. Modern molecular techniques, including expanded use of galactomannan testing, have further facilitated identification of fungal pathogens, allowing for aggressive interventions that appear to improve patient outcomes. Multiple interested societies have issued updated guidelines for antibiotic therapy of suspected neutropenic pneumonia. The benefit of antibiotic medications may be further enhanced by agents that promote host responses to infection.

SUMMARY

Neutropenic cancer patients have numerous potential causes for pulmonary infiltrates and clinical deterioration, with lower respiratory tract infections among the most deadly. Early clinical suspicion, diagnosis and intervention for neutropenic pneumonia provide cancer patients' best hope for survival.

Immunomodulatory therapy in yeast infections

Invasive yeast infections are a significant cause of morbidity and mortality in patients with defective immune response, such as those with cancer-related immunosuppression, organ transplantation or other immunodeficiencies, and neonates. Hospitalization in the intensive care unit may increase the risk for such infections. Despite the advent of new antifungal agents, the problem is escalating as the number of susceptible hosts increase and virulent, more resistant fungal strains emerge. Over the past few years, advances in immunology and molecular biology have greatly contributed to a better understanding of the pathogenesis of yeast infections. There is evidence that reconstitution of the host immune function is a major contributor to the resolution of yeast infections. Strategies aiming to increase the phagocyte number (e.g., granulocyte transfusions), to stimulate immune response (e.g., administration of hematopoietic growth factors and other proinflammatory cytokines) and to stimulate antigen-specific immunity (e.g., antibody therapy or vaccination) benefit patients at risk of, or suffering from, yeast infections. Further preclinical and clinical studies, as well as improving our understanding of immune system functions and dysfunctions, remain a future challenge.

High-dose caspofungin as a component of combination antifungal therapy in 91 patients with neoplastic diseases and hematopoietic stem cell transplantation: a critical review of short-term and long-term adverse events

The antifungal activity of echinocandins is concentration dependent. Previously, we demonstrated that high-dose caspofungin (HD-CSP; 100 mg daily) was well tolerated in 34 immunosuppressed patients with cancer and may have favorably influenced outcomes. We retrospectively assessed all 91 patients in whom HD-CSP was given for the treatment of invasive fungal disease (IFD). The median number of doses was 18.5 ± 21.5, and in 8 (9%) patients more than 40 doses were given. Most (62%) of the patients had leukemia. A total of 45 (49%) patients had undergone stem cell transplantation; 80% received allogeneic grafts and 47% had graft-versus-host disease. High-dose corticosteroids were given during antifungal therapy in 26 (29%) patients. In all, 8 (9%) patients had new elevation in serum bilirubin during HD-CSP therapy; normalization occurred after voriconazole and HD-CSP were discontinued in 4 patients each. No other short-term or delayed adverse events were observed. In all, 40 (44%) patients died of IFD. High-dose corticosteroids during HD-CSP (odds ratio [OR] 8, 95% confidence interval [CI] 2.1-30.4; P < .002) and starting HD-CSP in the critical care unit (OR 67.5, 95% CI 5.25-868.9; P < .001) were associated with death from fungal disease. Prolonged HD-CSP therapy was well tolerated. Drug-induced hyperbilirubinemia may pose a potential limitation for continued HD-CSP use in highly susceptible patients with hematologic neoplasms and stem cell transplantation.

Aerosolized amphotericin B lipid complex as adjunctive treatment for fungal lung infection in patients with cancer-related immunosuppression and recipients of hematopoietic stem cell transplantation

STUDY OBJECTIVE

Aerosolized amphotericin B lipid complex (aeABLC) has been successfully used to prevent fungal disease. Experience with aeABLC as treatment of fungal lung disease is limited.

DESIGN

We evaluated the safety and efficacy of aeABLC adjunct therapy for fungal lung disease in a retrospective study of 32 immunosuppressed adults. All values are given as ± standard deviation.

SETTING

National Cancer Institute-designated Comprehensive Cancer Center.

PATIENTS

Acute leukemia (69%) and severe neutropenia (63%) were common. Fifty-six percent of patients had undergone allogeneic hematopoietic stem cell transplantation 185 ± 424 days prior to aeABLC was commenced.

MEASUREMENT AND MAIN RESULTS

High-dose corticosteroids were administered during aeABLC in 28% of patients. Fungal lung disease was proven or probable in 41% of patients. Most patients (78%) received concurrent systemic antifungal therapy for a median of 14 ± 18 days before aeABLC. The median cumulative aeABLC dose was 1050 ± 2368 mg, and the median duration of aeABLC therapy was 28 ± 130 days. Most patients (78%) received 50 mg aeABLC twice daily. Partial or complete resolution of fungal lung disease was noted in 50% of patients. In three patients (9%) modest cough, mild bronchospasm, and transient chest pain with accompanying nausea and vomiting resolved completely after discontinuation of aeABLC. No patient required hospitalization for drug toxicity or had a serious (grade III or IV) drug-related adverse event.

CONCLUSION

Treatment with aeABLC was tolerated without serious toxicity and may be considered in the setting of severe immunosuppression, cancer, and/or hematopoietic stem cell transplantation in patients with difficult-to-treat fungal lung disease.

Use of healthy-donor granulocyte transfusions to treat infections in neutropenic patients with myeloid or lymphoid neoplasms: experience in 74 patients treated with 373 granulocyte transfusions

BACKGROUND/AIMS

Despite limited evidence for efficacy, granulocyte transfusions (GTX) are used to prevent and treat opportunistic infections in patients with neutropenia.

METHODS

Three hundred and seventy-three GTX given to 74 patients were assessed retrospectively.

RESULTS

GTX were discontinued because of clinical improvement more often in patients with severe infections than in patients without severe infections (27 vs. 12%; p ≤ 0.002), whereas deaths resulted in discontinuation of GTX therapy less often in patients with severe infections than without (8 vs. 39%; p ≤ 0.002). Patients who died by 12 weeks after GTX initiation were more likely to have leukemia (p = 0.03), not to have recovery of neutrophil counts (p < 0.0001), and to have started GTX during a critical care unit stay (p < 0.001). Uses of granulocyte colony-stimulating factor (p ≤ 0.02) and interferon-γ (p ≤ 0.04) were more common in patients who survived. In patients with comorbidities (31%; odds ratio, OR, 12.6; 95% confidence interval, CI, 2.4-65.7; p ≤ 0.003), GTX was started in the critical care unit (OR 8.8; 95% CI 2.5-30.9; p < 0.001), and a high total bilirubin level at the end of GTX (OR 2.1; 95% CI 1.1-4.2; p = 0.03) had a higher probability of death 12 weeks after GTX therapy commenced.

CONCLUSIONS

The possibility that a niche population may benefit from GTX requires further assessment.

Airway and parenchymal manifestations of pulmonary aspergillosis

Pulmonary aspergillosis encompasses a heterogeneous group of mycoses that result from either colonisation or pathogenic damage of lung tissue by Aspergillus fungi. These clinical entities range from relatively benign saprophytic hypersensitivity associated with fungal inhabitation to life threatening invasive disease. The diagnosis of pulmonary disorders related to Aspergillus is on the increase and it is more important than ever those both general and respiratory physicians have a good understanding of these disorders. This paper reviews the contemporary understanding of the clinical, radiographic and histopathological aspects of pulmonary aspergillosis.

ESCMID* guideline for the diagnosis and management of Candida diseases 2012: adults with haematological malignancies and after haematopoietic stem cell transplantation (HCT)

Fungal diseases still play a major role in morbidity and mortality in patients with haematological malignancies, including those undergoing haematopoietic stem cell transplantation. Although Aspergillus and other filamentous fungal diseases remain a major concern, Candida infections are still a major cause of mortality. This part of the ESCMID guidelines focuses on this patient population and reviews pertaining to prophylaxis, empirical/pre-emptive and targeted therapy of Candida diseases. Anti-Candida prophylaxis is only recommended for patients receiving allogeneic stem cell transplantation. The authors recognize that the recommendations would have most likely been different if the purpose would have been prevention of all fungal infections (e.g. aspergillosis). In targeted treatment of candidaemia, recommendations for treatment are available for all echinocandins, that is anidulafungin (AI), caspofungin (AI) and micafungin (AI), although a warning for resistance is expressed. Liposomal amphotericin B received a BI recommendation due to higher number of reported adverse events in the trials. Amphotericin B deoxycholate should not be used (DII); and fluconazole was rated CI because of a change in epidemiology in some areas in Europe. Removal of central venous catheters is recommended during candidaemia but if catheter retention is a clinical necessity, treatment with an echinocandin is an option (CII(t) ). In chronic disseminated candidiasis therapy, recommendations are liposomal amphotericin B for 8 weeks (AIII), fluconazole for >3 months or other azoles (BIII). Granulocyte transfusions are only an option in desperate cases of patients with Candida disease and neutropenia (CIII).

Impact of the mobilization regimen and the harvesting technique on the granulocyte yield in healthy donors for granulocyte transfusion therapy

BACKGROUND

Granulocyte mobilization and harvesting, the two major phases of granulocyte collection, have not been standardized.

STUDY DESIGN AND METHODS

The data on 123 granulocyte collections were retrospectively investigated for the effect of the mobilization regimen and the harvesting technique. After a single subcutaneous dose (600 µg) of granulocyte-colony-stimulating factor (G-CSF) with (n = 68) or without (n = 40) 8 mg of orally administered dexamethasone, 108 granulocyte donors underwent granulocyte collections. Moreover, 15 peripheral blood stem cell (PBSC) donors who had received 400 µg/m2 or 10 µg/kg G-CSF for 5 days underwent granulocyte collections on the day after the last PBSC collections (PBSC-GTX donors). Granulocyte harvesting was performed by leukapheresis with (n = 108) or without (n = 15) using high-molecular-weight hydroxyethyl starch (HES).

RESULTS

Granulocyte donors who received mobilization with G-CSF plus dexamethasone produced significantly higher granulocyte yields than those who received G-CSF alone (7.2 × 10(10)  ± 2.0 × 10(10) vs. 5.7 × 10(10)  ± 1.7 × 10(10) , p = 0.006). PBSC-GTX donors produced a remarkably high granulocyte yield (9.7 × 10(10)  ± 2.3 × 10(10) ). The use of HES was associated with better granulocyte collection efficiency (42 ± 7.8% vs. 10 ± 9.1%, p < 0.0001).

CONCLUSION

G-CSF plus dexamethasone produces higher granulocyte yields than G-CSF alone. Granulocyte collection from PBSC donors appears to be a rational strategy, since it produces high granulocyte yields when the related patients are at a high risk for infection and reduces difficulties in finding granulocyte donors. HES should be used in apheresis procedures.

Granulocyte macrophage colony-stimulating factor in 66 patients with myeloid or lymphoid neoplasms and recipients of hematopoietic stem cell transplantation with invasive fungal disease

BACKGROUND/AIMS

Adding granulocyte macrophage colony-stimulating factor (GM-CSF) may improve the response to antifungal therapy in immunosuppressed patients with invasive fungal disease (IFD).

METHODS

We retrospectively assessed 66 patients in whom GM-CSF was given during antifungal therapy.

RESULTS

Severe neutropenia (77%) and refractory/relapsed cancer (65%) were common in the group. Prior to GM-CSF therapy, 15% of patients received high-dose corticosteroids for a median of 30 ± 16 days [median cumulative dose (c.d.) 1,184 ± 1,019 mg], and 9 received steroids during GM-CSF therapy for a median of 16 ± 12 days (median c.d. 230 ± 1,314 mg). Mild toxic effects were noted in 9% of patients; there were no cases of cardiopulmonary toxicity. All-cause deaths were observed in 68% of patients and 48% died of progressive IFD. High-dose corticosteroids prior to GM-CSF (OR 24; 95% CI 2.21-264.9; p ≤ 0.009), GM-CSF started in the intensive care unit (OR 10; 95% CI 1.66-63.8; p ≤ 0.01), concurrent granulocyte transfusions (OR 5; 95% CI 1.27-16.8; p ≤ 0.02) and proven/probable IFD (OR 4; 95% CI 1-16.2; p ≤ 0.05) predicted antifungal treatment failure.

CONCLUSIONS

GM-CSF adjuvant therapy was tolerated without serous toxicity and antifungal treatment failure remained a challenge in patients treated with high-dose systemic corticosteroids.

Immunotherapy against invasive mold infections

Invasive infections due to filamentous fungi, such as Aspergillus spp., Zygomycetes, Scedosporium and Fusarium spp., cause significant morbidity and mortality in immunocompromised patients with hematological malignancies, recipients of hematopoietic stem cell transplants and those with chronic granulomatous disease. Despite antifungal therapy, the outcome is often unfavorable in these patients; immune restoration is considered as the cornerstone of successful treatment. Important aspects of human immune response against fungi include effective innate immune response expressed as effective phagocytic functions and a balance between proinflammatory and regulatory adaptive immune responses. A number of immunomodulatory approaches, including the administration of enhancing cytokines, adoptive transfer of pathogen-specific T lymphocytes and granulocyte transfusions have been investigated as adjunctive treatments against serious mold infections. Despite encouraging in vitro and in vivo data, current clinical evidence is not sufficient to allow firm recommendations on the use of these immunomodulatory modalities in serious mold infections.

Immunotherapy of infections caused by rare filamentous fungi

Invasive fungal infections caused by rare filamentous fungi constitute a significant cause of morbidity and mortality in patients with defective immune responses. Despite the advent of new antifungal agents, the problem is escalating as the number of susceptible hosts increases and virulent, more resistant fungal strains emerge. There is evidence that reconstitution of the host immune function is a major contributor to the resolution of these infections. Therapeutic modalities aimed at increasing phagocyte numbers, such as granulocyte transfusions, stimulating the immune response, such as administration of haematopoietic growth factors and other proinflammatory cytokines, or indirectly augmenting immune function have shown promising results in the preclinical setting. Because of the rarity of the infections, multicentre clinical trials are needed to demonstrate the efficacy and safety of the new immunomodulating approaches.

Infections in patients with hematologic neoplasms and hematopoietic stem cell transplantation: neutropenia, humoral, and splenic defects

Infections are common in patients with hematologic neoplasms and following allogeneic hematopoietic transplantation. Neutropenia and defects in adaptive B-cell-mediated immunity and/or lack of splenic function predispose patients to a host of diverse and often serious infections. It is important to recognize that patients who undergo treatment for hematologic neoplasms may have mixed immune defects, and their vulnerability to infection may continue to change, in part as a reflection of the dynamic developments in the practice of oncology. The main obstacle in providing targeted, evidence-based antimicrobial treatment is the unpredictable results of even the new generation of diagnostic assays. A definite diagnosis for most end-organ opportunistic diseases requires tissue samples that are seldom available. Because immune defects may coexist, empirical therapy is directed toward a wide spectrum of pathogens. Real-time information about innate and adaptive immune functions and the role of acute and chronic phase molecules may improve target-specific therapy.

Human NK cells display important antifungal activity against Aspergillus fumigatus, which is directly mediated by IFN-γ release

Despite the strong interest in the NK cell-mediated immunity toward malignant cells and viruses, there is a relative lack of data on the interplay between NK cells and filamentous fungi, especially Aspergillus fumigatus, which is the major cause of invasive aspergillosis. By studying the in vitro interaction between human NK cells and A. fumigatus, we found only germinated morphologies to be highly immunogenic, able to induce a Th1-like response, and capable of upregulating cytokines such as IFN-γ and TNF-α. Moreover, priming NK cells with human rIL-2 and stimulating NK cells by direct NK cell-pathogen contact were essential to induce damage against A. fumigatus. However, the most interesting finding was that NK cells did not mediate anti-Aspergillus cytotoxicity through degranulation of their cytotoxic proteins (perforin, granzymes, granulysine), but via an alternative mechanism involving soluble factor(s). To our knowledge, our study is the first to demonstrate that IFN-γ, released by NK cells, directly damages A. fumigatus, attributing new properties to both human NK cells and IFN-γ and suggesting them as possible therapeutic tools against IA.

Immunotherapy against invasive fungal diseases in stem cell transplant recipients

Despite the availability of new antifungal compounds, morbidity and mortality of invasive fungal disease in allogeneic hematopoietic stem cell recipients are still unacceptably high. Over the past decade, one could witness an exciting improvement of the understanding of the molecular pathogenesis and of the complexity of host antifungal immune responses. This, in turn, provides critical information to augment host immunity against fungal pathogens. Strategies for enhancing the immune system include the administration of effector and regulatory cells (e.g., granulocytes, antigen-specific T cells, dendritic cells) as well as the administration of recombinant cytokines, interferons and growth factors (e.g., interferon-γ, keratinocyte growth factor, granulocyte- and granulocyte-macrophage colony stimulating factor). One has to recognize at the same time, however, that data of in vitro assays and animal models cannot necessarily be transferred into the clinical setting. In addition, meaningful clinical trials in allogeneic stem cell recipients suffering from invasive fungal disease require sufficiently large and homogenous cohorts of patients and can only be performed in international collaboration, but may ultimately improve the outcome of allogeneic transplant recipients with invasive fungal disease.

Does combination of lipid formulation of amphotericin B and echinocandins improve outcome of invasive aspergillosis in hematological malignancy patients?

BACKGROUND

In vitro and in vivo studies suggested that combination of lipid formulation of amphotericin B (L-AMB) and echinocandins may have a synergistic or additive effect against Aspergillus. Furthermore, clinical studies suggested that this combination may improve response of invasive aspergillosis (IA).

METHODS

Between August 1993 and June 2008, the authors identified a total of 159 patients with hematological malignancies who received salvage therapy for IA, with L-AMB alone, echinocandins alone, or a combination of L-AMB and echinocandins. Clinical characteristics, response to salvage therapy, and death up to 12 weeks after initiation of salvage therapy were retrospectively determined for all patients.

RESULTS

Seventy patients received salvage therapy with L-AMB, 18 patients received echinocandins alone (89% of whom received caspofungin), and 71 patients received the combination therapy of amphotericin B and echinocandins (90% of who received caspofungin). The 3 salvage treatment groups were comparable in regard to clinical characteristics; graft versus host disease was more frequently encountered in the echinocandin group, whereas more patients in the L-AMB and combination groups had neutropenia and received immunotherapy. The response to salvage therapy was better in the echinocandin group (9% L-AMB, 28% echinocandins, and 21% for combination therapy). The 3 groups had a comparable rate of Aspergillus-related death (58%-64%) and overall mortality (61%-67%).

CONCLUSIONS

The combination of L-AMB and echinocandins offered no advantage in terms of improving response or reducing mortality over either drug alone. Hence, this combination will only add to the cost of therapy without any improvement in outcome in patients with hematological malignancies.

Infections in Patients with Cancer: Overview

Patients with neoplastic disease are often highly susceptible to severe infections. The following factors influence the types, severity, and response to therapy of these infections: (1) Changing epidemiology of infections; (2) cancer- and/or treatment-associated neutropenia; (3) acquired immune deficiency states such as cellular immune defect; (4) recent development of new-generation diagnostic tools including widely available DNA amplification tests; (5) effective intervention for infection prevention; (6) empiric or presumptive therapy during high-risk periods; (7) availability of new classes of highly active antimicrobial drugs; (8) strategies to promote hosts’ immune response; and (9) future measures. This introductory chapter intended for the reader to become familiar with the important historical milestones in the understanding and development in the field of infectious diseases in immunosuppressed patients with an underlying neoplasms and patients undergoing hematopoietic stem cell trans­plantation.

Human natural killer cells exhibit direct activity against Aspergillus fumigatus hyphae, but not against resting conidia

Because natural killer (NK) cells kill tumor cells and combat infections, there is growing interest in adoptively transferring NK cells to hematopoietic stem cell recipients. Unfortunately, in humans, the activity of NK cells against Aspergillus species, the major cause of invasive fungal infection in stem cell recipients, are poorly characterized. Our results show that unstimulated and interleukin-2 prestimulated human NK cells kill Aspergillus fumigatus hyphae but do not affect resting conidia. Killing is also induced by the supernatant of prestimulated NK cells and human perforin. The high levels of interferon-γ and granulocyte macrophage colony-stimulating factor produced by prestimulated NK cells are significantly reduced by Aspergillus, indicating an immunosuppressive effect of the fungus. Whereas Aspergillus hyphae activate NK cells, resting, and germinating, conidia and conidia of ΔrodA mutants lacking the hydrophobic surface layer do not. Our results suggest that adoptively transferred human NK cells may be a potential antifungal tool in the transplantation context.

Pulmonary aspergillosis: clinical presentation, diagnostic tests, management and complications

PURPOSE OF REVIEW

When functioning properly, the immune system recognizes inhaled fungi and controls their growth, while avoiding injurious inflammation and allergy. 'Aspergillosis' represents a spectrum of clinical diseases resulting from impaired or excessive immune responses. Invasive aspergillosis is principally disease of severely immunocompromised patients, whereas allergic forms of aspergillosis result from an excessive inflammatory response to hyphae colonizing the sinopulmonary tract. We will review insights gained in host defense against Aspergillus species and the immunopathogenesis of Aspergillus-related diseases as well as important advances made in fungal diagnostics and antifungal therapy.

RECENT FINDINGS

Important advances have been made in diagnosis of invasive aspergillosis and in antifungal agents. Voriconazole was superior to amphotericin B deoxycholate as primary therapy for invasive aspergillosis. There is significant interest in combination antifungal therapy for invasive aspergillosis. Fungal genomics offers a powerful opportunity to gain knowledge about fungal virulence factors that can be targets for drug development. In addition, new insights have been gained regarding host defense against Aspergillus species that may be exploited therapeutically.

SUMMARY

We have gained substantial knowledge regarding how the immune system recognizes inhaled fungi and calibrates the inflammatory response. There has also been substantial progress in tools to diagnose aspergillosis and in antifungal therapeutics. Future progress will likely involve the development of more refined diagnostic tools, new classes of antifungal agents, and greater knowledge of pathogen and host factors that predispose to aspergillosis.

Adoptive antifungal T cell immunotherapy--into the clinic?

The morbidity and mortality rates of invasive fungal infection in allogeneic stem cell recipients are still unacceptably high and have not been significantly improved by alternative antifungal strategies to date. Over the last few years, rapid methods for the clinical-scale generation of functionally active and well characterized antifungal T(H)1 cells have become available. In addition, current data on the use of donor-derived virus-specific T cells in allogeneic stem cell transplantation suggest that the risk of severe adverse events, in particular the risk of graft-versus-host disease, is negligible. Therefore, adoptive antifungal immunotherapeutic strategies should be evaluated in clinical trials. However, one has to recognize that these trials are only meaningful with sufficiently large and homogenous cohorts of patients and if the settings of adoptive antifungal immunotherapy are comparable. Ultimately, the strategy of adoptively transferring antifungal immune responses might improve the outcome in hematopoietic stem cell recipients suffering from invasive fungal infection.

Aspergillosis in hematopoietic stem cell transplant recipients: risk factors, prophylaxis, and treatment

This article discusses newer antifungal agents, recent randomized controlled trials, and the 2008 guidelines for treatment of aspergillosis in reference to hematopoietic stem cell transplantation (HSCT). Strategies such as reduced-intensity conditioning and agents such as infliximab shed new light on aspergillosis risk. The association between Toll-like receptor polymorphisms and aspergillosis is an exciting development. Posaconazole was evaluated in two randomized prophylaxis trials, and a large, randomized trial established voriconazole's therapeutic superiority to amphotericin. However, many questions remain regarding which patients benefit most from prophylaxis; resistance to newer antifungals; and combination, salvage, and immunomodulatory therapies. Current therapies and strategies have improved the outlook of HSCT recipients with invasive aspergillosis. Future directions include increasingly sophisticated risk stratification, clinical testing of combination therapies, and adjunctive immunomodulatory therapies.

Current therapeutic approaches to fungal infections in immunocompromised hematological patients

Invasive fungal infections are significant causes of morbidity and mortality in patients with hematological malignancies. Patients with acute myeloid leukemia and those who have undergone allogeneic hematopoietic stem cell transplantation are at especially high risk. Various fungal agents are responsible for this complication, but Aspergillus spp. and Candida spp. are the most frequently isolated micro-organisms; less commonly, infections could be caused by Zygomycetes or other rare molds or yeasts. Several new systemically-administered antifungal agents have been approved for clinical use since 2001; these agents include liposomal amphotericin B, voriconazole, caspofungin, and posaconazole, and they represent a major advance in antifungal therapy and have improved the prognosis of patients with hematological malignancies. This review focuses on therapeutic aspects of the management of fungal infections in hematological patients.

Inhaled therapeutics for prevention and treatment of pneumonia

The lungs are the most common site of serious infection owing to their large surface area exposed to the external environment and minimum barrier defense. However, this architecture makes the lungs readily available for topical therapy. Therapeutic aerosols include those directed towards improving mucociliary clearance of pathogens, stimulation of innate resistance to microbial infection, cytokine stimulation of immune function and delivery of antibiotics. In our opinion inhaled antimicrobials are underused, especially in patients with difficult-to-treat lung infections. The use of inhaled antimicrobial therapy has become an important part of the treatment of airway infection with Pseudomonas aeruginosa in cystic fibrosis and the prevention of invasive fungal infection in patients undergoing heart and lung transplantation. Cytokine inhaled therapy has also been explored in the treatment of neoplastic and infectious disease. The choice of pulmonary drug delivery systems remains critical as air-jet and ultrasonic nebulizer may deliver sub-optimum drug concentration if not used properly. In future development of this field, we recommend an emphasis on the study of the use of aerosolized hypertonic saline solution to reduce pathogen burden in the airways of subjects infected with microbes of low virulence, stimulation of innate resistance to prevent pneumonia in immunocompromised subjects using cytokines or synthetic pathogen-associated molecular pattern analogues and more opportunities for the use of inhaled antimicrobials. These therapeutics are still in their infancy but show great promise.

Recent advances in antifungal prevention and treatment

Invasive fungal infections are important causes of morbidity and mortality in patients with bone marrow failure syndromes and hematological malignancies, or who are undergoing allogeneic hematopoietic stem cell transplantation (HSCT). Current epidemiological trends indicate a shift toward infections by Aspergillus spp., non-albicans Candida spp., and previously uncommon fungal pathogens that have decreased susceptibility to the available antifungal agents. The last two decades have seen substantial improvements in the clinical, laboratory, and radiological diagnosis of these infections and the development of new antifungal compounds. Progress has been made in establishing disease definitions and paradigms for antifungal intervention and in the design and conduct of interventional clinical trials. Collectively, these advances have led to major but ongoing changes in the management of patients at risk of or being affected by invasive fungal infections. This article reviews current approaches to prevention and treatment of opportunistic fungal infections in immunocompromised patients with hematological disorders and discusses novel approaches to antifungal chemotherapy and adjunctive treatments.

Evolving strategies in the management of aspergillosis

Aspergillus spp. remain the most common causes of invasive mould infections among patients with hematologic malignancies and recipients of solid-organ and hematopoietic stem-cell transplants. Despite advances in prevention and treatment, invasive aspergillosis continues to be a deadly disease. This paper reviews current approaches to treatment of aspergillosis in adults, including surgical and immune-based strategies, and developments in prophylaxis for aspergillosis in high-risk patient populations.