Inteferon gamma and granulocyte–macrophage colony-stimulating factor augment the antifungal activity of human polymorphonuclear leukocytes againstScedosporiumspp.: comparison withAspergillusspp

American Society of Transplantation and Cellular Therapy Series: #8-Management and Prevention of Non-Aspergillus Molds in Hematopoietic Cell Transplantation Recipients

The Practice Guidelines Committee of the American Society of Transplantation and Cellular Therapy partnered with its Transplant Infectious Disease Special Interest Group to create a guideline focusing on non-Aspergillus invasive molds, which are uncommon yet lethal invasive fungal diseases in the peri-hematopoietic cell transplant (HCT) period. We used a compendium-style approach by dissecting this broad, heterogeneous, and highly complex topic into a series of standalone frequently asked questions (FAQs) and tables. Adult and pediatric infectious diseases and HCT content experts developed, then answered FAQs, and finalized topics with harmonized recommendations. All the evidence for non-Aspergillus invasive mold infection is non-RCT and mostly level III, therefore there are no recommendation grades, and instead key references are provided. Through this format, this "8th" topic in the series focuses on the relevant risk factors, diagnostic considerations, prophylaxis, and treatment approaches relevant to rare mold infections in the pre- and post-transplant periods.

Diagnosis and management of invasive fungal infections due to non-Aspergillus moulds

Invasive fungal infection (IFI) due to moulds other than Aspergillus are a significant cause of morbidity and mortality. Non-Aspergillus mould (NAM) infections appear to be on the increase due to an ever-expanding population of immunocompromised hosts. In this review, Mucorales, Scedosporium species, Lomentospora prolificans and Fusarium species are examined in detail, and the microbiology, risk factors, diagnosis and treatment of emerging NAMs such as Paecilomyces variotti, Purpureocillium lilacinum and Rasamsonia are summarized. The challenges in diagnosis are emphasized and the emerging importance of molecular methods is discussed. Treatment of IFI due to NAMs is a multi-pronged and multi-disciplinary approach. Surgery, correction of underlying risk factors, and augmentation of the host immune response are as important as antifungal therapy. Many of these NAMs are intrinsically resistant to the currently licensed antifungal agents, so selection of therapy needs to be guided by susceptibility testing. There are new antifungal agents in development, and these have the potential to improve the efficacy and safety of antifungal treatment in the future. Ongoing research is required to fully delineate the epidemiology of NAM infections, and to develop better diagnostic tools and treatments so that outcomes from these infections can continue to improve.

Scedosporiosis and lomentosporiosis: modern perspectives on these difficult-to-treat rare mold infections

SUMMARYAlthough Scedosporium species and Lomentospora prolificans are uncommon causes of invasive fungal diseases (IFDs), these infections are associated with high mortality and are costly to treat with a limited armamentarium of antifungal drugs. In light of recent advances, including in the area of new antifungals, the present review provides a timely and updated overview of these IFDs, with a focus on the taxonomy, clinical epidemiology, pathogenesis and host immune response, disease manifestations, diagnosis, antifungal susceptibility, and treatment. An expansion of hosts at risk for these difficult-to-treat infections has emerged over the last two decades given the increased use of, and broader population treated with, immunomodulatory and targeted molecular agents as well as wider adoption of antifungal prophylaxis. Clinical presentations differ not only between genera but also across the different Scedosporium species. L. prolificans is intrinsically resistant to most currently available antifungal agents, and the prognosis of immunocompromised patients with lomentosporiosis is poor. Development of, and improved access to, diagnostic modalities for early detection of these rare mold infections is paramount for timely targeted antifungal therapy and surgery if indicated. New antifungal agents (e.g., olorofim, fosmanogepix) with novel mechanisms of action and less cross-resistance to existing classes, availability of formulations for oral administration, and fewer drug-drug interactions are now in late-stage clinical trials, and soon, could extend options to treat scedosporiosis/lomentosporiosis. Much work remains to increase our understanding of these infections, especially in the pediatric setting. Knowledge gaps for future research are highlighted in the review.

Recombinant Human Granulocyte-Macrophage Colony-Stimulating Factor (rhu GM-CSF) as Adjuvant Therapy for Invasive Fungal Diseases

BACKGROUND

Sargramostim (yeast-derived, glycosylated recombinant human granulocyte-macrophage colony-stimulating factor [rhu GM-CSF]) augments innate and adaptive immune responses and accelerates hematopoietic recovery of chemotherapy-induced neutropenia. However, considerably less is known about its efficacy as adjunctive immunotherapy against invasive fungal diseases (IFDs).

METHODS

The clinical courses of 15 patients with pediatric malignancies and IFDs treated adjunctively with sargramostim at a single institution were analyzed in a retrospective cohort review. Further, a systematic review of published reports of rhu GM-CSF for IFDs was also conducted.

RESULTS

Among 65 cases, 15 were newly described pediatric patients and 50 were previously published cases of IFDs treated with rhu GM-CSF. Among the newly reported pediatric patients, IFDs were caused by Candida spp., Trichosporon sp., and molds (Aspergillus spp., Rhizopus sp., Lichtheimia sp., and Scedosporium sp). Twelve (80%) were neutropenic at baseline, and 12 (80%) were refractory to antifungal therapy. Among 12 evaluable patients, the overall response rate was 92% (8 [67%] complete responses, 3 [25%] partial responses, and 1 [8%] stable). Treatment is ongoing in the remaining 3 patients. Among 50 published cases (15 Candida spp., 13 Mucorales, 11 Aspergillus spp., 11 other organisms), 20 (40%) had baseline neutropenia and 36 (72%) were refractory to standard therapy before rhu GM-CSF administration. Consistent with responses in the newly reported patients, the overall response rate in the literature review was 82% (40 [80%] complete responses, 1 [2%] partial response, and 9 [18%] no response).

CONCLUSIONS

Sargramostim may be a potential adjunctive immunomodulator for selected patients with hematological malignancies and refractory IFDs.

Early production of proinflammatory cytokines in response to Scedosporium apiospermum during murine pulmonary infection

Scedosporium apiospermum is an opportunistic pathogen that can cause pulmonary infections in both immunosuppressive and immunocompetent patients. Cytokines are molecules that mediate the immune response to promote or eliminate fungal infections. In this work, we evaluated the cytokines profile in the lung and serum of mice infected with Scedosporium apiospermum. We found early production of IL-6, IL-1β and TNF-α cytokines in the lung of infected mice during the first 5 days of infection. We suggest that release of pro-inflammatory cytokines could play a role in the control of fungal invasion.

Lomentospora prolificans: An Emerging Opportunistic Fungal Pathogen

Lomentospora prolificans is an emerging opportunistic pathogen that primarily affects immunocompromised individuals leading to disseminated disease with high mortality rates while also causing infections in healthy populations. Successful recovery from infection is difficult due to high rates of intrinsic resistance to antifungals. Rapid and readily available diagnostic methods, aggressive surgical debridement wherever appropriate, and effective and timely antifungal treatment are the pillars for successful management. Future research will need to clarify the environmental niche of the fungus, further investigate the pathophysiology of infection and define species-specific therapeutic targets.

Cytoskeletal Alteration Is an Early Cellular Response in Pulmonary Epithelium Infected with Aspergillus fumigatus Rather than Scedosporium apiospermum

Invasive aspergillosis and scedosporiosis are life-threatening fungal infections with similar clinical manifestations in immunocompromised patients. Contrarily, Scedosporium apiospermum is susceptible to some azole derivative but often resistant to amphotericin B. Histopathological examination alone cannot diagnose these two fungal species. Pathogenesis studies could contribute to explore candidate protein markers for new diagnosis and treatment methods leading to a decrease in mortality. In the present study, proteomics was conducted to identify significantly altered proteins in A549 cells infected with or without Aspergillus fumigatus and S. apiospermum as measured at initial invasion. Protein validation was performed with immunogold labelling alongside immunohistochemical techniques in infected A549 cells and lungs from murine models. Further, cytokine production was measured, using the Bio-Plex-Multiplex immunoassay. The cytoskeletal proteins HSPA9, PA2G4, VAT1, PSMA2, PEX1, PTGES3, KRT1, KRT9, CLIP1 and CLEC20A were mainly changed during A. fumigatus infection, while the immunologically activated proteins WNT7A, GAPDH and ANXA2 were principally altered during S. apiospermum infection. These proteins are involved in fungal internalisation and structural destruction leading to pulmonary disorders. Interleukin (IL)-21, IL-1α, IL-22, IL-2, IL-8, IL-12, IL-17A, interferon-γ and tumour necrosis factor-α were upregulated in both aspergillosis and scedosporiosis, although more predominately in the latter, in accordance with chitin synthase-1 and matrix metalloproteinase levels. Our results demonstrated that during invasion, A. fumigatus primarily altered host cellular integrity, whereas S. apiospermum chiefly induced and extensively modulated host immune responses.

Consensus guidelines for the diagnosis and management of invasive fungal disease due to moulds other than Aspergillus in the haematology/oncology setting, 2021

Invasive fungal disease (IFD) due to moulds other than Aspergillus is a significant cause of mortality in patients with malignancies or post haemopoietic stem cell transplantation. The current guidelines focus on the diagnosis and management of the common non-Aspergillus moulds (NAM), such as Mucorales, Scedosporium species (spp.), Lomentospora prolificans and Fusarium spp. Rare but emerging NAM including Paecilomyces variotii, Purpureocillium lilacinum and Scopulariopsis spp. are also reviewed. Culture and histological examination of tissue biopsy specimens remain the mainstay of diagnosis, but molecular methods are increasingly being used. As NAM frequently disseminate, blood cultures and skin examination with biopsy of any suspicious lesions are critically important. Treatment requires a multidisciplinary approach with surgical debridement as a central component. Other management strategies include control of the underlying disease/predisposing factors, augmentation of the host response and the reduction of immunosuppression. Carefully selected antifungal therapy, guided by susceptibility testing, is critical to cure. We also outline novel antifungal agents still in clinical trial which offer substantial potential for improved outcomes in the future. Paediatric recommendations follow those of adults. Ongoing epidemiological research, improvement in diagnostics and the development of new antifungal agents will continue to improve the poor outcomes that have been traditionally associated with IFD due to NAM.

The Host Immune Response to Scedosporium/Lomentospora

Infections caused by the opportunistic pathogens Scedosporium/Lomentospora are on the rise. This causes problems in the clinic due to the difficulty in diagnosing and treating them. This review collates information published on immune response against these fungi, since an understanding of the mechanisms involved is of great interest in developing more effective strategies against them. Scedosporium/Lomentospora cell wall components, including peptidorhamnomannans (PRMs), α-glucans and glucosylceramides, are important immune response activators following their recognition by TLR2, TLR4 and Dectin-1 and through receptors that are yet unknown. After recognition, cytokine synthesis and antifungal activity of different phagocytes and epithelial cells is species-specific, highlighting the poor response by microglial cells against L. prolificans. Moreover, a great number of Scedosporium/Lomentospora antigens have been identified, most notably catalase, PRM and Hsp70 for their potential medical applicability. Against host immune response, these fungi contain evasion mechanisms, inducing host non-protective response, masking fungal molecular patterns, destructing host defense proteins and decreasing oxidative killing. In conclusion, although many advances have been made, many aspects remain to be elucidated and more research is necessary to shed light on the immune response to Scedosporium/Lomentospora.

Immunotherapy as an Antifungal Strategy in Immune Compromised Hosts

Purpose of Review

IFIs cause high morbidity and mortality in the immunocompromised host worldwide. Although highly effective, conventional antifungal chemotherapy faces new challenges due to late diagnosis and increasing numbers of drug-resistant fungal strains. Thus, antifungal immunotherapy represents a viable treatment option, and recent advances in the field are summarized in this review.

Recent Findings

Antifungal immunotherapies include application of immune cells as well as the administration of cytokines, growth factors, and antibodies. Novel strategies to treat IFIs in the immunocompromised host target intracellular signaling pathways using SMTs such as checkpoint inhibitors.

Summary

Studies using cytokines or chemokines exerted a potential adjuvant role to conventional antifungal therapy, but issues on toxicity for some agents have to be resolved. Cell-based immunotherapies are very labor-intense and costly, but NK cell transfer and CAR T cell therapy provide exciting strategies to combat IFIs. Antibody-mediated protection and checkpoint inhibition are additional novel immunotherapeutic approaches.

Insights into the interaction of Scedosporium apiospermum, Scedosporium aurantiacum, Scedosporium minutisporum, and Lomentospora prolificans with lung epithelial cells

Scedosporium spp. and Lomentospora prolificans are filamentous fungi that emerged as human pathogens; however, their mechanisms of virulence/pathogenesis are still largely unknown. In the present work, we have evaluated the interaction of S. apiospermum, S. minutisporum, S. aurantiacum, and L. prolificans with lung epithelial cells (A549 line). The results showed that conidia were able to interact with A549 cells, displaying association indexes of 73.20, 117.98, 188.01, and 241.63 regarding S. apiospermum, L. prolificans, S. minutisporum, and S. aurantiacum, respectively. Light microscopy images evidenced morphological changes in epithelial cells, including rounding and detachment, especially during the interaction with L. prolificans. Plasma membrane injuries were detected in A549 cells after 1 h of co-culturing with S. aurantiacum and S. minutisporum and after 4 h with S. apiospermum and L. prolificans, as judged by the passive incorporation of propidium iodide. After 24 h of fungi-epithelial cells interaction, only mycelia were observed covering the A549 monolayer. Interestingly, the mycelial trap induced severe damage in the A549 cells, culminating in epithelial cell death. Our results demonstrate some relevant events that occur during the contact between lung epithelial cells and Scedosporium/Lomentospora species, including conidial adhesion and hyphal growth with consequent irreversible injury on A549 cells, adding light to the infection process caused by these opportunistic and multidrug-resistant fungi.

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.

Involvement of the Dectin-1 Receptor upon the Effector Mechanisms of Human Phagocytic Cells against Paracoccidioides brasiliensis

Paracoccidioidomycosis (PCM), a systemic mycosis endemic in Latin America, occurs after inhalation of mycelial components of Paracoccidioides spp. When the fungus reaches the lungs and interacts with the alveolar macrophages and other cells, phagocytic cells such as neutrophils and monocytes are immediately recruited to the injured site. The interaction between surface molecules of pathogens and homologous receptors, present on the surface membrane of phagocytes, modulates the innate immune cell activation. Studies have shown the importance of fungal recognition by the Dectin-1 receptor, which can induce a series of cellular protective responses against fungi. The objective of the present study was to evaluate Dectin-1 receptor expression and the effector mechanisms of human monocytes and neutrophils activated or not with different cytokines, such as IFN-γ, TNF-α, and GM-CSF, followed by the challenge with Paracoccidioides brasiliensis (P. brasiliensis or Pb265). Therefore, analysis of Dectin-1 receptor expression was done by flow cytometry whereas the effector mechanisms were evaluated by fungal recovery by colony-forming unit (CFU) counting and hydrogen peroxide (H₂O₂) production. Our results showed that, after treatment with IFN-γ, TNF-α, and GM-CSF and challenge with Pb265, cells, especially monocytes, demonstrated an increase in Dectin-1 expression. Both types of cells treated with the cytokines exhibited a decreased fungal recovery and, conversely, an increased production of H₂O₂. However, when cultures were treated with an anti-Dectin-1 monoclonal antibody, to block the P. brasiliensis binding, a decrease in H₂O₂ production and an increase in fungal recovery were detected. This effect was observed in all cultures treated with the specific monoclonal antibody. These results show the involvement of the Dectin-1 receptor in fungal recognition and its consequent participation in the induction of the killing mechanisms against P. brasiliensis.

Immunomodulation as a Therapy for Aspergillus Infection: Current Status and Future Perspectives

Invasive aspergillosis (IA) is the most serious life-threatening infectious complication of intensive remission induction chemotherapy and allogeneic stem cell transplantation in patients with a variety of hematological malignancies. Aspergillus fumigatus is the most commonly isolated species from cases of IA. Despite the various improvements that have been made with preventative strategies and the development of antifungal drugs, there is an urgent need for new therapeutic approaches that focus on strategies to boost the host’s immune response, since immunological recovery is recognized as being the major determinant of the outcome of IA. Here, we aim to summarize current knowledge about a broad variety of immunotherapeutic approaches against IA, including therapies based on the transfer of distinct immune cell populations, and the administration of cytokines and antibodies.

Scedosporium and Lomentospora: an updated overview of underrated opportunists

Species of Scedosporium and Lomentospora are considered as emerging opportunists, affecting immunosuppressed and otherwise debilitated patients, although classically they are known from causing trauma-associated infections in healthy individuals. Clinical manifestations range from local infection to pulmonary colonization and severe invasive disease, in which mortality rates may be over 80%. These unacceptably high rates are due to the clinical status of patients, diagnostic difficulties, and to intrinsic antifungal resistance of these fungi. In consequence, several consortia have been founded to increase research efforts on these orphan fungi. The current review presents recent findings and summarizes the most relevant points, including the Scedosporium/Lomentospora taxonomy, environmental distribution, epidemiology, pathology, virulence factors, immunology, diagnostic methods, and therapeutic strategies.

Successful Treatment of Invasive Conidiobolus Infection During Therapy for Acute Lymphoblastic Leukemia

Invasive fungal infections are a serious cause of morbidity and mortality in patients with hematologic malignancies. Conidiobolus species are molds within the order Entomophthorales and may disseminate to become rapidly fatal in immunocompromised individuals. This species of fungal infections are often multidrug resistant (MDR) and present unique therapeutic challenges. Reports of Conidiobolus infections are rare in pediatric oncology. We report the successful treatment of an adolescent male with B-cell lymphoblastic leukemia and MDR invasive sinopulmonary Conidiobolus infection with emphasis on early and aggressive neutrophil support with surgical debridement. The strategies described could be applied to other MDR fungal infections.

Recent Advances in the Treatment of Scedosporiosis and Fusariosis

Species of Scedosporium and Fusarium are considered emerging opportunistic pathogens, causing invasive fungal diseases in humans that are known as scedosporiosis and fusariosis, respectively. These mold infections typically affect patients with immune impairment; however, cases have been reported in otherwise healthy individuals. Clinical manifestations vary considerably, ranging from isolated superficial infection to deep-seated invasive infection—affecting multiple organs—which is often lethal. While there have been a number of advances in the detection of these infections, including the use of polymerase chain reaction (PCR) and matrix-assisted laser desorption ionization/time-of-flight mass spectrometry (MALDI-TOF MS), diagnosis is often delayed, leading to substantial morbidity and mortality. Although the optimal therapy is controversial, there have also been notable advances in the treatment of these diseases, which often depend on a combination of antifungal therapy, reversal of immunosuppression, and in some cases, surgical resection. In this paper, we review these advances and examine how the management of scedosporiosis and fusariosis may change in the near future.

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.

Pathobiology of Lomentospora prolificans: could this species serve as a model of primary antifungal resistance?

The number of fungal isolates resistant to antifungal drugs has increased dramatically over the last few years and has become an important concern for clinicians. Among these isolates, fungi showing multidrug resistance are particularly worrying because of the difficulties associated with their treatment. These factors hamper the successful recovery of patients and drastically raise mortality rates. Antifungal resistance is multifactorial and several mechanisms in different fungi have been described. There is a need to study these mechanisms in depth; however, the study of antifungal drug resistance separately for each individual species makes progress in the field very slow and tedious. The selection of a multiresistant microorganism as a model for understanding resistance mechanisms and extrapolating the results to other species could help in the search for a solution. In this mini-review, we describe the pathobiology of Lomentospora (Scedosporium) prolificans, paying special attention to its intrinsic resistance to all currently available antifungal agents. The characteristics of L. prolificans offer several advantages: the possibility of using a single microorganism for the study of resistance to different drugs, even cases of double and triple resistance; it is biologically safe for society in general as no new genetically-modified strains are needed for the experiments; it is homologous with other fungal species, and there is repetitiveness between different strains. In conclusion, we propose L. prolificans as a candidate for consideration as a fungal model for the study of resistance mechanisms against antifungal agents.

Scedosporium apiospermum infections and the role of combination antifungal therapy and GM-CSF: A case report and review of the literature

Scedosporium apiospermum, a ubiquitous environmental mold, is increasingly reported as causing invasive fungal disease in immunocompromised hosts. It poses a therapeutic challenge due to its intrinsic resistance to traditional antifungals and ability to recur despite demonstrating susceptibility. We present an immunocompromised patient with a cutaneous S. apiospermum infection that disseminated despite treatment with voriconazole, the drug of choice. Adding echinocandins and GM-CSF provided partial recovery, indicating a potential synergistic role of dual-antifungal and immunotherapeutic agents.

Effect of Granulocyte-Macrophage Colony-Stimulating Factor on Prevention and Treatment of Invasive Fungal Disease in Recipients of Allogeneic Stem-Cell Transplantation: A Prospective Multicenter Randomized Phase IV Trial

PURPOSE

For recipients of allogeneic hematopoietic stem-cell transplantation (alloHSCT), we hypothesized that prophylactic therapy during neutropenia with granulocyte-macrophage colony-stimulating factor (GM-CSF) decreases invasive fungal disease (IFD).

PATIENTS AND METHODS

We randomly assigned 206 patients undergoing alloHSCT to receive once-daily subcutaneous GM-CSF (5 to 7 μg/kg per day), granulocyte colony-stimulating factor (G-CSF; 5 to 7 μg/kg per day), or a combination of G-CSF and GM-CSF (2 to 3 μg/kg per day each). Treatment was started on day 5 after transplantation and was continued until the absolute neutrophil count was ≥ 1.5 × 10(9)/L for 2 consecutive days. The primary outcomes were 100-day incidence of proven and probable IFD and response rate of antifungal treatment.

RESULTS

For the intent-to-treat population, there was no significant difference in 100-day incidences of proven and probable IFD among the three groups. The antifungal treatment response was better in the GM-CSF group and G-CSF+GM-CSF group than in G-CSF group from day 22 to day 100 (P = .009). The 100-day cumulative mortality after transplantation was lower in the GM-CSF group than in the G-CSF group (10.3% v 24.6%, respectively; P = .037). The GM-CSF and G-CSF+GM-CSF groups had lower 100-day transplantation-related mortality than the G-CSF group (8.8%, 8.7%, and 21.7%, respectively; P = .034). After a median follow-up of 600 days, IFD-related mortality was lower in the groups that received GM-CSF or G-CSF+GM-CSF compared with G-CSF (1.47%, 1.45%, and 11.59%, respectively; P = .016). There were no significant differences in relapse, graft-versus-host disease, or hemorrhage-related mortality among the three groups of patients.

CONCLUSION

For recipients of alloHSCT, compared with G-CSF, prophylactic GM-CSF was associated with lower 100-day transplantation-related mortality, lower 100-day cumulative mortality, and lower 600-day IFD-related mortality.

Pathogenesis and host defence against Mucorales: the role of cytokines and interaction with antifungal drugs

Innate immune response, including macrophages, neutrophils and dendritic cells and their respective receptors, plays an important role in host defences against Mucorales with differential activity against specific fungal species, while adaptive immunity is not the first line of defence. A number of endogenous and exogenous factors, such as cytokines and growth factors as well as certain antifungal agents have been found that they influence innate immune response to these organisms. Used alone or especially in combination have been shown to exert antifungal effects against Mucorales species. These findings suggest novel ways of adjunctive therapy for patients with invasive mucormycosis.

Aspergillus-associated airway disease, inflammation, and the innate immune response

Aspergillus moulds exist ubiquitously as spores that are inhaled in large numbers daily. Whilst most are removed by anatomical barriers, disease may occur in certain circumstances. Depending on the underlying state of the human immune system, clinical consequences can ensue ranging from an excessive immune response during allergic bronchopulmonary aspergillosis to the formation of an aspergilloma in the immunocompetent state. The severest infections occur in those who are immunocompromised where invasive pulmonary aspergillosis results in high mortality rates. The diagnosis of Aspergillus-associated pulmonary disease is based on clinical, radiological, and immunological testing. An understanding of the innate and inflammatory consequences of exposure to Aspergillus species is critical in accounting for disease manifestations and preventing sequelae. The major components of the innate immune system involved in recognition and removal of the fungus include phagocytosis, antimicrobial peptide production, and recognition by pattern recognition receptors. The cytokine response is also critical facilitating cell-to-cell communication and promoting the initiation, maintenance, and resolution of the host response. In the following review, we discuss the above areas with a focus on the innate and inflammatory response to airway Aspergillus exposure and how these responses may be modulated for therapeutic benefit.

[Iliofemoral cutaneous mucormycosis with endopelvic extension in an immunocompetent child]

Mucormycosis is a rare opportunistic fungal infection with clinical polymorphism and is rapidly extensive and destructive. It is caused by fungi of the mucorales group in the environment and generally arises in the context of immunosuppression. Often difficult and late, diagnosis is based on mycological and histological examination. We report the case of a 10-year-old patient admitted for a pruritic erythematous scaly eruption located in the right inguinal area associated with satellite lymphadenopathy and lymphedema of the right lower limb. The histological study of the cutaneous biopsy revealed a granulomatous reaction with filaments. The mycological examination of the collection of the cutaneous lesion showed mucorales filaments and a stump of Absidia corymbifera was isolated. Abdomino-pelvic CT showed muscular extension with vascular and ureteral englobement. The diagnosis of cutaneous mucormycosis was made. Immunological investigations were normal. Treatment included itraconazole for 3months followed by IV amphotericin B for 1month, with favorable clinical and radiological progression. Mucormycosis is an uncommon fungal infection whose cutaneous localization is rare. It occurs exceptionally in immunocompetent patients and is clinically manifested by a vesicular and pustular rash progressing to ulceration. The diagnosis is confirmed by mycological and histological studies. Treatment consists of antifungal therapy associated with surgical excision of necrotic and infected tissue.

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.

Cross-protective TH1 immunity against Aspergillus fumigatus and Candida albicans

T cell–mediated heterologous immunity to different pathogens is promising for the development of immunotherapeutic strategies. Aspergillus fumigatus and Candida albicans, the 2 most common fungal pathogens causing severe infections in immunocompromised patients, are controlled by CD4+ type 1 helper T (TH1) cells in humans and mice, making induction of fungus-specific CD4+ TH1 immunity an appealing strategy for antifungal therapy. We identified an immunogenic epitope of the A fumigatus cell wall glucanase Crf1 that can be presented by 3 common major histocompatibility complex class II alleles and that induces memory CD4+ TH1 cells with a diverse T-cell receptor repertoire that is cross-reactive to C albicans. In BALB/c mice, the Crf1 protein also elicits cross-protection against lethal infection with C albicans that is mediated by the same epitope as in humans. These data illustrate the existence of T cell–based cross-protection for the 2 distantly related clinically relevant fungal pathogens that may foster the development of immunotherapeutic strategies.

Local innate host response and filamentous fungi in patients with cystic fibrosis

Filamentous fungi especially Aspergillus spp. and Scedosporium spp. can colonize the lungs of cystic fibrosis (CF) patients. Persistent infection by these organisms may cause deterioration of lung function, mycetomas or local invasive disease. Although CF patients exert an excessive inflammatory response to inhaled bacteria, very little is known about the local innate immune response to filamentous fungi. In this paper, we review the innate immune response of respiratory tract of healthy individuals to filamentous fungi with some inference to CF patients and link the latter to existing data. We also report some preliminary findings on the in vitro antifungal responses of human phagocytes against Aspergillus spp. isolated from CF patients. Translation of these in vitro findings to appropriate in vivo systems and into clinical trials of immunomodulatory treatments may lead to improved strategies for appropriate innate host defenses in CF patients persistently infected with filamentous fungi.

Host immune response against Scedosporium species

Scedosporium apiospermum and Scedosporium prolificans cause therapy-refractory infections in immunocompromised and immunocompetent hosts. While innate immune response is believed to be critical for the host defense against these fungi, its role has only recently been elucidated. Undefined pathogen-associated molecular patterns on the surface of conidia and hyphae are recognized by pattern-recognition receptors (PRRs) on the membrane of phagocytes, and the signal is transmitted intracellularly. PRRs that are important in the recognition of both fungal species are human Toll-like receptors (or Toll receptors in Drosophila melanogaster) and dectin-1. These induce signals responsible for the activation of genes leading to an effective host defense, especially those encoding pro-inflammatory cytokines. Both species are efficiently phagocytosed and elicit an oxidative burst by neutrophils and monocytes. While cytokines, such as interleukin-15, granulocyte-macrophage colony-stimulating factor, granulocyte colony-stimulating factor and interferon-gamma, have been found in vitro to variably modulate antifungal activity of human phagocytes, cytokines in vivo activities are less well documented. Certain antifungal agents exert immunopharmacological effects on phagocytes against S. apiospermum and S. prolificans. Translation of these in vitro findings to appropriate in vivo systems and into clinical trials may lead to improved strategies for augmenting innate host defenses in patients infected with these emerging pathogens.

Scedosporium prolificans: an emerging pathogen in France?

For the last ten years, non-Aspergillus mold species have been increasingly involved in human invasive infections, probably as a consequence of more intense immunosuppression and prolonged patient survival, and of selective pressure since antifungal agents are currently used for prophylaxis or therapy. Scedosporium prolificans, one of these emerging fungi, has been isolated in a broad spectrum of clinical presentations in humans, including respiratory-tract colonization, superficial or locally invasive infections, and disseminated infections in immunocompromised patients. Here, we report the recent emergence of invasive infections due to S. prolificans in France, and describe four new cases diagnosed during the last six years. Only one disseminated scedosporiosis has been reported before this in France, in 1994. Three out of our four cases were breakthrough infections in immunocompromised patients receiving posaconazole or voriconazole therapy. The aims of the present review were thus to gain a better understanding of scedosporiosis epidemiology and clinical features, and to review recent advances in multimodal management of these infections, including surgery, recovery and/or enhancement of immunity, and antifungal combinations, especially voriconazole plus terbinafine.

Immunomodulatory effects of voriconazole on monocytes challenged with Aspergillus fumigatus: differential role of Toll-like receptors

Voriconazole (VRC) has activity against Aspergillus fumigatus, the most frequent cause of invasive aspergillosis in immunocompromised patients. The combination of VRC and A. fumigatus hyphae induced a more pronounced profile of expression of genes encoding inflammatory molecules in human monocytes than Aspergillus alone did. Herein, we provide further evidence of the potential mechanism underlying this immunomodulatory effect of VRC on human monocytes in response to A. fumigatus hyphae. A significant additive antifungal effect was shown when VRC was combined with monocytes against A. fumigatus hyphae. Both A. fumigatus hyphae and VRC induced pronounced profiles of mRNA and protein expression of Toll-like receptor 2 (TLR2) as well as tumor necrosis factor alpha (TNF-alpha) in THP-1 monocytic cells compared to untreated cells. The VRC-induced increase was greater than that induced by hyphae. The combination of VRC and hyphae increased mRNA and protein expression of TLR2 and TNF-alpha to even higher levels than did either VRC or hyphae alone. In contrast, TLR4 expression, both at the mRNA and protein levels, was not increased by either VRC or hyphae or their combination. In addition, significantly more NF-kappaB was translocated to the nuclei of THP-1 cells treated with VRC than untreated cells. While VRC induced more NF-kappaB than hyphae did, treatment with the combination of the two factors induced the greatest NF-kappaB expression. The pronounced profile of TLR2 signaling, TNF-alpha expression, and NF-kappaB activation in the presence of VRC suggests an immunomodulatory effect leading to a more efficient response to A. fumigatus.

Infections caused by Scedosporium spp

Scedosporium spp. are increasingly recognized as causes of resistant life-threatening infections in immunocompromised patients. Scedosporium spp. also cause a wide spectrum of conditions, including mycetoma, saprobic involvement and colonization of the airways, sinopulmonary infections, extrapulmonary localized infections, and disseminated infections. Invasive scedosporium infections are also associated with central nervous infection following near-drowning accidents. The most common sites of infection are the lungs, sinuses, bones, joints, eyes, and brain. Scedosporium apiospermum and Scedosporium prolificans are the two principal medically important species of this genus. Pseudallescheria boydii, the teleomorph of S. apiospermum, is recognized by the presence of cleistothecia. Recent advances in molecular taxonomy have advanced the understanding of the genus Scedosporium and have demonstrated a wider range of species than heretofore recognized. Studies of the pathogenesis of and immune response to Scedosporium spp. underscore the importance of innate host defenses in protection against these organisms. Microbiological diagnosis of Scedosporium spp. currently depends upon culture and morphological characterization. Molecular tools for clinical microbiological detection of Scedosporium spp. are currently investigational. Infections caused by S. apiospermum and P. boydii in patients and animals may respond to antifungal triazoles. By comparison, infections caused by S. prolificans seldom respond to medical therapy alone. Surgery and reversal of immunosuppression may be the only effective therapeutic options for infections caused by S. prolificans.

Infection with Scedosporium apiospermum and S. prolificans, Australia

S. prolificans has become a major pathogen in immunocompromised patients.

Scedosporium apiospermum and S. prolificans are fungi of increasing clinical importance, particularly in persons with underlying diseases. We reviewed the records of 59 patients in Australia from whom Scedosporium spp. were isolated from June 30, 1997, through December 31, 2003. S. apiospermum was isolated predominantly from the respiratory tracts of 28 of 31 patients with underlying lung diseases and resulted in 2 infections and 1 death. The annual number of S. apiospermum isolates remained constant. S. prolificans was isolated from 28 patients only after November 1999. Eight patients with acute myeloid leukemia or hematopoietic stem cell transplants had invasive infection; 4 had fungemia and 6 died from infection. S. prolificans caused locally invasive infection in 2 immunocompetent patients and was found in the respiratory tract of 18 patients with underlying respiratory disease but did not cause fungemia or deaths in these patients. Scedosporium spp. showed distinct clinical and epidemiologic features.

Scedosporium apiospermum infection after near-drowning

Scedosporium apiospermum and its teleomorph (sexual form) Pseudallescheria boydii are ubiquitous saprophytic fungi, which under specific conditions, such as near-drowning, may cause therapy-refractory and life-threatening infections. We reviewed 22 cases (eight children and 14 adults) of S. apiospermum infection after near-drowning reported in the literature including an additional paediatric case from our institution. Scedosporiosis after near-drowning was associated with high mortality (16/23, 70%) even in immunocompetent hosts. It affected mainly young (mean age 24 years) and immunocompetent (83% with no apparent immune defect) males (male to female ratio 2.5 : 1). Scedosporiosis after near-drowning was a slow progressive disease (mean survival time 87 days) involving virtually all body organs. However, central nervous system (CNS) dissemination predominated (21/23, 91%) presenting mainly as multiple brain abscesses (15/23, 65%). All 23 patients showed preceding clinical and/or radiological evidence of lung disease indicating the mode of invasion. Diagnosis was delayed (median time to diagnosis 28 days) and was made by culture (16/23, 69.5%) or culture and tissue examination (7/23, 30.5%). The majority of the patients (20/23, 87%) received antifungal treatment and underwent neurosurgery. While the optimal treatment remains undefined, the most recent reports indicated voriconazole as a potentially effective option. Better knowledge of scedosporiosis after near-drowning could lead to improved intervention and ultimately to more favourable outcome.

Effect of interleukin-10 on the Paracoccidioides brasiliensis killing by gamma-interferon activated human neutrophils

Paracoccidioidomycosis, a deep mycosis endemic in Latin America, is a chronic granulomatous disease caused by the fungus Paracoccidioides brasiliensis. Phagocytic cells play a critical role against this fungus, and several studies have shown the effects of activator and suppressive cytokines on macrophage and monocyte functions. However, studies on polymorphonuclear neutrophils (PMNs), that are the first cells recruited to the infection sites, are scarcer. Thus, the objective of this paper was to assess whether interleukin-10 (IL-10), a potent anti-inflammatory cytokine, is able to block the activity of IFN-gamma-activated human PMNs upon P. brasiliensis intracellular killing, in vitro. The results showed that IFN-gamma-activated PMNs have an effective fungicidal activity against the fungus. This activity was associated with the release of high levels of H(2)O(2), the metabolite involved in phagocytic cells antifungal activities. However, the concomitant incubation of these cells with IFN-gamma and IL-10 significantly blocked IFN-gamma activation. As a consequence, PMNs killing activity and H(2)O(2) release were inhibited. Together, our results show the importance of PMNs exposure to activator or suppressor cytokines in the early stages of paracoccidioidomycosis infection.

In vitro infection of human dendritic cells by Aspergillus fumigatus conidia triggers the secretion of chemokines for neutrophil and Th1 lymphocyte recruitment

Given the role played by chemokines in the selective homing of immune cells, we sought to characterize the profile of chemokines produced by human dendritic cells (DC) following in vitro Aspergillus fumigatus infection and their ability to recruit cells involved in the antifungal defense. At the onset of A. fumigatus infection, DC released elevated amounts of CXCL8 that promote the migration of polymorphonuclear cells (PMN). Moreover, soluble factors released from A. fumigatus-infected DC increased also the surface expression of two activation markers, CD11b and CD18, on PMN. A. fumigatus infection resulted also in CCL3, CCL4, CXCL10 and CCL20 productions that induce the migration of effector memory Th1 cells. Moreover, the late expression of CCL19 suggests that A. fumigatus-infected DC could be implicated in the migration of CCR7+ naïve T cells and mature DC in lymph nodes. Together these results suggested the involvement of human DC in the regulation of innate and adaptive immunity against A. fumigatus through the recruitment of cells active in the fungal destruction.

Scedosporium apiospermum (Pseudoallescheria boydii) Infection in Lung Transplant Recipients

BACKGROUND

Scedosporium apiospermum, the asexual counterpart of the teleomorph Pseudallescheria boydii, is increasingly recognized as an important opportunistic pathogen in transplant recipients. Infection is associated with a high rate of dissemination and poor outcome overall.

METHODS

A retrospective analysis of The Cleveland Clinic lung transplant database identified 5 patients with S. apiospermum isolated from respiratory tract specimens. Demographic data and lung transplant outcomes were obtained by review of medical records.

RESULTS

S. apiospermum was isolated from respiratory culture in 5 lung transplant recipients. Disseminated disease developed in 3 patients, whereas 2 appeared only to be colonized.

CONCLUSIONS

Our experience and review of the literature highlights the importance of early diagnosis and differentiation from Aspergillus, since Scedosporium is inherently resistant to amphotericin B. Effective therapeutic approaches being explored include combinations of anti-fungals, because even the newer triazoles have a 50% response rate in clinical studies. Surgical débridement and immune recovery are associated with improved prognosis, favoring the use of agents that expedite immune reconstitution in these patients. Close monitoring of clinical improvement and frequent reevaluation of treatment is essential.

Paracoccidioides brasiliensiskilling by IFN-γ, TNF-α and GM-CSF activated human neutrophils: role for oxygen metabolites

Paracoccidioidomycosis, a deep mycosis endemic in Latin America, is a chronic granulomatous disease caused by the fungus Paracoccidioides brasiliensis. Phagocytic cells play a critical role against the fungus and several papers show the effects of activator and suppressive cytokines on macrophage and monocyte functions. However, the studies focusing on polymorphonuclear neutrophils (PMNs) antifungal functions are scarcer. Thus, the objective of the present paper was to assess the capacity of human PMNs to kill virulent P. brasiliensis strain in vitro, before and after priming with different cytokines. Moreover, the involvement of oxygen metabolites in this activity was evaluated. Nonactivated cells failed to exhibit antifungal activity. However, when these cells were IFN-gamma, TNF-alpha or GM-CSF activated, a significative fungicidal activity was detected. This process was significantly inhibited when P. brasiliensis challenge occurred in presence of catalase (CAT - a scavenger of H2O2) and superoxide dismutase (SOD - a scavenger of superoxide anion). From these results it is concluded that cytokines activation is required for P. brasiliensis killing by human PMNs, and that H2O2 and superoxide anion participate as effectors molecules in this process.

Scedosporium apiospermum: changing clinical spectrum of a therapy-refractory opportunist*

Current knowledge on the opportunist Scedosporium apiospermum (teleomorph: Pseudallescheria boydii), generated over a period of more than 120 years, is reviewed. The natural environmental habitat of the fungus is unknown; nutrient-rich, brackish waters like river estuaria have been suggested. The fungus is strongly promoted by agricultural and particularly by industrial pollution.