Invasive Fungal Infection in Haematopoietic Stem Cell Transplant Recipients: Epidemiology from the Transplant Physician’s Viewpoint

From Bioinspired Glue to Medicine: Polydopamine as a Biomedical Material

Biological structures have emerged through millennia of evolution, and nature has fine-tuned the material properties in order to optimise the structure-function relationship. Following this paradigm, polydopamine (PDA), which was found to be crucial for the adhesion of mussels to wet surfaces, was hence initially introduced as a coating substance to increase the chemical reactivity and surface adhesion properties. Structurally, polydopamine is very similar to melanin, which is a pigment of human skin responsible for the protection of underlying skin layers by efficiently absorbing light with potentially harmful wavelengths. Recent findings have shown the subsequent release of the energy (in the form of heat) upon light excitation, presenting it as an ideal candidate for photothermal applications. Thus, polydopamine can both be used to (i) coat nanoparticle surfaces and to (ii) form capsules and ultra-small (nano)particles/nanocomposites while retaining bulk characteristics (i.e., biocompatibility, stability under UV irradiation, heat conversion, and activity during photoacoustic imaging). Due to the aforementioned properties, polydopamine-based materials have since been tested in adhesive and in energy-related as well as in a range of medical applications such as for tumour ablation, imaging, and drug delivery. In this review, we focus upon how different forms of the material can be synthesised and the use of polydopamine in biological and biomedical applications.

Risks and outcomes of invasive fungal infections in pediatric allogeneic hematopoietic stem cell transplant recipients receiving fluconazole prophylaxis: a multicenter cohort study by the Turkish Pediatric Bone Marrow Transplantation Study Group

Invasive fungal infections (IFIs) are a major cause of infection-related morbidity and mortality in patients undergoing allogeneic hematopoietic stem cell transplantation (HSCT). Data from pediatric settings are scarce. To determine the incidence, risk factors and outcomes of IFIs in a 180-day period post-transplantation, 408 pediatric patients who underwent allogeneic HSCT were retrospectively analyzed. The study included only proven and probable IFIs. The cumulative incidences of IFI were 2.7%, 5.0%, and 6.5% at 30, 100, and 180 days post-transplantation, respectively. According to the multivariate analysis, the factors associated with increased IFI risk in the 180-day period post-HSCT were previous HSCT history (hazard ratio [HR], 4.57; 95% confidence interval [CI] 1.42-14.71; P = .011), use of anti-thymocyte globulin (ATG) (HR, 2.94; 95% CI 1.27-6.80; P = .012), grade III-IV acute graft-versus-host-disease (GVHD) (HR, 2.91; 95% CI 1.24-6.80; P = .014) and late or no lymphocyte engraftment (HR, 2.71; 95% CI 1.30-5.62; P = .007). CMV reactivation was marginally associated with an increased risk of IFI development (HR, 1.91; 95% CI 0.97-3.74; P = .063). IFI-related mortality was 1.5%, and case fatality rate was 27.0%.The close monitoring of IFIs in pediatric patients with severe acute GVHD who receive ATG during conditioning is critical to reduce morbidity and mortality after allogeneic HSCT, particularly among those with prior HSCT and no or late lymphocyte engraftment.

Infections in Hematopoietic Cell Transplant Recipients: Results From the Organ Transplant Infection Project, a Multicenter, Prospective, Cohort Study

Background

Infection is a major cause of morbidity and mortality after allogeneic hematopoietic cell transplantation (HCT). Our object was to better define the epidemiology and outcomes of infections after HCT.

Methods

This was a prospective, multicenter cohort study of HCT recipients and conducted from 2006 to 2011.

The study included 4 US transplant centers and 444 HCT recipients. Data were prospectively collected for up to 30 months after HCT using a standardized data collection tool.

Results

The median age was 53 years, and median follow up was 413 (range, 5–980) days. The most common reason for HCT was hematologic malignancy (87%). The overall crude mortality was 52%. Death was due to underlying disease in 44% cases and infection in 21%. Bacteremia occurred in 231 (52%) cases and occurred early posttransplant (median day 48). Gram-negative bloodstream infections were less frequent than Gram-positive, but it was associated with higher mortality (45% vs 13%, P = .02). Clostridium difficile infection developed in 148 patients (33%) at a median of 27 days post-HCT. There were 53 invasive fungal infections (IFIs) among 48 patients (11%). The median time to IFI was 142 days. Of 155 patients with cytomegalovirus (CMV) infection, 4% had CMV organ involvement. Varicella zoster infection (VZV) occurred in 13 (4%) cases and was disseminated in 2. Infection with respiratory viruses was seen in 49 patients. Pneumocystis jirovecii pneumonia was rare (1%), and there were no documented cases of nocardiosis, toxoplasmosis, endemic mycoses, or mycobacterial infection. This study lacked standardized antifungal and antiviral prophylactic strategies.

Conclusions

Infection remains a significant cause of morbidity and mortality after HCT. Bacteremias and C difficile infection are frequent, particularly in the early posttransplant period. The rate of IFI is approximately 10%. Organ involvement with CMV is infrequent, as are serious infections with VZV and herpes simplex virus, likely reflecting improved prevention strategies.

Risk Factors and Outcomes of Invasive Fungal Infections in Allogeneic Hematopoietic Cell Transplant Recipients

Allogeneic hematopoietic cell transplant (HCT) recipients are at increased risk of invasive fungal infections (IFI), which are associated with a high mortality rate. We evaluated the impact of IFI in allogeneic HCT patients. In total, 541 consecutive allogeneic HCT recipients were included. The cumulative incidence of any IFI and mold infections at 1-year post-HCT was 10 and 7%, respectively. Median times to IFI and mold infection were 200 and 210 days, respectively. There was a trend toward fewer IFI and mold infections in the last several years. Both acute graft-versus-host disease (GVHD) (OR 1.83, p = 0.05) and corticosteroid duration (OR 1.0, p = 0.026) were significantly associated with increased risk of IFI, acute GVHD (OR 2.3, p = 0.027) emerged as the most important association with mold infections. Any IFI [HR 4.1 (2.79-6.07), p < 0.0001] and mold infections [HR 3.34 (2.1-5.1), p < 0.0001] were independently associated with non-relapse mortality (NRM). This association persisted in the setting of both acute and chronic GVHD. Corticosteroid treatment for >90 days was also significantly associated with higher NRM [HR 1.9 (1.3-2.6), p < 0.0001]. This study highlights the impact of IFI on NRM among HCT patients. The decrease in number of IFI and mold infections over the last several years may reflect the benefit of prophylaxis with mold-active antifungal agents.

Aspergillosis of the Heart and Lung and Review of Published Reports on Fungal Endocarditis

Invasive aspergillosis (IA) is increasingly diagnosed in high-risk patients. The lesions are usually located in the lungs and/or sinuses, and the fungus may spread haematogenously to different organs; however, involvement of the heart during IA is very rare. We describe a unique case of invasive aspergillosis of the heart septum and the lungs in the allogeneic haematopoietic stem cell transplant recipient.

Experience with anidulafungin in patients with allogeneic hematopoietic stem cell transplantation and graft-versus-host disease

BACKGROUND

It is well known that both acute and chronic graft-versus-host disease (GVHD) are associated with invasive fungal disease (IFD). Because the galactomannan antigen diagnostic test has low specificity and sensitivity outside of the neutropenic period, many institutions use posaconazole or voriconazole for IFD prophylaxis during GVHD treatment. Moreover, several factors, mainly hepatic impairment, can limit the use of extended spectrum azoles, both in prophylaxis or treatment.

METHODS

We retrospectively analyzed 25 patients with allogeneic hematopoietic stem cell transplantation (HSCT) and GVHD - grade III-IV acute GHVD (n = 15), progressive chronic GVHD (n = 7), and "overlap" GVHD (n = 3) - who received intravenous anidulafungin (200 mg on day 1, followed by 100 mg once daily). If necessary, anidulafungin treatment was followed by oral administration of 200 mg voriconazole twice a day or 200 mg posaconazole 3 times daily until patients were considered not at risk for IFD.

RESULTS

Twenty-one patients (85%) received anidulafungin as prophylaxis and 5 patients (15%) received it as treatment. Median duration of intravenous anidulafungin administration was 8 days (range 6-17). Seven patients (28%) presented mild adverse effects, with no significant interactions with calcineurin inhibitors. Sequentially, 4 patients received voriconazole and 6 posaconazole. Two patients (8%) developed IFD after anidulafungin withdrawal: 1 with Candida albicans and the other with Mucor, 8 and 5 days after withdrawal, respectively.

CONCLUSIONS

Our results are of interest owing to the absence of data in the literature on anidulafungin use in HSCT patients with GVHD, and suggest that anidulafungin, because of its spectrum, pharmacological profile, low toxicity, and absence of interactions with immunosuppressants, could be a drug of choice in this setting.

Tolerability and outcome of once weekly liposomal amphotericin B for the prevention of invasive fungal infections in hematopoietic stem cell transplant patients with graft-versus-host disease

BACKGROUND

Invasive fungal infections remain problematic in immunosuppressed allogeneic stem cell transplant recipients and the use of corticosteroids for the treatment of graft-versus-host-disease can increase the risk threefold. Although antifungal prophylaxis has been shown to decrease the incidence of infection, the optimal antifungal prophylactic regimen in this patient population has yet to be identified.Since early diagnosis of fungal infections might not be possible and the treatment of established fungal infections might be difficult and associated with high infection-related mortality, prevention has become an important strategy in reducing overall morbidity and mortality. While triazoles are the preferred agents, some patients are unable to tolerate them and an alternative drug is warranted.

OBJECTIVES

To assess the tolerability of once weekly liposomal amphotericin B as a prophylactic strategy in patients undergoing stem cell transplantation by evaluating any adverse events leading to its discontinuation. In terms of efficacy, to also compare the outcome and incidence of invasive fungal infections in patients who received amphotericin B, triazoles, and echinocandins.

RESULTS

A total of 101 allogeneic transplant recipients receiving corticosteroids for the treatment of graft-versus-host-disease and antifungal prophylaxis were evaluated from August 2009 to September 2012. Liposomal amphotericin B 3 mg/kg intravenous once weekly was found to be well tolerated. The incidence of invasive fungal infections was 19%, 17%, and 7% in the liposomal amphotericin B, echinocandin, and triazole groups, respectively. Two deaths occurred in the liposomal amphotericin B group and one death occurred in the echinocandin group. None of the deaths were fungal infection related.

CONCLUSION

Antifungal prophylaxis with liposomal amphotericin B was well tolerated, but the incidence of invasive fungal infections in patients receiving liposomal amphotericin B was higher than other antifungal agents in this study. The optimal dose and schedule of liposomal amphotericin B for antifungal prophylaxis in this patient population are still not known and considering its broad spectrum activity, prospective trials in comparison to triazoles are warranted.

Clinical challenge: fatal mucormycotic osteomyelitis caused by Rhizopus microsporus despite aggressive multimodal treatment

BACKGROUND

Mucormycosis is an invasive mycotic disease caused by fungi in the zygomycetes class. Although ubiquitous in the environment, zygomycetes are rarely known to cause invasive disease in immunocompromised hosts with a high mortality even under aggressive antifungal and surgical therapy. Clinically, mucormycosis frequently affects the sinus occasionally showing pulmonary or cerebral involvement. However skeletal manifestation with Rhizopus microsporus (RM) osteomyelitis leading to emergency surgical proximal femoral resection with fatal outcome has not been described yet.

CASE PRESENTATION

We report the case of a 73-year-old male suffering from myelodysplastic syndrome with precedent bone marrow transplantation. Six months after transplantation he consulted our internal medicine department in a septic condition with a four week history of painful swelling of the right hip. Radiography, computed tomography and magnetic resonance imaging revealed multiple bone infarcts in both femurs. In the right femoral head, neck and trochanteric region a recent infarct showed massive secondary osteomyelitis, breaking through the medial cortex. Emergency surgical proximal femoral resection was performed due to extensive bone and soft tissue destruction. Microbiological and basic local alignment search tool (BLAST) analysis revealed RM. Amphotericin B and posaconazole treatment with septic revision surgery was performed. However the disease ran a rapid course and was fatal two months after hospital admission.

CONCLUSION

This alarming result with extensive RM osteomyelitis in the proximal femur of an immunocompromised patient may hopefully warn medical staff to perform early imaging and aggressive surgical supported multimodal treatment in similar cases.

Disseminated Rhizopus microsporus infection following allogeneic hematopoietic stem cell transplantation in a child with severe aplastic anemia

Disseminated Rhizopus microsporus infections are uncommon in children and are resistant to echinocandin and azole antifungal agents. We describe a child with severe aplastic anemia who developed disseminated R. microsporus infection following allogeneic hematopoietic stem cell transplantation. R. microsporus was identified microscopically in the hepatic drain culture and was confirmed on the basis of 18S rRNA and 28S rRNA sequence analyses. The patient was treated successfully with hepatic drainage and amphotericin B deoxycholate.

Risk factors for invasive fungal disease after allogeneic hematopoietic stem cell transplantation: a single center experience

Invasive fungal disease (IFD) is a major cause of morbidity and mortality after hematopoietic stem cell transplantation (HCT). We performed a retrospective review of 271 adults with a hematologic malignancy undergoing allogeneic HCT to determine the incidence of and risk factors for IFD and to examine the impact of IFD on nonrelapse mortality and overall survival. We defined IFD using standard criteria and selected proven and probable cases for analysis. Diagnoses in the study group included acute leukemia (42%), non-Hodgkin lymphoma (24%), myelodysplastic syndrome (15%), chronic lymphocytic leukemia (5%), and other hematologic disorders (14%). Conditioning included reduced-intensity (64%) and myeloablative (36%) regimens. Donor sources were HLA-matched sibling (60%), matched unrelated (20%), haploidentical (12%), and cord blood (8%). A total of 51 episodes of IFD were observed in 42 subjects (15%). Aspergillus spp (47%) was the most frequent causative organism, followed by Candida spp (43%). The majority of IFD cases (67%) were reported after day +100 post-HCT. In multivariate analysis, haploidentical donor transplantation (hazard ratio [HR], 3.82; 95% confidence interval [CI], 1.49-9.77; P = .005) and grade II-IV acute graft-versus-host disease (HR, 2.55; 95% CI, 1.07-6.10; P = .03) were risk factors for the development of IFD. Conversely, higher infused CD34(+) cell dose was associated with a lower risk of IFD (HR, 0.80; 95% CI, 0.68-0.94; P = .006, per 1 × 10(6) cells/kg increase in CD34(+) cell infusion). IFD-related mortality was 33.3%. Nonrelapse mortality was significantly higher in patients who developed IFD compared with those without IFD (P < .001, log-rank test). Patients with IFD had lower overall survival (5.8 months versus 76.1 months; P < .001, log-rank test). Further studies exploring strategies to increase the infused cell dose and determine adequate prophylaxis, especially against aspergillus, beyond day +100 are needed.

Defective pulmonary innate immune responses post-stem cell transplantation; review and results from one model system

Infectious pulmonary complications limit the success of hematopoietic stem cell transplantation (HSCT) as a therapy for malignant and non-malignant disorders. Susceptibility to pathogens in both autologous and allogeneic HSCT recipients persists despite successful immune reconstitution. As studying the causal effects of these immune defects in the human population can be limiting, a bone marrow transplant (BMT) mouse model can be used to understand the defect in mounting a productive innate immune response post-transplantation. When syngeneic BMT is performed, this system allows the study of BMT-induced alterations in innate immune cell function that are independent of the confounding effects of immunosuppressive therapy and graft-versus-host disease. Studies from several laboratories, including our own show that pulmonary susceptibility to bacterial infections post-BMT are largely due to alterations in the lung alveolar macrophages. Changes in these cells post-BMT include cytokine and eicosanoid dysregulations, scavenger receptor alterations, changes in micro RNA profiles, and alterations in intracellular signaling molecules that limit bacterial phagocytosis and killing. The changes that occur highlight mechanisms that promote susceptibility to infections commonly afflicting HSCT recipients and provide insight into therapeutic targets that may improve patient outcomes post-HSCT.

Infection in neutropenic patients with cancer

Neutropenic fever sepsis syndromes are common among patients with cancer who are receiving intensive cytotoxic systemic therapy. Recognition of the syndromes and timely initial antibacterial therapy is critical for survival and treatment success. Outcomes are linked to myeloid reconstitution and recovery from neutropenia, control of active comorbidities, and appropriate treatment of the infections that underlie the sepsis syndrome. Hematologists and oncologists must be clear about the prognosis and treatment goals to work effectively with critical care physicians toward the best outcomes for patients with cancer who develop neutropenic sepsis syndromes.

[Detection of Aspergillus antigen galactomannan using ELISA method: validation of the performances of the method for accreditation]

Diagnosis of invasive aspergillosis for patients with high risk of infection is based on the monitoring of Aspergillus antigenemia assessed by the detection of galactomannan in serum by a sandwich-type ELISA (Biorad(®)). The validation of the method was displayed according to the guide COFRAC SH GTA 04. The internal quality control system settled, involves two quality control samples made of pools of sera (negative and positive). The repeatability of the measurements, as estimated by the coefficients of variation (CV), obtained by two different technicians was found from 9 to 13.7% for the positive control. The CV of the negative control, for which the provider indicates it is not useful in the analytical process, was found from 7.1 to 30%. In our experience it could be an indicator of environmental contamination. The evaluation of the intermediary fidelity was 15.7% for the positive control and 22.5% for the negative one. In the lack of reference material (International Standard) and recommendation from scientific societies, performances obtained will be discussed according to the results reported in the technical form of the supplier and those obtained by 39 laboratories participating in the only available external quality assessment program organized in France by ProBioQual(®) where the CV of reproducibility are 44.7% of unit (mean index 0.131) for the negative control and 18% (mean index 1.089) for the positive one in 2011.

What is the role of the (1→3)-β-D-glucan assay in the screening of patients undergoing autologous haematopoietic stem-cell transplantation?

The aim of this study is to determine the clinical contribution of (1→3)-β-d-glucan (BDG) screening in the case of patients undergoing autologous haematopoietic stem-cell transplantation (HSCT). The records at our stem-cell transplantation centre were reviewed to identify the patients who underwent autologous HSCT between April 2009 and December 2010. Patients were classified as having proven invasive aspergillosis (IA), probable IA, or possible IA on the basis of the criteria established by the European Organization for Research and Treatment of Cancer and Mycoses Study Group (independent of the BDG results). During the study period, the patients were screened for BDG twice a week from transplant (day 0) until engraftment. Three patients were diagnosed with probable IA and five were diagnosed with possible IA. A total of 354 serum samples from 79 patients who met the study inclusion criteria were used for statistical analysis. At the cut-off value of 80 pg ml(-1) , the sensitivity was 27.2% [95% confidence interval (CI); 7.3-60.6]; specificity, 94.4% (95% CI; 91.3-96.5); positive predictive value, 6.2%; and negative predictive, 93.7%. The clinical contribution of the BDG assay as a screening test was relatively limited in this cohort of patients undergoing autologous HSCT.

Invasive fungal diseases in haematopoietic cell transplant recipients and in patients with acute myeloid leukaemia or myelodysplasia in Brazil

Invasive fungal disease (IFD) shows distinct regional incidence patterns and epidemiological features depending on the geographic region. We conducted a prospective survey in eight centres in Brazil from May 2007 to July 2009. All haematopoietic cell transplant (HCT) recipients and patients with acute myeloid leukaemia (AML) or myelodysplasia (MDS) were followed from admission until 1 year (HCT) or end of consolidation therapy (AML/MDS). The 12-month cumulative incidence (CI) of proven or probable IFD was calculated, and curves were compared using the Grey test. Among 237 AML/MDS patients and 700 HCT recipients (378 allogeneic, 322 autologous), the 1-year CI of IFD in AML/MDS, allogeneic HCT and autologous HCT was 18.7%, 11.3% and 1.9% (p <0.001), respectively. Fusariosis (23 episodes), aspergillosis (20 episodes) and candidiasis (11 episodes) were the most frequent IFD. The 1-year CI of aspergillosis and fusariosis in AML/MDS, allogeneic HCT and autologous HCT were 13.4%, 2.3% and 0% (p <0.001), and 5.2%, 3.8% and 0.6% (p 0.01), respectively. The 6-week probability of survival was 53%, and was lower in cases of fusariosis (41%). We observed a high burden of IFD and a high incidence and mortality for fusariosis in this first multicentre epidemiological study of IFD in haematological patients in Brazil.

Polydopamine--a nature-inspired polymer coating for biomedical science

Polymer coatings are of central importance for many biomedical applications. In the past few years, poly(dopamine) (PDA) has attracted considerable interest for various types of biomedical applications. This feature article outlines the basic chemistry and material science regarding PDA and discusses its successful application from coatings for interfacing with cells, to drug delivery and biosensing. Although many questions remain open, the primary aim of this feature article is to illustrate the advent of PDA on its way to become a popular polymer for bioengineering purposes.

The incidence and risk factors of invasive fungal infection after haploidentical haematopoietic stem cell transplantation without in vitro T-cell depletion

In recent years, we have successfully established a novel method of haploidentical haematopoietic stem cell transplantation (HSCT) without in vitro T-cell depletion. This study was aimed at analysing the incidence and risk factors of invasive fungal infection (IFI) with this transplantation method. The study comprised 291 patients who had undergone haploidentical HSCT from 1 January 2007 to 31 December 2008. IFI was diagnosed according to the European Organization for Research and Treatment of Cancer/Mycoses Study Group 2002 criteria, and only proven or probable cases of IFI were regarded as true cases. A total of 39 patients were documented as having IFI, including four proven cases and 35 probable cases. The median time of diagnosis was 26 days (range: 6-405 days) after transplantation. The cumulative incidence rates of IFI at 40 days, 1 year, 2 years and 3 years after transplantation were 8.25%, 13.1%, 13.4% and 13.4%, respectively. Multivariate analysis identified platelet engraftment time (>17 days) (p 0.027; hazard ratio (HR) 2.432; 95% CI 1.105-5.355), a high risk of underlying disease (p 0.001; HR 2.916; 95% CI 1.515-5.611) and grade III-IV acute graft-versus-host disease (p 0.019; HR 2.407; 95% CI 1.154-5.022) as risk factors for IFI. The incidence rates of IFI in patients with no, one, two or three risk factors at 3 years after transplantation were 4.48%, 7.86%, 29.6% and 23.1%, respectively. In conclusion, IFI is an important complication following haploidentical HSCT without in vitro T-cell depletion.

Population pharmacokinetics of liposomal amphotericin B and caspofungin in allogeneic hematopoietic stem cell recipients

Liposomal amphotericin B (LAMB) and caspofungin (CAS) are important antifungal agents in allogeneic hematopoietic stem cell transplant (aHSCT) recipients. Little is known, however, about the pharmacokinetics (PK) of both agents and their combination in this population. The PK of LAMB and CAS and the potential for PK interactions between both agents were investigated within a risk-stratified, randomized phase II clinical trial in 53 adult aHSCT recipients with granulocytopenia and refractory fever. Patients received either LAMB (n = 17; 3 mg/kg once a day [QD]), CAS (n = 19; 50 mg QD; day 1, 70 mg), or the combination of both (CAS-LAMB; n = 17) for a median duration of 10 to 13 days (range, 4 to 28 days) until defervescence and granulocyte recovery. PK sampling was performed on days 1 and 4. Drug concentrations in plasma (LAMB, 405 samples; CAS, 458 samples) were quantified by high-pressure liquid chromatography and were analyzed using population pharmacokinetic modeling. CAS concentration data best fitted a two-compartment model with a proportional error model and interindividual variability (IIV) for clearance (CL) and central volume of distribution (V(1)) (CL, 0.462 liter/h ± 25%; V(1), 8.33 liters ± 29%; intercompartmental clearance [Q], 1.25 liters/h; peripheral volume of distribution [V(2)], 3.59 liters). Concentration data for LAMB best fitted a two-compartment model with a proportional error model and IIV for all parameters (CL, 1.22 liters/h ± 64%; V(1), 19.2 liters ± 38%; Q, 2.18 liters/h ± 47%; V(2), 52.8 liters ± 84%). Internal model validation showed predictability and robustness of both models. None of the covariates tested (LAMB or CAS comedication, gender, body weight, age, body surface area, serum bilirubin, and creatinine clearance) further improved the models. In summary, the disposition of LAMB and CAS was best described by two-compartment models. Drug exposures in aHSCT patients were comparable to those in other populations, and no PK interactions were observed between the two compounds.

Diagnosing invasive fungal disease in critically ill patients

Fungal infections are increasing, with a changing landscape of pathogens and emergence of new groups at risk for invasive disease. We review current diagnostic techniques, focusing on studies in critically ill patients. Microbiological cultures, the current "gold standard", demonstrate poor sensitivity, thus diagnosis of invasive disease in the critically ill is difficult. This diagnostic dilemma results in under- or over-treatment of patients, potentially contributing to poor outcomes and antifungal resistance. While other current diagnostic tests perform moderately well, many lack timeliness, efficacy, and are negatively affected by treatments common to critically ill patients. New nucleic acid-based research is promising.

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.

Randomized comparison of safety and pharmacokinetics of caspofungin, liposomal amphotericin B, and the combination of both in allogeneic hematopoietic stem cell recipients

The combination of liposomal amphotericin B (LAMB) and caspofungin (CAS) holds promise to improve the outcome of opportunistic invasive mycoses with poor prognosis. Little is known, however, about the safety and pharmacokinetics of the combination in patients at high risk for these infections. The safety and pharmacokinetics of the combination of LAMB and CAS were investigated in a risk-stratified, randomized, multicenter phase II clinical trial in 55 adult allogeneic hematopoietic stem cell recipients (aHSCT) with granulocytopenia and refractory fever. The patients received either CAS (50 mg/day; day 1, 70 mg), LAMB (3 mg/kg of body weight/day), or the combination of both (CASLAMB) until defervescence and granulocyte recovery. Safety, development of invasive fungal infections, and survival were assessed through day 14 after the end of therapy. Pharmacokinetic sampling and analysis were performed on days 1 and 4. All three regimens were well tolerated. Premature study drug discontinuations due to grade III/IV adverse events occurred in 1/18, 2/20, and 0/17 patients randomized to CAS, LAMB, and CASLAMB, respectively. Adverse events not leading to study drug discontinuation were frequent but similar across cohorts, except for a higher frequency of hypokalemia with CASLAMB (P < 0.05). Drug exposures were similar for patients receiving combination therapy and those randomized to monotherapy. There was no apparent difference in the occurrence of proven/probable invasive fungal infections and survival through day 14 after the end of therapy. CASLAMB combination therapy in immunocompromised aHSCT patients was as safe as monotherapy with CAS or LAMB and had similar plasma pharmacokinetics, lending support to further investigations of the combination in the management of patients with invasive opportunistic mycoses.