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242 result(s) for "Lung Diseases, Fungal - prevention "
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Aerosolized Liposomal Amphotericin B for the Prevention of Invasive Pulmonary Aspergillosis during Prolonged Neutropenia: A Randomized, Placebo-Controlled Trial
Background. Invasive pulmonary aspergillosis (IPA) is a significant problem in patients with chemotherapy-induced prolonged neutropenia. Because pulmonary deposition of conidia is the first step in developing IPA, we hypothesized that inhalation of liposomal amphotericin B would prevent IPA. Methods. We performed a randomized, placebo-controlled trial of patients with hematologic disease with expected neutropenia for ⩾10 days. Patients were randomized to receive liposomal amphotericin B or placebo inhalation twice a week, using an adaptive aerosol delivery system, until neutrophil counts increased to >300 cells/mm3. In subsequent neutropenic episodes, the assigned treatment was restarted. The primary end point was the occurrence of IPA according to European Organization for Research and the Treatment of Cancer-Mycoses Study Group definitions. Kaplan-Meier curves were compared with log-rank tests for intent-to-treat and on-treatment populations. Results. A total of 271 patients were studied during 407 neutropenic episodes. According to the intent-to-treat analysis, 18 of 132 patients in the placebo group developed IPA versus 6 of 139 patients in the liposomal amphotericin B group (odds ratio, 0.26; 95% confidence interval, 0.09–0.72; P=.005). According to the on-treatment analysis, 13 of 97 patients receiving placebo versus 2 of 91 receiving liposomal amphotericin B developed IPA (odds ratio, 0.14; 95% confidence interval, 0.02–0.66; P=.007). Some adverse effects, but none serious, in the liposomal amphotericin B group were reported, most frequently coughing (16 patients vs. 1 patient; P=.002). Conclusion. In high-risk patients, prophylactic inhalation of liposomal amphotericin B significantly reduced the incidence of IPA.
Stroke-Associated Pneumonia: Major Advances and Obstacles
Background: Stroke-associated pneumonia (SAP) has been implicated in the morbidity, mortality and increased medical cost after acute ischemic stroke. The annual cost of SAP during hospitalization in the United States approaches USD 459 million. The incidence and prognosis of SAP among intensive care unit (ICU) patients have not been thoroughly investigated. We reviewed the pathophysiology, microbiology, incidence, risk factors, outcomes and prophylaxis of SAP with special attention to ICU studies. Methods: To determine the incidence, risk factors and prognosis of acute SAP, PubMed was searched using the terms ‘pneumonia' AND ‘neurology intensive unit' and the MeSH terms ‘stroke' AND ‘pneumonia'. Non-English literature, case reports and chronic SAP studies were excluded. Studies were classified into 5 categories according to the setting they were performed in: neurological intensive care units (NICUs), medical intensive care units (MICUs), stroke units, mixed studies combining more than one setting or when the settings were not specified and rehabilitation studies. Results: The incidences of SAP in the following settings were: NICUs 4.1-56.6%, MICUs 17-50%, stroke units 3.9-44%, mixed studies 3.9-23.8% and rehabilitation 3.2-11%. The majority of NICU and MICU studies were heterogeneous including different neurovascular diseases, which partly explains the wide range of SAP incidence. The higher incidence in the majority of ICU studies compared to stroke units or acute floor studies is likely explained by the presence of mechanical ventilation, higher stroke severity causing higher rates of aspiration and stroke-induced immunodepression among ICU patients. The short-term mortality of SAP was increased among the mixed and stroke unit studies ranging between 10.1 and 37.3%. SAP was associated with worse functional outcome in the majority of stroke unit and floor studies. Mortality was less consistent among NICU and MICU studies. This difference could be due to the heterogeneity of ICU studies and the effect of small sample size or other independent risk factors for mortality such as the larger neurological deficit, mechanical ventilation, and age, which may simultaneously increase the risk of SAP and mortality confounding the outcomes of SAP itself. The pathophysiology of SAP is likely explained by aspiration combined with stroke-induced immunodepression through complex humeral and neural pathways that include the hypothalamic-pituitary-adrenal axis, parasympathetic and sympathetic systems. Conclusions: A unified definition of SAP, strict inclusion criteria, and the presence of a long-term follow-up need to be applied to the future prospective studies to better identify the incidence and prognosis of SAP, especially among ICU patients.
Vaccination with Recombinant Cryptococcus Proteins in Glucan Particles Protects Mice against Cryptococcosis in a Manner Dependent upon Mouse Strain and Cryptococcal Species
Development of a vaccine to protect against cryptococcosis is a priority given the enormous global burden of disease in at-risk individuals. Using glucan particles (GPs) as a delivery system, we previously demonstrated that mice vaccinated with crude Cryptococcus -derived alkaline extracts were protected against lethal challenge with Cryptococcus neoformans and Cryptococcus gattii . The goal of the present study was to identify protective protein antigens that could be used in a subunit vaccine. Using biased and unbiased approaches, six candidate antigens (Cda1, Cda2, Cda3, Fpd1, MP88, and Sod1) were selected, recombinantly expressed in Escherichia coli , purified, and loaded into GPs. Three mouse strains (C57BL/6, BALB/c, and DR4) were then vaccinated with the antigen-laden GPs, following which they received a pulmonary challenge with virulent C. neoformans and C. gattii strains. Four candidate vaccines (GP-Cda1, GP-Cda2, GP-Cda3, and GP-Sod1) afforded a significant survival advantage in at least one mouse model; some vaccine combinations provided added protection over that seen with either antigen alone. Vaccine-mediated protection against C. neoformans did not necessarily predict protection against C. gattii . Vaccinated mice developed pulmonary inflammatory responses that effectively contained the infection; many surviving mice developed sterilizing immunity. Predicted T helper cell epitopes differed between mouse strains and in the degree to which they matched epitopes predicted in humans. Thus, we have discovered cryptococcal proteins that make promising candidate vaccine antigens. Protection varied depending on the mouse strain and cryptococcal species, suggesting that a successful human subunit vaccine will need to contain multiple antigens, including ones that are species specific. IMPORTANCE The encapsulated fungi Cryptococcus neoformans and Cryptococcus gattii are responsible for nearly 200,000 deaths annually, mostly in immunocompromised individuals. An effective vaccine could substantially reduce the burden of cryptococcosis. However, a major gap in cryptococcal vaccine development has been the discovery of protective antigens to use in vaccines. Here, six cryptococcal proteins with potential as vaccine antigens were expressed recombinantly and purified. Mice were then vaccinated with glucan particle preparations containing each antigen. Of the six candidate vaccines, four protected mice from a lethal cryptococcal challenge. However, the degree of protection varied as a function of mouse strain and cryptococcal species. These preclinical studies identify cryptococcal proteins that could serve as candidate vaccine antigens and provide a proof of principle regarding the feasibility of protein antigen-based vaccines to protect against cryptococcosis. The encapsulated fungi Cryptococcus neoformans and Cryptococcus gattii are responsible for nearly 200,000 deaths annually, mostly in immunocompromised individuals. An effective vaccine could substantially reduce the burden of cryptococcosis. However, a major gap in cryptococcal vaccine development has been the discovery of protective antigens to use in vaccines. Here, six cryptococcal proteins with potential as vaccine antigens were expressed recombinantly and purified. Mice were then vaccinated with glucan particle preparations containing each antigen. Of the six candidate vaccines, four protected mice from a lethal cryptococcal challenge. However, the degree of protection varied as a function of mouse strain and cryptococcal species. These preclinical studies identify cryptococcal proteins that could serve as candidate vaccine antigens and provide a proof of principle regarding the feasibility of protein antigen-based vaccines to protect against cryptococcosis.
Galactomannan and Computed Tomography–Based Preemptive Antifungal Therapy in Neutropenic Patients at High Risk for Invasive Fungal Infection: A Prospective Feasibility Study
Background. Empirical antifungal therapy is the standard treatment for persistent or relapsing antibiotic-resistant neutropenic fever. However, overtreatment resulting in increased toxicity and treatment-related cost is a major shortcoming of such therapy. We assessed the feasibility of a \"preemptive\" approach based on the incorporation of sensitive, noninvasive diagnostic tests for consecutive high-risk neutropenic patients who had received fluconazole prophylaxis while avoiding empirical therapy. Methods. A total of 136 treatment episodes for persons who were at risk of acquiring invasive fungal infection (IFI) were screened for the presence of galactomannan with an enzyme immunoassay. A diagnostic evaluation, which included thoracic computed tomography scanning (HRCT) and bronchoscopy with lavage, was performed on the basis of well-defined clinical, radiological, and microbiological criteria. Only seropositive patients and patients with a positive microbiological test result plus supportive radiological findings received liposomal amphotericin B. Results. Neutropenic fever developed in 117 episodes, of which at least 41 episodes (35%) satisfied existing criteria for empirical antifungal therapy. However, our protocol-driven preemptive approach reduced the rate of antifungal use for these episodes from 35% to 7.7% (a 78% reduction) and led to the early initiation of antifungal therapy in 10 episodes (7.3%) that were clinically not suspected of being IFI. No undetected cases of invasive aspergillosis were identified; 1 case of zygomycosis was missed. Breakthrough candidemia was diagnosed by conventional culture techniques and was treated successfully. With use of a preemptive approach, the 12-week survival rate for patients with IFI was 63.6% (it was 63.1% for those with invasive aspergillosis). Conclusion. Preemptive therapy based on enzyme immunoassay and HRCT reduced the exposure to expensive and potentially toxic drugs and offered effective antifungal control, but it failed to detect non-Aspergillus IFI.
Progress in Definition, Prevention and Treatment of Fungal Infections in Cystic Fibrosis
Cystic fibrosis (CF) is a chronic lethal multi-system condition; however, most of the morbidity and mortality is dependent on the status of the respiratory system. Progressive respiratory decline is mediated by chronic infection and inflammation, punctuated by important acute events known as pulmonary exacerbations which can lead to accelerated decline. The main bacterial species causing infections include Pseudomonas aeruginosa , Staphylococcus aureus , Haemophilus influenzae and Achromobacter xylosoxidans. In addition to bacteria, fungi are detected in a significant number of patients. The impact of fungal colonization of the airways is still not completely elucidated, but an increasing body of evidence suggests an important role for moulds and yeasts. Although fungal infections are rare, fungi can cause severe pneumonia requiring appropriate targeted treatment. The most common fungi in respiratory samples of patients with CF are Aspergillus fumigatus , Aspergillus terreus and Scedosporium species for filamentous fungi, and yeasts such as Candida albicans and Candida glabrata. Therapeutic strategies depend on the detected fungus and the underlying clinical status of the patient. The antifungal therapy can range from a simple monotherapy up to a combination of three different drugs. Treatment course may be indicated in some patients for two weeks and in others for up to six months, and in rare cases even longer. New antifungal drugs have been developed and are being tested in clinical studies offering the hope of therapeutic alternatives to existing drugs. Identifying relevant risk factors and diagnostic criteria for fungal colonization and infection is crucial to enabling an adequate prevention, diagnosis and treatment.
Ethanolic Extract Propolis-Loaded Niosomes Diminish Phospholipase B1, Biofilm Formation, and Intracellular Replication of Cryptococcus neoformans in Macrophages
Secretory phospholipase B1 (PLB1) and biofilms act as microbial virulence factors and play an important role in pulmonary cryptococcosis. This study aims to formulate the ethanolic extract of propolis-loaded niosomes (Nio-EEP) and evaluate the biological activities occurring during PLB1 production and biofilm formation of Cryptococcus neoformans. Some physicochemical characterizations of niosomes include a mean diameter of 270 nm in a spherical shape, a zeta-potential of −10.54 ± 1.37 mV, and 88.13 ± 0.01% entrapment efficiency. Nio-EEP can release EEP in a sustained manner and retains consistent physicochemical properties for a month. Nio-EEP has the capability to permeate the cellular membranes of C. neoformans, causing a significant decrease in the mRNA expression level of PLB1. Interestingly, biofilm formation, biofilm thickness, and the expression level of biofilm-related genes (UGD1 and UXS1) were also significantly reduced. Pre-treating with Nio-EEP prior to yeast infection reduced the intracellular replication of C. neoformans in alveolar macrophages by 47%. In conclusion, Nio-EEP mediates as an anti-virulence agent to inhibit PLB1 and biofilm production for preventing fungal colonization on lung epithelial cells and also decreases the intracellular replication of phagocytosed cryptococci. This nano-based EEP delivery might be a potential therapeutic strategy in the prophylaxis and treatment of pulmonary cryptococcosis in the future.
Itraconazole Comedication Increases Systemic Levels of Inhaled Fluticasone in Lung Transplant Recipients
Background: After lung transplantation (LTx), inhaled corticosteroids may be prescribed and at the same time prophylaxis against fungal infections with itraconazole is common. In our center, the addition of inhaled fluticasone propionate to systemic immunosuppression resulted in clinical Cushing’s syndrome in 4 lung transplant recipients on itraconazole comedication. Objectives: The current study was undertaken to compare systemic levels of inhaled fluticasone in patients with and without concomitant itraconazole therapy. Methods: The single-center, prospective controlled study was performed in the LTx program in Zurich, Switzerland. Twenty stable recipients, 1–7 years after LTx, on a prednisone maintenance dose (5–7.5 mg/day) gave informed consent and were assigned to 2 groups: (A) without itraconazole comedication and (B) currently on itraconazole, being continued during the study period. The patients of both groups started inhalation of 1 mg fluticasone propionate twice daily for 14 days with a powder disc inhaler. Plasma fluticasone levels were measured before the start of the study and on day 14. Results: Fluticasone levels before starting the treatment were below the detection limit in all 17 patients (7 in group A and 10 in group B) adhering to the study protocol. Baseline characteristics (underlying disease, age at LTx, time since LTx, FEV 1 ) were comparable between the 2 groups. On study day 14, plasma fluticasone levels had increased to detectable levels in all patients (A: 273 ± 124 pg/ml, B: 701 ± 131 pg/ml), i.e. to significantly higher (p = 0.038) concentrations in patients on itraconazole. Conclusions: Itraconazole comedication substantially increases systemic levels of inhaled fluticasone, most likely by inhibiting the cytochrome P450 3A4 enzyme system and thus the clearance of fluticasone. Accumulation of fluticasone can result in increased systemic effects and therefore comedication has to be taken into consideration when inhaled fluticasone is prescribed.
Breakthrough invasive fungal diseases during echinocandin treatment in high-risk hospitalized hematologic patients
The frequency of breakthrough invasive fungal diseases (IFDs) during echinocandin therapy is unclear. We retrospectively analyzed 534 hematologic patients treated with echinocandin (caspofungin, N  = 55; micafungin, N  = 306; anidulafungin, N  = 173). Four proven IFDs were found, caused by Candida parapsilosis ( N  = 2), C. parapsilosis and Candida glabrata ( N  = 1), and Fusarium species ( N  = 1). Four cases of possible IFDs were observed, all showing pulmonary infection. One case showed features suggestive of hepatosplenic candidiasis. Six of these eight cases had previously received the purine analog clofarabine. Breakthrough IFD during echinocandin treatment occurred infrequently (1.5 %), caused predominantly by Candida species. Clofarabine usage was an important risk factor.
Heat-killed yeast protects diabetic ketoacidotic-steroid treated mice from pulmonary mucormycosis
•HKY vaccine protects against DKA/steroid treated mice with pulmonary mucormycosis.•This is the first illustration of HKY efficacy in classically immunosuppressed mice.•HKY induces antibodies that react with Rhizopus oryzae cell wall antigens.•Our results broaden the HKY efficacy spectrum to a fifth mycosis.•Our data warrant the future development of HKY as a pan-fungal vaccine. Previous studies have shown that vaccination with heat-killed yeast, Saccharomyces cerevisiae (HKY), protects mice against systemic candidiasis, aspergillosis, cryptococcosis or coccidioidomycosis. Here we sought to define the potential use of HKY as a vaccine to protect mice from mucormycosis. Mice were vaccinated with different regimens of HKY prior to induction of diabetes. Diabetic ketoacidotic (DKA) mice were then treated with steroids prior to intratracheal challenge with Rhizopus oryzae. All regimens of HKY vaccine improved survival of DKA mice and reduced fungal burden in the primary target organ, lungs, as determined by qPCR. Furthermore, compared to mice vaccinated with diluent, vaccination with HKY substantially increased the mouse immune response as determined by detection of increased anti-Rhizopus antibody titers. Our results show that HKY protects steroid-treated DKA mice from pulmonary R. oryzae infection. Considering its demonstrated efficacy against other fungal infections, HKY is a promising candidate for development as a panfungal vaccine.
Aspergillus infection in lung transplant recipients with cystic fibrosis: Risk factors and outcomes comparison to other types of transplant recipients
To characterize Aspergillus infections in lung transplant recipients with cystic fibrosis (CF). A retrospective analysis of 32 consecutive lung transplant recipients with CF who underwent bilateral lung transplant at the University of Wisconsin from 1994 to 2000 to determine the incidence, risk factors, and consequences of Aspergillus infection. The findings were compared to 101 non-CF recipients of lung transplants (93) and heart-lung transplants (8) for other transplant indications. A university hospital. Lung transplant recipients with CF or other indications for transplantation. None. Seventeen of 32 CF recipients (53%) had Aspergillus fumigatus isolated from their respiratory secretions prior to undergoing transplantation. Ten of these 17 (59%) recipients had A fumigatus persistently found in their respiratory secretions posttransplant vs 6 of 15 CF patients (40%) who had not been colonized pretransplant and 28 of 101 of the non-CF recipients (28%). Four of the preoperatively colonized CF recipients developed tracheobronchial aspergillosis (TBA) just distal to the bronchial anastomoses, and one recipient had dehiscence of the involved anastomosis. None of the CF recipients developed disseminated aspergillosis or pneumonia. Prophylactic antifungal therapy did not prevent TBA, and IV amphotericin B therapy was required to clear the infection in all four patients, with endobronchial debridement of necrotic tissue required in two of them. In contrast, 10 of the non-CF (10%) recipients developed Aspergillus infections posttransplant (TBA, 4 recipients; pneumonitis, 6 recipients), and only 3 patients had successful treatment and long-term survival (TBA, 2 patients; pneumonia, 1 patient). Donor lung ischemia time, cytomegalovirus infection or pneumonia, or pretransplant mechanical ventilation did not increase the risk of developing TBA in CF recipients. The risk of TBA for patients receiving lung transplants for CF warrants early surveillance bronchoscopy to detect TBA, particularly in recipients with pretransplant colonization.